Manual Pages  — PTHREAD_CREATE

pthread_create – create a new thread

LIBRARY SYNOPSIS DESCRIPTION RETURN VALUES ERRORS SEE ALSO STANDARDS

POSIX Threads Library (libpthread, -lpthread)

#include <pthread.h>

int
pthread_create(pthread_t *restrict thread, const pthread_attr_t *restrict attr, void *(*start_routine)(void *), void *restrict arg);

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 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.

If successful, the pthread_create() function will return zero. Otherwise an error number will be returned to indicate the error.

The pthread_create() function can return any of the following errors:

[ENOMEM]
	The system lacked the necessary resources to create another thread.
[EAGAIN]
	The system-imposed limit on the total number of threads in a process [PTHREAD_THREADS_MAX] would be exceeded.
[EAGAIN]
	The RACCT_NTHR limit would be exceeded; see racct(2).
[EPERM]
	The caller does not have permission to set the scheduling parameters or scheduling policy.
[EINVAL]
	A value specified by attr is invalid.
[EDEADLK]
	The CPU set specified by attr would prevent the thread from running on any CPU.
[EFAULT]
	The stack base specified by attr is invalid, or the kernel was unable to put required initial data on the stack.

The pthread_create() function conforms to IEEE Std 1003.1-96 ("POSIX.1").