# SOME DESCRIPTIVE TITLE
# Copyright (C) YEAR Free Software Foundation, Inc.
# This file is distributed under the same license as the PACKAGE package.
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: PACKAGE VERSION\n"
"POT-Creation-Date: 2024-06-01 05:51+0200\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
"Language-Team: LANGUAGE <LL@li.org>\n"
"Language: \n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"

#. type: TH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "futex"
msgstr ""

#. type: TH
#: archlinux debian-unstable opensuse-tumbleweed
#, no-wrap
msgid "2024-05-02"
msgstr ""

#. type: TH
#: archlinux debian-unstable
#, no-wrap
msgid "Linux man-pages 6.8"
msgstr ""

#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "NAME"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "futex - fast user-space locking"
msgstr ""

#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "LIBRARY"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Standard C library (I<libc>, I<-lc>)"
msgstr ""

#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "SYNOPSIS"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid ""
"B<#include E<lt>linux/futex.hE<gt>>      /* Definition of B<FUTEX_*> constants */\n"
"B<#include E<lt>sys/syscall.hE<gt>>      /* Definition of B<SYS_*> constants */\n"
"B<#include E<lt>unistd.hE<gt>>\n"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid ""
"B<long syscall(SYS_futex, uint32_t *>I<uaddr>B<, int >I<futex_op>B<, uint32_t >I<val>B<,>\n"
"B<             const struct timespec *>I<timeout>B<,>I< >  /* or: B<uint32_t >I<val2>B< */>\n"
"B<             uint32_t *>I<uaddr2>B<, uint32_t >I<val3>B<);>\n"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"I<Note>: glibc provides no wrapper for B<futex>(), necessitating the use of "
"B<syscall>(2)."
msgstr ""

#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "DESCRIPTION"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The B<futex>()  system call provides a method for waiting until a certain "
"condition becomes true.  It is typically used as a blocking construct in the "
"context of shared-memory synchronization.  When using futexes, the majority "
"of the synchronization operations are performed in user space.  A user-space "
"program employs the B<futex>()  system call only when it is likely that the "
"program has to block for a longer time until the condition becomes true.  "
"Other B<futex>()  operations can be used to wake any processes or threads "
"waiting for a particular condition."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A futex is a 32-bit value\\[em]referred to below as a I<futex "
"word>\\[em]whose address is supplied to the B<futex>()  system call.  "
"(Futexes are 32 bits in size on all platforms, including 64-bit systems.)  "
"All futex operations are governed by this value.  In order to share a futex "
"between processes, the futex is placed in a region of shared memory, created "
"using (for example)  B<mmap>(2)  or B<shmat>(2).  (Thus, the futex word may "
"have different virtual addresses in different processes, but these addresses "
"all refer to the same location in physical memory.)  In a multithreaded "
"program, it is sufficient to place the futex word in a global variable "
"shared by all threads."
msgstr ""

#
#.  Notes from Darren Hart (Dec 2015):
#.      Totally ordered with respect futex operations refers to semantics
#.      of the ACQUIRE/RELEASE operations and how they impact ordering of
#.      memory reads and writes. The kernel futex operations are protected
#.      by spinlocks, which ensure that all operations are serialized
#.      with respect to one another.
#.      This is a lot to attempt to define in this document. Perhaps a
#.      reference to linux/Documentation/memory-barriers.txt as a footnote
#.      would be sufficient? Or perhaps for this manual, "serialized" would
#.      be sufficient, with a footnote regarding "totally ordered" and a
#.      pointer to the memory-barrier documentation?
#.  FIXME(Torvald Riegel):
#.  Eventually we want to have some text in NOTES to satisfy
#.  the reference in the following sentence
#.      See NOTES for a detailed specification of
#.      the synchronization semantics.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"When executing a futex operation that requests to block a thread, the kernel "
"will block only if the futex word has the value that the calling thread "
"supplied (as one of the arguments of the B<futex>()  call) as the expected "
"value of the futex word.  The loading of the futex word's value, the "
"comparison of that value with the expected value, and the actual blocking "
"will happen atomically and will be totally ordered with respect to "
"concurrent operations performed by other threads on the same futex word.  "
"Thus, the futex word is used to connect the synchronization in user space "
"with the implementation of blocking by the kernel.  Analogously to an atomic "
"compare-and-exchange operation that potentially changes shared memory, "
"blocking via a futex is an atomic compare-and-block operation."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"One use of futexes is for implementing locks.  The state of the lock (i.e., "
"acquired or not acquired)  can be represented as an atomically accessed flag "
"in shared memory.  In the uncontended case, a thread can access or modify "
"the lock state with atomic instructions, for example atomically changing it "
"from not acquired to acquired using an atomic compare-and-exchange "
"instruction.  (Such instructions are performed entirely in user mode, and "
"the kernel maintains no information about the lock state.)  On the other "
"hand, a thread may be unable to acquire a lock because it is already "
"acquired by another thread.  It then may pass the lock's flag as a futex "
"word and the value representing the acquired state as the expected value to "
"a B<futex>()  wait operation.  This B<futex>()  operation will block if and "
"only if the lock is still acquired (i.e., the value in the futex word still "
"matches the \"acquired state\").  When releasing the lock, a thread has to "
"first reset the lock state to not acquired and then execute a futex "
"operation that wakes threads blocked on the lock flag used as a futex word "
"(this can be further optimized to avoid unnecessary wake-ups).  See "
"B<futex>(7)  for more detail on how to use futexes."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Besides the basic wait and wake-up futex functionality, there are further "
"futex operations aimed at supporting more complex use cases."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Note that no explicit initialization or destruction is necessary to use "
"futexes; the kernel maintains a futex (i.e., the kernel-internal "
"implementation artifact)  only while operations such as B<FUTEX_WAIT>, "
"described below, are being performed on a particular futex word."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "Arguments"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The I<uaddr> argument points to the futex word.  On all platforms, futexes "
"are four-byte integers that must be aligned on a four-byte boundary.  The "
"operation to perform on the futex is specified in the I<futex_op> argument; "
"I<val> is a value whose meaning and purpose depends on I<futex_op>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The remaining arguments (I<timeout>, I<uaddr2>, and I<val3>)  are required "
"only for certain of the futex operations described below.  Where one of "
"these arguments is not required, it is ignored."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"For several blocking operations, the I<timeout> argument is a pointer to a "
"I<timespec> structure that specifies a timeout for the operation.  However, "
"notwithstanding the prototype shown above, for some operations, the least "
"significant four bytes of this argument are instead used as an integer whose "
"meaning is determined by the operation.  For these operations, the kernel "
"casts the I<timeout> value first to I<unsigned long>, then to I<uint32_t>, "
"and in the remainder of this page, this argument is referred to as I<val2> "
"when interpreted in this fashion."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Where it is required, the I<uaddr2> argument is a pointer to a second futex "
"word that is employed by the operation."
msgstr ""

#
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The interpretation of the final integer argument, I<val3>, depends on the "
"operation."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "Futex operations"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The I<futex_op> argument consists of two parts: a command that specifies the "
"operation to be performed, bitwise ORed with zero or more options that "
"modify the behaviour of the operation.  The options that may be included in "
"I<futex_op> are as follows:"
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_PRIVATE_FLAG> (since Linux 2.6.22)"
msgstr ""

#.  commit 34f01cc1f512fa783302982776895c73714ebbc2
#.  I.e., It allows the kernel choose the fast path for validating
#.  the user-space address and avoids expensive VMA lookups,
#.  taking reference counts on file backing store, and so on.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This option bit can be employed with all futex operations.  It tells the "
"kernel that the futex is process-private and not shared with another process "
"(i.e., it is being used for synchronization only between threads of the same "
"process).  This allows the kernel to make some additional performance "
"optimizations."
msgstr ""

#.  except the obsolete FUTEX_FD, for which the "private" flag was
#.  meaningless
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"As a convenience, I<E<lt>linux/futex.hE<gt>> defines a set of constants with "
"the suffix B<_PRIVATE> that are equivalents of all of the operations listed "
"below, but with the B<FUTEX_PRIVATE_FLAG> ORed into the constant value.  "
"Thus, there are B<FUTEX_WAIT_PRIVATE>, B<FUTEX_WAKE_PRIVATE>, and so on."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_CLOCK_REALTIME> (since Linux 2.6.28)"
msgstr ""

#.  commit 1acdac104668a0834cfa267de9946fac7764d486
#.  commit 337f13046ff03717a9e99675284a817527440a49
#.  commit bf22a6976897977b0a3f1aeba6823c959fc4fdae
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This option bit can be employed only with the B<FUTEX_WAIT_BITSET>, "
"B<FUTEX_WAIT_REQUEUE_PI>, (since Linux 4.5)  B<FUTEX_WAIT>, and (since Linux "
"5.14)  B<FUTEX_LOCK_PI2> operations."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If this option is set, the kernel measures the I<timeout> against the "
"B<CLOCK_REALTIME> clock."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If this option is not set, the kernel measures the I<timeout> against the "
"B<CLOCK_MONOTONIC> clock."
msgstr ""

