Task: Separate Finalize into Reduce And Free

In preparation of TBB we need to split the finalize function into reduce
and free. Reduce is used to combine results and free for freeing any
allocated memory.

The reduce function is called to join user data chunk into another, to reduce the
result to the original userdata_chunk memory. These functions should have no side
effects so that they can be run on any thread.
The free functions should free data created during execution (TaskParallelRangeFunc).

Original patch by Brecht van Lommel
{rB61f49db843cf5095203112226ae386f301be1e1a}.

Reviewed By: Brecht van Lommel, Bastien Montagne

Differential Revision: https://developer.blender.org/D7394

1 files changed, 12 insertions, 4 deletions

diff --git a/source/blender/blenlib/BLI_task.h b/source/blender/blenlib/BLI_task.h
index 898e4be5f92..78370e98202 100644
--- a/source/blender/blenlib/BLI_task.h
+++ b/source/blender/blenlib/BLI_task.h
@@ -146,12 +146,14 @@ typedef struct TaskParallelTLS {
   void *userdata_chunk;
 } TaskParallelTLS;
 
-typedef void (*TaskParallelFinalizeFunc)(void *__restrict userdata,
-                                         void *__restrict userdata_chunk);
-
 typedef void (*TaskParallelRangeFunc)(void *__restrict userdata,
                                       const int iter,
                                       const TaskParallelTLS *__restrict tls);
+typedef void (*TaskParallelReduceFunc)(const void *__restrict userdata,
+                                       void *__restrict chunk_join,
+                                       void *__restrict chunk);
+
+typedef void (*TaskParallelFreeFunc)(const void *__restrict userdata, void *__restrict chunk);
 
 typedef struct TaskParallelSettings {
   /* Whether caller allows to do threading of the particular range.
@@ -171,7 +173,13 @@ typedef struct TaskParallelSettings {
   /* Function called from calling thread once whole range have been
    * processed.
    */
-  TaskParallelFinalizeFunc func_finalize;
+  /* Function called to join user data chunk into another, to reduce
+   * the result to the original userdata_chunk memory.
+   * The reduce functions should have no side effects, so that they
+   * can be run on any thread. */
+  TaskParallelReduceFunc func_reduce;
+  /* Function called to free data created by TaskParallelRangeFunc. */
+  TaskParallelFreeFunc func_free;
   /* Minimum allowed number of range iterators to be handled by a single
    * thread. This allows to achieve following:
    * - Reduce amount of threading overhead.