ee1de6a067
_foo - wrapped system call foo - weak definition to _foo and for cancellation points: _foo - wrapped system call __foo - enter cancellation point, call _foo(), leave cancellation point foo - weak definition to __foo Change use of global _thread_run to call a function to get the currently running thread. Make all pthread_foo functions weak definitions to _pthread_foo, where _pthread_foo is the implementation. This allows an application to provide its own pthread functions. Provide slightly different versions of pthread_mutex_lock and pthread_mutex_init so that we can tell the difference between a libc mutex and an application mutex. Threads holding mutexes internal to libc should never be allowed to exit, call signal handlers, or cancel. Approved by: -arch
331 lines
9.7 KiB
C
331 lines
9.7 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 <sys/param.h>
|
|
#include <sys/mman.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_ctxtype_offset = OFF(ctxtype);
|
|
int _thread_ctx_offset = OFF(ctx);
|
|
#undef OFF
|
|
|
|
int _thread_PS_RUNNING_value = PS_RUNNING;
|
|
int _thread_PS_DEAD_value = PS_DEAD;
|
|
int _thread_CTX_JB_NOSIG_value = CTX_JB_NOSIG;
|
|
int _thread_CTX_JB_value = CTX_JB;
|
|
int _thread_CTX_SJB_value = CTX_SJB;
|
|
int _thread_CTX_UC_value = CTX_UC;
|
|
|
|
#pragma weak 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 memory for a default-size stack: */
|
|
else if (pattr->stacksize_attr == PTHREAD_STACK_DEFAULT) {
|
|
struct stack *spare_stack;
|
|
|
|
/* Allocate or re-use a default-size stack. */
|
|
|
|
/*
|
|
* Use the garbage collector mutex for synchronization
|
|
* of the spare stack list.
|
|
*/
|
|
if (pthread_mutex_lock(&_gc_mutex) != 0)
|
|
PANIC("Cannot lock gc mutex");
|
|
|
|
if ((spare_stack = SLIST_FIRST(&_stackq)) != NULL) {
|
|
/* Use the spare stack. */
|
|
SLIST_REMOVE_HEAD(&_stackq, qe);
|
|
|
|
/* Unlock the garbage collector mutex. */
|
|
if (pthread_mutex_unlock(&_gc_mutex) != 0)
|
|
PANIC("Cannot unlock gc mutex");
|
|
|
|
stack = sizeof(struct stack)
|
|
+ (void *) spare_stack
|
|
- PTHREAD_STACK_DEFAULT;
|
|
} else {
|
|
/* Allocate a new stack. */
|
|
stack = _next_stack + PTHREAD_STACK_GUARD;
|
|
|
|
/*
|
|
* Even if stack allocation fails, we don't want
|
|
* to try to use this location again, so
|
|
* unconditionally decrement _next_stack. Under
|
|
* normal operating conditions, the most likely
|
|
* reason for an mmap() error is a stack
|
|
* overflow of the adjacent thread stack.
|
|
*/
|
|
_next_stack -= (PTHREAD_STACK_DEFAULT
|
|
+ PTHREAD_STACK_GUARD);
|
|
|
|
/* Unlock the garbage collector mutex. */
|
|
if (pthread_mutex_unlock(&_gc_mutex) != 0)
|
|
PANIC("Cannot unlock gc mutex");
|
|
|
|
/* Stack: */
|
|
if (mmap(stack, PTHREAD_STACK_DEFAULT,
|
|
PROT_READ | PROT_WRITE, MAP_STACK,
|
|
-1, 0) == MAP_FAILED) {
|
|
ret = EAGAIN;
|
|
free(new_thread);
|
|
}
|
|
}
|
|
}
|
|
/*
|
|
* The user wants a stack of a particular size. Lets hope they
|
|
* really know what they want, and simply malloc the stack.
|
|
*/
|
|
else if ((stack = (void *) malloc(pattr->stacksize_attr))
|
|
== NULL) {
|
|
/* Insufficient memory to create a thread: */
|
|
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));
|
|
|
|
/* Initialize the rest of the frame: */
|
|
new_thread->ctxtype = CTX_JB_NOSIG;
|
|
|
|
/* 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;
|
|
|
|
/* Initialise the join queue for the new thread: */
|
|
TAILQ_INIT(&(new_thread->join_queue));
|
|
|
|
/* 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");
|
|
}
|