#
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The operation specified in I<futex_op> is one of the following:"
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_WAIT> (since Linux 2.6.0)"
msgstr ""

#.  Strictly speaking, since some time in Linux 2.5.x
#.  FIXME: Torvald, I think we may need to add some explanation of
#.  "totally ordered" here.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation tests that the value at the futex word pointed to by the "
"address I<uaddr> still contains the expected value I<val>, and if so, then "
"sleeps waiting for a B<FUTEX_WAKE> operation on the futex word.  The load of "
"the value of the futex word is an atomic memory access (i.e., using atomic "
"machine instructions of the respective architecture).  This load, the "
"comparison with the expected value, and starting to sleep are performed "
"atomically and totally ordered with respect to other futex operations on the "
"same futex word.  If the thread starts to sleep, it is considered a waiter "
"on this futex word.  If the futex value does not match I<val>, then the call "
"fails immediately with the error B<EAGAIN>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The purpose of the comparison with the expected value is to prevent lost "
"wake-ups.  If another thread changed the value of the futex word after the "
"calling thread decided to block based on the prior value, and if the other "
"thread executed a B<FUTEX_WAKE> operation (or similar wake-up) after the "
"value change and before this B<FUTEX_WAIT> operation, then the calling "
"thread will observe the value change and will not start to sleep."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If the I<timeout> is not NULL, the structure it points to specifies a "
"timeout for the wait.  (This interval will be rounded up to the system clock "
"granularity, and is guaranteed not to expire early.)  The timeout is by "
"default measured according to the B<CLOCK_MONOTONIC> clock, but, since Linux "
"4.5, the B<CLOCK_REALTIME> clock can be selected by specifying "
"B<FUTEX_CLOCK_REALTIME> in I<futex_op>.  If I<timeout> is NULL, the call "
"blocks indefinitely."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"I<Note>: for B<FUTEX_WAIT>, I<timeout> is interpreted as a I<relative> "
"value.  This differs from other futex operations, where I<timeout> is "
"interpreted as an absolute value.  To obtain the equivalent of B<FUTEX_WAIT> "
"with an absolute timeout, employ B<FUTEX_WAIT_BITSET> with I<val3> specified "
"as B<FUTEX_BITSET_MATCH_ANY>."
msgstr ""

#
#
#.  FIXME . (Torvald) I think we should remove this.  Or maybe adapt to a
#.  different example.
#.      For
#.      .BR futex (7),
#.      this call is executed if decrementing the count gave a negative value
#.      (indicating contention),
#.      and will sleep until another process or thread releases
#.      the futex and executes the
#.      .B FUTEX_WAKE
#.      operation.
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The arguments I<uaddr2> and I<val3> are ignored."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_WAKE> (since Linux 2.6.0)"
msgstr ""

#.  Strictly speaking, since Linux 2.5.x
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation wakes at most I<val> of the waiters that are waiting (e.g., "
"inside B<FUTEX_WAIT>)  on the futex word at the address I<uaddr>.  Most "
"commonly, I<val> is specified as either 1 (wake up a single waiter) or "
"B<INT_MAX> (wake up all waiters).  No guarantee is provided about which "
"waiters are awoken (e.g., a waiter with a higher scheduling priority is not "
"guaranteed to be awoken in preference to a waiter with a lower priority)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The arguments I<timeout>, I<uaddr2>, and I<val3> are ignored."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_FD> (from Linux 2.6.0 up to and including Linux 2.6.25)"
msgstr ""

#.  Strictly speaking, from Linux 2.5.x to Linux 2.6.25
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation creates a file descriptor that is associated with the futex "
"at I<uaddr>.  The caller must close the returned file descriptor after use.  "
"When another process or thread performs a B<FUTEX_WAKE> on the futex word, "
"the file descriptor indicates as being readable with B<select>(2), "
"B<poll>(2), and B<epoll>(7)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The file descriptor can be used to obtain asynchronous notifications: if "
"I<val> is nonzero, then, when another process or thread executes a "
"B<FUTEX_WAKE>, the caller will receive the signal number that was passed in "
"I<val>."
msgstr ""

#
#.  commit 82af7aca56c67061420d618cc5a30f0fd4106b80
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Because it was inherently racy, B<FUTEX_FD> has been removed from Linux "
"2.6.26 onward."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_REQUEUE> (since Linux 2.6.0)"
msgstr ""

#
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation performs the same task as B<FUTEX_CMP_REQUEUE> (see below), "
"except that no check is made using the value in I<val3>.  (The argument "
"I<val3> is ignored.)"
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_CMP_REQUEUE> (since Linux 2.6.7)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation first checks whether the location I<uaddr> still contains the "
"value I<val3>.  If not, the operation fails with the error B<EAGAIN>.  "
"Otherwise, the operation wakes up a maximum of I<val> waiters that are "
"waiting on the futex at I<uaddr>.  If there are more than I<val> waiters, "
"then the remaining waiters are removed from the wait queue of the source "
"futex at I<uaddr> and added to the wait queue of the target futex at "
"I<uaddr2>.  The I<val2> argument specifies an upper limit on the number of "
"waiters that are requeued to the futex at I<uaddr2>."
msgstr ""

#.  FIXME(Torvald) Is the following correct?  Or is just the decision
#.  which threads to wake or requeue part of the atomic operation?
#.  Notes from a f2f conversation with Thomas Gleixner (Aug 2015): ###
#. 	The operation is serialized with respect to operations on both
#. 	source and target futex. No other waiter can enqueue itself
#. 	for waiting and no other waiter can dequeue itself because of
#. 	a timeout or signal.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The load from I<uaddr> is an atomic memory access (i.e., using atomic "
"machine instructions of the respective architecture).  This load, the "
"comparison with I<val3>, and the requeueing of any waiters are performed "
"atomically and totally ordered with respect to other operations on the same "
"futex word."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Typical values to specify for I<val> are 0 or 1.  (Specifying B<INT_MAX> is "
"not useful, because it would make the B<FUTEX_CMP_REQUEUE> operation "
"equivalent to B<FUTEX_WAKE>.)  The limit value specified via I<val2> is "
"typically either 1 or B<INT_MAX>.  (Specifying the argument as 0 is not "
"useful, because it would make the B<FUTEX_CMP_REQUEUE> operation equivalent "
"to B<FUTEX_WAIT>.)"
msgstr ""

#.  But, as Rich Felker points out, there remain valid use cases for
#.  FUTEX_REQUEUE, for example, when the calling thread is requeuing
#.  the target(s) to a lock that the calling thread owns
#.      From: Rich Felker <dalias@libc.org>
#.      Date: Wed, 29 Oct 2014 22:43:17 -0400
#.      To: Darren Hart <dvhart@infradead.org>
#.      CC: libc-alpha@sourceware.org, ...
#.      Subject: Re: Add futex wrapper to glibc?
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The B<FUTEX_CMP_REQUEUE> operation was added as a replacement for the "
"earlier B<FUTEX_REQUEUE>.  The difference is that the check of the value at "
"I<uaddr> can be used to ensure that requeueing happens only under certain "
"conditions, which allows race conditions to be avoided in certain use cases."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Both B<FUTEX_REQUEUE> and B<FUTEX_CMP_REQUEUE> can be used to avoid "
"\"thundering herd\" wake-ups that could occur when using B<FUTEX_WAKE> in "
"cases where all of the waiters that are woken need to acquire another "
"futex.  Consider the following scenario, where multiple waiter threads are "
"waiting on B, a wait queue implemented using a futex:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid ""
"lock(A)\n"
"while (!check_value(V)) {\n"
"    unlock(A);\n"
"    block_on(B);\n"
"    lock(A);\n"
"};\n"
"unlock(A);\n"
msgstr ""

#
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If a waker thread used B<FUTEX_WAKE>, then all waiters waiting on B would be "
"woken up, and they would all try to acquire lock A.  However, waking all of "
"the threads in this manner would be pointless because all except one of the "
"threads would immediately block on lock A again.  By contrast, a requeue "
"operation wakes just one waiter and moves the other waiters to lock A, and "
"when the woken waiter unlocks A then the next waiter can proceed."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_WAKE_OP> (since Linux 2.6.14)"
msgstr ""

