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-rw-r--r--mysys/my_pthread.c467
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diff --git a/mysys/my_pthread.c b/mysys/my_pthread.c
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+/* Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
+
+/* Functions to get threads more portable */
+
+#define DONT_REMAP_PTHREAD_FUNCTIONS
+
+#include "mysys_priv.h"
+#include <signal.h>
+#include <m_string.h>
+#include <thr_alarm.h>
+#include <my_pthread.h>
+
+#if (defined(__BSD__) || defined(_BSDI_VERSION))
+#define SCHED_POLICY SCHED_RR
+#else
+#define SCHED_POLICY SCHED_OTHER
+#endif
+
+/*
+ Some functions for RTS threads, AIX, Siemens Unix and UnixWare 7
+ (and DEC OSF/1 3.2 too)
+*/
+
+int my_pthread_create_detached=1;
+
+/* localtime_r for SCO 3.2V4.2 */
+
+#if !defined(HAVE_LOCALTIME_R) || !defined(HAVE_GMTIME_R)
+
+extern mysql_mutex_t LOCK_localtime_r;
+
+#endif
+
+#if !defined(HAVE_LOCALTIME_R)
+struct tm *localtime_r(const time_t *clock, struct tm *res)
+{
+ struct tm *tmp;
+ mysql_mutex_lock(&LOCK_localtime_r);
+ tmp=localtime(clock);
+ *res= *tmp;
+ mysql_mutex_unlock(&LOCK_localtime_r);
+ return res;
+}
+#endif
+
+#if !defined(HAVE_GMTIME_R)
+/*
+ Reentrant version of standard gmtime() function.
+ Needed on some systems which don't implement it.
+*/
+
+struct tm *gmtime_r(const time_t *clock, struct tm *res)
+{
+ struct tm *tmp;
+ mysql_mutex_lock(&LOCK_localtime_r);
+ tmp= gmtime(clock);
+ *res= *tmp;
+ mysql_mutex_unlock(&LOCK_localtime_r);
+ return res;
+}
+#endif
+
+/****************************************************************************
+** Replacement of sigwait if the system doesn't have one (like BSDI 3.0)
+**
+** Note:
+** This version of sigwait() is assumed to called in a loop so the signalmask
+** is permanently modified to reflect the signal set. This is done to get
+** a much faster implementation.
+**
+** This implementation isn't thread safe: It assumes that only one
+** thread is using sigwait.
+**
+** If one later supplies a different signal mask, all old signals that
+** was used before are unblocked and set to SIGDFL.
+**
+** Author: Gary Wisniewski <garyw@spidereye.com.au>, much modified by Monty
+****************************************************************************/
+
+#if !defined(HAVE_SIGWAIT) && !defined(sigwait) && !defined(_WIN32) && !defined(HAVE_rts_threads)
+
+#if !defined(DONT_USE_SIGSUSPEND)
+
+static sigset_t sigwait_set,rev_sigwait_set,px_recd;
+
+void px_handle_sig(int sig)
+{
+ sigaddset(&px_recd, sig);
+}
+
+
+void sigwait_setup(sigset_t *set)
+{
+ int i;
+ struct sigaction sact,sact1;
+ sigset_t unblock_mask;
+
+ sact.sa_flags = 0;
+ sact.sa_handler = px_handle_sig;
+ memcpy(&sact.sa_mask, set, sizeof(*set)); /* handler isn't thread_safe */
+ sigemptyset(&unblock_mask);
+ pthread_sigmask(SIG_UNBLOCK,(sigset_t*) 0,&rev_sigwait_set);
+
+ for (i = 1; i <= sizeof(sigwait_set)*8; i++)
+ {
+ if (sigismember(set,i))
+ {
+ sigdelset(&rev_sigwait_set,i);
+ if (!sigismember(&sigwait_set,i))
+ sigaction(i, &sact, (struct sigaction*) 0);
+ }
+ else
+ {
+ sigdelset(&px_recd,i); /* Don't handle this */
+ if (sigismember(&sigwait_set,i))
+ { /* Remove the old handler */
+ sigaddset(&unblock_mask,i);
+ sigdelset(&rev_sigwait_set,i);
+ sact1.sa_flags = 0;
+ sact1.sa_handler = SIG_DFL;
+ sigemptyset(&sact1.sa_mask);
+ sigaction(i, &sact1, 0);
+ }
+ }
+ }
+ memcpy(&sigwait_set, set, sizeof(*set));
+ pthread_sigmask(SIG_BLOCK,(sigset_t*) set,(sigset_t*) 0);
+ pthread_sigmask(SIG_UNBLOCK,&unblock_mask,(sigset_t*) 0);
+}
+
+
+int sigwait(sigset_t *setp, int *sigp)
+{
+ if (memcmp(setp,&sigwait_set,sizeof(sigwait_set)))
+ sigwait_setup(setp); /* Init or change of set */
+
+ for (;;)
+ {
+ /*
+ This is a fast, not 100% portable implementation to find the signal.
