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Use mutex instead of low level thread lock to implement spinlock, this

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avoids signal to be blocked when otherwise it can be handled.
This commit is contained in:
davidxu 2003-12-09 02:37:40 +00:00
parent 22c52834eb
commit 7813286b21
2 changed files with 36 additions and 60 deletions
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48
lib/libkse/thread/thr_spinlock.c
View File

@ -44,13 +44,12 @@
struct spinlock_extra {
spinlock_t *owner;
struct lock lock;
struct pthread *crit;
pthread_mutex_t lock;
};
static void init_spinlock(spinlock_t *lck);
static struct lock spinlock_static_lock;
static pthread_mutex_t spinlock_static_lock;
static struct spinlock_extra extra[MAX_SPINLOCKS];
static int spinlock_count = 0;
static int initialized = 0;
@ -64,14 +63,11 @@ void
_spinunlock(spinlock_t *lck)
{
struct spinlock_extra *extra;
struct pthread *curthr = _get_curthread();
extra = (struct spinlock_extra *)lck->fname;
THR_ASSERT(extra->crit == curthr, "_spinunlock called without owned.");
THR_LOCK_RELEASE(curthr, &extra->lock);
pthread_mutex_unlock(&extra->lock);
}
/*
* Lock a location for the running thread. Yield to allow other
* threads to run if this thread is blocked because the lock is
@ -81,21 +77,20 @@ _spinunlock(spinlock_t *lck)
void
_spinlock(spinlock_t *lck)
{
struct spinlock_extra *extra;
struct pthread *curthr;
struct spinlock_extra *extra;
THR_ASSERT(__isthreaded != 0, "Spinlock called when not threaded.");
THR_ASSERT(initialized != 0, "Spinlocks not initialized.");
if (!__isthreaded)
PANIC("Spinlock called when not threaded.");
if (!initialized)
PANIC("Spinlocks not initialized.");
/*
* Try to grab the lock and loop if another thread grabs
* it before we do.
*/
curthr = _get_curthread();
if (lck->fname == NULL)
init_spinlock(lck);
extra = (struct spinlock_extra *)lck->fname;
THR_LOCK_ACQUIRE(curthr, &extra->lock);
extra->crit = curthr;
pthread_mutex_lock(&extra->lock);
}
/*
@ -117,16 +112,15 @@ _spinlock_debug(spinlock_t *lck, char *fname, int lineno)
static void
init_spinlock(spinlock_t *lck)
{
struct pthread *curthr = _get_curthread();
THR_LOCK_ACQUIRE(curthr, &spinlock_static_lock);
pthread_mutex_lock(&spinlock_static_lock);
if ((lck->fname == NULL) && (spinlock_count < MAX_SPINLOCKS)) {
lck->fname = (char *)&extra[spinlock_count];
extra[spinlock_count].owner = lck;
spinlock_count++;
}
THR_LOCK_RELEASE(curthr, &spinlock_static_lock);
THR_ASSERT(lck->fname != NULL, "Exceeded max spinlocks");
pthread_mutex_unlock(&spinlock_static_lock);
if (lck->fname == NULL)
PANIC("Exceeded max spinlocks");
}
void
@ -135,20 +129,14 @@ _thr_spinlock_init(void)
int i;
if (initialized != 0) {
_lock_reinit(&spinlock_static_lock, LCK_ADAPTIVE,
_thr_lock_wait, _thr_lock_wakeup);
for (i = 0; i < spinlock_count; i++) {
_lock_reinit(&extra[i].lock, LCK_ADAPTIVE,
_thr_lock_wait, _thr_lock_wakeup);
}
spinlock_count = 0;
_thr_mutex_reinit(&spinlock_static_lock);
for (i = 0; i < spinlock_count; i++)
_thr_mutex_reinit(&extra[i].lock);
} else {
if (_lock_init(&spinlock_static_lock, LCK_ADAPTIVE,
_thr_lock_wait, _thr_lock_wakeup) != 0)
if (pthread_mutex_init(&spinlock_static_lock, NULL))
PANIC("Cannot initialize spinlock_static_lock");
for (i = 0; i < MAX_SPINLOCKS; i++) {
if (_lock_init(&extra[i].lock, LCK_ADAPTIVE,
_thr_lock_wait, _thr_lock_wakeup) != 0)
if (pthread_mutex_init(&extra[i].lock, NULL))
PANIC("Cannot initialize spinlock extra");
}
initialized = 1;

