pthread(3) BSD Library Functions Manual pthread(3)

NAME

 pthread -- POSIX thread functions

SYNOPSIS

 #include <pthread.h>

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
 (*child)(void))
 Registers handlers to be called before and after
 fork()

ATTRIBUTE OBJECT ROUTINES

 int pthread_attr_destroy(pthread_attr_t *attr)
 Destroy a thread attributes object.
 int pthread_attr_getinheritsched(const pthread_attr_t *attr, int
 *inheritsched)
 Get the inherit scheduling attribute from a thread
 attributes object.
 int pthread_attr_getschedparam(const pthread_attr_t *attr, struct
 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.
 int pthread_attr_setstackaddr(pthread_attr_t *attr, void *stackaddr)
 Set the stack address attribute in a thread attributes
 object.
 int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate)
 Set the detach state in a thread attributes object.

MUTEX ROUTINES

 int pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
 Destroy a mutex attributes object.
 int pthread_mutexattr_init(pthread_mutexattr_t *attr)
 Initialize a mutex attributes object with default val-
 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)
 Atomically unlock the specified mutex and block on a
 condition or until the specified time passes.
 int pthread_cond_wait(pthread_cond_t *, pthread_mutex_t *mutex)
 Atomically unlock the specified mutex and block on a
 condition.

READ/WRITE LOCK ROUTINES

 int pthread_rwlock_destroy(pthread_rwlock_t *lock)
 Destroy a read/write lock object.
 int pthread_rwlock_init(pthread_rwlock_t *lock, const
 pthread_rwlockattr_t *attr)
 Initialize a read/write lock object.
 int pthread_rwlock_rdlock(pthread_rwlock_t *lock)
 Lock a read/write lock for reading, blocking until the
 lock can be acquired.
 int pthread_rwlock_tryrdlock(pthread_rwlock_t *lock)
 Attempt to lock a read/write lock for reading, without
 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

 The default system libraries include pthread functions. No additional
 libraries or CFLAGS are necessary to use these interfaces.

SEE ALSO

 pthread_atfork(3) , pthread_attr(3) , pthread_attr_init_destroy(3) ,
 pthread_attr_getdetachstate(3) , pthread_attr_getinheritsched(3) ,
 pthread_attr_getschedparam(3) , pthread_attr_getschedpolicy(3) ,
 pthread_attr_getscope(3) , pthread_attr_getstackaddr(3) ,
 pthread_attr_getstacksize(3) , pthread_attr_init(3) ,
 pthread_attr_init_destroy(3) , pthread_attr_setdetachstate(3) ,
 pthread_attr_setinheritsched(3) , pthread_attr_setschedparam(3) ,
 pthread_attr_setschedpolicy(3) , pthread_attr_setscope(3) ,
 pthread_attr_setstackaddr(3) , pthread_attr_setstacksize(3) ,
 pthread_cancel(3) , pthread_cleanup_pop(3) , pthread_cleanup_push(3) ,
 pthread_cond_broadcast(3) , pthread_cond_destroy(3) , pthread_cond_init(3) ,
 pthread_cond_signal(3) , pthread_cond_timedwait(3) , pthread_cond_wait(3) ,
 pthread_condattr(3) , pthread_condattr_destroy(3) ,
 pthread_condattr_init(3) , pthread_create(3) , pthread_detach(3) ,
 pthread_equal(3) , pthread_exit(3) , pthread_getschedparam(3) ,
 pthread_getspecific(3) , pthread_join(3) , pthread_key_create(3) ,
 pthread_key_delete(3) , pthread_mutex_destroy(3) , pthread_mutex_init(3) ,
 pthread_mutex_lock(3) , pthread_mutex_trylock(3) , pthread_mutex_unlock(3) ,
 pthread_mutexattr(3) , pthread_mutexattr_destroy(3) ,
 pthread_mutexattr_getprioceiling(3) , pthread_mutexattr_getprotocol(3) ,
 pthread_mutexattr_gettype(3) , pthread_mutexattr_init(3) ,
 pthread_mutexattr_setprioceiling(3) , pthread_mutexattr_setprotocol(3) ,
 pthread_mutexattr_settype(3) , pthread_once(3) , pthread_rwlock_destroy(3) ,
 pthread_rwlock_init(3) , pthread_rwlock_rdlock(3) ,
 pthread_rwlock_tryrdlock(3) , pthread_rwlock_trywrlock(3) ,
 pthread_rwlock_unlock(3) , pthread_rwlock_wrlock(3) ,
 pthread_rwlockattr_destroy(3) , pthread_rwlockattr_getpshared(3) ,
 pthread_rwlockattr_init(3) , pthread_rwlockattr_setpshared(3) ,
 pthread_self(3) , pthread_setcancelstate(3)  pthread_setcanceltype(3) 
 pthread_setschedparam(3)  pthread_setspecific(3)  pthread_testcancel(3) 

STANDARDS

 The functions with the pthread_ prefix and not _np suffix or
 pthread_rwlock prefix conform to ISO/IEC 9945-1:1996 (``POSIX.1'').
 The functions with the pthread_ prefix and _np suffix are non-portable
 extensions to POSIX threads.
 The functions with the pthread_rwlock prefix are extensions created by
 The Open Group as part of the Version 2 of the Single UNIX Specification
 (``SUSv2'').
Darwin November 5, 2001 Darwin