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/* Linuxthreads - a simple clone()-based implementation of Posix */
/* threads for Linux. */
/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
/* */
/* This program is free software; you can redistribute it and/or */
/* modify it under the terms of the GNU Library General Public License */
/* as published by the Free Software Foundation; either version 2 */
/* of the License, or (at your option) any later version. */
/* */
/* This program is distributed in the hope that it will be useful, */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
/* GNU Library General Public License for more details. */
/* Thread termination and joining */
#include <errno.h>
#include <sched.h>
#include <unistd.h>
#include "pthread.h"
#include "internals.h"
#include "spinlock.h"
#include "restart.h"
void pthread_exit(void * retval)
{
pthread_descr self = thread_self();
pthread_descr joining;
struct pthread_request request;
/* Reset the cancellation flag to avoid looping if the cleanup handlers
contain cancellation points */
self->p_canceled = 0;
/* Call cleanup functions and destroy the thread-specific data */
__pthread_perform_cleanup();
__pthread_destroy_specifics();
/* Store return value */
acquire(self->p_spinlock);
self->p_retval = retval;
/* Say that we've terminated */
self->p_terminated = 1;
/* See if someone is joining on us */
joining = self->p_joining;
release(self->p_spinlock);
/* Restart joining thread if any */
if (joining != NULL) restart(joining);
/* If this is the initial thread, block until all threads have terminated.
If another thread calls exit, we'll be terminated from our signal
handler. */
if (self == __pthread_main_thread && __pthread_manager_request >= 0) {
request.req_thread = self;
request.req_kind = REQ_MAIN_THREAD_EXIT;
__libc_write(__pthread_manager_request, (char *)&request, sizeof(request));
suspend(self);
}
/* Exit the process (but don't flush stdio streams, and don't run
atexit functions). */
_exit(0);
}
int pthread_join(pthread_t thread_id, void ** thread_return)
{
volatile pthread_descr self = thread_self();
struct pthread_request request;
pthread_handle handle = thread_handle(thread_id);
pthread_descr th;
acquire(&handle->h_spinlock);
if (invalid_handle(handle, thread_id)) {
release(&handle->h_spinlock);
return ESRCH;
}
th = handle->h_descr;
if (th == self) {
release(&handle->h_spinlock);
return EDEADLK;
}
/* If detached or already joined, error */
if (th->p_detached || th->p_joining != NULL) {
release(&handle->h_spinlock);
return EINVAL;
}
/* If not terminated yet, suspend ourselves. */
if (! th->p_terminated) {
th->p_joining = self;
release(&handle->h_spinlock);
suspend_with_cancellation(self);
/* This is a cancellation point */
if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE) {
th->p_joining = NULL;
pthread_exit(PTHREAD_CANCELED);
}
acquire(&handle->h_spinlock);
}
/* Get return value */
if (thread_return != NULL) *thread_return = th->p_retval;
release(&handle->h_spinlock);
/* Send notification to thread manager */
if (__pthread_manager_request >= 0) {
request.req_thread = self;
request.req_kind = REQ_FREE;
request.req_args.free.thread = th;
__libc_write(__pthread_manager_request,
(char *) &request, sizeof(request));
}
return 0;
}
int pthread_detach(pthread_t thread_id)
{
int terminated;
struct pthread_request request;
pthread_handle handle = thread_handle(thread_id);
pthread_descr th;
acquire(&handle->h_spinlock);
if (invalid_handle(handle, thread_id)) {
release(&handle->h_spinlock);
return ESRCH;
}
th = handle->h_descr;
/* If already detached, error */
if (th->p_detached) {
release(&handle->h_spinlock);
return EINVAL;
}
/* If already joining, don't do anything. */
if (th->p_joining != NULL) {
release(&handle->h_spinlock);
return 0;
}
/* Mark as detached */
th->p_detached = 1;
terminated = th->p_terminated;
release(&handle->h_spinlock);
/* If already terminated, notify thread manager to reclaim resources */
if (terminated && __pthread_manager_request >= 0) {
request.req_thread = thread_self();
request.req_kind = REQ_FREE;
request.req_args.free.thread = th;
__libc_write(__pthread_manager_request,
(char *) &request, sizeof(request));
}
return 0;
}
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