pthread_rwlock_timedwrlocStandard C Library Funcpthread_rwlock_timedwrlock(3C)NAME
pthread_rwlock_timedwrlock, pthread_rwlock_reltimedwrlock_np - lock a
read-write lock for writing
SYNOPSIS
cc -mt [ flag... ] file... [ library... ]
#include <pthread.h>
#include <time.h>
int pthread_rwlock_timedwrlock(pthread_rwlock_t *restrict rwlock,
const struct timespec *restrict abs_timeout);
int pthread_rwlock_reltimedwrlock_np(pthread_rwlock_t *restrict rwlock,
const struct timespec *restrict rel_timeout);
DESCRIPTION
The pthread_rwlock_timedwrlock() function applies a write lock to the
read-write lock referenced by rwlock as in the
pthread_rwlock_wrlock(3C) function. If the lock cannot be acquired
without waiting for other threads to unlock the lock, this wait will be
terminated when the specified timeout expires. The timeout expires when
the absolute time specified by abs_timeout passes, as measured by the
CLOCK_REALTIME clock (that is, when the value of that clock equals or
exceeds abs_timeout), or if the absolute time specified by abs_timeout
has already been passed at the time of the call.
The pthread_rwlock_reltimedwrlock_np() function is identical to the
pthread_rwlock_timedwrlock() function, except that the timeout is spec‐
ified as a relative time interval. The timeout expires when the time
interval specified by rel_timeout passes, as measured by the
CLOCK_REALTIME clock, or if the time interval specified by rel_timeout
is negative at the time of the call.
The resolution of the timeout is the resolution of the CLOCK_REALTIME
clock. The timespec data type is defined in the <time.h> header. Under
no circumstances does either function fail with a timeout if the lock
can be acquired immediately. The validity of the abs_timeout parameter
need not be checked if the lock can be immediately acquired.
If a signal that causes a signal handler to be executed is delivered to
a thread blocked on a read- write lock with a call to
pthread_rwlock_timedwrlock() or pthread_rwlock_reltimedwrlock_np(),
upon return from the signal handler the thread resumes waiting for the
lock as if it was not interrupted.
The calling thread can deadlock if at the time the call is made it
holds the read-write lock. The results are undefined if this function
is called with an uninitialized read-write lock.
RETURN VALUES
The pthread_rwlock_timedwrlock() and pthread_rwlock_reltimedwrlock_np()
functions return 0 if the lock for writing on the read-write lock
object referenced by rwlock is acquired. Otherwise, an error number is
returned to indicate the error.
ERRORS
The pthread_rwlock_timedwrlock() and pthread_rwlock_reltimedwrlock_np()
functions will fail if:
ETIMEDOUT The lock could not be acquired before the specified time‐
out expired.
The pthread_rwlock_timedwrlock() and pthread_rwlock_reltimedwrlock_np()
functions may fail if:
EDEADLK The calling thread already holds the rwlock.
EINVAL The value specified by rwlock does not refer to an initial‐
ized read-write lock object, or the timeout nanosecond value
is less than zero or greater than or equal to 1,000 million.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Committed │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │MT-Safe │
├─────────────────────────────┼─────────────────────────────┤
│Standard │For pthread_rwlock_timedwr‐ │
│ │lock(), see standards(5). │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOpthread_rwlock_destroy(3C), pthread_rwlock_rdlock(3C),
pthread_rwlock_timedrdlock(3C), pthread_rwlock_trywrlock(3C),
pthread_rwlock_unlock(3C), pthread_rwlock_wrlock(3C), attributes(5),
standards(5)SunOS 5.11 30 Jan 2004 pthread_rwlock_timedwrlock(3C)
