don't share event between cl contexts

1 files changed, 5 insertions, 8 deletions

diff --git a/balls.c b/balls.c
index 24f2f1a..19adc34 100644
--- a/balls.c
+++ b/balls.c
@@ -533,7 +533,6 @@ setKernelArgs(void) {
 
 void
 animate(int v) {
-	cl_event readEvent;
 	int err;
 	clock_t tstart, elapsed;
 	unsigned int nextFrame;
@@ -544,20 +543,18 @@ animate(int v) {
 	collideBalls();
 	collideWalls();
 
-	/* Copy new positions from CPU to host asynchronously. */
-	err = clEnqueueReadBuffer(cpuQueue, positionsCpuBuf, CL_FALSE, 0, nBalls*2*sizeof(float), positionsHostBuf, 0, NULL, &readEvent);
+	display();
+
+	/* Copy new positions from CPU to host. */
+	err = clEnqueueReadBuffer(cpuQueue, positionsCpuBuf, CL_TRUE, 0, nBalls*2*sizeof(float), positionsHostBuf, 0, NULL, NULL);
 	if (err < 0)
 		sysfatal("Failed to copy positions from CPU to host.\n");
 
-	display();
-
 	/* Copy new positions from host to GPU. */
-	err = clEnqueueWriteBuffer(gpuQueue, positionsGpuBuf, CL_TRUE, 0, nBalls*2*sizeof(float), positionsHostBuf, 1, &readEvent, NULL);
+	err = clEnqueueWriteBuffer(gpuQueue, positionsGpuBuf, CL_TRUE, 0, nBalls*2*sizeof(float), positionsHostBuf, 0, NULL, NULL);
 	if (err < 0)
 		sysfatal("Failed to copy positions from host to GPU.\n");
 
-	clReleaseEvent(readEvent);
-
 	elapsed = (clock() - tstart) / (CLOCKS_PER_SEC / MS_PER_S);
 	nextFrame = (elapsed > FRAME_TIME_MS) ? 0 : FRAME_TIME_MS-elapsed;
 	glutTimerFunc(nextFrame, animate, 0);