#.  commit 4732efbeb997189d9f9b04708dc26bf8613ed721
#. 	Author: Jakub Jelinek <jakub@redhat.com>
#. 	Date:   Tue Sep 6 15:16:25 2005 -0700
#.  FIXME. (Torvald) The glibc condvar implementation is currently being
#.      revised (e.g., to not use an internal lock anymore).
#.      It is probably more future-proof to remove this paragraph.
#.  [Torvald, do you have an update here?]
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation was added to support some user-space use cases where more "
"than one futex must be handled at the same time.  The most notable example "
"is the implementation of B<pthread_cond_signal>(3), which requires "
"operations on two futexes, the one used to implement the mutex and the one "
"used in the implementation of the wait queue associated with the condition "
"variable.  B<FUTEX_WAKE_OP> allows such cases to be implemented without "
"leading to high rates of contention and context switching."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The B<FUTEX_WAKE_OP> operation is equivalent to executing the following code "
"atomically and totally ordered with respect to other futex operations on any "
"of the two supplied futex words:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid ""
"uint32_t oldval = *(uint32_t *) uaddr2;\n"
"*(uint32_t *) uaddr2 = oldval I<op> I<oparg>;\n"
"futex(uaddr, FUTEX_WAKE, val, 0, 0, 0);\n"
"if (oldval I<cmp> I<cmparg>)\n"
"    futex(uaddr2, FUTEX_WAKE, val2, 0, 0, 0);\n"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "In other words, B<FUTEX_WAKE_OP> does the following:"
msgstr ""

#. type: IP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "\\[bu]"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"saves the original value of the futex word at I<uaddr2> and performs an "
"operation to modify the value of the futex at I<uaddr2>; this is an atomic "
"read-modify-write memory access (i.e., using atomic machine instructions of "
"the respective architecture)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"wakes up a maximum of I<val> waiters on the futex for the futex word at "
"I<uaddr>; and"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"dependent on the results of a test of the original value of the futex word "
"at I<uaddr2>, wakes up a maximum of I<val2> waiters on the futex for the "
"futex word at I<uaddr2>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The operation and comparison that are to be performed are encoded in the "
"bits of the argument I<val3>.  Pictorially, the encoding is:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid ""
"+---+---+-----------+-----------+\n"
"|op |cmp|   oparg   |  cmparg   |\n"
"+---+---+-----------+-----------+\n"
"  4   4       12          12    E<lt>== # of bits\n"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Expressed in code, the encoding is:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid ""
"#define FUTEX_OP(op, oparg, cmp, cmparg) \\e\n"
"                (((op & 0xf) E<lt>E<lt> 28) | \\e\n"
"                ((cmp & 0xf) E<lt>E<lt> 24) | \\e\n"
"                ((oparg & 0xfff) E<lt>E<lt> 12) | \\e\n"
"                (cmparg & 0xfff))\n"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"In the above, I<op> and I<cmp> are each one of the codes listed below.  The "
"I<oparg> and I<cmparg> components are literal numeric values, except as "
"noted below."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The I<op> component has one of the following values:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid ""
"FUTEX_OP_SET        0  /* uaddr2 = oparg; */\n"
"FUTEX_OP_ADD        1  /* uaddr2 += oparg; */\n"
"FUTEX_OP_OR         2  /* uaddr2 |= oparg; */\n"
"FUTEX_OP_ANDN       3  /* uaddr2 &= \\[ti]oparg; */\n"
"FUTEX_OP_XOR        4  /* uaddr2 \\[ha]= oparg; */\n"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"In addition, bitwise ORing the following value into I<op> causes I<(1\\ "
"E<lt>E<lt>\\ oparg)> to be used as the operand:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "FUTEX_OP_ARG_SHIFT  8  /* Use (1 E<lt>E<lt> oparg) as operand */\n"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The I<cmp> field is one of the following:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid ""
"FUTEX_OP_CMP_EQ     0  /* if (oldval == cmparg) wake */\n"
"FUTEX_OP_CMP_NE     1  /* if (oldval != cmparg) wake */\n"
"FUTEX_OP_CMP_LT     2  /* if (oldval E<lt> cmparg) wake */\n"
"FUTEX_OP_CMP_LE     3  /* if (oldval E<lt>= cmparg) wake */\n"
"FUTEX_OP_CMP_GT     4  /* if (oldval E<gt> cmparg) wake */\n"
"FUTEX_OP_CMP_GE     5  /* if (oldval E<gt>= cmparg) wake */\n"
msgstr ""

#
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The return value of B<FUTEX_WAKE_OP> is the sum of the number of waiters "
"woken on the futex I<uaddr> plus the number of waiters woken on the futex "
"I<uaddr2>."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_WAIT_BITSET> (since Linux 2.6.25)"
msgstr ""

#.  commit cd689985cf49f6ff5c8eddc48d98b9d581d9475d
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation is like B<FUTEX_WAIT> except that I<val3> is used to provide "
"a 32-bit bit mask to the kernel.  This bit mask, in which at least one bit "
"must be set, is stored in the kernel-internal state of the waiter.  See the "
"description of B<FUTEX_WAKE_BITSET> for further details."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If I<timeout> is not NULL, the structure it points to specifies an absolute "
"timeout for the wait operation.  If I<timeout> is NULL, the operation can "
"block indefinitely."
msgstr ""

#
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The I<uaddr2> argument is ignored."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_WAKE_BITSET> (since Linux 2.6.25)"
msgstr ""

#.  commit cd689985cf49f6ff5c8eddc48d98b9d581d9475d
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation is the same as B<FUTEX_WAKE> except that the I<val3> argument "
"is used to provide a 32-bit bit mask to the kernel.  This bit mask, in which "
"at least one bit must be set, is used to select which waiters should be "
"woken up.  The selection is done by a bitwise AND of the \"wake\" bit mask "
"(i.e., the value in I<val3>)  and the bit mask which is stored in the kernel-"
"internal state of the waiter (the \"wait\" bit mask that is set using "
"B<FUTEX_WAIT_BITSET>).  All of the waiters for which the result of the AND "
"is nonzero are woken up; the remaining waiters are left sleeping."
msgstr ""

#
#
#.  According to http://locklessinc.com/articles/futex_cheat_sheet/:
#.     "The original reason for the addition of these extensions
#.      was to improve the performance of pthread read-write locks
#.      in glibc. However, the pthreads library no longer uses the
#.      same locking algorithm, and these extensions are not used
#.      without the bitset parameter being all ones.
#.  The page goes on to note that the FUTEX_WAIT_BITSET operation
#.  is nevertheless used (with a bit mask of all ones) in order to
#.  obtain the absolute timeout functionality that is useful
#.  for efficiently implementing Pthreads APIs (which use absolute
#.  timeouts); FUTEX_WAIT provides only relative timeouts.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The effect of B<FUTEX_WAIT_BITSET> and B<FUTEX_WAKE_BITSET> is to allow "
"selective wake-ups among multiple waiters that are blocked on the same "
"futex.  However, note that, depending on the use case, employing this bit-"
"mask multiplexing feature on a futex can be less efficient than simply using "
"multiple futexes, because employing bit-mask multiplexing requires the "
"kernel to check all waiters on a futex, including those that are not "
"interested in being woken up (i.e., they do not have the relevant bit set in "
"their \"wait\" bit mask)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The constant B<FUTEX_BITSET_MATCH_ANY>, which corresponds to all 32 bits set "
"in the bit mask, can be used as the I<val3> argument for "
"B<FUTEX_WAIT_BITSET> and B<FUTEX_WAKE_BITSET>.  Other than differences in "
"the handling of the I<timeout> argument, the B<FUTEX_WAIT> operation is "
"equivalent to B<FUTEX_WAIT_BITSET> with I<val3> specified as "
"B<FUTEX_BITSET_MATCH_ANY>; that is, allow a wake-up by any waker.  The "
"B<FUTEX_WAKE> operation is equivalent to B<FUTEX_WAKE_BITSET> with I<val3> "
"specified as B<FUTEX_BITSET_MATCH_ANY>; that is, wake up any waiter(s)."
msgstr ""

#
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The I<uaddr2> and I<timeout> arguments are ignored."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "Priority-inheritance futexes"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Linux supports priority-inheritance (PI) futexes in order to handle priority-"
"inversion problems that can be encountered with normal futex locks.  "
"Priority inversion is the problem that occurs when a high-priority task is "
"blocked waiting to acquire a lock held by a low-priority task, while tasks "
"at an intermediate priority continuously preempt the low-priority task from "
"the CPU.  Consequently, the low-priority task makes no progress toward "
"releasing the lock, and the high-priority task remains blocked."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Priority inheritance is a mechanism for dealing with the priority-inversion "
"problem.  With this mechanism, when a high-priority task becomes blocked by "
"a lock held by a low-priority task, the priority of the low-priority task is "
"temporarily raised to that of the high-priority task, so that it is not "
"preempted by any intermediate level tasks, and can thus make progress toward "
"releasing the lock.  To be effective, priority inheritance must be "
"transitive, meaning that if a high-priority task blocks on a lock held by a "
"lower-priority task that is itself blocked by a lock held by another "
"intermediate-priority task (and so on, for chains of arbitrary length), then "
"both of those tasks (or more generally, all of the tasks in a lock chain)  "
"have their priorities raised to be the same as the high-priority task."
msgstr ""