+ Because the handler is blocked there should be at most 1 bit set, but
+ the specification on this is somewhat shady so we use a set instead a
+ single variable.
+ */
+
+ ulong *ptr= (ulong*) &px_recd;
+ ulong *end=ptr+sizeof(px_recd)/sizeof(ulong);
+
+ for ( ; ptr != end ; ptr++)
+ {
+ if (*ptr)
+ {
+ ulong set= *ptr;
+ int found= (int) ((char*) ptr - (char*) &px_recd)*8+1;
+ while (!(set & 1))
+ {
+ found++;
+ set>>=1;
+ }
+ *sigp=found;
+ sigdelset(&px_recd,found);
+ return 0;
+ }
+ }
+ sigsuspend(&rev_sigwait_set);
+ }
+ return 0;
+}
+#else /* !DONT_USE_SIGSUSPEND */
+
+/****************************************************************************
+** Replacement of sigwait if the system doesn't have one (like BSDI 3.0)
+**
+** Note:
+** This version of sigwait() is assumed to called in a loop so the signalmask
+** is permanently modified to reflect the signal set. This is done to get
+** a much faster implementation.
+**
+** This implementation uses a extra thread to handle the signals and one
+** must always call sigwait() with the same signal mask!
+**
+** BSDI 3.0 NOTE:
+**
+** pthread_kill() doesn't work on a thread in a select() or sleep() loop?
+** After adding the sleep to sigwait_thread, all signals are checked and
+** delivered every second. This isn't that terrible performance vice, but
+** someone should report this to BSDI and ask for a fix!
+** Another problem is that when the sleep() ends, every select() in other
+** threads are interrupted!
+****************************************************************************/
+
+static sigset_t pending_set;
+static bool inited=0;
+static pthread_cond_t COND_sigwait;
+static pthread_mutex_t LOCK_sigwait;
+
+
+void sigwait_handle_sig(int sig)
+{
+ pthread_mutex_lock(&LOCK_sigwait);
+ sigaddset(&pending_set, sig);
+ pthread_cond_signal(&COND_sigwait); /* inform sigwait() about signal */
+ pthread_mutex_unlock(&LOCK_sigwait);
+}
+
+void *sigwait_thread(void *set_arg)
+{
+ sigset_t *set=(sigset_t*) set_arg;
+
+ int i;
+ struct sigaction sact;
+ sact.sa_flags = 0;
+ sact.sa_handler = sigwait_handle_sig;
+ memcpy(&sact.sa_mask, set, sizeof(*set)); /* handler isn't thread_safe */
+ sigemptyset(&pending_set);
+
+ for (i = 1; i <= sizeof(pending_set)*8; i++)
+ {
+ if (sigismember(set,i))
+ {
+ sigaction(i, &sact, (struct sigaction*) 0);
+ }
+ }
+ /* Ensure that init_thr_alarm() is called */
+ DBUG_ASSERT(thr_client_alarm);
+ sigaddset(set, thr_client_alarm);
+ pthread_sigmask(SIG_UNBLOCK,(sigset_t*) set,(sigset_t*) 0);
+ alarm_thread=pthread_self(); /* For thr_alarm */
+
+ for (;;)
+ { /* Wait for signals */
+ sleep(1); /* Because of broken BSDI */
+ }
+}
+
+
+int sigwait(sigset_t *setp, int *sigp)
+{
+ if (!inited)
+ {
+ pthread_attr_t thr_attr;
+ pthread_t sigwait_thread_id;
+ inited=1;
+ sigemptyset(&pending_set);
+ pthread_mutex_init(&LOCK_sigwait, MY_MUTEX_INIT_FAST);
+ pthread_cond_init(&COND_sigwait, NULL);
+
+ pthread_attr_init(&thr_attr);
