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diff --git a/upstream/mageia-cauldron/man3pm/Thread::Semaphore.3pm b/upstream/mageia-cauldron/man3pm/Thread::Semaphore.3pm new file mode 100644 index 00000000..7e0ba5f2 --- /dev/null +++ b/upstream/mageia-cauldron/man3pm/Thread::Semaphore.3pm @@ -0,0 +1,215 @@ +.\" -*- mode: troff; coding: utf-8 -*- +.\" Automatically generated by Pod::Man 5.01 (Pod::Simple 3.43) +.\" +.\" Standard preamble: +.\" ======================================================================== +.de Sp \" Vertical space (when we can't use .PP) +.if t .sp .5v +.if n .sp +.. +.de Vb \" Begin verbatim text +.ft CW +.nf +.ne \\$1 +.. +.de Ve \" End verbatim text +.ft R +.fi +.. +.\" \*(C` and \*(C' are quotes in nroff, nothing in troff, for use with C<>. +.ie n \{\ +. ds C` "" +. ds C' "" +'br\} +.el\{\ +. ds C` +. ds C' +'br\} +.\" +.\" Escape single quotes in literal strings from groff's Unicode transform. +.ie \n(.g .ds Aq \(aq +.el .ds Aq ' +.\" +.\" If the F register is >0, we'll generate index entries on stderr for +.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index +.\" entries marked with X<> in POD. Of course, you'll have to process the +.\" output yourself in some meaningful fashion. +.\" +.\" Avoid warning from groff about undefined register 'F'. +.de IX +.. +.nr rF 0 +.if \n(.g .if rF .nr rF 1 +.if (\n(rF:(\n(.g==0)) \{\ +. if \nF \{\ +. de IX +. tm Index:\\$1\t\\n%\t"\\$2" +.. +. if !\nF==2 \{\ +. nr % 0 +. nr F 2 +. \} +. \} +.\} +.rr rF +.\" ======================================================================== +.\" +.IX Title "Thread::Semaphore 3pm" +.TH Thread::Semaphore 3pm 2023-11-28 "perl v5.38.2" "Perl Programmers Reference Guide" +.\" For nroff, turn off justification. Always turn off hyphenation; it makes +.\" way too many mistakes in technical documents. +.if n .ad l +.nh +.SH NAME +Thread::Semaphore \- Thread\-safe semaphores +.SH VERSION +.IX Header "VERSION" +This document describes Thread::Semaphore version 2.13 +.SH SYNOPSIS +.IX Header "SYNOPSIS" +.Vb 5 +\& use Thread::Semaphore; +\& my $s = Thread::Semaphore\->new(); +\& $s\->down(); # Also known as the semaphore P operation. +\& # The guarded section is here +\& $s\->up(); # Also known as the semaphore V operation. +\& +\& # Decrement the semaphore only if it would immediately succeed. +\& if ($s\->down_nb()) { +\& # The guarded section is here +\& $s\->up(); +\& } +\& +\& # Forcefully decrement the semaphore even if its count goes below 0. +\& $s\->down_force(); +\& +\& # The default value for semaphore operations is 1 +\& my $s = Thread::Semaphore\->new($initial_value); +\& $s\->down($down_value); +\& $s\->up($up_value); +\& if ($s\->down_nb($down_value)) { +\& ... +\& $s\->up($up_value); +\& } +\& $s\->down_force($down_value); +.Ve +.SH DESCRIPTION +.IX Header "DESCRIPTION" +Semaphores provide a mechanism to regulate access to resources. Unlike +locks, semaphores aren't tied to particular scalars, and so may be used to +control access to anything you care to use them for. +.PP +Semaphores don't limit their values to zero and one, so they can be used to +control access to some resource that there may be more than one of (e.g., +filehandles). Increment and decrement amounts aren't fixed at one either, +so threads can reserve or return multiple resources at once. +.SH METHODS +.IX Header "METHODS" +.IP \->\fBnew()\fR 8 +.IX Item "->new()" +.PD 0 +.IP \->new(NUMBER) 8 +.IX Item "->new(NUMBER)" +.PD +\&\f(CW\*(C`new\*(C'\fR creates a new semaphore, and initializes its count to the specified +number (which must be an integer). If no number is specified, the +semaphore's count defaults to 1. +.IP \->\fBdown()\fR 8 +.IX Item "->down()" +.PD 0 +.IP \->down(NUMBER) 8 +.IX Item "->down(NUMBER)" +.PD +The \f(CW\*(C`down\*(C'\fR method decreases the semaphore's count by the specified number +(which must