#
#.  Quoting Darren Hart:
#.      These opcodes paired with the PI futex value policy (described below)
#.      defines a "futex" as PI aware. These were created very specifically
#.      in support of PI pthread_mutexes, so it makes a lot more sense to
#.      talk about a PI aware pthread_mutex, than a PI aware futex, since
#.      there is a lot of policy and scaffolding that has to be built up
#.      around it to use it properly (this is what a PI pthread_mutex is).
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"From a user-space perspective, what makes a futex PI-aware is a policy "
"agreement (described below)  between user space and the kernel about the "
"value of the futex word, coupled with the use of the PI-futex operations "
"described below.  (Unlike the other futex operations described above, the PI-"
"futex operations are designed for the implementation of very specific IPC "
"mechanisms.)"
msgstr ""

#.        mtk: The following text is drawn from the Hart/Guniguntala paper
#.        (listed in SEE ALSO), but I have reworded some pieces
#.        significantly.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The PI-futex operations described below differ from the other futex "
"operations in that they impose policy on the use of the value of the futex "
"word:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "If the lock is not acquired, the futex word's value shall be 0."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If the lock is acquired, the futex word's value shall be the thread ID (TID; "
"see B<gettid>(2))  of the owning thread."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If the lock is owned and there are threads contending for the lock, then the "
"B<FUTEX_WAITERS> bit shall be set in the futex word's value; in other words, "
"this value is:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "FUTEX_WAITERS | TID\n"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(Note that is invalid for a PI futex word to have no owner and "
"B<FUTEX_WAITERS> set.)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"With this policy in place, a user-space application can acquire an "
"unacquired lock or release a lock using atomic instructions executed in user "
"mode (e.g., a compare-and-swap operation such as I<cmpxchg> on the x86 "
"architecture).  Acquiring a lock simply consists of using compare-and-swap "
"to atomically set the futex word's value to the caller's TID if its previous "
"value was 0.  Releasing a lock requires using compare-and-swap to set the "
"futex word's value to 0 if the previous value was the expected TID."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If a futex is already acquired (i.e., has a nonzero value), waiters must "
"employ the B<FUTEX_LOCK_PI> or B<FUTEX_LOCK_PI2> operations to acquire the "
"lock.  If other threads are waiting for the lock, then the B<FUTEX_WAITERS> "
"bit is set in the futex value; in this case, the lock owner must employ the "
"B<FUTEX_UNLOCK_PI> operation to release the lock."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"In the cases where callers are forced into the kernel (i.e., required to "
"perform a B<futex>()  call), they then deal directly with a so-called RT-"
"mutex, a kernel locking mechanism which implements the required priority-"
"inheritance semantics.  After the RT-mutex is acquired, the futex value is "
"updated accordingly, before the calling thread returns to user space."
msgstr ""

#.  tglx (July 2015):
#.      If there are multiple waiters on a pi futex then a wake pi operation
#.      will wake the first waiter and hand over the lock to this waiter. This
#.      includes handing over the rtmutex which represents the futex in the
#.      kernel. The strict requirement is that the futex owner and the rtmutex
#.      owner must be the same, except for the update period which is
#.      serialized by the futex internal locking. That means the kernel must
#.      update the user-space value prior to returning to user space
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"It is important to note that the kernel will update the futex word's value "
"prior to returning to user space.  (This prevents the possibility of the "
"futex word's value ending up in an invalid state, such as having an owner "
"but the value being 0, or having waiters but not having the B<FUTEX_WAITERS> "
"bit set.)"
msgstr ""

#.  tglx (July 2015):
#.      The FUTEX_OWNER_DIED bit can also be set on uncontended futexes, where
#.      the kernel has no state associated. This happens via the robust futex
#.      mechanism. In that case the futex value will be set to
#.      FUTEX_OWNER_DIED. The robust futex mechanism is also available for non
#.      PI futexes.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If a futex has an associated RT-mutex in the kernel (i.e., there are blocked "
"waiters)  and the owner of the futex/RT-mutex dies unexpectedly, then the "
"kernel cleans up the RT-mutex and hands it over to the next waiter.  This in "
"turn requires that the user-space value is updated accordingly.  To indicate "
"that this is required, the kernel sets the B<FUTEX_OWNER_DIED> bit in the "
"futex word along with the thread ID of the new owner.  User space can detect "
"this situation via the presence of the B<FUTEX_OWNER_DIED> bit and is then "
"responsible for cleaning up the stale state left over by the dead owner."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"PI futexes are operated on by specifying one of the values listed below in "
"I<futex_op>.  Note that the PI futex operations must be used as paired "
"operations and are subject to some additional requirements:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"B<FUTEX_LOCK_PI>, B<FUTEX_LOCK_PI2>, and B<FUTEX_TRYLOCK_PI> pair with "
"B<FUTEX_UNLOCK_PI>.  B<FUTEX_UNLOCK_PI> must be called only on a futex owned "
"by the calling thread, as defined by the value policy, otherwise the error "
"B<EPERM> results."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"B<FUTEX_WAIT_REQUEUE_PI> pairs with B<FUTEX_CMP_REQUEUE_PI>.  This must be "
"performed from a non-PI futex to a distinct PI futex (or the error B<EINVAL> "
"results).  Additionally, I<val> (the number of waiters to be woken) must be "
"1 (or the error B<EINVAL> results)."
msgstr ""

#
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The PI futex operations are as follows:"
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_LOCK_PI> (since Linux 2.6.18)"
msgstr ""

#.  commit c87e2837be82df479a6bae9f155c43516d2feebc
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation is used after an attempt to acquire the lock via an atomic "
"user-mode instruction failed because the futex word has a nonzero "
"value\\[em]specifically, because it contained the (PID-namespace-specific) "
"TID of the lock owner."
msgstr ""

#
#
#
#
#.  tglx (July 2015):
#.      The operation here is similar to the FUTEX_WAIT logic. When the user
#.      space atomic acquire does not succeed because the futex value was non
#.      zero, then the waiter goes into the kernel, takes the kernel internal
#.      lock and retries the acquisition under the lock. If the acquisition
#.      does not succeed either, then it sets the FUTEX_WAITERS bit, to signal
#.      the lock owner that it needs to go into the kernel. Here is the pseudo
#.      code:
#.      	lock(kernel_lock);
#.      retry:
#.      	/*
#.      	 * Owner might have unlocked in user space before we
#.      	 * were able to set the waiter bit.
#.               */
#.              if (atomic_acquire(futex) == SUCCESS) {
#.      	   unlock(kernel_lock());
#.      	   return 0;
#.      	}
#.      	/*
#.      	 * Owner might have unlocked after the above atomic_acquire()
#.      	 * attempt.
#.      	 */
#.      	if (atomic_set_waiters_bit(futex) != SUCCESS)
#.      	   goto retry;
#.      	queue_waiter();
#.      	unlock(kernel_lock);
#.      	block();
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The operation checks the value of the futex word at the address I<uaddr>.  "
"If the value is 0, then the kernel tries to atomically set the futex value "
"to the caller's TID.  If the futex word's value is nonzero, the kernel "
"atomically sets the B<FUTEX_WAITERS> bit, which signals the futex owner that "
"it cannot unlock the futex in user space atomically by setting the futex "
"value to 0.  After that, the kernel:"
msgstr ""

#. type: IP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "(1)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Tries to find the thread which is associated with the owner TID."
msgstr ""

#. type: IP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Creates or reuses kernel state on behalf of the owner.  (If this is the "
"first waiter, there is no kernel state for this futex, so kernel state is "
"created by locking the RT-mutex and the futex owner is made the owner of the "
"RT-mutex.  If there are existing waiters, then the existing state is reused.)"
msgstr ""

#. type: IP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "(3)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Attaches the waiter to the futex (i.e., the waiter is enqueued on the RT-"
"mutex waiter list)."
msgstr ""

#
#.  August 2015:
#.      mtk: If the realm is restricted purely to SCHED_OTHER (SCHED_NORMAL)
#.           processes, does the nice value come into play also?
#.      tglx: No. SCHED_OTHER/NORMAL tasks are handled in FIFO order
#.  (i.e., task 1 blocks on lock A, held by task 2,
#.  while task 2 blocks on lock B, held by task 3)
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If more than one waiter exists, the enqueueing of the waiter is in "
"descending priority order.  (For information on priority ordering, see the "
"discussion of the B<SCHED_DEADLINE>, B<SCHED_FIFO>, and B<SCHED_RR> "
"scheduling policies in B<sched>(7).)  The owner inherits either the waiter's "
"CPU bandwidth (if the waiter is scheduled under the B<SCHED_DEADLINE> "
"policy) or the waiter's priority (if the waiter is scheduled under the "
"B<SCHED_RR> or B<SCHED_FIFO> policy).  This inheritance follows the lock "
"chain in the case of nested locking and performs deadlock detection."
msgstr ""

