fanotify_init.2, fanotify.7: Document FAN_REPORT_TID

[thirdparty/man-pages.git] / man3 / sem_wait.3

diff --git a/man3/sem_wait.3 b/man3/sem_wait.3
index 23a2a33cb9828affa5305b6be31f8da911dc7ed9..11179b771178310977c6b40c8ca1039e87ccef02 100644 (file)
--- a/man3/sem_wait.3
+++ b/man3/sem_wait.3
@@ -1,6 +1,7 @@
 '\" t
 .\" Copyright (C) 2006 Michael Kerrisk <mtk.manpages@gmail.com>
 .\"
+.\" %%%LICENSE_START(VERBATIM)
 .\" Permission is granted to make and distribute verbatim copies of this
 .\" manual provided the copyright notice and this permission notice are
 .\" preserved on all copies.
@@ -20,30 +21,31 @@
 .\"
 .\" Formatted or processed versions of this manual, if unaccompanied by
 .\" the source, must acknowledge the copyright and authors of this work.
+.\" %%%LICENSE_END
 .\"
-.TH SEM_WAIT 3 2012-05-13 "Linux" "Linux Programmer's Manual"
+.TH SEM_WAIT 3 2017-09-15 "Linux" "Linux Programmer's Manual"
 .SH NAME
 sem_wait, sem_timedwait, sem_trywait \- lock a semaphore
 .SH SYNOPSIS
 .nf
 .B #include <semaphore.h>
-.sp
+.PP
 .BI "int sem_wait(sem_t *" sem );
-.sp
+.PP
 .BI "int sem_trywait(sem_t *" sem );
-.sp
+.PP
 .BI "int sem_timedwait(sem_t *" sem ", const struct timespec *" abs_timeout );
 .fi
-.sp
+.PP
 Link with \fI\-pthread\fP.
-.sp
+.PP
 .in -4n
 Feature Test Macro Requirements for glibc (see
 .BR feature_test_macros (7)):
 .in
-.sp
+.PP
 .BR sem_timedwait ():
-_POSIX_C_SOURCE\ >=\ 200112L || _XOPEN_SOURCE\ >=\ 600
+_POSIX_C_SOURCE\ >=\ 200112L
 .SH DESCRIPTION
 .BR sem_wait ()
 decrements (locks) the semaphore pointed to by
@@ -54,7 +56,7 @@ If the semaphore currently has the value zero,
 then the call blocks until either it becomes possible to perform
 the decrement (i.e., the semaphore value rises above zero),
 or a signal handler interrupts the call.
-
+.PP
 .BR sem_trywait ()
 is the same as
 .BR sem_wait (),
@@ -64,7 +66,7 @@ then call returns an error
 set to
 .BR EAGAIN )
 instead of blocking.
-
+.PP
 .BR sem_timedwait ()
 is the same as
 .BR sem_wait (),
@@ -77,15 +79,15 @@ The
 argument points to a structure that specifies an absolute timeout
 in seconds and nanoseconds since the Epoch, 1970-01-01 00:00:00 +0000 (UTC).
 This structure is defined as follows:
-
-.nf
+.PP
 .in +4n
+.EX
 struct timespec {
     time_t tv_sec;      /* Seconds */
     long   tv_nsec;     /* Nanoseconds [0 .. 999999999] */
 };
+.EE
 .in
-.fi
 .PP
 If the timeout has already expired by the time of the call,
 and the semaphore could not be locked immediately,
@@ -95,7 +97,7 @@ fails with a timeout error
 .RI ( errno
 set to
 .BR ETIMEDOUT ).
-
+.PP
 If the operation can be performed immediately, then
 .BR sem_timedwait ()
 never fails with a timeout error, regardless of the value of
@@ -138,16 +140,22 @@ is less than 0, or greater than or equal to 1000 million.
 The call timed out before the semaphore could be locked.
 .\" POSIX.1-2001 also allows EDEADLK -- "A deadlock condition
 .\" was detected", but this does not occur on Linux(?).
+.SH ATTRIBUTES
+For an explanation of the terms used in this section, see
+.BR attributes (7).
+.TS
+allbox;
+lbw26 lb lb
+l l l.
+Interface      Attribute       Value
+T{
+.BR sem_wait (),
+.BR sem_trywait (),
+.BR sem_timedwait ()
+T}     Thread safety   MT-Safe
+.TE
 .SH CONFORMING TO
-POSIX.1-2001.
-.SH NOTES
-A signal handler always interrupts a blocked call to
-one of these functions, regardless of the use of the
-.BR sigaction (2)
-.B SA_RESTART
-flag.
-.\" sem_wait() is always interrupted on most other implementations,
-.\" but on FreeBSD 5.4 SA_RESTART does cause restarting.
+POSIX.1-2001, POSIX.1-2008.
 .SH EXAMPLE
 .PP
 The (somewhat trivial) program shown below operates on an
@@ -167,9 +175,9 @@ The second command-line argument specifies the length
 of the timeout, in seconds, for
 .BR sem_timedwait ().
 The following shows what happens on two different runs of the program:
-
+.PP
 .in +4n
-.nf
+.EX
 .RB "$" " ./a.out 2 3"
 About to call sem_timedwait()
 sem_post() from handler
@@ -177,11 +185,11 @@ sem_timedwait() succeeded
 .RB "$" " ./a.out 2 1"
 About to call sem_timedwait()
 sem_timedwait() timed out
-.fi
+.EE
 .in
 .SS Program source
 \&
-.nf
+.EX
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -256,7 +264,7 @@ main(int argc, char *argv[])
 
     exit((s == 0) ? EXIT_SUCCESS : EXIT_FAILURE);
 }
-.fi
+.EE
 .SH SEE ALSO
 .BR clock_gettime (2),
 .BR sem_getvalue (3),