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winlin
ccf1abbd 2 parents b2e1e40d 8327a57b

Merge branch 'srs.master'

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正在显示 1 个修改的文件 包含 680 行增加 和 681 行删除
/*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is the Netscape Portable Runtime library.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1994-2000 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s): Silicon Graphics, Inc.
*
* Portions created by SGI are Copyright (C) 2000-2001 Silicon
* Graphics, Inc. All Rights Reserved.
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License Version 2 or later (the
* "GPL"), in which case the provisions of the GPL are applicable
* instead of those above. If you wish to allow use of your
* version of this file only under the terms of the GPL and not to
* allow others to use your version of this file under the MPL,
* indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by
* the GPL. If you do not delete the provisions above, a recipient
* may use your version of this file under either the MPL or the
* GPL.
*/
/*
* This file is derived directly from Netscape Communications Corporation,
* and consists of extensive modifications made during the year(s) 1999-2000.
*/
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include "common.h"
/* Global data */
_st_vp_t _st_this_vp; /* This VP */
_st_thread_t *_st_this_thread; /* Current thread */
int _st_active_count = 0; /* Active thread count */
time_t _st_curr_time = 0; /* Current time as returned by time(2) */
st_utime_t _st_last_tset; /* Last time it was fetched */
int st_poll(struct pollfd *pds, int npds, st_utime_t timeout)
{
struct pollfd *pd;
struct pollfd *epd = pds + npds;
_st_pollq_t pq;
_st_thread_t *me = _ST_CURRENT_THREAD();
int n;
if (me->flags & _ST_FL_INTERRUPT) {
me->flags &= ~_ST_FL_INTERRUPT;
errno = EINTR;
return -1;
}
if ((*_st_eventsys->pollset_add)(pds, npds) < 0) {
return -1;
}
pq.pds = pds;
pq.npds = npds;
pq.thread = me;
pq.on_ioq = 1;
_ST_ADD_IOQ(pq);
if (timeout != ST_UTIME_NO_TIMEOUT) {
_ST_ADD_SLEEPQ(me, timeout);
}
me->state = _ST_ST_IO_WAIT;
_ST_SWITCH_CONTEXT(me);
n = 0;
if (pq.on_ioq) {
/* If we timed out, the pollq might still be on the ioq. Remove it */
_ST_DEL_IOQ(pq);
(*_st_eventsys->pollset_del)(pds, npds);
} else {
/* Count the number of ready descriptors */
for (pd = pds; pd < epd; pd++) {
if (pd->revents) {
n++;
}
}
}
if (me->flags & _ST_FL_INTERRUPT) {
me->flags &= ~_ST_FL_INTERRUPT;
errno = EINTR;
return -1;
}
return n;
}
void _st_vp_schedule(void)
{
_st_thread_t *trd;
if (_ST_RUNQ.next != &_ST_RUNQ) {
/* Pull thread off of the run queue */
trd = _ST_THREAD_PTR(_ST_RUNQ.next);
_ST_DEL_RUNQ(trd);
} else {
/* If there are no threads to run, switch to the idle thread */
trd = _st_this_vp.idle_thread;
}
ST_ASSERT(trd->state == _ST_ST_RUNNABLE);
/* Resume the thread */
trd->state = _ST_ST_RUNNING;
_ST_RESTORE_CONTEXT(trd);
}
/*
* Initialize this Virtual Processor
*/
int st_init(void)
{
_st_thread_t *trd;
if (_st_active_count) {
/* Already initialized */
return 0;
}
/* We can ignore return value here */
st_set_eventsys(ST_EVENTSYS_DEFAULT);
if (_st_io_init() < 0) {
return -1;
}
memset(&_st_this_vp, 0, sizeof(_st_vp_t));
ST_INIT_CLIST(&_ST_RUNQ);
ST_INIT_CLIST(&_ST_IOQ);
ST_INIT_CLIST(&_ST_ZOMBIEQ);
#ifdef DEBUG
ST_INIT_CLIST(&_ST_THREADQ);
#endif
if ((*_st_eventsys->init)() < 0) {
return -1;
}
