freebsd-dev/lib/libpthread/thread/thr_create.c
Daniel Eischen 69c287d288 This has been sitting in my local tree long enough. Remove the use
of an alternate signal stack for handling signals.  Let the kernel
send signals on the stack of the current thread and teach the threads
signal handler how to deliver signals to the current thread if it
needs to.  Also, always store a threads context as a jmp_buf.  Eventually
this will change to be a ucontext_t or mcontext_t.

Other small nits.  Use struct pthread * instead of pthread_t in internal
library routines.  The threads code wants struct pthread *, and pthread_t
doesn't necessarily have to be the same.

Reviewed by:	jasone
2002-02-09 19:58:41 +00:00

268 lines
7.8 KiB
C

/*
* Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <stddef.h>
#include <sys/time.h>
#include <machine/reg.h>
#include <pthread.h>
#include "pthread_private.h"
#include "libc_private.h"
static u_int64_t next_uniqueid = 1;
#define OFF(f) offsetof(struct pthread, f)
int _thread_next_offset = OFF(tle.tqe_next);
int _thread_uniqueid_offset = OFF(uniqueid);
int _thread_state_offset = OFF(state);
int _thread_name_offset = OFF(name);
int _thread_ctx_offset = OFF(ctx);
#undef OFF
int _thread_PS_RUNNING_value = PS_RUNNING;
int _thread_PS_DEAD_value = PS_DEAD;
__weak_reference(_pthread_create, pthread_create);
int
_pthread_create(pthread_t * thread, const pthread_attr_t * attr,
void *(*start_routine) (void *), void *arg)
{
struct pthread *curthread = _get_curthread();
struct itimerval itimer;
int f_gc = 0;
int ret = 0;
pthread_t gc_thread;
pthread_t new_thread;
pthread_attr_t pattr;
void *stack;
/*
* Locking functions in libc are required when there are
* threads other than the initial thread.
*/
__isthreaded = 1;
/* Allocate memory for the thread structure: */
if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL) {
/* Insufficient memory to create a thread: */
ret = EAGAIN;
} else {
/* Check if default thread attributes are required: */
if (attr == NULL || *attr == NULL) {
/* Use the default thread attributes: */
pattr = &pthread_attr_default;
} else {
pattr = *attr;
}
/* Check if a stack was specified in the thread attributes: */
if ((stack = pattr->stackaddr_attr) != NULL) {
}
/* Allocate a stack: */
else {
stack = _thread_stack_alloc(pattr->stacksize_attr,
pattr->guardsize_attr);
if (stack == NULL) {
ret = EAGAIN;
free(new_thread);
}
}
/* Check for errors: */
if (ret != 0) {
} else {
/* Initialise the thread structure: */
memset(new_thread, 0, sizeof(struct pthread));
new_thread->slice_usec = -1;
new_thread->stack = stack;
new_thread->start_routine = start_routine;
new_thread->arg = arg;
new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
PTHREAD_CANCEL_DEFERRED;
/*
* Write a magic value to the thread structure
* to help identify valid ones:
*/
new_thread->magic = PTHREAD_MAGIC;
/* Initialise the thread for signals: */
new_thread->sigmask = curthread->sigmask;
new_thread->sigmask_seqno = 0;
/* Initialize the signal frame: */
new_thread->curframe = NULL;
/* Initialise the jump buffer: */
_setjmp(new_thread->ctx.jb);
/*
* Set up new stack frame so that it looks like it
* returned from a longjmp() to the beginning of
* _thread_start().
*/
SET_RETURN_ADDR_JB(new_thread->ctx.jb, _thread_start);
/* The stack starts high and builds down: */
SET_STACK_JB(new_thread->ctx.jb,
(long)new_thread->stack + pattr->stacksize_attr
- sizeof(double));
/* Copy the thread attributes: */
memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr));
/*
* Check if this thread is to inherit the scheduling
* attributes from its parent:
*/
if (new_thread->attr.flags & PTHREAD_INHERIT_SCHED) {
/* Copy the scheduling attributes: */
new_thread->base_priority =
curthread->base_priority &
~PTHREAD_SIGNAL_PRIORITY;
new_thread->attr.prio =
curthread->base_priority &
~PTHREAD_SIGNAL_PRIORITY;
new_thread->attr.sched_policy =
curthread->attr.sched_policy;
} else {
/*
* Use just the thread priority, leaving the
* other scheduling attributes as their
* default values:
*/
new_thread->base_priority =
new_thread->attr.prio;
}
new_thread->active_priority = new_thread->base_priority;
new_thread->inherited_priority = 0;
/* Initialize joiner to NULL (no joiner): */
new_thread->joiner = NULL;
/* Initialize the mutex queue: */
TAILQ_INIT(&new_thread->mutexq);
/* Initialise hooks in the thread structure: */
new_thread->specific_data = NULL;
new_thread->cleanup = NULL;
new_thread->flags = 0;
new_thread->poll_data.nfds = 0;
new_thread->poll_data.fds = NULL;
new_thread->continuation = NULL;
/*
* Defer signals to protect the scheduling queues
* from access by the signal handler:
*/
_thread_kern_sig_defer();
/*
* Initialise the unique id which GDB uses to
* track threads.
*/
new_thread->uniqueid = next_uniqueid++;
/*
* Check if the garbage collector thread
* needs to be started.
*/
f_gc = (TAILQ_FIRST(&_thread_list) == _thread_initial);
/* Add the thread to the linked list of all threads: */
TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle);
if (pattr->suspend == PTHREAD_CREATE_SUSPENDED)
new_thread->state = PS_SUSPENDED;
else {
new_thread->state = PS_RUNNING;
PTHREAD_PRIOQ_INSERT_TAIL(new_thread);
}
/*
* Undefer and handle pending signals, yielding
* if necessary.
*/
_thread_kern_sig_undefer();
/* Return a pointer to the thread structure: */
(*thread) = new_thread;
if (f_gc != 0) {
/* Install the scheduling timer: */
itimer.it_interval.tv_sec = 0;
itimer.it_interval.tv_usec = _clock_res_usec;
itimer.it_value = itimer.it_interval;
if (setitimer(_ITIMER_SCHED_TIMER, &itimer,
NULL) != 0)
PANIC("Cannot set interval timer");
}
/* Schedule the new user thread: */
_thread_kern_sched(NULL);
/*
* Start a garbage collector thread
* if necessary.
*/
if (f_gc && pthread_create(&gc_thread,NULL,
_thread_gc,NULL) != 0)
PANIC("Can't create gc thread");
}
}
/* Return the status: */
return (ret);
}
void
_thread_start(void)
{
struct pthread *curthread = _get_curthread();
/* We just left the scheduler via longjmp: */
_thread_kern_in_sched = 0;
/* Run the current thread's start routine with argument: */
pthread_exit(curthread->start_routine(curthread->arg));
/* This point should never be reached. */
PANIC("Thread has resumed after exit");
}