Enable reading and writing buffers (blocking)

README.md

@@ -21,8 +21,8 @@ It is mainly developed and tested on Linux and with Intel and Nvidia GPUs. It sh
   - [ ] querying info
 - [ ] buffers
   - [*] creating and releasing buffers
-  - [ ] writing buffers
-  - [ ] reading buffers
+  - [x] writing buffers (blocking only for now)
+  - [x] reading buffers (blocking only for now)
   - [ ] querying info
 - [ ] program objects
   - [ ] creating and releasing program objects

commandqueue.go

@@ -8,7 +8,10 @@ package opencl
 #endif
 */
 import "C"
-import "fmt"
+import (
+	"fmt"
+	"unsafe"
+)
 
 type CommandQueue struct {
 	queue C.cl_command_queue
@@ -61,3 +64,25 @@ func (q CommandQueue) Release() error {
 	}
 	return nil
 }
+
+func (q CommandQueue) EnqueueReadBuffer(memory Memory, offset uintptr, buffer []byte, waitList []Event) error {
+	var clEventsPtr unsafe.Pointer
+	if len(waitList) > 0 {
+		clEventsPtr = unsafe.Pointer(&asCLEventList(waitList)[0])
+	}
+	if err := C.clEnqueueReadBuffer(q.queue, memory.memory, C.CL_TRUE, C.size_t(offset), C.size_t(len(buffer)), unsafe.Pointer(&buffer[0]), C.cl_uint(len(waitList)), clEventsPtr, nil); err != C.CL_SUCCESS {
+		return fmt.Errorf("failed to enqueue read: %d", err)
+	}
+	return nil
+}
+
+func (q CommandQueue) EnqueueWriteBuffer(memory Memory, offset uintptr, buffer []byte, waitList []Event) error {
+	var clEventsPtr unsafe.Pointer
+	if len(waitList) > 0 {
+		clEventsPtr = unsafe.Pointer(&asCLEventList(waitList)[0])
+	}
+	if err := C.clEnqueueWriteBuffer(q.queue, memory.memory, C.CL_TRUE, C.size_t(offset), C.size_t(len(buffer)), unsafe.Pointer(&buffer[0]), C.cl_uint(len(waitList)), clEventsPtr, nil); err != C.CL_SUCCESS {
+		return fmt.Errorf("Failed to enqueue write: %d", err)
+	}
+	return nil
+}

event.go

+package opencl
+
+/*
+#ifdef __APPLE__
+#include <OpenCL/opencl.h>
+#else
+#include <CL/cl.h>
+#endif
+*/
+import "C"
+import "fmt"
+
+type Event struct {
+	event C.cl_event
+}
+
+func (e Event) Release() error {
+	err := C.clReleaseEvent(e.event)
+	if err != C.CL_SUCCESS {
+		return fmt.Errorf("failed to release event: %d", err)
+	}
+	return nil
+}
+
+func asCLEventList(events []Event) []C.cl_event {
+	result := make([]C.cl_event, len(events))
+	for i, e := range events {
+		result[i] = e.event
+	}
+	return result
+}