_st_this_vp.pagesize = getpagesize();
_st_this_vp.last_clock = st_utime();
/*
* Create idle thread
*/
_st_this_vp.idle_thread = st_thread_create(_st_idle_thread_start, NULL, 0, 0);
if (!_st_this_vp.idle_thread) {
return -1;
}
_st_this_vp.idle_thread->flags = _ST_FL_IDLE_THREAD;
_st_active_count--;
_ST_DEL_RUNQ(_st_this_vp.idle_thread);
/*
* Initialize primordial thread
*/
trd = (_st_thread_t *) calloc(1, sizeof(_st_thread_t) +
(ST_KEYS_MAX * sizeof(void *)));
if (!trd) {
return -1;
}
trd->private_data = (void **) (trd + 1);
trd->state = _ST_ST_RUNNING;
trd->flags = _ST_FL_PRIMORDIAL;
_ST_SET_CURRENT_THREAD(trd);
_st_active_count++;
#ifdef DEBUG
_ST_ADD_THREADQ(trd);
#endif
return 0;
}
#ifdef ST_SWITCH_CB
st_switch_cb_t st_set_switch_in_cb(st_switch_cb_t cb)
{
st_switch_cb_t ocb = _st_this_vp.switch_in_cb;
_st_this_vp.switch_in_cb = cb;
return ocb;
}
st_switch_cb_t st_set_switch_out_cb(st_switch_cb_t cb)
{
st_switch_cb_t ocb = _st_this_vp.switch_out_cb;
_st_this_vp.switch_out_cb = cb;
return ocb;
}
#endif
/*
* Start function for the idle thread
*/
/* ARGSUSED */
void *_st_idle_thread_start(void *arg)
{
_st_thread_t *me = _ST_CURRENT_THREAD();
while (_st_active_count > 0) {
/* Idle vp till I/O is ready or the smallest timeout expired */
_ST_VP_IDLE();
/* Check sleep queue for expired threads */
_st_vp_check_clock();
me->state = _ST_ST_RUNNABLE;
_ST_SWITCH_CONTEXT(me);
}
/* No more threads */
exit(0);
/* NOTREACHED */
return NULL;
}
void st_thread_exit(void *retval)
{
_st_thread_t *trd = _ST_CURRENT_THREAD();
trd->retval = retval;
_st_thread_cleanup(trd);
_st_active_count--;
if (trd->term) {
/* Put thread on the zombie queue */
trd->state = _ST_ST_ZOMBIE;
_ST_ADD_ZOMBIEQ(trd);
/* Notify on our termination condition variable */
st_cond_signal(trd->term);
/* Switch context and come back later */
_ST_SWITCH_CONTEXT(trd);
/* Continue the cleanup */
st_cond_destroy(trd->term);
trd->term = NULL;
}
#ifdef DEBUG
_ST_DEL_THREADQ(trd);
#endif
if (!(trd->flags & _ST_FL_PRIMORDIAL)) {
_st_stack_free(trd->stack);
}
/* Find another thread to run */
_ST_SWITCH_CONTEXT(trd);
/* Not going to land here */
}
int st_thread_join(_st_thread_t *trd, void **retvalp)
{
_st_cond_t *term = trd->term;
/* Can't join a non-joinable thread */
if (term == NULL) {
errno = EINVAL;
return -1;
}
if (_ST_CURRENT_THREAD() == trd) {
errno = EDEADLK;
return -1;
}
/* Multiple threads can't wait on the same joinable thread */
if (term->wait_q.next != &term->wait_q) {
errno = EINVAL;
return -1;
}
while (trd->state != _ST_ST_ZOMBIE) {
if (st_cond_timedwait(term, ST_UTIME_NO_TIMEOUT) != 0) {
return -1;
}
}
if (retvalp) {
*retvalp = trd->retval;
}
/*
* Remove target thread from the zombie queue and make it runnable.
* When it gets scheduled later, it will do the clean up.
*/
trd->state = _ST_ST_RUNNABLE;
_ST_DEL_ZOMBIEQ(trd);
_ST_ADD_RUNQ(trd);
return 0;
}
void _st_thread_main(void)
{
_st_thread_t *trd = _ST_CURRENT_THREAD();
/*
* Cap the stack by zeroing out the saved return address register
* value. This allows some debugging/profiling tools to know when
* to stop unwinding the stack. It's a no-op on most platforms.
*/
MD_CAP_STACK(&trd);
/* Run thread main */
trd->retval = (*trd->start)(trd->arg);
/* All done, time to go away */
st_thread_exit(trd->retval);
}
/*
* Insert "thread" into the timeout heap, in the position
* specified by thread->heap_index. See docs/timeout_heap.txt
* for details about the timeout heap.