48
lib/libpthread/thread/thr_spinlock.c
View File

@ -44,13 +44,12 @@
struct spinlock_extra {
spinlock_t *owner;
struct lock lock;
struct pthread *crit;
pthread_mutex_t lock;
};
static void init_spinlock(spinlock_t *lck);
static struct lock spinlock_static_lock;
static pthread_mutex_t spinlock_static_lock;
static struct spinlock_extra extra[MAX_SPINLOCKS];
static int spinlock_count = 0;
static int initialized = 0;
@ -64,14 +63,11 @@ void
_spinunlock(spinlock_t *lck)
{
struct spinlock_extra *extra;
struct pthread *curthr = _get_curthread();
extra = (struct spinlock_extra *)lck->fname;
THR_ASSERT(extra->crit == curthr, "_spinunlock called without owned.");
THR_LOCK_RELEASE(curthr, &extra->lock);
pthread_mutex_unlock(&extra->lock);
}
/*
* Lock a location for the running thread. Yield to allow other
* threads to run if this thread is blocked because the lock is
@ -81,21 +77,20 @@ _spinunlock(spinlock_t *lck)
void
_spinlock(spinlock_t *lck)
{
struct spinlock_extra *extra;
struct pthread *curthr;
struct spinlock_extra *extra;
THR_ASSERT(__isthreaded != 0, "Spinlock called when not threaded.");
THR_ASSERT(initialized != 0, "Spinlocks not initialized.");
if (!__isthreaded)
PANIC("Spinlock called when not threaded.");
if (!initialized)
PANIC("Spinlocks not initialized.");
/*
* Try to grab the lock and loop if another thread grabs
* it before we do.
*/
curthr = _get_curthread();
if (lck->fname == NULL)
init_spinlock(lck);
extra = (struct spinlock_extra *)lck->fname;
THR_LOCK_ACQUIRE(curthr, &extra->lock);
extra->crit = curthr;
pthread_mutex_lock(&extra->lock);
}
/*
@ -117,16 +112,15 @@ _spinlock_debug(spinlock_t *lck, char *fname, int lineno)
static void
init_spinlock(spinlock_t *lck)
{
struct pthread *curthr = _get_curthread();
THR_LOCK_ACQUIRE(curthr, &spinlock_static_lock);
pthread_mutex_lock(&spinlock_static_lock);
if ((lck->fname == NULL) && (spinlock_count < MAX_SPINLOCKS)) {
lck->fname = (char *)&extra[spinlock_count];
extra[spinlock_count].owner = lck;
spinlock_count++;
}
THR_LOCK_RELEASE(curthr, &spinlock_static_lock);
THR_ASSERT(lck->fname != NULL, "Exceeded max spinlocks");
pthread_mutex_unlock(&spinlock_static_lock);
if (lck->fname == NULL)
PANIC("Exceeded max spinlocks");
}
void
@ -135,20 +129,14 @@ _thr_spinlock_init(void)
int i;
if (initialized != 0) {
_lock_reinit(&spinlock_static_lock, LCK_ADAPTIVE,
_thr_lock_wait, _thr_lock_wakeup);
for (i = 0; i < spinlock_count; i++) {
_lock_reinit(&extra[i].lock, LCK_ADAPTIVE,
_thr_lock_wait, _thr_lock_wakeup);
}
spinlock_count = 0;
_thr_mutex_reinit(&spinlock_static_lock);
for (i = 0; i < spinlock_count; i++)
_thr_mutex_reinit(&extra[i].lock);
} else {
if (_lock_init(&spinlock_static_lock, LCK_ADAPTIVE,
_thr_lock_wait, _thr_lock_wakeup) != 0)
if (pthread_mutex_init(&spinlock_static_lock, NULL))
PANIC("Cannot initialize spinlock_static_lock");
for (i = 0; i < MAX_SPINLOCKS; i++) {
if (_lock_init(&extra[i].lock, LCK_ADAPTIVE,
_thr_lock_wait, _thr_lock_wakeup) != 0)
if (pthread_mutex_init(&extra[i].lock, NULL))
PANIC("Cannot initialize spinlock extra");
}
initialized = 1;