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authorBill Wendling <wendling@ncsa.uiuc.edu>2000-06-06 20:50:18 (GMT)
committerBill Wendling <wendling@ncsa.uiuc.edu>2000-06-06 20:50:18 (GMT)
commit90bc20edb598f4cb787b03d20a7ff6c2b9466ab0 (patch)
treed1466d89a2f433895752e22646e915e68980522f /src
parent8cb2d8c6af82b128d06e56f430562d80764b00ec (diff)
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[svn-r2348] The way the pthread_t object was being initialized wasn't correct for all
platforms. Also, it's not entirely certain that a value of 0 isn't a valid thread ID. So, I changed the pthread_t object to be a pointer to pthread_t with the appropriate memory management this entails. Part of the validity of this approach rests on the fact that one can assign a variable which is a structure to another variable of the same type and all fields within will be copied appropriately...See! C *does* do some things correctly :-).
Diffstat (limited to 'src')
-rw-r--r--src/H5TS.c37
-rw-r--r--src/H5TSprivate.h2
2 files changed, 26 insertions, 13 deletions
diff --git a/src/H5TS.c b/src/H5TS.c
index 7c29a95..dcf018f 100644
--- a/src/H5TS.c
+++ b/src/H5TS.c
@@ -37,9 +37,6 @@ pthread_key_t H5TS_errstk_key_g;
pthread_key_t H5TS_cancel_key_g;
hbool_t H5TS_allow_concurrent_g = FALSE; /* concurrent APIs override this */
-/* Local variable declarations */
-static pthread_t H5TS_null_g; /* Set to ``null'' with HDmemset for comparing*/
-
/* Local function definitions */
#ifdef NOT_USED
static void H5TS_mutex_init(H5TS_mutex_t *mutex);
@@ -72,8 +69,7 @@ H5TS_first_thread_init(void)
H5_g.H5_libinit_g = FALSE;
/* set the two pthread_t objects to ``null'' */
- HDmemset(&H5_g.init_lock.owner_thread, 0, sizeof(pthread_t));
- HDmemset(&H5TS_null_g, 0, sizeof(pthread_t));
+ H5_g.init_lock.owner_thread = NULL;
/* initialize global API mutex lock */
pthread_mutex_init(&H5_g.init_lock.atomic_lock, NULL);
@@ -115,7 +111,7 @@ H5TS_first_thread_init(void)
static void
H5TS_mutex_init(H5TS_mutex_t *mutex)
{
- HDmemset(&H5_g.init_lock.owner_thread, 0, sizeof(pthread_t));
+ H5_g.init_lock.owner_thread = NULL;
pthread_mutex_init(&mutex->atomic_lock, NULL);
pthread_cond_init(&mutex->cond_var, NULL);
mutex->lock_count = 0;
@@ -157,20 +153,36 @@ H5TS_mutex_lock(H5TS_mutex_t *mutex)
if (ret_value)
return ret_value;
- if (pthread_equal(pthread_self(), mutex->owner_thread)) {
+ if (mutex->owner_thread && pthread_equal(pthread_self(), *mutex->owner_thread)) {
/* already owned by self - increment count */
mutex->lock_count++;
- } else if (pthread_equal(mutex->owner_thread, H5TS_null_g)) {
+ } else if (!mutex->owner_thread) {
/* no one else has locked it - set owner and grab lock */
- mutex->owner_thread = pthread_self();
+ mutex->owner_thread = H5MM_malloc(sizeof(pthread_t));
+
+ if (!mutex->owner_thread) {
+ H5E_push(H5E_RESOURCE, H5E_NOSPACE, "H5TS_mutex_lock",
+ __FILE__, __LINE__, "memory allocation failed");
+ return FAIL;
+ }
+
+ *mutex->owner_thread = pthread_self();
mutex->lock_count = 1;
} else {
/* if already locked by someone else */
for (;;) {
pthread_cond_wait(&mutex->cond_var, &mutex->atomic_lock);
- if (pthread_equal(mutex->owner_thread, H5TS_null_g)) {
- mutex->owner_thread = pthread_self();
+ if (!mutex->owner_thread) {
+ mutex->owner_thread = H5MM_malloc(sizeof(pthread_t));
+
+ if (!mutex->owner_thread) {
+ H5E_push(H5E_RESOURCE, H5E_NOSPACE, "H5TS_mutex_lock",
+ __FILE__, __LINE__, "memory allocation failed");
+ return FAIL;
+ }
+
+ *mutex->owner_thread = pthread_self();
mutex->lock_count = 1;
break;
}
@@ -219,7 +231,8 @@ H5TS_mutex_unlock(H5TS_mutex_t *mutex)
mutex->lock_count--;
if (mutex->lock_count == 0) {
- HDmemset(&mutex->owner_thread, 0, sizeof(pthread_t));
+ H5MM_xfree(mutex->owner_thread);
+ mutex->owner_thread = NULL;
ret_value = pthread_cond_signal(&mutex->cond_var);
if (ret_value) {
diff --git a/src/H5TSprivate.h b/src/H5TSprivate.h
index 525450c..2d88637 100644
--- a/src/H5TSprivate.h
+++ b/src/H5TSprivate.h
@@ -25,7 +25,7 @@
/* Library level data structures */
typedef struct H5TS_mutex_struct {
- pthread_t owner_thread; /* current lock owner */
+ pthread_t *owner_thread; /* current lock owner */
pthread_mutex_t atomic_lock; /* lock for atomicity of new mechanism */
pthread_cond_t cond_var; /* condition variable */
unsigned int lock_count;