*/
static _st_thread_t **heap_insert(_st_thread_t *trd)
{
int target = trd->heap_index;
int s = target;
_st_thread_t **p = &_ST_SLEEPQ;
int bits = 0;
int bit;
int index = 1;
while (s) {
s >>= 1;
bits++;
}
for (bit = bits - 2; bit >= 0; bit--) {
if (trd->due < (*p)->due) {
_st_thread_t *t = *p;
trd->left = t->left;
trd->right = t->right;
*p = trd;
trd->heap_index = index;
trd = t;
}
index <<= 1;
if (target & (1 << bit)) {
p = &((*p)->right);
index |= 1;
} else {
p = &((*p)->left);
}
}
trd->heap_index = index;
*p = trd;
trd->left = trd->right = NULL;
return p;
}
/*
* Delete "thread" from the timeout heap.
*/
static void heap_delete(_st_thread_t *trd)
{
_st_thread_t *t, **p;
int bits = 0;
int s, bit;
/* First find and unlink the last heap element */
p = &_ST_SLEEPQ;
s = _ST_SLEEPQ_SIZE;
while (s) {
s >>= 1;
bits++;
}
for (bit = bits - 2; bit >= 0; bit--) {
if (_ST_SLEEPQ_SIZE & (1 << bit)) {
p = &((*p)->right);
} else {
p = &((*p)->left);
}
}
t = *p;
*p = NULL;
--_ST_SLEEPQ_SIZE;
if (t != trd) {
/*
* Insert the unlinked last element in place of the element we are deleting
*/
t->heap_index = trd->heap_index;
p = heap_insert(t);
t = *p;
t->left = trd->left;
t->right = trd->right;
/*
* Reestablish the heap invariant.
*/
for (;;) {
_st_thread_t *y; /* The younger child */
int index_tmp;
if (t->left == NULL) {
break;
} else if (t->right == NULL) {
y = t->left;
} else if (t->left->due < t->right->due) {
y = t->left;
} else {
y = t->right;
}
if (t->due > y->due) {
_st_thread_t *tl = y->left;
_st_thread_t *tr = y->right;
*p = y;
if (y == t->left) {
y->left = t;
y->right = t->right;
p = &y->left;
} else {
y->left = t->left;
y->right = t;
p = &y->right;
}
t->left = tl;
t->right = tr;
index_tmp = t->heap_index;
t->heap_index = y->heap_index;
y->heap_index = index_tmp;
} else {
break;
}
}
}
trd->left = trd->right = NULL;
}
void _st_add_sleep_q(_st_thread_t *trd, st_utime_t timeout)
{
trd->due = _ST_LAST_CLOCK + timeout;
trd->flags |= _ST_FL_ON_SLEEPQ;
trd->heap_index = ++_ST_SLEEPQ_SIZE;
heap_insert(trd);
}
void _st_del_sleep_q(_st_thread_t *trd)
{
heap_delete(trd);
trd->flags &= ~_ST_FL_ON_SLEEPQ;
}
void _st_vp_check_clock(void)
{
_st_thread_t *trd;
st_utime_t elapsed, now;
now = st_utime();
elapsed = now - _ST_LAST_CLOCK;
_ST_LAST_CLOCK = now;
if (_st_curr_time && now - _st_last_tset > 999000) {
_st_curr_time = time(NULL);
_st_last_tset = now;
}
while (_ST_SLEEPQ != NULL) {
trd = _ST_SLEEPQ;
ST_ASSERT(trd->flags & _ST_FL_ON_SLEEPQ);
if (trd->due > now) {
break;
}
_ST_DEL_SLEEPQ(trd);
/* If thread is waiting on condition variable, set the time out flag */
if (trd->state == _ST_ST_COND_WAIT) {
trd->flags |= _ST_FL_TIMEDOUT;
}
/* Make thread runnable */
ST_ASSERT(!(trd->flags & _ST_FL_IDLE_THREAD));
trd->state = _ST_ST_RUNNABLE;
_ST_ADD_RUNQ(trd);
}
}
void st_thread_interrupt(_st_thread_t* trd)
{
/* If thread is already dead */
if (trd->state == _ST_ST_ZOMBIE) {
return;
}
trd->flags |= _ST_FL_INTERRUPT;
if (trd->state == _ST_ST_RUNNING || trd->state == _ST_ST_RUNNABLE) {
return;
}
if (trd->flags & _ST_FL_ON_SLEEPQ) {
_ST_DEL_SLEEPQ(trd);
}
/* Make thread runnable */
trd->state = _ST_ST_RUNNABLE;
_ST_ADD_RUNQ(trd);
}
_st_thread_t *st_thread_create(void *(*start)(void *arg), void *arg, int joinable, int stk_size)
{
_st_thread_t *trd;
_st_stack_t *stack;
void **ptds;
char *sp;
/* Adjust stack size */
if (stk_size == 0) {
stk_size = ST_DEFAULT_STACK_SIZE;
}
stk_size = ((stk_size + _ST_PAGE_SIZE - 1) / _ST_PAGE_SIZE) * _ST_PAGE_SIZE;
stack = _st_stack_new(stk_size);
if (!stack) {
return NULL;
}
/* Allocate thread object and per-thread data off the stack */
#if defined (MD_STACK_GROWS_DOWN)
sp = stack->stk_top;
/*
* The stack segment is split in the middle. The upper half is used
* as backing store for the register stack which grows upward.