+ pthread_attr_setscope(&thr_attr,PTHREAD_SCOPE_PROCESS);
+ pthread_attr_setdetachstate(&thr_attr,PTHREAD_CREATE_DETACHED);
+ pthread_create(&sigwait_thread_id, &thr_attr, sigwait_thread, setp);
+ pthread_attr_destroy(&thr_attr);
+ }
+
+ pthread_mutex_lock(&LOCK_sigwait);
+ for (;;)
+ {
+ ulong *ptr= (ulong*) &pending_set;
+ ulong *end=ptr+sizeof(pending_set)/sizeof(ulong);
+
+ for ( ; ptr != end ; ptr++)
+ {
+ if (*ptr)
+ {
+ ulong set= *ptr;
+ int found= (int) ((char*) ptr - (char*) &pending_set)*8+1;
+ while (!(set & 1))
+ {
+ found++;
+ set>>=1;
+ }
+ *sigp=found;
+ sigdelset(&pending_set,found);
+ pthread_mutex_unlock(&LOCK_sigwait);
+ return 0;
+ }
+ }
+ pthread_cond_wait(&COND_sigwait, &LOCK_sigwait);
+ }
+ return 0;
+}
+
+#endif /* DONT_USE_SIGSUSPEND */
+#endif /* HAVE_SIGWAIT */
+
+
+/****************************************************************************
+ The following functions fixes that all pthread functions should work
+ according to latest posix standard
+****************************************************************************/
+
+/* Undefined wrappers set my_pthread.h so that we call os functions */
+#undef pthread_mutex_init
+#undef pthread_mutex_lock
+#undef pthread_mutex_unlock
+#undef pthread_mutex_destroy
+#undef pthread_mutex_wait
+#undef pthread_mutex_timedwait
+#undef pthread_mutex_trylock
+#undef pthread_mutex_t
+#undef pthread_cond_init
+#undef pthread_cond_wait
+#undef pthread_cond_timedwait
+#undef pthread_cond_t
+#undef pthread_attr_getstacksize
+
+/*****************************************************************************
+ Patches for HPUX
+ We need these because the pthread_mutex.. code returns -1 on error,
+ instead of the error code.
+
+ Note that currently we only remap pthread_ functions used by MySQL.
+ If we are depending on the value for some other pthread_xxx functions,
+ this has to be added here.
+****************************************************************************/
+
+#if defined(HPUX10)
+
+int my_pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
+ struct timespec *abstime)
+{
+ int error=pthread_cond_timedwait(cond, mutex, abstime);
+ if (error == -1) /* Safety if the lib is fixed */
+ {
+ if (!(error=errno))
+ error= ETIMEDOUT; /* Can happen on HPUX */
+ }
+ if (error == EAGAIN) /* Correct errno to Posix */
+ error= ETIMEDOUT;
+ return error;
+}
+#endif
+
+#if defined(HPUX10)
+
+void my_pthread_attr_getstacksize(pthread_attr_t *connection_attrib,
+ size_t *stack_size)
+{
+ *stack_size= pthread_attr_getstacksize(*connection_attrib);
+}
+#endif
+
+
+#ifdef HAVE_POSIX1003_4a_MUTEX
+/*
+ In HP-UX-10.20 and other old Posix 1003.4a Draft 4 implementations
+ pthread_mutex_trylock returns 1 on success, not 0 like
+ pthread_mutex_lock
+
+ From the HP-UX-10.20 man page:
+ RETURN VALUES
+ If the function fails, errno may be set to one of the following
+ values:
+ Return | Error | Description
+ _______|__________|_________________________________________
+ 1 | | Successful completion.