#
#
#.  2016-07-07 response from Thomas Gleixner on LKML:
#.  From: Thomas Gleixner <tglx@linutronix.de>
#.  Date: 6 July 2016 at 20:57
#.  Subject: Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op
#.  On Thu, 23 Jun 2016, Michael Kerrisk (man-pages) wrote:
#.  > On 06/23/2016 08:28 PM, Darren Hart wrote:
#.  > > And as a follow-on, what is the reason for FUTEX_LOCK_PI only using
#.  > > CLOCK_REALTIME? It seems reasonable to me that a user may want to wait a
#.  > > specific amount of time, regardless of wall time.
#.  >
#.  > Yes, that's another weird inconsistency.
#.  The reason is that phtread_mutex_timedlock() uses absolute timeouts based on
#.  CLOCK_REALTIME. glibc folks asked to make that the default behaviour back
#.  then when we added LOCK_PI.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The I<timeout> argument provides a timeout for the lock attempt.  If "
"I<timeout> is not NULL, the structure it points to specifies an absolute "
"timeout, measured against the B<CLOCK_REALTIME> clock.  If I<timeout> is "
"NULL, the operation will block indefinitely."
msgstr ""

#
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The I<uaddr2>, I<val>, and I<val3> arguments are ignored."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_LOCK_PI2> (since Linux 5.14)"
msgstr ""

#
#.  commit bf22a6976897977b0a3f1aeba6823c959fc4fdae
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation is the same as B<FUTEX_LOCK_PI>, except that the clock "
"against which I<timeout> is measured is selectable.  By default, the "
"(absolute) timeout specified in I<timeout> is measured against the "
"B<CLOCK_MONOTONIC> clock, but if the B<FUTEX_CLOCK_REALTIME> flag is "
"specified in I<futex_op>, then the timeout is measured against the "
"B<CLOCK_REALTIME> clock."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_TRYLOCK_PI> (since Linux 2.6.18)"
msgstr ""

#.  commit c87e2837be82df479a6bae9f155c43516d2feebc
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation tries to acquire the lock at I<uaddr>.  It is invoked when a "
"user-space atomic acquire did not succeed because the futex word was not 0."
msgstr ""

#.  Paraphrasing a f2f conversation with Thomas Gleixner about the
#.  above point (Aug 2015): ###
#. 	There is a rare possibility of a race condition involving an
#. 	uncontended futex with no owner, but with waiters.  The
#. 	kernel-user-space contract is that if a futex is nonzero, you must
#. 	go into kernel.  The futex was owned by a task, and that task dies
#. 	but there are no waiters, so the futex value is non zero.
#. 	Therefore, the next locker has to go into the kernel,
#. 	so that the kernel has a chance to clean up. (CMXCH on zero
#. 	in user space would fail, so kernel has to clean up.)
#.  Darren Hart (Oct 2015):
#.      The trylock in the kernel has more state, so it can independently
#.      verify the flags that user space must trust implicitly.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Because the kernel has access to more state information than user space, "
"acquisition of the lock might succeed if performed by the kernel in cases "
"where the futex word (i.e., the state information accessible to use-space) "
"contains stale state (B<FUTEX_WAITERS> and/or B<FUTEX_OWNER_DIED>).  This "
"can happen when the owner of the futex died.  User space cannot handle this "
"condition in a race-free manner, but the kernel can fix this up and acquire "
"the futex."
msgstr ""

#
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The I<uaddr2>, I<val>, I<timeout>, and I<val3> arguments are ignored."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_UNLOCK_PI> (since Linux 2.6.18)"
msgstr ""

#.  commit c87e2837be82df479a6bae9f155c43516d2feebc
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation wakes the top priority waiter that is waiting in "
"B<FUTEX_LOCK_PI> or B<FUTEX_LOCK_PI2> on the futex address provided by the "
"I<uaddr> argument."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This is called when the user-space value at I<uaddr> cannot be changed "
"atomically from a TID (of the owner) to 0."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_CMP_REQUEUE_PI> (since Linux 2.6.31)"
msgstr ""

#.  commit 52400ba946759af28442dee6265c5c0180ac7122
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This operation is a PI-aware variant of B<FUTEX_CMP_REQUEUE>.  It requeues "
"waiters that are blocked via B<FUTEX_WAIT_REQUEUE_PI> on I<uaddr> from a non-"
"PI source futex (I<uaddr>)  to a PI target futex (I<uaddr2>)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"As with B<FUTEX_CMP_REQUEUE>, this operation wakes up a maximum of I<val> "
"waiters that are waiting on the futex at I<uaddr>.  However, for "
"B<FUTEX_CMP_REQUEUE_PI>, I<val> is required to be 1 (since the main point is "
"to avoid a thundering herd).  The remaining waiters are removed from the "
"wait queue of the source futex at I<uaddr> and added to the wait queue of "
"the target futex at I<uaddr2>."
msgstr ""

#
#
#.  val2 is the cap on the number of requeued waiters.
#.  In the glibc pthread_cond_broadcast() implementation, this argument
#.  is specified as INT_MAX, and for pthread_cond_signal() it is 0.
#.        The page at http://locklessinc.com/articles/futex_cheat_sheet/
#.        notes that "priority-inheritance Futex to priority-inheritance
#.        Futex requeues are currently unsupported". However, probably
#.        the page does not need to say nothing about this, since
#.        Thomas Gleixner commented (July 2015): "they never will be
#.        supported because they make no sense at all"
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The I<val2> and I<val3> arguments serve the same purposes as for "
"B<FUTEX_CMP_REQUEUE>."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_WAIT_REQUEUE_PI> (since Linux 2.6.31)"
msgstr ""

#.  commit 52400ba946759af28442dee6265c5c0180ac7122
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Wait on a non-PI futex at I<uaddr> and potentially be requeued (via a "
"B<FUTEX_CMP_REQUEUE_PI> operation in another task) onto a PI futex at "
"I<uaddr2>.  The wait operation on I<uaddr> is the same as for B<FUTEX_WAIT>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The waiter can be removed from the wait on I<uaddr> without requeueing on "
"I<uaddr2> via a B<FUTEX_WAKE> operation in another task.  In this case, the "
"B<FUTEX_WAIT_REQUEUE_PI> operation fails with the error B<EAGAIN>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The I<val3> argument is ignored."
msgstr ""

#
#
#
#
#
#.  Darren Hart notes that a patch to allow glibc to fully support
#.  PI-aware pthreads condition variables has not yet been accepted into
#.  glibc. The story is complex, and can be found at
#.  https://sourceware.org/bugzilla/show_bug.cgi?id=11588
#.  Darren notes that in the meantime, the patch is shipped with various
#.  PREEMPT_RT-enabled Linux systems.
#.  Related to the preceding, Darren proposed that somewhere, man-pages
#.  should document the following point:
#.      While the Linux kernel, since Linux 2.6.31, supports requeueing of
#.      priority-inheritance (PI) aware mutexes via the
#.      FUTEX_WAIT_REQUEUE_PI and FUTEX_CMP_REQUEUE_PI futex operations,
#.      the glibc implementation does not yet take full advantage of this.
#.      Specifically, the condvar internal data lock remains a non-PI aware
#.      mutex, regardless of the type of the pthread_mutex associated with
#.      the condvar. This can lead to an unbounded priority inversion on
#.      the internal data lock even when associating a PI aware
#.      pthread_mutex with a condvar during a pthread_cond*_wait
#.      operation. For this reason, it is not recommended to rely on
#.      priority inheritance when using pthread condition variables.
#.  The problem is that the obvious location for this text is
#.  the pthread_cond*wait(3) man page. However, such a man page
#.  does not currently exist.
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The B<FUTEX_WAIT_REQUEUE_PI> and B<FUTEX_CMP_REQUEUE_PI> were added to "
"support a fairly specific use case: support for priority-inheritance-aware "
"POSIX threads condition variables.  The idea is that these operations should "
"always be paired, in order to ensure that user space and the kernel remain "
"in sync.  Thus, in the B<FUTEX_WAIT_REQUEUE_PI> operation, the user-space "
"application pre-specifies the target of the requeue that takes place in the "
"B<FUTEX_CMP_REQUEUE_PI> operation."
msgstr ""