* The lower half is used for the traditional memory stack which
* grows downward. Both stacks start in the middle and grow outward
* from each other.
*/
/**
The below comments is by winlin:
The Stack public structure:
+--------------------------------------------------------------+
| stack |
+--------------------------------------------------------------+
bottom top
The code bellow use the stack as:
+-----------------+-----------------+-------------+------------+
| stack of thread |pad+align(128B+) |thread(336B) | keys(128B) |
+-----------------+-----------------+-------------+------------+
bottom sp trd ptds top
(context[0].__jmpbuf.sp) (private_data)
*/
sp = sp - (ST_KEYS_MAX * sizeof(void *));
ptds = (void **) sp;
sp = sp - sizeof(_st_thread_t);
trd = (_st_thread_t *) sp;
/* Make stack 64-byte aligned */
if ((unsigned long)sp & 0x3f) {
sp = sp - ((unsigned long)sp & 0x3f);
}
stack->sp = sp - _ST_STACK_PAD_SIZE;
#else
#error "Only Supports Stack Grown Down"
#endif
memset(trd, 0, sizeof(_st_thread_t));
memset(ptds, 0, ST_KEYS_MAX * sizeof(void *));
/* Initialize thread */
trd->private_data = ptds;
trd->stack = stack;
trd->start = start;
trd->arg = arg;
// by winlin, expand macro MD_INIT_CONTEXT
#if defined(__mips__)
MD_SETJMP((trd)->context);
trd->context[0].__jmpbuf[0].__pc = (__ptr_t) _st_thread_main;
trd->context[0].__jmpbuf[0].__sp = stack->sp;
#else
int ret_setjmp = 0;
if ((ret_setjmp = MD_SETJMP((trd)->context)) != 0) {
_st_thread_main();
}
MD_GET_SP(trd) = (long) (stack->sp);
#endif
/* If thread is joinable, allocate a termination condition variable */
if (joinable) {
trd->term = st_cond_new();
if (trd->term == NULL) {
_st_stack_free(trd->stack);
return NULL;
}
}
/* Make thread runnable */
trd->state = _ST_ST_RUNNABLE;
_st_active_count++;
_ST_ADD_RUNQ(trd);
#ifdef DEBUG
_ST_ADD_THREADQ(trd);
#endif
return trd;
}
_st_thread_t *st_thread_self(void)
{
return _ST_CURRENT_THREAD();
}
#ifdef DEBUG
/* ARGSUSED */
void _st_show_thread_stack(_st_thread_t *trd, const char *messg)
{
}
/* To be set from debugger */
int _st_iterate_threads_flag = 0;
void _st_iterate_threads(void)
{
static _st_thread_t *trd = NULL;
static jmp_buf orig_jb, save_jb;
_st_clist_t *q;
if (!_st_iterate_threads_flag) {
if (trd) {
memcpy(trd->context, save_jb, sizeof(jmp_buf));
MD_LONGJMP(orig_jb, 1);
}
return;
}
if (trd) {
memcpy(trd->context, save_jb, sizeof(jmp_buf));
_st_show_thread_stack(trd, NULL);
} else {
if (MD_SETJMP(orig_jb)) {
_st_iterate_threads_flag = 0;
trd = NULL;
_st_show_thread_stack(trd, "Iteration completed");
return;
}
trd = _ST_CURRENT_THREAD();
_st_show_thread_stack(trd, "Iteration started");
}
q = trd->tlink.next;
if (q == &_ST_THREADQ) {
q = q->next;
}
ST_ASSERT(q != &_ST_THREADQ);
trd = _ST_THREAD_THREADQ_PTR(q);
if (trd == _ST_CURRENT_THREAD()) {
MD_LONGJMP(orig_jb, 1);
}
memcpy(save_jb, trd->context, sizeof(jmp_buf));
MD_LONGJMP(trd->context, 1);
}
#endif /* DEBUG */
/*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is the Netscape Portable Runtime library.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1994-2000 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s): Silicon Graphics, Inc.
