"PTHREAD_RWLOCK_RDLOCK"(P) manual page

From 3562e78743202e43aec8727005182a2558117eca Mon Sep 17 00:00:00 2001 From: marha Date: Sun, 28 Jun 2009 22:07:26 +0000 Subject: Checked in the following released items: xkeyboard-config-1.4.tar.gz ttf-bitstream-vera-1.10.tar.gz font-alias-1.0.1.tar.gz font-sun-misc-1.0.0.tar.gz font-sun-misc-1.0.0.tar.gz font-sony-misc-1.0.0.tar.gz font-schumacher-misc-1.0.0.tar.gz font-mutt-misc-1.0.0.tar.gz font-misc-misc-1.0.0.tar.gz font-misc-meltho-1.0.0.tar.gz font-micro-misc-1.0.0.tar.gz font-jis-misc-1.0.0.tar.gz font-isas-misc-1.0.0.tar.gz font-dec-misc-1.0.0.tar.gz font-daewoo-misc-1.0.0.tar.gz font-cursor-misc-1.0.0.tar.gz font-arabic-misc-1.0.0.tar.gz font-winitzki-cyrillic-1.0.0.tar.gz font-misc-cyrillic-1.0.0.tar.gz font-cronyx-cyrillic-1.0.0.tar.gz font-screen-cyrillic-1.0.1.tar.gz font-xfree86-type1-1.0.1.tar.gz font-adobe-utopia-type1-1.0.1.tar.gz font-ibm-type1-1.0.0.tar.gz font-bitstream-type1-1.0.0.tar.gz font-bitstream-speedo-1.0.0.tar.gz font-bh-ttf-1.0.0.tar.gz font-bh-type1-1.0.0.tar.gz font-bitstream-100dpi-1.0.0.tar.gz font-bh-lucidatypewriter-100dpi-1.0.0.tar.gz font-bh-100dpi-1.0.0.tar.gz font-adobe-utopia-100dpi-1.0.1.tar.gz font-adobe-100dpi-1.0.0.tar.gz font-util-1.0.1.tar.gz font-bitstream-75dpi-1.0.0.tar.gz font-bh-lucidatypewriter-75dpi-1.0.0.tar.gz font-adobe-utopia-75dpi-1.0.1.tar.gz font-bh-75dpi-1.0.0.tar.gz bdftopcf-1.0.1.tar.gz font-adobe-75dpi-1.0.0.tar.gz mkfontscale-1.0.6.tar.gz openssl-0.9.8k.tar.gz bigreqsproto-1.0.2.tar.gz xtrans-1.2.2.tar.gz resourceproto-1.0.2.tar.gz inputproto-1.4.4.tar.gz compositeproto-0.4.tar.gz damageproto-1.1.0.tar.gz zlib-1.2.3.tar.gz xkbcomp-1.0.5.tar.gz freetype-2.3.9.tar.gz pthreads-w32-2-8-0-release.tar.gz pixman-0.12.0.tar.gz kbproto-1.0.3.tar.gz evieext-1.0.2.tar.gz fixesproto-4.0.tar.gz recordproto-1.13.2.tar.gz randrproto-1.2.2.tar.gz scrnsaverproto-1.1.0.tar.gz renderproto-0.9.3.tar.gz xcmiscproto-1.1.2.tar.gz fontsproto-2.0.2.tar.gz xextproto-7.0.3.tar.gz xproto-7.0.14.tar.gz libXdmcp-1.0.2.tar.gz libxkbfile-1.0.5.tar.gz libfontenc-1.0.4.tar.gz libXfont-1.3.4.tar.gz libX11-1.1.5.tar.gz libXau-1.0.4.tar.gz libxcb-1.1.tar.gz xorg-server-1.5.3.tar.gz --- pthreads/manual/pthread_rwlock_rdlock.html | 168 +++++++++++++++++++++++++++++ 1 file changed, 168 insertions(+) create mode 100644 pthreads/manual/pthread_rwlock_rdlock.html (limited to 'pthreads/manual/pthread_rwlock_rdlock.html') diff --git a/pthreads/manual/pthread_rwlock_rdlock.html b/pthreads/manual/pthread_rwlock_rdlock.html new file mode 100644 index 000000000..3b63f255c --- /dev/null +++ b/pthreads/manual/pthread_rwlock_rdlock.html @@ -0,0 +1,168 @@ + + + + + "PTHREAD_RWLOCK_RDLOCK"(P) manual page + + + + + + + +