#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "RETURN VALUE"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"In the event of an error (and assuming that B<futex>()  was invoked via "
"B<syscall>(2)), all operations return -1 and set I<errno> to indicate the "
"error."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The return value on success depends on the operation, as described in the "
"following list:"
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_WAIT>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Returns 0 if the caller was woken up.  Note that a wake-up can also be "
"caused by common futex usage patterns in unrelated code that happened to "
"have previously used the futex word's memory location (e.g., typical futex-"
"based implementations of Pthreads mutexes can cause this under some "
"conditions).  Therefore, callers should always conservatively assume that a "
"return value of 0 can mean a spurious wake-up, and use the futex word's "
"value (i.e., the user-space synchronization scheme)  to decide whether to "
"continue to block or not."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_WAKE>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Returns the number of waiters that were woken up."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_FD>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Returns the new file descriptor associated with the futex."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_REQUEUE>"
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_CMP_REQUEUE>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Returns the total number of waiters that were woken up or requeued to the "
"futex for the futex word at I<uaddr2>.  If this value is greater than "
"I<val>, then the difference is the number of waiters requeued to the futex "
"for the futex word at I<uaddr2>."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_WAKE_OP>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Returns the total number of waiters that were woken up.  This is the sum of "
"the woken waiters on the two futexes for the futex words at I<uaddr> and "
"I<uaddr2>."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_WAIT_BITSET>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Returns 0 if the caller was woken up.  See B<FUTEX_WAIT> for how to "
"interpret this correctly in practice."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_WAKE_BITSET>"
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_LOCK_PI>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Returns 0 if the futex was successfully locked."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_LOCK_PI2>"
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_TRYLOCK_PI>"
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_UNLOCK_PI>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Returns 0 if the futex was successfully unlocked."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_CMP_REQUEUE_PI>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Returns the total number of waiters that were woken up or requeued to the "
"futex for the futex word at I<uaddr2>.  If this value is greater than "
"I<val>, then difference is the number of waiters requeued to the futex for "
"the futex word at I<uaddr2>."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<FUTEX_WAIT_REQUEUE_PI>"
msgstr ""

#
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Returns 0 if the caller was successfully requeued to the futex for the futex "
"word at I<uaddr2>."
msgstr ""

#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "ERRORS"
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<EACCES>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "No read access to the memory of a futex word."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<EAGAIN>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_WAIT>, B<FUTEX_WAIT_BITSET>, B<FUTEX_WAIT_REQUEUE_PI>)  The value "
"pointed to by I<uaddr> was not equal to the expected value I<val> at the "
"time of the call."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"B<Note>: on Linux, the symbolic names B<EAGAIN> and B<EWOULDBLOCK> (both of "
"which appear in different parts of the kernel futex code)  have the same "
"value."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_CMP_REQUEUE>, B<FUTEX_CMP_REQUEUE_PI>)  The value pointed to by "
"I<uaddr> is not equal to the expected value I<val3>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_LOCK_PI>, B<FUTEX_LOCK_PI2>, B<FUTEX_TRYLOCK_PI>, "
"B<FUTEX_CMP_REQUEUE_PI>)  The futex owner thread ID of I<uaddr> (for "
"B<FUTEX_CMP_REQUEUE_PI>: I<uaddr2>)  is about to exit, but has not yet "
"handled the internal state cleanup.  Try again."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<EDEADLK>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_LOCK_PI>, B<FUTEX_LOCK_PI2>, B<FUTEX_TRYLOCK_PI>, "
"B<FUTEX_CMP_REQUEUE_PI>)  The futex word at I<uaddr> is already locked by "
"the caller."
msgstr ""

#
#.  FIXME . I see that kernel/locking/rtmutex.c uses EDEADLK in some
#.        places, and EDEADLOCK in others. On almost all architectures
#.        these constants are synonymous. Is there a reason that both
#.        names are used?
#.        tglx (July 2015): "No. We should probably fix that."
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_CMP_REQUEUE_PI>)  While requeueing a waiter to the PI futex for the "
"futex word at I<uaddr2>, the kernel detected a deadlock."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<EFAULT>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A required pointer argument (i.e., I<uaddr>, I<uaddr2>, or I<timeout>)  did "
"not point to a valid user-space address."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<EINTR>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A B<FUTEX_WAIT> or B<FUTEX_WAIT_BITSET> operation was interrupted by a "
"signal (see B<signal>(7)).  Before Linux 2.6.22, this error could also be "
"returned for a spurious wakeup; since Linux 2.6.22, this no longer happens."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<EINVAL>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The operation in I<futex_op> is one of those that employs a timeout, but the "
"supplied I<timeout> argument was invalid (I<tv_sec> was less than zero, or "
"I<tv_nsec> was not less than 1,000,000,000)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The operation specified in I<futex_op> employs one or both of the pointers "
"I<uaddr> and I<uaddr2>, but one of these does not point to a valid "
"object\\[em]that is, the address is not four-byte-aligned."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_WAIT_BITSET>, B<FUTEX_WAKE_BITSET>)  The bit mask supplied in "
"I<val3> is zero."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_CMP_REQUEUE_PI>)  I<uaddr> equals I<uaddr2> (i.e., an attempt was "
"made to requeue to the same futex)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "(B<FUTEX_FD>)  The signal number supplied in I<val> is invalid."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_WAKE>, B<FUTEX_WAKE_OP>, B<FUTEX_WAKE_BITSET>, B<FUTEX_REQUEUE>, "
"B<FUTEX_CMP_REQUEUE>)  The kernel detected an inconsistency between the user-"
"space state at I<uaddr> and the kernel state\\[em]that is, it detected a "
"waiter which waits in B<FUTEX_LOCK_PI> or B<FUTEX_LOCK_PI2> on I<uaddr>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_LOCK_PI>, B<FUTEX_LOCK_PI2>, B<FUTEX_TRYLOCK_PI>, "
"B<FUTEX_UNLOCK_PI>)  The kernel detected an inconsistency between the user-"
"space state at I<uaddr> and the kernel state.  This indicates either state "
"corruption or that the kernel found a waiter on I<uaddr> which is waiting "
"via B<FUTEX_WAIT> or B<FUTEX_WAIT_BITSET>."
msgstr ""

#.  From a conversation with Thomas Gleixner (Aug 2015): ###
#. 	The kernel sees: I have non PI state for a futex you tried to
#.      tell me was PI
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_CMP_REQUEUE_PI>)  The kernel detected an inconsistency between the "
"user-space state at I<uaddr2> and the kernel state; that is, the kernel "
"detected a waiter which waits via B<FUTEX_WAIT> or B<FUTEX_WAIT_BITSET> on "
"I<uaddr2>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_CMP_REQUEUE_PI>)  The kernel detected an inconsistency between the "
"user-space state at I<uaddr> and the kernel state; that is, the kernel "
"detected a waiter which waits via B<FUTEX_WAIT> or B<FUTEX_WAIT_BITSET> on "
"I<uaddr>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_CMP_REQUEUE_PI>)  The kernel detected an inconsistency between the "
"user-space state at I<uaddr> and the kernel state; that is, the kernel "
"detected a waiter which waits on I<uaddr> via B<FUTEX_LOCK_PI> or "
"B<FUTEX_LOCK_PI2> (instead of B<FUTEX_WAIT_REQUEUE_PI>)."
msgstr ""

#.  This deals with the case:
#.      wait_requeue_pi(A, B);
#.      requeue_pi(A, C);
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_CMP_REQUEUE_PI>)  An attempt was made to requeue a waiter to a "
"futex other than that specified by the matching B<FUTEX_WAIT_REQUEUE_PI> "
"call for that waiter."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "(B<FUTEX_CMP_REQUEUE_PI>)  The I<val> argument is not 1."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Invalid argument."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<ENFILE>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_FD>)  The system-wide limit on the total number of open files has "
"been reached."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<ENOMEM>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_LOCK_PI>, B<FUTEX_LOCK_PI2>, B<FUTEX_TRYLOCK_PI>, "
"B<FUTEX_CMP_REQUEUE_PI>)  The kernel could not allocate memory to hold state "
"information."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<ENOSYS>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Invalid operation specified in I<futex_op>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The B<FUTEX_CLOCK_REALTIME> option was specified in I<futex_op>, but the "
"accompanying operation was neither B<FUTEX_WAIT>, B<FUTEX_WAIT_BITSET>, "
"B<FUTEX_WAIT_REQUEUE_PI>, nor B<FUTEX_LOCK_PI2>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_LOCK_PI>, B<FUTEX_LOCK_PI2>, B<FUTEX_TRYLOCK_PI>, "
"B<FUTEX_UNLOCK_PI>, B<FUTEX_CMP_REQUEUE_PI>, B<FUTEX_WAIT_REQUEUE_PI>)  A "
"run-time check determined that the operation is not available.  The PI-futex "
"operations are not implemented on all architectures and are not supported on "
"some CPU variants."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<EPERM>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_LOCK_PI>, B<FUTEX_LOCK_PI2>, B<FUTEX_TRYLOCK_PI>, "
"B<FUTEX_CMP_REQUEUE_PI>)  The caller is not allowed to attach itself to the "
"futex at I<uaddr> (for B<FUTEX_CMP_REQUEUE_PI>: the futex at I<uaddr2>).  "
"(This may be caused by a state corruption in user space.)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_UNLOCK_PI>)  The caller does not own the lock represented by the "
"futex word."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<ESRCH>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_LOCK_PI>, B<FUTEX_LOCK_PI2>, B<FUTEX_TRYLOCK_PI>, "
"B<FUTEX_CMP_REQUEUE_PI>)  The thread ID in the futex word at I<uaddr> does "
"not exist."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(B<FUTEX_CMP_REQUEUE_PI>)  The thread ID in the futex word at I<uaddr2> does "
"not exist."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<ETIMEDOUT>"
msgstr ""

