PTHREAD_CREATE(3) BSD Library Functions Manual PTHREAD_CREATE(3)NAMEpthread_create — create a new thread
SYNOPSIS
#include <pthread.h>
int
pthread_create(pthread_t *restrict thread,
const pthread_attr_t *restrict attr, void *(*start_routine)(void *),
void *restrict arg);
DESCRIPTION
The pthread_create() function is used to create a new thread, with
attributes specified by attr, within a process. If attr is NULL, the
default attributes are used. If the attributes specified by attr are
modified later, the thread's attributes are not affected. Upon success‐
ful completion, pthread_create() will store the ID of the created thread
in the location specified by thread.
Upon its creation, the thread executes start_routine, with arg as its
sole argument. If start_routine returns, the effect is as if there was
an implicit call to pthread_exit(), using the return value of
start_routine as the exit status. Note that the thread in which main()
was originally invoked differs from this. When it returns from main(),
the effect is as if there was an implicit call to exit(), using the
return value of main() as the exit status.
Upon thread exit the storage for the thread must be reclaimed by another
thread via a call to pthread_join(). Alternatively, pthread_detach() may
be called on the thread to indicate that the system may automatically
reclaim the thread storage upon exit. The pthread_attr_setdetachstate()
function may be used on the attr argument passed to pthread_create() in
order to achieve the same effect as a call to pthread_detach() on the
newly created thread.
The signal state of the new thread is initialized as:
· The signal mask is inherited from the creating thread.
· The set of signals pending for the new thread is empty.
RETURN VALUES
If successful, the pthread_create() function will return zero. Other‐
wise, an error number will be returned to indicate the error.
ERRORSpthread_create() will fail if:
[EAGAIN] The system lacked the necessary resources to create
another thread, or the system-imposed limit on the
total number of threads in a process
[PTHREAD_THREADS_MAX] would be exceeded.
[EINVAL] The value specified by attr is invalid.
SEE ALSOfork(2), pthread_cleanup_pop(3), pthread_cleanup_push(3),
pthread_detach(3), pthread_exit(3), pthread_join(3)STANDARDSpthread_create() conforms to ISO/IEC 9945-1:1996 (“POSIX.1”).
BSD April 4, 1996 BSD