POSIX Threads for Windows – REFERENCE - Pthreads-w32

Reference Index

Table of Contents

Name

pthread_rwlock_rdlock, pthread_rwlock_tryrdlock - lock a +read-write lock object for reading +

Synopsis

#include <pthread.h> +

int pthread_rwlock_rdlock(pthread_rwlock_t *rwlock); +
int pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock); + +

Description

The pthread_rwlock_rdlock function shall apply a read lock +to the read-write lock referenced by rwlock. The calling +thread acquires the read lock if a writer does not hold the lock and +there are no writers blocked on the lock. +

Pthreads-win32 does not prefer either writers or readers in +acquiring the lock – all threads enter a single prioritised FIFO +queue. While this may not be optimally efficient for some +applications, it does ensure that one type does not starve the other.

A thread may hold multiple concurrent read locks on rwlock +(that is, successfully call the pthread_rwlock_rdlock function +n times). If so, the application shall ensure that the thread +performs matching unlocks (that is, it calls the +pthread_rwlock_unlock(3) +function n times). +

The pthread_rwlock_tryrdlock function shall apply a read +lock as in the pthread_rwlock_rdlock function, with the +exception that the function shall fail if the equivalent +pthread_rwlock_rdlock call would have blocked the calling +thread. In no case shall the pthread_rwlock_tryrdlock function +ever block; it always either acquires the lock or fails and returns +immediately. +

Results are undefined if any of these functions are called with an +uninitialized read-write lock. +

Pthreads-w32 does not detect deadlock if the thread already +owns the lock for writing.

Pthreads-w32 defines _POSIX_READER_WRITER_LOCKS in +pthread.h as 200112L to indicate that the reader/writer routines are +implemented and may be used.

Return Value

If successful, the pthread_rwlock_rdlock function shall +return zero; otherwise, an error number shall be returned to indicate +the error. +

The pthread_rwlock_tryrdlock function shall return zero if +the lock for reading on the read-write lock object referenced by +rwlock is acquired. Otherwise, an error number shall be +returned to indicate the error. +

Errors

The pthread_rwlock_tryrdlock function shall fail if: +

EBUSY +: + The read-write lock could not be acquired for reading because a + writer holds the lock or a writer with the appropriate priority was + blocked on it. +

+The pthread_rwlock_rdlock and pthread_rwlock_tryrdlock +functions may fail if: +

EINVAL +: + The value specified by rwlock does not refer to an + initialized read-write lock object. +
+ EAGAIN +: + The read lock could not be acquired because the maximum number of + read locks for rwlock has been exceeded. +

+These functions shall not return an error code of [EINTR]. +

The following sections are informative. +

Examples

None. +

Application Usage

Applications using these functions may be subject to priority +inversion, as discussed in the Base Definitions volume of +IEEE Std 1003.1-2001, Section 3.285, Priority Inversion. +

Rationale

None. +

Future Directions

None. +

Copyright

Portions of this text are reprinted and reproduced in electronic +form from IEEE Std 1003.1, 2003 Edition, Standard for Information +Technology -- Portable Operating System Interface (POSIX), The Open +Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the +Institute of Electrical and Electronics Engineers, Inc and The Open +Group. In the event of any discrepancy between this version and the +original IEEE and The Open Group Standard, the original IEEE and The +Open Group Standard is the referee document. The original Standard +can be obtained online at http://www.opengroup.org/unix/online.html +. +

Modified by Ross Johnson for use with Pthreads-w32.

Table of Contents

Name +
+
Synopsis +
+
Description +
+
Return + Value +
+
Errors +
+
Examples +
+
Application + Usage +
+
Rationale +
+
Future + Directions +
+
See + Also +
+
Copyright +
+

+ + -- cgit v1.2.3