PTHREAD_CREATE(3) | Library Functions Manual | PTHREAD_CREATE(3)

# 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”).

July 9, 2010 | NetBSD 9.0