Source codes

1 files changed, 52 insertions, 0 deletions

diff --git a/Whisper/CPU/ParallelForRunner.h b/Whisper/CPU/ParallelForRunner.h
new file mode 100644
index 0000000..baef647
--- /dev/null
+++ b/Whisper/CPU/ParallelForRunner.h
@@ -0,0 +1,52 @@
+#pragma once
+#include "LargeBuffer.h"
+
+namespace CpuCompute
+{
+	// Callback interface for the parallel `for`
+	__interface iComputeRange
+	{
+		// The implementation calls this method on multiple thread pool threads in parallel, and aggregates status codes.
+		HRESULT __stdcall compute( size_t begin, size_t end ) const;
+	};
+
+	// Similar to ThreadPoolWork in parallelFor.h, optimized to be used as a direct replacement of OpenMP pool.
+	class alignas( 64 ) ParallelForRunner
+	{
+	public:
+		ParallelForRunner( int threads );
+		~ParallelForRunner();
+
+		HRESULT setThreadsCount( int threads );
+
+		HRESULT parallelFor( iComputeRange& compute, size_t length, size_t minBatch = 1 );
+
+		// Allocate a temporary buffer for the calling thread.
+		// The pointer is guaranteed to be aligned by page size = 4kb
+		void* threadLocalBuffer( size_t cb );
+
+	private:
+
+		int maxThreads;
+		PTP_WORK work = nullptr;
+		iComputeRange* computeRange = nullptr;
+		size_t countItems = 0;
+		size_t countThreads = 0;
+
+		// Aligning by cache lines.
+		// Avoiding cache line sharing between CPU cores improves performance, despite wasting a few bytes of memory.
+		struct alignas( 64 ) ThreadBuffer
+		{
+			LargeBuffer memory;
+			size_t cb = 0;
+		};
+		std::vector<ThreadBuffer> threadBuffers;
+
+		alignas( 64 ) volatile long threadIndex = 0;
+		volatile HRESULT status = S_OK;
+
+		void runBatch( size_t ith ) noexcept;
+
+		static void __stdcall workCallbackStatic( PTP_CALLBACK_INSTANCE Instance, void* pv, PTP_WORK Work ) noexcept;
+	};
+}
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