#
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The operation in I<futex_op> employed the timeout specified in I<timeout>, "
"and the timeout expired before the operation completed."
msgstr ""

#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "STANDARDS"
msgstr ""

#. type: Plain text
#: archlinux debian-unstable fedora-40 fedora-rawhide mageia-cauldron
#: opensuse-leap-15-6 opensuse-tumbleweed
msgid "Linux."
msgstr ""

#. type: SH
#: archlinux debian-unstable fedora-40 fedora-rawhide mageia-cauldron
#: opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "HISTORY"
msgstr ""

#. type: Plain text
#: archlinux debian-unstable fedora-40 fedora-rawhide mageia-cauldron
#: opensuse-leap-15-6 opensuse-tumbleweed
msgid "Linux 2.6.0."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Initial futex support was merged in Linux 2.5.7 but with different semantics "
"from what was described above.  A four-argument system call with the "
"semantics described in this page was introduced in Linux 2.5.40.  A fifth "
"argument was added in Linux 2.5.70, and a sixth argument was added in Linux "
"2.6.7."
msgstr ""

#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "EXAMPLES"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The program below demonstrates use of futexes in a program where a parent "
"process and a child process use a pair of futexes located inside a shared "
"anonymous mapping to synchronize access to a shared resource: the terminal.  "
"The two processes each write I<nloops> (a command-line argument that "
"defaults to 5 if omitted)  messages to the terminal and employ a "
"synchronization protocol that ensures that they alternate in writing "
"messages.  Upon running this program we see output such as the following:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid ""
"$ B<./futex_demo>\n"
"Parent (18534) 0\n"
"Child  (18535) 0\n"
"Parent (18534) 1\n"
"Child  (18535) 1\n"
"Parent (18534) 2\n"
"Child  (18535) 2\n"
"Parent (18534) 3\n"
"Child  (18535) 3\n"
"Parent (18534) 4\n"
"Child  (18535) 4\n"
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "Program source"
msgstr ""

#. type: Plain text
#: archlinux debian-unstable fedora-40 fedora-rawhide mageia-cauldron
#: opensuse-tumbleweed
#, no-wrap
msgid ""
"/* futex_demo.c\n"
"\\&\n"
"   Usage: futex_demo [nloops]\n"
"                    (Default: 5)\n"
"\\&\n"
"   Demonstrate the use of futexes in a program where parent and child\n"
"   use a pair of futexes located inside a shared anonymous mapping to\n"
"   synchronize access to a shared resource: the terminal. The two\n"
"   processes each write \\[aq]num-loops\\[aq] messages to the terminal and employ\n"
"   a synchronization protocol that ensures that they alternate in\n"
"   writing messages.\n"
"*/\n"
"#define _GNU_SOURCE\n"
"#include E<lt>err.hE<gt>\n"
"#include E<lt>errno.hE<gt>\n"
"#include E<lt>linux/futex.hE<gt>\n"
"#include E<lt>stdatomic.hE<gt>\n"
"#include E<lt>stdint.hE<gt>\n"
"#include E<lt>stdio.hE<gt>\n"
"#include E<lt>stdlib.hE<gt>\n"
"#include E<lt>sys/mman.hE<gt>\n"
"#include E<lt>sys/syscall.hE<gt>\n"
"#include E<lt>sys/time.hE<gt>\n"
"#include E<lt>sys/wait.hE<gt>\n"
"#include E<lt>unistd.hE<gt>\n"
"\\&\n"
"static uint32_t *futex1, *futex2, *iaddr;\n"
"\\&\n"
"static int\n"
"futex(uint32_t *uaddr, int futex_op, uint32_t val,\n"
"      const struct timespec *timeout, uint32_t *uaddr2, uint32_t val3)\n"
"{\n"
"    return syscall(SYS_futex, uaddr, futex_op, val,\n"
"                   timeout, uaddr2, val3);\n"
"}\n"
"\\&\n"
"/* Acquire the futex pointed to by \\[aq]futexp\\[aq]: wait for its value to\n"
"   become 1, and then set the value to 0. */\n"
"\\&\n"
"static void\n"
"fwait(uint32_t *futexp)\n"
"{\n"
"    long            s;\n"
"    const uint32_t  one = 1;\n"
"\\&\n"
"    /* atomic_compare_exchange_strong(ptr, oldval, newval)\n"
"       atomically performs the equivalent of:\n"
"\\&\n"
"           if (*ptr == *oldval)\n"
"               *ptr = newval;\n"
"\\&\n"
"       It returns true if the test yielded true and *ptr was updated. */\n"
"\\&\n"
"    while (1) {\n"
"\\&\n"
"        /* Is the futex available? */\n"
"        if (atomic_compare_exchange_strong(futexp, &one, 0))\n"
"            break;      /* Yes */\n"
"\\&\n"
"        /* Futex is not available; wait. */\n"
"\\&\n"
"        s = futex(futexp, FUTEX_WAIT, 0, NULL, NULL, 0);\n"
"        if (s == -1 && errno != EAGAIN)\n"
"            err(EXIT_FAILURE, \"futex-FUTEX_WAIT\");\n"
"    }\n"
"}\n"
"\\&\n"
"/* Release the futex pointed to by \\[aq]futexp\\[aq]: if the futex currently\n"
"   has the value 0, set its value to 1 and then wake any futex waiters,\n"
"   so that if the peer is blocked in fwait(), it can proceed. */\n"
"\\&\n"
"static void\n"
"fpost(uint32_t *futexp)\n"
"{\n"
"    long            s;\n"
"    const uint32_t  zero = 0;\n"
"\\&\n"
"    /* atomic_compare_exchange_strong() was described\n"
"       in comments above. */\n"
"\\&\n"
"    if (atomic_compare_exchange_strong(futexp, &zero, 1)) {\n"
"        s = futex(futexp, FUTEX_WAKE, 1, NULL, NULL, 0);\n"
"        if (s  == -1)\n"
"            err(EXIT_FAILURE, \"futex-FUTEX_WAKE\");\n"
"    }\n"
"}\n"
"\\&\n"
"int\n"
"main(int argc, char *argv[])\n"
"{\n"
"    pid_t         childPid;\n"
"    unsigned int  nloops;\n"
"\\&\n"
"    setbuf(stdout, NULL);\n"
"\\&\n"
"    nloops = (argc E<gt> 1) ? atoi(argv[1]) : 5;\n"
"\\&\n"
"    /* Create a shared anonymous mapping that will hold the futexes.\n"
"       Since the futexes are being shared between processes, we\n"
"       subsequently use the \"shared\" futex operations (i.e., not the\n"
"       ones suffixed \"_PRIVATE\"). */\n"
"\\&\n"
"    iaddr = mmap(NULL, sizeof(*iaddr) * 2, PROT_READ | PROT_WRITE,\n"
"                 MAP_ANONYMOUS | MAP_SHARED, -1, 0);\n"
"    if (iaddr == MAP_FAILED)\n"
"        err(EXIT_FAILURE, \"mmap\");\n"
"\\&\n"
"    futex1 = &iaddr[0];\n"
"    futex2 = &iaddr[1];\n"
"\\&\n"
"    *futex1 = 0;        /* State: unavailable */\n"
"    *futex2 = 1;        /* State: available */\n"
"\\&\n"
"    /* Create a child process that inherits the shared anonymous\n"
"       mapping. */\n"
"\\&\n"
"    childPid = fork();\n"
"    if (childPid == -1)\n"
"        err(EXIT_FAILURE, \"fork\");\n"
"\\&\n"
"    if (childPid == 0) {        /* Child */\n"
"        for (unsigned int j = 0; j E<lt> nloops; j++) {\n"
"            fwait(futex1);\n"
"            printf(\"Child  (%jd) %u\\en\", (intmax_t) getpid(), j);\n"
"            fpost(futex2);\n"
"        }\n"
"\\&\n"
"        exit(EXIT_SUCCESS);\n"
"    }\n"
"\\&\n"
"    /* Parent falls through to here. */\n"
"\\&\n"
"    for (unsigned int j = 0; j E<lt> nloops; j++) {\n"
"        fwait(futex2);\n"
"        printf(\"Parent (%jd) %u\\en\", (intmax_t) getpid(), j);\n"
"        fpost(futex1);\n"
"    }\n"
"\\&\n"
"    wait(NULL);\n"
"\\&\n"
"    exit(EXIT_SUCCESS);\n"
"}\n"
msgstr ""