*
* Portions created by SGI are Copyright (C) 2000-2001 Silicon
* Graphics, Inc. All Rights Reserved.
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License Version 2 or later (the
* "GPL"), in which case the provisions of the GPL are applicable
* instead of those above. If you wish to allow use of your
* version of this file only under the terms of the GPL and not to
* allow others to use your version of this file under the MPL,
* indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by
* the GPL. If you do not delete the provisions above, a recipient
* may use your version of this file under either the MPL or the
* GPL.
*/
/*
* This file is derived directly from Netscape Communications Corporation,
* and consists of extensive modifications made during the year(s) 1999-2000.
*/
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include "common.h"
/* Global data */
_st_vp_t _st_this_vp; /* This VP */
_st_thread_t *_st_this_thread; /* Current thread */
int _st_active_count = 0; /* Active thread count */
time_t _st_curr_time = 0; /* Current time as returned by time(2) */
st_utime_t _st_last_tset; /* Last time it was fetched */
int st_poll(struct pollfd *pds, int npds, st_utime_t timeout)
{
struct pollfd *pd;
struct pollfd *epd = pds + npds;
_st_pollq_t pq;
_st_thread_t *me = _ST_CURRENT_THREAD();
int n;
if (me->flags & _ST_FL_INTERRUPT) {
me->flags &= ~_ST_FL_INTERRUPT;
errno = EINTR;
return -1;
}
if ((*_st_eventsys->pollset_add)(pds, npds) < 0) {
return -1;
}
pq.pds = pds;
pq.npds = npds;
pq.thread = me;
pq.on_ioq = 1;
_ST_ADD_IOQ(pq);
if (timeout != ST_UTIME_NO_TIMEOUT) {
_ST_ADD_SLEEPQ(me, timeout);
}
me->state = _ST_ST_IO_WAIT;
_ST_SWITCH_CONTEXT(me);
n = 0;
if (pq.on_ioq) {
/* If we timed out, the pollq might still be on the ioq. Remove it */
_ST_DEL_IOQ(pq);
(*_st_eventsys->pollset_del)(pds, npds);
} else {
/* Count the number of ready descriptors */
for (pd = pds; pd < epd; pd++) {
if (pd->revents) {
n++;
}
}
}
if (me->flags & _ST_FL_INTERRUPT) {
me->flags &= ~_ST_FL_INTERRUPT;
errno = EINTR;
return -1;
}
return n;
}
void _st_vp_schedule(void)
{
_st_thread_t *trd;
if (_ST_RUNQ.next != &_ST_RUNQ) {
/* Pull thread off of the run queue */
trd = _ST_THREAD_PTR(_ST_RUNQ.next);
_ST_DEL_RUNQ(trd);
} else {
/* If there are no threads to run, switch to the idle thread */
trd = _st_this_vp.idle_thread;
}
ST_ASSERT(trd->state == _ST_ST_RUNNABLE);
/* Resume the thread */
trd->state = _ST_ST_RUNNING;
_ST_RESTORE_CONTEXT(trd);
}
/*
* Initialize this Virtual Processor
*/
int st_init(void)
{
_st_thread_t *trd;
if (_st_active_count) {
/* Already initialized */
return 0;
}
/* We can ignore return value here */
st_set_eventsys(ST_EVENTSYS_DEFAULT);
if (_st_io_init() < 0) {
return -1;
}
memset(&_st_this_vp, 0, sizeof(_st_vp_t));
ST_INIT_CLIST(&_ST_RUNQ);
ST_INIT_CLIST(&_ST_IOQ);
ST_INIT_CLIST(&_ST_ZOMBIEQ);
#ifdef DEBUG
ST_INIT_CLIST(&_ST_THREADQ);
#endif
if ((*_st_eventsys->init)() < 0) {
return -1;
}
_st_this_vp.pagesize = getpagesize();
_st_this_vp.last_clock = st_utime();
/*
* Create idle thread
*/
_st_this_vp.idle_thread = st_thread_create(_st_idle_thread_start, NULL, 0, 0);
if (!_st_this_vp.idle_thread) {
return -1;
}
