NAME

pthread_create — create a new thread

LIBRARY

POSIX Threads Library (libpthread, -lpthread)

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.

The attributes specified via attr are copied into the new thread. Any subsequent modifications to the attributes object attr points to will have no effect upon already-created threads. It is thus also safe to pass the same attr to multiple calls to pthread_create().

Upon successful completion pthread_create() will store the ID of the created thread in the location specified by thread. The thread is created executing start_routine with arg as its sole argument.

If the 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.

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. Otherwise an error number will be returned to indicate the error.

ERRORS

pthread_create() shall fail if:

[EAGAIN]

The system lacks 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 ALSO

fork(2), pthread_attr(3), pthread_cleanup_pop(3), pthread_cleanup_push(3), pthread_exit(3), pthread_join(3)

STANDARDS

The function conforms to IEEE Std 1003.1-2001 (“POSIX.1”).