#.  SRC END
#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "SEE ALSO"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"B<get_robust_list>(2), B<restart_syscall>(2), "
"B<pthread_mutexattr_getprotocol>(3), B<futex>(7), B<sched>(7)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The following kernel source files:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "I<Documentation/pi-futex.txt>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "I<Documentation/futex-requeue-pi.txt>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "I<Documentation/locking/rt-mutex.txt>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "I<Documentation/locking/rt-mutex-design.txt>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "I<Documentation/robust-futex-ABI.txt>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Franke, H., Russell, R., and Kirwood, M., 2002.  I<Fuss, Futexes and "
"Furwocks: Fast Userlevel Locking in Linux> (from proceedings of the Ottawa "
"Linux Symposium 2002),"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"E<.UR http://kernel.org\\:/doc\\:/ols\\:/2002\\:/ols2002-pages-479-495.pdf> "
"E<.UE>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Hart, D., 2009. I<A futex overview and update>, E<.UR http://lwn.net/"
"Articles/360699/> E<.UE>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Hart, D.\\& and Guniguntala, D., 2009.  I<Requeue-PI: Making glibc Condvars "
"PI-Aware> (from proceedings of the 2009 Real-Time Linux Workshop), E<.UR "
"http://lwn.net/images/conf/rtlws11/papers/proc/p10.pdf> E<.UE>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Drepper, U., 2011. I<Futexes Are Tricky>, E<.UR http://www.akkadia.org/"
"drepper/futex.pdf> E<.UE>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Futex example library, futex-*.tar.bz2 at"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"E<.UR https://mirrors.kernel.org\\:/pub\\:/linux\\:/kernel\\:/people\\:/"
"rusty/> E<.UE>"
msgstr ""

#. type: TH
#: debian-bookworm
#, no-wrap
msgid "2023-02-05"
msgstr ""

#. type: TH
#: debian-bookworm
#, no-wrap
msgid "Linux man-pages 6.03"
msgstr ""

#. type: SH
#: debian-bookworm
#, no-wrap
msgid "VERSIONS"
msgstr ""

#. type: Plain text
#: debian-bookworm
msgid ""
"Futexes were first made available in a stable kernel release with Linux "
"2.6.0."
msgstr ""

#. type: Plain text
#: debian-bookworm
msgid "This system call is Linux-specific."
msgstr ""

#. type: SH
#: debian-bookworm
#, no-wrap
msgid "NOTES"
msgstr ""

#
#.  TODO FIXME(Torvald) Above, we cite this section and claim it contains
#.  details on the synchronization semantics; add the C11 equivalents
#.  here (or whatever we find consensus for).
#. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
#. type: Plain text
#: debian-bookworm
msgid ""
"Several higher-level programming abstractions are implemented via futexes, "
"including POSIX semaphores and various POSIX threads synchronization "
"mechanisms (mutexes, condition variables, read-write locks, and barriers)."
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid "/* futex_demo.c\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"   Usage: futex_demo [nloops]\n"
"                    (Default: 5)\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"   Demonstrate the use of futexes in a program where parent and child\n"
"   use a pair of futexes located inside a shared anonymous mapping to\n"
"   synchronize access to a shared resource: the terminal. The two\n"
"   processes each write \\[aq]num-loops\\[aq] messages to the terminal and employ\n"
"   a synchronization protocol that ensures that they alternate in\n"
"   writing messages.\n"
"*/\n"
"#define _GNU_SOURCE\n"
"#include E<lt>err.hE<gt>\n"
"#include E<lt>errno.hE<gt>\n"
"#include E<lt>linux/futex.hE<gt>\n"
"#include E<lt>stdatomic.hE<gt>\n"
"#include E<lt>stdint.hE<gt>\n"
"#include E<lt>stdio.hE<gt>\n"
"#include E<lt>stdlib.hE<gt>\n"
"#include E<lt>sys/mman.hE<gt>\n"
"#include E<lt>sys/syscall.hE<gt>\n"
"#include E<lt>sys/time.hE<gt>\n"
"#include E<lt>sys/wait.hE<gt>\n"
"#include E<lt>unistd.hE<gt>\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid "static uint32_t *futex1, *futex2, *iaddr;\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"static int\n"
"futex(uint32_t *uaddr, int futex_op, uint32_t val,\n"
"      const struct timespec *timeout, uint32_t *uaddr2, uint32_t val3)\n"
"{\n"
"    return syscall(SYS_futex, uaddr, futex_op, val,\n"
"                   timeout, uaddr2, val3);\n"
"}\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"/* Acquire the futex pointed to by \\[aq]futexp\\[aq]: wait for its value to\n"
"   become 1, and then set the value to 0. */\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"static void\n"
"fwait(uint32_t *futexp)\n"
"{\n"
"    long            s;\n"
"    const uint32_t  one = 1;\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"    /* atomic_compare_exchange_strong(ptr, oldval, newval)\n"
"       atomically performs the equivalent of:\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"           if (*ptr == *oldval)\n"
"               *ptr = newval;\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid "       It returns true if the test yielded true and *ptr was updated. */\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid "    while (1) {\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"        /* Is the futex available? */\n"
"        if (atomic_compare_exchange_strong(futexp, &one, 0))\n"
"            break;      /* Yes */\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid "        /* Futex is not available; wait. */\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"        s = futex(futexp, FUTEX_WAIT, 0, NULL, NULL, 0);\n"
"        if (s == -1 && errno != EAGAIN)\n"
"            err(EXIT_FAILURE, \"futex-FUTEX_WAIT\");\n"
"    }\n"
"}\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"/* Release the futex pointed to by \\[aq]futexp\\[aq]: if the futex currently\n"
"   has the value 0, set its value to 1 and then wake any futex waiters,\n"
"   so that if the peer is blocked in fwait(), it can proceed. */\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"static void\n"
"fpost(uint32_t *futexp)\n"
"{\n"
"    long            s;\n"
"    const uint32_t  zero = 0;\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"    /* atomic_compare_exchange_strong() was described\n"
"       in comments above. */\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"    if (atomic_compare_exchange_strong(futexp, &zero, 1)) {\n"
"        s = futex(futexp, FUTEX_WAKE, 1, NULL, NULL, 0);\n"
"        if (s  == -1)\n"
"            err(EXIT_FAILURE, \"futex-FUTEX_WAKE\");\n"
"    }\n"
"}\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"int\n"
"main(int argc, char *argv[])\n"
"{\n"
"    pid_t         childPid;\n"
"    unsigned int  nloops;\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid "    setbuf(stdout, NULL);\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid "    nloops = (argc E<gt> 1) ? atoi(argv[1]) : 5;\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"    /* Create a shared anonymous mapping that will hold the futexes.\n"
"       Since the futexes are being shared between processes, we\n"
"       subsequently use the \"shared\" futex operations (i.e., not the\n"
"       ones suffixed \"_PRIVATE\"). */\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"    iaddr = mmap(NULL, sizeof(*iaddr) * 2, PROT_READ | PROT_WRITE,\n"
"                 MAP_ANONYMOUS | MAP_SHARED, -1, 0);\n"
"    if (iaddr == MAP_FAILED)\n"
"        err(EXIT_FAILURE, \"mmap\");\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"    futex1 = &iaddr[0];\n"
"    futex2 = &iaddr[1];\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"    *futex1 = 0;        /* State: unavailable */\n"
"    *futex2 = 1;        /* State: available */\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"    /* Create a child process that inherits the shared anonymous\n"
"       mapping. */\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"    childPid = fork();\n"
"    if (childPid == -1)\n"
"        err(EXIT_FAILURE, \"fork\");\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"    if (childPid == 0) {        /* Child */\n"
"        for (unsigned int j = 0; j E<lt> nloops; j++) {\n"
"            fwait(futex1);\n"
"            printf(\"Child  (%jd) %u\\en\", (intmax_t) getpid(), j);\n"
"            fpost(futex2);\n"
"        }\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"        exit(EXIT_SUCCESS);\n"
"    }\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid "    /* Parent falls through to here. */\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"    for (unsigned int j = 0; j E<lt> nloops; j++) {\n"
"        fwait(futex2);\n"
"        printf(\"Parent (%jd) %u\\en\", (intmax_t) getpid(), j);\n"
"        fpost(futex1);\n"
"    }\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid "    wait(NULL);\n"
msgstr ""

#. type: Plain text
#: debian-bookworm opensuse-leap-15-6
#, no-wrap
msgid ""
"    exit(EXIT_SUCCESS);\n"
"}\n"
msgstr ""

#. type: TH
#: fedora-40 fedora-rawhide mageia-cauldron
#, no-wrap
msgid "2023-10-31"
msgstr ""

#. type: TH
#: fedora-40 mageia-cauldron
#, no-wrap
msgid "Linux man-pages 6.06"
msgstr ""

#. type: TH
#: fedora-rawhide
#, no-wrap
msgid "Linux man-pages 6.7"
msgstr ""

#. type: TH
#: opensuse-leap-15-6
#, no-wrap
msgid "2023-03-30"
msgstr ""

#. type: TH
#: opensuse-leap-15-6
#, no-wrap
msgid "Linux man-pages 6.04"
msgstr ""

#. type: TH
#: opensuse-tumbleweed
#, no-wrap
msgid "Linux man-pages (unreleased)"
msgstr ""