be an integer >= 1), or by one if no number is specified. +.Sp +If the semaphore's count would drop below zero, this method will block +until such time as the semaphore's count is greater than or equal to the +amount you're \f(CW\*(C`down\*(C'\fRing the semaphore's count by. +.Sp +This is the semaphore "P operation" (the name derives from the Dutch +word "pak", which means "capture" \-\- the semaphore operations were +named by the late Dijkstra, who was Dutch). +.IP \->\fBdown_nb()\fR 8 +.IX Item "->down_nb()" +.PD 0 +.IP \->down_nb(NUMBER) 8 +.IX Item "->down_nb(NUMBER)" +.PD +The \f(CW\*(C`down_nb\*(C'\fR method attempts to decrease the semaphore's count by the +specified number (which must be an integer >= 1), or by one if no number +is specified. +.Sp +If the semaphore's count would drop below zero, this method will return +\&\fIfalse\fR, and the semaphore's count remains unchanged. Otherwise, the +semaphore's count is decremented and this method returns \fItrue\fR. +.IP \->\fBdown_force()\fR 8 +.IX Item "->down_force()" +.PD 0 +.IP \->down_force(NUMBER) 8 +.IX Item "->down_force(NUMBER)" +.PD +The \f(CW\*(C`down_force\*(C'\fR method decreases the semaphore's count by the specified +number (which must be an integer >= 1), or by one if no number is specified. +This method does not block, and may cause the semaphore's count to drop +below zero. +.IP \->down_timed(TIMEOUT) 8 +.IX Item "->down_timed(TIMEOUT)" +.PD 0 +.IP "\->down_timed(TIMEOUT, NUMBER)" 8 +.IX Item "->down_timed(TIMEOUT, NUMBER)" +.PD +The \f(CW\*(C`down_timed\*(C'\fR method attempts to decrease the semaphore's count by 1 +or by the specified number within the specified timeout period given in +seconds (which must be an integer >= 0). +.Sp +If the semaphore's count would drop below zero, this method will block +until either the semaphore's count is greater than or equal to the +amount you're \f(CW\*(C`down\*(C'\fRing the semaphore's count by, or until the timeout is +reached. +.Sp +If the timeout is reached, this method will return \fIfalse\fR, and the +semaphore's count remains unchanged. Otherwise, the semaphore's count is +decremented and this method returns \fItrue\fR. +.IP \->\fBup()\fR 8 +.IX Item "->up()" +.PD 0 +.IP \->up(NUMBER) 8 +.IX Item "->up(NUMBER)" +.PD +The \f(CW\*(C`up\*(C'\fR method increases the semaphore's count by the number specified +(which must be an integer >= 1), or by one if no number is specified. +.Sp +This will unblock any thread that is blocked trying to \f(CW\*(C`down\*(C'\fR the +semaphore if the \f(CW\*(C`up\*(C'\fR raises the semaphore's count above the amount that +the \f(CW\*(C`down\*(C'\fR is trying to decrement it by. For example, if three threads +are blocked trying to \f(CW\*(C`down\*(C'\fR a semaphore by one, and another thread \f(CW\*(C`up\*(C'\fRs +the semaphore by two, then two of the blocked threads (which two is +indeterminate) will become unblocked. +.Sp +This is the semaphore "V operation" (the name derives from the Dutch +word "vrij", which means "release"). +.SH NOTES +.IX Header "NOTES" +Semaphores created by Thread::Semaphore can be used in both threaded and +non-threaded applications. This allows you to write modules and packages +that potentially make use of semaphores, and that will function in either +environment. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +Thread::Semaphore on MetaCPAN: +<https://metacpan.org/release/Thread\-Semaphore> +.PP +Code repository for CPAN distribution: +<https://github.com/Dual\-Life/Thread\-Semaphore> +.PP +threads, threads::shared +.PP +Sample code in the \fIexamples\fR directory of this distribution on CPAN. +.SH MAINTAINER +.IX Header "MAINTAINER" +Jerry D. Hedden, <jdhedden\ AT\ cpan\ DOT\ org> +.SH LICENSE +.IX Header "LICENSE" +This program is free software; you can redistribute it and/or modify it under +the same terms as Perl itself. |