diff options
author | Bruno Haible <bruno@clisp.org> | 2018-06-18 18:16:34 +0200 |
---|---|---|
committer | Bruno Haible <bruno@clisp.org> | 2018-06-18 18:16:34 +0200 |
commit | 8584beae8e0f4ac4a5c128d35da43241761501db (patch) | |
tree | 64c722e63d43cbc34609384ef900adcf9bfcc31c /m4/pthread_rwlock_rdlock.m4 | |
parent | 0d45ec7c033c165ad73a6509c7fa84aa67edf4ea (diff) | |
download | gnulib-8584beae8e0f4ac4a5c128d35da43241761501db.tar.gz |
pthread_rwlock_rdlock: Add comments regarding glibc behaviour.
* m4/pthread_rwlock_rdlock.m4: Add comment.
* doc/posix-functions/pthread_rwlock_rdlock.texi: Mention that rwlocks
are reader-preferring in glibc.
* doc/posix-functions/pthread_rwlock_tryrdlock.texi: Likwise.
* doc/posix-functions/pthread_rwlock_timedrdlock.texi: Likewise.
Diffstat (limited to 'm4/pthread_rwlock_rdlock.m4')
-rw-r--r-- | m4/pthread_rwlock_rdlock.m4 | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/m4/pthread_rwlock_rdlock.m4 b/m4/pthread_rwlock_rdlock.m4 index 9c1d5d0193..6812b4f4e2 100644 --- a/m4/pthread_rwlock_rdlock.m4 +++ b/m4/pthread_rwlock_rdlock.m4 @@ -1,4 +1,4 @@ -# pthread_rwlock_rdlock.m4 serial 1 +# pthread_rwlock_rdlock.m4 serial 2 dnl Copyright (C) 2017-2018 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -23,12 +23,14 @@ dnl time, a phenomenon called "writer starvation". dnl Without such a guarantee, applications have a hard time avoiding writer dnl starvation. dnl -dnl POSIX:2008 makes this requirement only for implementations that support TPS +dnl POSIX:2017 makes this requirement only for implementations that support TPS dnl (Thread Priority Scheduling) and only for the scheduling policies SCHED_FIFO dnl and SCHED_RR, see dnl http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_rdlock.html -dnl but test verifies the guarantee regardless of TPS and regardless of +dnl but this test verifies the guarantee regardless of TPS and regardless of dnl scheduling policy. +dnl Glibc currently does not provide this guarantee, see +dnl https://sourceware.org/bugzilla/show_bug.cgi?id=13701 AC_DEFUN([gl_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER], [ AC_REQUIRE([gl_THREADLIB_EARLY]) |