data management: New functions

    starpu_data_acquire_cb_sequential_consistency() and
    starpu_data_acquire_on_node_cb_sequential_consistency() which
    allows to enable or disable sequential consistency

ChangeLog

@@ -36,6 +36,10 @@ New features:
 Small features:
   * Add cl_arg_free field to enable automatic free(cl_arg) on task
     destroy.
+  * New functions starpu_data_acquire_cb_sequential_consistency() and
+    starpu_data_acquire_on_node_cb_sequential_consistency() which allows
+    to enable or disable sequential consistency
+
 
 StarPU 1.1.0 (svn revision xxxx)
 ==============================================

doc/doxygen/chapters/api/data_management.doxy

@@ -226,6 +226,20 @@ are not disabled. Contrary to starpu_data_acquire(), this function is
 non-blocking and may be called from task callbacks. Upon successful
 completion, this function returns 0.
 
+\fn int starpu_data_acquire_cb_sequential_consistency(starpu_data_handle_t handle, enum starpu_data_access_mode mode, void (*callback)(void *), void *arg, int sequential_consistency)
+\ingroup API_Data_Management
+Equivalent of starpu_data_acquire_cb() with the possibility of enabling or disabling data dependencies.
+When the data specified in \p handle is available in the appropriate access
+mode, the \p callback function is executed. The application may access
+the requested data during the execution of this \p callback. The \p callback
+function must call starpu_data_release() once the application does not
+need to access the piece of data anymore. Note that implicit data
+dependencies are also enforced by starpu_data_acquire_cb_sequential_consistency() in case they
+are not disabled specifically for the given \p handle or by the parameter \p sequential_consistency.
+Similarly to starpu_data_acquire_cb(), this function is
+non-blocking and may be called from task callbacks. Upon successful
+completion, this function returns 0.
+
 \fn int starpu_data_acquire_on_node(starpu_data_handle_t handle, unsigned node, enum starpu_data_access_mode mode)
 \ingroup API_Data_Management
 This is the same as starpu_data_acquire(), except that the data
@@ -237,6 +251,12 @@ This is the same as starpu_data_acquire_cb(), except that the
 data will be available on the given memory node instead of main
 memory.
 
+\int int starpu_data_acquire_on_node_cb_sequential_consistency(starpu_data_handle_t handle, unsigned node, enum starpu_data_access_mode mode, void (*callback)(void *), void *arg, int sequential_consistency)
+\ingroup API_Data_Management
+This is the same as starpu_data_acquire_cb_sequential_consistency(), except that the
+data will be available on the given memory node instead of main
+memory.
+
 \def STARPU_DATA_ACQUIRE_CB(handle, mode, code)
 \ingroup API_Data_Management
 STARPU_DATA_ACQUIRE_CB() is the same as starpu_data_acquire_cb(),

include/starpu_data.h

@@ -60,6 +60,9 @@ int starpu_data_acquire(starpu_data_handle_t handle, enum starpu_data_access_mod
 int starpu_data_acquire_on_node(starpu_data_handle_t handle, unsigned node, enum starpu_data_access_mode mode);
 int starpu_data_acquire_cb(starpu_data_handle_t handle, enum starpu_data_access_mode mode, void (*callback)(void *), void *arg);
 int starpu_data_acquire_on_node_cb(starpu_data_handle_t handle, unsigned node, enum starpu_data_access_mode mode, void (*callback)(void *), void *arg);
+int starpu_data_acquire_cb_sequential_consistency(starpu_data_handle_t handle, enum starpu_data_access_mode mode, void (*callback)(void *), void *arg, int sequential_consistency);
+int starpu_data_acquire_on_node_cb_sequential_consistency(starpu_data_handle_t handle, unsigned node, enum starpu_data_access_mode mode, void (*callback)(void *), void *arg, int sequential_consistency);
+
 #ifdef __GCC__
 #  define STARPU_DATA_ACQUIRE_CB(handle, mode, code) do \
 	{ \						\

src/datawizard/user_interactions.c

@@ -115,8 +115,9 @@ static void starpu_data_acquire_cb_pre_sync_callback(void *arg)
 }
 
 /* The data must be released by calling starpu_data_release later on */
-int starpu_data_acquire_on_node_cb(starpu_data_handle_t handle, unsigned node,
-			   enum starpu_data_access_mode mode, void (*callback)(void *), void *arg)
+int starpu_data_acquire_on_node_cb_sequential_consistency(starpu_data_handle_t handle, unsigned node,
+							  enum starpu_data_access_mode mode, void (*callback)(void *), void *arg,
+							  int sequential_consistency)
 {
 	STARPU_ASSERT(handle);
 	STARPU_ASSERT_MSG(handle->nchildren == 0, "Acquiring a partitioned data (%p) is not possible", handle);
@@ -137,8 +138,8 @@ int starpu_data_acquire_on_node_cb(starpu_data_handle_t handle, unsigned node,
 	wrapper->post_sync_task = NULL;
 
 	STARPU_PTHREAD_MUTEX_LOCK(&handle->sequential_consistency_mutex);
-	int sequential_consistency = handle->sequential_consistency;
-	if (sequential_consistency)
+	int handle_sequential_consistency = handle->sequential_consistency;
+	if (handle_sequential_consistency && sequential_consistency)
 	{
 		struct starpu_task *new_task;
 		wrapper->pre_sync_task = starpu_task_create();
@@ -180,12 +181,25 @@ int starpu_data_acquire_on_node_cb(starpu_data_handle_t handle, unsigned node,
 	return 0;
 }
 
+
+int starpu_data_acquire_on_node_cb(starpu_data_handle_t handle, unsigned node,
+				   enum starpu_data_access_mode mode, void (*callback)(void *), void *arg)
+{
+	return starpu_data_acquire_on_node_cb_sequential_consistency(handle, node, mode, callback, arg, 1);
+}
+
 int starpu_data_acquire_cb(starpu_data_handle_t handle,
 			   enum starpu_data_access_mode mode, void (*callback)(void *), void *arg)
 {
 	return starpu_data_acquire_on_node_cb(handle, 0, mode, callback, arg);
 }
 
+int starpu_data_acquire_cb_sequential_consistency(starpu_data_handle_t handle,
+						  enum starpu_data_access_mode mode, void (*callback)(void *), void *arg, int sequential_consistency)
+{
+	return starpu_data_acquire_on_node_cb_sequential_consistency(handle, 0, mode, callback, arg, sequential_consistency);
+}
+
 /*
  *	Block data request from application
  */