_st_this_vp.idle_thread->flags = _ST_FL_IDLE_THREAD;
_st_active_count--;
_ST_DEL_RUNQ(_st_this_vp.idle_thread);
/*
* Initialize primordial thread
*/
trd = (_st_thread_t *) calloc(1, sizeof(_st_thread_t) +
(ST_KEYS_MAX * sizeof(void *)));
if (!trd) {
return -1;
}
trd->private_data = (void **) (trd + 1);
trd->state = _ST_ST_RUNNING;
trd->flags = _ST_FL_PRIMORDIAL;
_ST_SET_CURRENT_THREAD(trd);
_st_active_count++;
#ifdef DEBUG
_ST_ADD_THREADQ(trd);
#endif
return 0;
}
#ifdef ST_SWITCH_CB
st_switch_cb_t st_set_switch_in_cb(st_switch_cb_t cb)
{
st_switch_cb_t ocb = _st_this_vp.switch_in_cb;
_st_this_vp.switch_in_cb = cb;
return ocb;
}
st_switch_cb_t st_set_switch_out_cb(st_switch_cb_t cb)
{
st_switch_cb_t ocb = _st_this_vp.switch_out_cb;
_st_this_vp.switch_out_cb = cb;
return ocb;
}
#endif
/*
* Start function for the idle thread
*/
/* ARGSUSED */
void *_st_idle_thread_start(void *arg)
{
_st_thread_t *me = _ST_CURRENT_THREAD();
while (_st_active_count > 0) {
/* Idle vp till I/O is ready or the smallest timeout expired */
_ST_VP_IDLE();
/* Check sleep queue for expired threads */
_st_vp_check_clock();
me->state = _ST_ST_RUNNABLE;
_ST_SWITCH_CONTEXT(me);
}
/* No more threads */
exit(0);
/* NOTREACHED */
return NULL;
}
void st_thread_exit(void *retval)
{
_st_thread_t *trd = _ST_CURRENT_THREAD();
trd->retval = retval;
_st_thread_cleanup(trd);
_st_active_count--;
if (trd->term) {
/* Put thread on the zombie queue */
trd->state = _ST_ST_ZOMBIE;
_ST_ADD_ZOMBIEQ(trd);
/* Notify on our termination condition variable */
st_cond_signal(trd->term);
/* Switch context and come back later */
_ST_SWITCH_CONTEXT(trd);
/* Continue the cleanup */
st_cond_destroy(trd->term);
trd->term = NULL;
}
#ifdef DEBUG
_ST_DEL_THREADQ(trd);
#endif
if (!(trd->flags & _ST_FL_PRIMORDIAL)) {
_st_stack_free(trd->stack);
}
/* Find another thread to run */
_ST_SWITCH_CONTEXT(trd);
/* Not going to land here */
}
int st_thread_join(_st_thread_t *trd, void **retvalp)
{
_st_cond_t *term = trd->term;
/* Can't join a non-joinable thread */
if (term == NULL) {
errno = EINVAL;
return -1;
}
if (_ST_CURRENT_THREAD() == trd) {
errno = EDEADLK;
return -1;
}
/* Multiple threads can't wait on the same joinable thread */
if (term->wait_q.next != &term->wait_q) {
errno = EINVAL;
return -1;
}
while (trd->state != _ST_ST_ZOMBIE) {
if (st_cond_timedwait(term, ST_UTIME_NO_TIMEOUT) != 0) {
return -1;
}
}
if (retvalp) {
*retvalp = trd->retval;
}
/*
* Remove target thread from the zombie queue and make it runnable.
* When it gets scheduled later, it will do the clean up.
*/
trd->state = _ST_ST_RUNNABLE;
_ST_DEL_ZOMBIEQ(trd);
_ST_ADD_RUNQ(trd);
return 0;
}
void _st_thread_main(void)
{
_st_thread_t *trd = _ST_CURRENT_THREAD();
/*
* Cap the stack by zeroing out the saved return address register
* value. This allows some debugging/profiling tools to know when
* to stop unwinding the stack. It's a no-op on most platforms.
*/
MD_CAP_STACK(&trd);
/* Run thread main */
trd->retval = (*trd->start)(trd->arg);
/* All done, time to go away */
st_thread_exit(trd->retval);
}
/*
* Insert "thread" into the timeout heap, in the position
* specified by thread->heap_index. See docs/timeout_heap.txt
* for details about the timeout heap.
