NAME
pthread_join() — wait for the termination of a specified thread
SYNOPSIS
#include <pthread.h>
int pthread_join(
pthread_t thread,
void **value_ptr
);
PARAMETERS
- thread
Thread whose termination is awaited by the caller.
- value_ptr
Pointer to the location where the exit status of
thread
is returned.
DESCRIPTION
The
pthread_join()
function waits for the termination of the target
thread.
If the target
thread
has already terminated, this function returns immediately.
Only threads created with a
detachstate
attribute value of
PTHREAD_CREATE_JOINABLE
may be specified in the target
thread
parameter.
On successful return from
pthread_join(),
the
value_ptr
argument, if it is not a null pointer, will contain the value
passed to
pthread_exit()
by the terminating thread.
When a
pthread_join()
call returns successfully, the caller is guaranteed the target thread
has terminated.
If more than one thread calls
pthread_join()
for the same target thread, one thread is guaranteed to return
successfully.
Undefined behavior results for other callers specifying the same thread.
If the thread calling
pthread_join()
is canceled, the target thread shall not be joined.
The exit status of the target
thread
will remain available for another thread to call
pthread_join().
If the target
thread
was canceled, its exit status is
PTHREAD_CANCELED.
It is unspecified whether a thread that has exited, but remains unjoined,
counts against the
{_POSIX_THREAD_THREADS_MAX}
limit.
RETURN VALUE
Upon successful completion,
pthread_join()
returns zero. Otherwise, an error number is returned to indicate the error
(the
errno
variable is not set).
ERRORS
If any of the following occur, the
pthread_join()
function returns the corresponding error number:
- [EINVAL]
The value specified by
thread
does not refer to a joinable thread.
- [ESRCH]
No thread could be found corresponding to
thread.
For each of the following conditions, if the condition is detected, the
pthread_join()
function returns the corresponding error number:
- [EDEADLK]
This operation would result in process deadlock or
thread
specifies the calling thread.
AUTHOR
pthread_join()
was derived from the IEEE POSIX P1003.1c standard.
STANDARDS CONFORMANCE
pthread_join(): POSIX 1003.1c.
Printable version