+ 0 | | The mutex is locked; therefore, it was
+ | | not acquired.
+ -1 | [EINVAL] | The value specified by mutex is invalid.
+
+*/
+
+/*
+ Convert pthread_mutex_trylock to return values according to latest POSIX
+
+ RETURN VALUES
+ 0 If we are able successfully lock the mutex.
+ EBUSY Mutex was locked by another thread
+ # Other error number returned by pthread_mutex_trylock()
+ (Not likely)
+*/
+
+int my_pthread_mutex_trylock(pthread_mutex_t *mutex)
+{
+ int error= pthread_mutex_trylock(mutex);
+ if (error == 1)
+ return 0; /* Got lock on mutex */
+ if (error == 0) /* Someon else is locking mutex */
+ return EBUSY;
+ if (error == -1) /* Safety if the lib is fixed */
+ error= errno; /* Probably invalid parameter */
+ return error;
+}
+#endif /* HAVE_POSIX1003_4a_MUTEX */
+
+/* Some help functions */
+
+int pthread_dummy(int ret)
+{
+ return ret;
+}
+
+
+/*
+ pthread_attr_setstacksize() without so much platform-dependency
+
+ Return: The actual stack size if possible.
+*/
+
+size_t my_setstacksize(pthread_attr_t *attr, size_t stacksize)
+{
+ size_t guard_size __attribute__((unused))= 0;
+
+#if defined(__ia64__) || defined(__ia64)
+ /*
+ On IA64, half of the requested stack size is used for "normal stack"
+ and half for "register stack". The space measured by check_stack_overrun
+ is the "normal stack", so double the request to make sure we have the
+ caller-expected amount of normal stack.
+
+ NOTE: there is no guarantee that the register stack can't grow faster
+ than normal stack, so it's very unclear that we won't dump core due to
+ stack overrun despite check_stack_overrun's efforts. Experimentation
+ shows that in the execution_constants test, the register stack grows
+ less than half as fast as normal stack, but perhaps other scenarios are
+ less forgiving. If it turns out that more space is needed for the
+ register stack, that could be forced (rather inefficiently) by using a
+ multiplier higher than 2 here.
+ */
+ stacksize *= 2;
+#endif
+
+ /*
+ On many machines, the "guard space" is subtracted from the requested
+ stack size, and that space is quite large on some platforms. So add
+ it to our request, if we can find out what it is.
+ */
+#ifdef HAVE_PTHREAD_ATTR_GETGUARDSIZE
+ if (pthread_attr_getguardsize(attr, &guard_size))
+ guard_size = 0; /* if can't find it out, treat as 0 */
+#endif /* HAVE_PTHREAD_ATTR_GETGUARDSIZE */
+
+ pthread_attr_setstacksize(attr, stacksize + guard_size);
+
+ /* Retrieve actual stack size if possible */
+#ifdef HAVE_PTHREAD_ATTR_GETSTACKSIZE
+ {
+ size_t real_stack_size= 0;
+ /* We must ignore real_stack_size = 0 as Solaris 2.9 can return 0 here */
+ if (pthread_attr_getstacksize(attr, &real_stack_size) == 0 &&
+ real_stack_size > guard_size)
+ {
+ real_stack_size -= guard_size;
+ if (real_stack_size < stacksize)
+ stacksize= real_stack_size;
+ }
+ }
+#endif /* HAVE_PTHREAD_ATTR_GETSTACKSIZE */
+
+#if defined(__ia64__) || defined(__ia64)
+ stacksize /= 2;
+#endif
+ return stacksize;
+}
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