From daee9821068c5b66d94fc8b6b5f8f13e5019a3bf Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.alekhin@intel.com>
Date: Thu, 6 Jul 2017 13:25:32 +0300
Subject: [PATCH] ocl: rework events handling with clSetEventCallback

---
 modules/core/src/ocl.cpp | 36 ++++++++++++++++++++++++------------
 1 file changed, 24 insertions(+), 12 deletions(-)

diff --git a/modules/core/src/ocl.cpp b/modules/core/src/ocl.cpp
index 7d7c24e210..4e30d6b415 100644
--- a/modules/core/src/ocl.cpp
+++ b/modules/core/src/ocl.cpp
@@ -1962,7 +1962,7 @@ KernelArg KernelArg::Constant(const Mat& m)
 struct Kernel::Impl
 {
     Impl(const char* kname, const Program& prog) :
-        refcount(1), e(0), nu(0)
+        refcount(1), isInProgress(false), nu(0)
     {
         cl_program ph = (cl_program)prog.ptr();
         cl_int retval = 0;
@@ -2005,11 +2005,15 @@ struct Kernel::Impl
         images.push_back(image);
     }
 
-    void finit()
+    void finit(cl_event e)
     {
+        CV_UNUSED(e);
+#if 0
+        printf("event::callback(%p)\n", e); fflush(stdout);
+#endif
         cleanupUMats();
         images.clear();
-        if(e) { clReleaseEvent(e); e = 0; }
+        isInProgress = false;
         release();
     }
 
@@ -2025,9 +2029,9 @@ struct Kernel::Impl
     cv::String name;
 #endif
     cl_kernel handle;
-    cl_event e;
     enum { MAX_ARRS = 16 };
     UMatData* u[MAX_ARRS];
+    bool isInProgress;
     int nu;
     std::list<Image2D> images;
     bool haveTempDstUMats;
@@ -2037,9 +2041,9 @@ struct Kernel::Impl
 
 extern "C" {
 
-static void CL_CALLBACK oclCleanupCallback(cl_event, cl_int, void *p)
+static void CL_CALLBACK oclCleanupCallback(cl_event e, cl_int, void *p)
 {
-    ((cv::ocl::Kernel::Impl*)p)->finit();
+    ((cv::ocl::Kernel::Impl*)p)->finit(e);
 }
 
 }
@@ -2246,7 +2250,7 @@ bool Kernel::run(int dims, size_t _globalsize[], size_t _localsize[],
 {
     CV_INSTRUMENT_REGION_OPENCL_RUN(p->name.c_str());
 
-    if(!p || !p->handle || p->e != 0)
+    if(!p || !p->handle || p->isInProgress)
         return false;
 
     cl_command_queue qq = getQueue(q);
@@ -2265,9 +2269,10 @@ bool Kernel::run(int dims, size_t _globalsize[], size_t _localsize[],
         return true;
     if( p->haveTempDstUMats )
         sync = true;
+    cl_event asyncEvent = 0;
     cl_int retval = clEnqueueNDRangeKernel(qq, p->handle, (cl_uint)dims,
                                            offset, globalsize, _localsize, 0, 0,
-                                           sync ? 0 : &p->e);
+                                           sync ? 0 : &asyncEvent);
 #if CV_OPENCL_SHOW_RUN_ERRORS
     if (retval != CL_SUCCESS)
     {
@@ -2283,18 +2288,22 @@ bool Kernel::run(int dims, size_t _globalsize[], size_t _localsize[],
     else
     {
         p->addref();
-        CV_OclDbgAssert(clSetEventCallback(p->e, CL_COMPLETE, oclCleanupCallback, p) == CL_SUCCESS);
+        p->isInProgress = true;
+        CV_OclDbgAssert(clSetEventCallback(asyncEvent, CL_COMPLETE, oclCleanupCallback, p) == CL_SUCCESS);
     }
+    if (asyncEvent)
+        clReleaseEvent(asyncEvent);
     return retval == CL_SUCCESS;
 }
 
 bool Kernel::runTask(bool sync, const Queue& q)
 {
-    if(!p || !p->handle || p->e != 0)
+    if(!p || !p->handle || p->isInProgress)
         return false;
 
     cl_command_queue qq = getQueue(q);
-    cl_int retval = clEnqueueTask(qq, p->handle, 0, 0, sync ? 0 : &p->e);
+    cl_event asyncEvent = 0;
+    cl_int retval = clEnqueueTask(qq, p->handle, 0, 0, sync ? 0 : &asyncEvent);
     if( sync || retval != CL_SUCCESS )
     {
         CV_OclDbgAssert(clFinish(qq) == CL_SUCCESS);
@@ -2303,8 +2312,11 @@ bool Kernel::runTask(bool sync, const Queue& q)
     else
     {
         p->addref();
-        CV_OclDbgAssert(clSetEventCallback(p->e, CL_COMPLETE, oclCleanupCallback, p) == CL_SUCCESS);
+        p->isInProgress = true;
+        CV_OclDbgAssert(clSetEventCallback(asyncEvent, CL_COMPLETE, oclCleanupCallback, p) == CL_SUCCESS);
     }
+    if (asyncEvent)
+        clReleaseEvent(asyncEvent);
     return retval == CL_SUCCESS;
 }