DESCRIPTION
POSIX threads are a set of functions that support applications with
requirements for multiple flows of control, called threads, within a
process. Multithreading is used to improve the performance of a program.
The POSIX thread functions are summarized in this section in the follow-
ing groups:
o Thread Routines
o Attribute Object Routines
o Mutex Routines
o Condition Variable Routines
o Read/Write Lock Routines
o Per-Thread Context Routines
o Cleanup Routines
THREAD ROUTINES
int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void
*(*start_routine)(void *), void *arg)
Creates a new thread of execution.
int pthread_detach(pthread_t thread)
Marks a thread for deletion.
int pthread_equal(pthread_t t1, pthread_t t2)
Compares two thread IDs.
void pthread_exit(void *value_ptr)
Terminates the calling thread.
int pthread_join(pthread_t thread, void **value_ptr)
Causes the calling thread to wait for the termination
of the specified thread.
int pthread_cancel(pthread_t thread)
Cancels execution of a thread.
int pthread_once(pthread_once_t *once_control, void
(*init_routine)(void))
Calls an initialization routine once.
pthread_t pthread_self(void)
Returns the thread ID of the calling thread.
int pthread_atfork(void (*prepare)(void), void (*parent)(void), void
sched_param *param)
Get the scheduling parameter attribute from a thread
attributes object.
int pthread_attr_getschedpolicy(const pthread_attr_t *attr, int *policy)
Get the scheduling policy attribute from a thread
attributes object.
int pthread_attr_getscope(const pthread_attr_t *attr, int
*contentionscope)
Get the contention scope attribute from a thread
attributes object.
int pthread_attr_getstacksize(const pthread_attr_t *attr, size_t
*stacksize)
Get the stack size attribute from a thread attributes
object.
int pthread_attr_getstackaddr(const pthread_attr_t *attr, void
**stackaddr)
Get the stack address attribute from a thread
attributes object.
int pthread_attr_getdetachstate(const pthread_attr_t *attr, int
*detachstate)
Get the detach state attribute from a thread
attributes object.
int pthread_attr_init(pthread_attr_t *attr)
Initialize a thread attributes object with default
values.
int pthread_attr_setinheritsched(pthread_attr_t *attr, int inheritsched)
Set the inherit scheduling attribute in a thread
attributes object.
int pthread_attr_setschedparam(pthread_attr_t *attr, const struct
sched_param *param)
Set the scheduling parameter attribute in a thread
attributes object.
int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy)
Set the scheduling policy attribute in a thread
attributes object.
int pthread_attr_setscope(pthread_attr_t *attr, int contentionscope)
Set the contention scope attribute in a thread
attributes object.
int pthread_attr_setstacksize(pthread_attr_t *attr, size_t stacksize)
Set the stack size attribute in a thread attributes
object.
ues.
int pthread_mutex_destroy(pthread_mutex_t *mutex)
Destroy a mutex.
int pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t
*attr)
Initialize a mutex with specified attributes.
int pthread_mutex_lock(pthread_mutex_t *mutex)
Lock a mutex and block until it becomes available.
int pthread_mutex_trylock(pthread_mutex_t *mutex)
Try to lock a mutex, but don't block if the mutex is
locked by another thread, including the current
thread.
int pthread_mutex_unlock(pthread_mutex_t *mutex)
Unlock a mutex.
CONDITION VARIABLE ROUTINES
int pthread_condattr_init(pthread_condattr_t *attr)
Initialize a condition variable attributes object with
default values.
int pthread_condattr_destroy(pthread_condattr_t *attr)
Destroy a condition variable attributes object.
int pthread_cond_broadcast(pthread_cond_t *cond)
Unblock all threads currently blocked on the specified
condition variable.
int pthread_cond_destroy(pthread_cond_t *cond)
Destroy a condition variable.
int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t
*attr)
Initialize a condition variable with specified
attributes.
int pthread_cond_signal(pthread_cond_t *cond)
Unblock at least one of the threads blocked on the
specified condition variable.
int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
const struct timespec *abstime)
Wait no longer than the specified time for a condition
and lock the specified mutex.
int pthread_cond_wait(pthread_cond_t *, pthread_mutex_t *mutex)
Wait for a condition and lock the specified mutex.
blocking if the lock is unavailable.
int pthread_rwlock_trywrlock(pthread_rwlock_t *lock)
Attempt to lock a read/write lock for writing, without
blocking if the lock is unavailable.
int pthread_rwlock_unlock(pthread_rwlock_t *lock)
Unlock a read/write lock.
int pthread_rwlock_wrlock(pthread_rwlock_t *lock)
Lock a read/write lock for writing, blocking until the
lock can be acquired.
int pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr)
Destroy a read/write lock attribute object.
int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *attr, int
*pshared)
Retrieve the process shared setting for the read/write
lock attribute object.
int pthread_rwlockattr_init(pthread_rwlockattr_t *attr)
Initialize a read/write lock attribute object.
int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr, int
pshared)
Set the process shared setting for the read/write lock
attribute object.
PER-THREAD CONTEXT ROUTINES
int pthread_key_create(pthread_key_t *key, void (*routine)(void *))
Create a thread-specific data key.
int pthread_key_delete(pthread_key_t key)
Delete a thread-specific data key.
void * pthread_getspecific(pthread_key_t key)
Get the thread-specific value for the specified key.
int pthread_setspecific(pthread_key_t key, const void *value_ptr)
Set the thread-specific value for the specified key.
CLEANUP ROUTINES
void pthread_cleanup_pop(int execute)
Remove the routine at the top of the calling thread's
cancellation cleanup stack and optionally invoke it.
void pthread_cleanup_push(void (*routine)(void *), void *routine_arg)
Push the specified cancellation cleanup handler onto
the calling thread's cancellation stack.
INSTALLATION
pthread_rwlock_rdlock(3), pthread_rwlock_unlock(3),
pthread_rwlock_wrlock(3), pthread_self(3), pthread_setspecific(3)
STANDARDS
The functions in libc with the pthread_ prefix and not _np suffix or
pthread_rwlock prefix conform to ISO/IEC 9945-1:1996 (``POSIX.1'').
The functions in libc with the pthread_ prefix and _np suffix are non-
portable extensions to POSIX threads.
The functions in libc with the pthread_rwlock prefix are extensions cre-
ated by The Open Group as part of the Version 2 of the Single UNIX
Specification (``SUSv2'').
Darwin November 5, 2001 Darwin
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