*/
static _st_thread_t **heap_insert(_st_thread_t *trd)
{
int target = trd->heap_index;
int s = target;
_st_thread_t **p = &_ST_SLEEPQ;
int bits = 0;
int bit;
int index = 1;
while (s) {
s >>= 1;
bits++;
}
for (bit = bits - 2; bit >= 0; bit--) {
if (trd->due < (*p)->due) {
_st_thread_t *t = *p;
trd->left = t->left;
trd->right = t->right;
*p = trd;
trd->heap_index = index;
trd = t;
}
index <<= 1;
if (target & (1 << bit)) {
p = &((*p)->right);
index |= 1;
} else {
p = &((*p)->left);
}
}
trd->heap_index = index;
*p = trd;
trd->left = trd->right = NULL;
return p;
}
/*
* Delete "thread" from the timeout heap.
*/
static void heap_delete(_st_thread_t *trd)
{
_st_thread_t *t, **p;
int bits = 0;
int s, bit;
/* First find and unlink the last heap element */
p = &_ST_SLEEPQ;
s = _ST_SLEEPQ_SIZE;
while (s) {
s >>= 1;
bits++;
}
for (bit = bits - 2; bit >= 0; bit--) {
if (_ST_SLEEPQ_SIZE & (1 << bit)) {
p = &((*p)->right);
} else {
p = &((*p)->left);
}
}
t = *p;
*p = NULL;
--_ST_SLEEPQ_SIZE;
if (t != trd) {
/*
* Insert the unlinked last element in place of the element we are deleting
*/
t->heap_index = trd->heap_index;
p = heap_insert(t);
t = *p;
t->left = trd->left;
t->right = trd->right;
/*
* Reestablish the heap invariant.
*/
for (;;) {
_st_thread_t *y; /* The younger child */
int index_tmp;
if (t->left == NULL) {
break;
} else if (t->right == NULL) {
y = t->left;
} else if (t->left->due < t->right->due) {
y = t->left;
} else {
y = t->right;
}
if (t->due > y->due) {
_st_thread_t *tl = y->left;
_st_thread_t *tr = y->right;
*p = y;
if (y == t->left) {
y->left = t;
y->right = t->right;
p = &y->left;
} else {
y->left = t->left;
y->right = t;
p = &y->right;
}
t->left = tl;
t->right = tr;
index_tmp = t->heap_index;
t->heap_index = y->heap_index;
y->heap_index = index_tmp;
} else {
break;
}
}
}
trd->left = trd->right = NULL;
}
void _st_add_sleep_q(_st_thread_t *trd, st_utime_t timeout)
{
trd->due = _ST_LAST_CLOCK + timeout;
trd->flags |= _ST_FL_ON_SLEEPQ;
trd->heap_index = ++_ST_SLEEPQ_SIZE;
heap_insert(trd);
}
void _st_del_sleep_q(_st_thread_t *trd)
{
heap_delete(trd);
trd->flags &= ~_ST_FL_ON_SLEEPQ;
}
void _st_vp_check_clock(void)
{
_st_thread_t *trd;
st_utime_t elapsed, now;
now = st_utime();
elapsed = now - _ST_LAST_CLOCK;
_ST_LAST_CLOCK = now;
if (_st_curr_time && now - _st_last_tset > 999000) {
_st_curr_time = time(NULL);
_st_last_tset = now;
}
while (_ST_SLEEPQ != NULL) {
trd = _ST_SLEEPQ;
ST_ASSERT(trd->flags & _ST_FL_ON_SLEEPQ);
if (trd->due > now) {
break;
}
_ST_DEL_SLEEPQ(trd);
/* If thread is waiting on condition variable, set the time out flag */
if (trd->state == _ST_ST_COND_WAIT) {
trd->flags |= _ST_FL_TIMEDOUT;
}
/* Make thread runnable */
ST_ASSERT(!(trd->flags & _ST_FL_IDLE_THREAD));
trd->state = _ST_ST_RUNNABLE;
_ST_ADD_RUNQ(trd);
}
}
void st_thread_interrupt(_st_thread_t* trd)
{
/* If thread is already dead */
if (trd->state == _ST_ST_ZOMBIE) {
return;
}
trd->flags |= _ST_FL_INTERRUPT;
if (trd->state == _ST_ST_RUNNING || trd->state == _ST_ST_RUNNABLE) {
return;
}
if (trd->flags & _ST_FL_ON_SLEEPQ) {
_ST_DEL_SLEEPQ(trd);
}
/* Make thread runnable */
trd->state = _ST_ST_RUNNABLE;
_ST_ADD_RUNQ(trd);
}
_st_thread_t *st_thread_create(void *(*start)(void *arg), void *arg, int joinable, int stk_size)
{
_st_thread_t *trd;
_st_stack_t *stack;
void **ptds;
char *sp;
/* Adjust stack size */
if (stk_size == 0) {
stk_size = ST_DEFAULT_STACK_SIZE;
}
stk_size = ((stk_size + _ST_PAGE_SIZE - 1) / _ST_PAGE_SIZE) * _ST_PAGE_SIZE;
stack = _st_stack_new(stk_size);
if (!stack) {
return NULL;
}
/* Allocate thread object and per-thread data off the stack */
#if defined (MD_STACK_GROWS_DOWN)
sp = stack->stk_top;
/*
* The stack segment is split in the middle. The upper half is used
* as backing store for the register stack which grows upward.
