[Beignet] [PATCH V2] Fix the bug of multi-thread crash

[junyan.he at inbox.com]

From: Junyan He <junyan.he at linux.intel.com>

The cl_thread has a potential problem.
If the threads are created and destroyed very fast,
while the queue remain avaible, the resource of
destroyed thread will not be free correctly and will
be wrongly reused by later created thread.

V2:
   Use a easy way to handle this case. We do not clear
   the resource and just keep it. The later thread will
   not wrongly reuse it. The thread number will not be
   a very huge, so it is reasonable to clear all the
   resource when the command queue is destroyed.

Signed-off-by: Junyan He <junyan.he at linux.intel.com>
---
 src/cl_thread.c | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/src/cl_thread.c b/src/cl_thread.c
index d4de1b3..0d99574 100644
--- a/src/cl_thread.c
+++ b/src/cl_thread.c
@@ -37,7 +37,6 @@ static int thread_array_num = 1;
 static int *thread_slot_map = NULL;
 static int thread_magic_num = 1;
 static pthread_mutex_t thread_queue_map_lock = PTHREAD_MUTEX_INITIALIZER;
-static pthread_key_t destroy_key;
 
 static __thread int thread_id = -1;
 static __thread int thread_magic = -1;
@@ -55,13 +54,6 @@ typedef struct _queue_thread_private {
   pthread_mutex_t thread_data_lock;
 } queue_thread_private;
 
-static void thread_data_destructor(void *dummy) {
-  pthread_mutex_lock(&thread_queue_map_lock);
-  thread_slot_map[thread_id] = 0;
-  pthread_mutex_unlock(&thread_queue_map_lock);
-  free(dummy);
-}
-
 static thread_spec_data * __create_thread_spec_data(cl_command_queue queue, int create)
 {
   queue_thread_private *thread_private = ((queue_thread_private *)(queue->thread_data));
@@ -69,7 +61,6 @@ static thread_spec_data * __create_thread_spec_data(cl_command_queue queue, int
   int i = 0;
 
   if (thread_id == -1) {
-    void * dummy = malloc(sizeof(int));
 
     pthread_mutex_lock(&thread_queue_map_lock);
     for (i = 0; i < thread_array_num; i++) {
@@ -90,8 +81,6 @@ static thread_spec_data * __create_thread_spec_data(cl_command_queue queue, int
 
     thread_magic = thread_magic_num++;
     pthread_mutex_unlock(&thread_queue_map_lock);
-
-    pthread_setspecific(destroy_key, dummy);
   }
 
   pthread_mutex_lock(&thread_private->thread_data_lock);
@@ -129,7 +118,6 @@ void* cl_thread_data_create(void)
     thread_slot_map = calloc(thread_array_num, sizeof(int));
     pthread_mutex_unlock(&thread_queue_map_lock);
 
-    pthread_key_create(&destroy_key, thread_data_destructor);
   }
 
   pthread_mutex_init(&thread_private->thread_data_lock, NULL);
@@ -238,7 +226,6 @@ void cl_thread_data_destroy(cl_command_queue queue)
   thread_spec_data** threads_data;
 
   pthread_mutex_lock(&thread_private->thread_data_lock);
-  assert(thread_private->threads_data_num == thread_array_num);
   threads_data_num = thread_private->threads_data_num;
   threads_data = thread_private->threads_data;
   thread_private->threads_data_num = 0;
-- 
1.9.1