[feature] make scratch_seq thread-safe

Add mutex to make request creation and destruction thread-safe. As we
need to deal both we requests and tiles during these functions, we lock
the entire section.

src/aml.h

@@ -732,6 +732,7 @@ struct aml_scratch_seq_data {
 	void * sch_ptr;
 	struct aml_vector tilemap;
 	struct aml_vector requests;
+	pthread_mutex_t lock;
 };
 
 struct aml_scratch_seq_ops {

src/scratch_seq.c

@@ -69,6 +69,7 @@ int aml_scratch_seq_create_request(struct aml_scratch_data *d,
 
 	struct aml_scratch_request_seq *req;
 
+	pthread_mutex_lock(&scratch->data.lock);
 	req = aml_vector_add(&scratch->data.requests);
 	/* init the request */
 	if(type == AML_SCRATCH_REQUEST_TYPE_PUSH)
@@ -125,6 +126,7 @@ int aml_scratch_seq_create_request(struct aml_scratch_data *d,
 					     scratchptr, *scratchid,
 					     srcptr, srcid);
 	}
+	pthread_mutex_unlock(&scratch->data.lock);
 	scratch->ops.doit(&scratch->data, req);
 
 	*r = (struct aml_scratch_request *)req;
@@ -147,12 +149,14 @@ int aml_scratch_seq_destroy_request(struct aml_scratch_data *d,
 	aml_scratch_request_seq_destroy(req);
 
 	/* destroy removes the tile from the scratch */
+	pthread_mutex_lock(&scratch->data.lock);
 	if(req->type == AML_SCRATCH_REQUEST_TYPE_PUSH)
 		tile = aml_vector_get(&scratch->data.tilemap,req->srcid);
 	else if(req->type == AML_SCRATCH_REQUEST_TYPE_PULL)
 		tile = aml_vector_get(&scratch->data.tilemap,req->dstid);
 	aml_vector_remove(&scratch->data.tilemap, tile);
 	aml_vector_remove(&scratch->data.requests, req);
+	pthread_mutex_unlock(&scratch->data.lock);
 	return 0;
 }
 
@@ -171,12 +175,14 @@ int aml_scratch_seq_wait_request(struct aml_scratch_data *d,
 
 	/* cleanup a completed request. In case of push, free up the tile */
 	aml_scratch_request_seq_destroy(req);
+	pthread_mutex_lock(&scratch->data.lock);
 	if(req->type == AML_SCRATCH_REQUEST_TYPE_PUSH)
 	{
 		tile = aml_vector_get(&scratch->data.tilemap,req->srcid);
 		aml_vector_remove(&scratch->data.tilemap, tile);
 	}
 	aml_vector_remove(&scratch->data.requests, req);
+	pthread_mutex_unlock(&scratch->data.lock);
 	return 0;
 }
 
@@ -243,6 +249,7 @@ int aml_scratch_seq_vinit(struct aml_scratch *d, va_list ap)
 	size_t tilesize = aml_tiling_tilesize(scratch->data.tiling, 0);
 	scratch->data.sch_ptr = aml_area_calloc(scratch->data.sch_area,
 						nbtiles, tilesize);
+	pthread_mutex_init(&scratch->data.lock, NULL);
 	return 0;
 }
 int aml_scratch_seq_init(struct aml_scratch *d, ...)
@@ -261,5 +268,6 @@ int aml_scratch_seq_destroy(struct aml_scratch *d)
 	aml_vector_destroy(&scratch->data.requests);
 	aml_vector_destroy(&scratch->data.tilemap);
 	aml_area_free(scratch->data.sch_area, scratch->data.sch_ptr);
+	pthread_mutex_destroy(&scratch->data.lock);
 	return 0;
 }