job system updates, cpu performance improvements

WickedEngine/wiJobSystem.h

@@ -3,10 +3,14 @@
 #include <functional>
 #include <atomic>
 
-struct wiJobDispatchArgs
+struct wiJobArgs
 {
-	uint32_t jobIndex;
-	uint32_t groupIndex;
+	uint32_t jobIndex;		// job index relative to dispatch (like SV_DispatchThreadID in HLSL)
+	uint32_t groupID;		// group index relative to dispatch (like SV_GroupID in HLSL)
+	uint32_t groupIndex;	// job index relative to group (like SV_GroupIndex in HLSL)
+	bool isFirstJobInGroup;	// is the current job the first one in the group?
+	bool isLastJobInGroup;	// is the current job the last one in the group?
+	void* sharedmemory;		// stack memory shared within the current group (jobs within a group execute serially)
 };
 
 namespace wiJobSystem
@@ -21,14 +25,17 @@ namespace wiJobSystem
 		std::atomic<uint32_t> counter{ 0 };
 	};
 
-	// Add a job to execute asynchronously. Any idle thread will execute this job.
-	void Execute(context& ctx, const std::function<void()>& job);
+	// Add a task to execute asynchronously. Any idle thread will execute this.
+	void Execute(context& ctx, const std::function<void(wiJobArgs)>& task);
 
-	// Divide a job onto multiple jobs and execute in parallel.
+	// Divide a task onto multiple jobs and execute in parallel.
 	//	jobCount	: how many jobs to generate for this task.
 	//	groupSize	: how many jobs to execute per thread. Jobs inside a group execute serially. It might be worth to increase for small jobs
-	//	func		: receives a wiJobDispatchArgs as parameter
-	void Dispatch(context& ctx, uint32_t jobCount, uint32_t groupSize, const std::function<void(wiJobDispatchArgs)>& job);
+	//	task		: receives a wiJobArgs as parameter
+	void Dispatch(context& ctx, uint32_t jobCount, uint32_t groupSize, const std::function<void(wiJobArgs)>& task, size_t sharedmemory_size = 0);
+
+	// Returns the amount of job groups that will be created for a set number of jobs and group size
+	uint32_t DispatchGroupCount(uint32_t jobCount, uint32_t groupSize);
 
 	// Check if any threads are working currently or not
 	bool IsBusy(const context& ctx);