* The lower half is used for the traditional memory stack which
* grows downward. Both stacks start in the middle and grow outward
* from each other.
*/
/**
The below comments is by winlin:
The Stack public structure:
+--------------------------------------------------------------+
| stack |
+--------------------------------------------------------------+
bottom top
The code bellow use the stack as:
+-----------------+-----------------+-------------+------------+
| stack of thread |pad+align(128B+) |thread(336B) | keys(128B) |
+-----------------+-----------------+-------------+------------+
bottom sp trd ptds top
(context[0].__jmpbuf.sp) (private_data)
*/
sp = sp - (ST_KEYS_MAX * sizeof(void *));
ptds = (void **) sp;
sp = sp - sizeof(_st_thread_t);
trd = (_st_thread_t *) sp;
/* Make stack 64-byte aligned */
if ((unsigned long)sp & 0x3f) {
sp = sp - ((unsigned long)sp & 0x3f);
}
stack->sp = sp - _ST_STACK_PAD_SIZE;
#else
#error "Only Supports Stack Grown Down"
#endif
memset(trd, 0, sizeof(_st_thread_t));
memset(ptds, 0, ST_KEYS_MAX * sizeof(void *));
/* Initialize thread */
trd->private_data = ptds;
trd->stack = stack;
trd->start = start;
trd->arg = arg;
// by winlin, expand macro MD_INIT_CONTEXT
#if defined(__mips__)
MD_SETJMP((trd)->context);
trd->context[0].__jmpbuf[0].__pc = (__ptr_t) _st_thread_main;
trd->context[0].__jmpbuf[0].__sp = stack->sp;
#else
if (MD_SETJMP((trd)->context)) {
_st_thread_main();
}
MD_GET_SP(trd) = (long) (stack->sp);
#endif
/* If thread is joinable, allocate a termination condition variable */
if (joinable) {
trd->term = st_cond_new();
if (trd->term == NULL) {
_st_stack_free(trd->stack);
return NULL;
}
}
/* Make thread runnable */
trd->state = _ST_ST_RUNNABLE;
_st_active_count++;
_ST_ADD_RUNQ(trd);
#ifdef DEBUG
_ST_ADD_THREADQ(trd);
#endif
return trd;
}
_st_thread_t *st_thread_self(void)
{
return _ST_CURRENT_THREAD();
}
#ifdef DEBUG
/* ARGSUSED */
void _st_show_thread_stack(_st_thread_t *trd, const char *messg)
{
}
/* To be set from debugger */
int _st_iterate_threads_flag = 0;
void _st_iterate_threads(void)
{
static _st_thread_t *trd = NULL;
static jmp_buf orig_jb, save_jb;
_st_clist_t *q;
if (!_st_iterate_threads_flag) {
if (trd) {
memcpy(trd->context, save_jb, sizeof(jmp_buf));
MD_LONGJMP(orig_jb, 1);
}
return;
}
if (trd) {
memcpy(trd->context, save_jb, sizeof(jmp_buf));
_st_show_thread_stack(trd, NULL);
} else {
if (MD_SETJMP(orig_jb)) {
_st_iterate_threads_flag = 0;
trd = NULL;
_st_show_thread_stack(trd, "Iteration completed");
return;
}
trd = _ST_CURRENT_THREAD();
_st_show_thread_stack(trd, "Iteration started");
}
q = trd->tlink.next;
if (q == &_ST_THREADQ) {
q = q->next;
}
ST_ASSERT(q != &_ST_THREADQ);
trd = _ST_THREAD_THREADQ_PTR(q);
if (trd == _ST_CURRENT_THREAD()) {
MD_LONGJMP(orig_jb, 1);
}
memcpy(save_jb, trd->context, sizeof(jmp_buf));
MD_LONGJMP(trd->context, 1);
}
#endif /* DEBUG */
... ...