From 147b78b7e49661324148be23ef5e1fcfd004d97f Mon Sep 17 00:00:00 2001
From: Not Zed <notzed@gmail.com>
Date: Sun, 26 Jan 2020 18:23:59 +1030
Subject: [PATCH] Just use the ByteBuffer address to directly unmap the memory.
 Thanks go to Maurizio Cimadamore <maurizio.cimadamore@oracle.com> for the
 suggestion.

---
 .../classes/au/notzed/zcl/CLCommandQueue.java | 36 ++-----------------
 .../tests/au/notzed/zcl/CLBufferTest.java     |  2 ++
 2 files changed, 5 insertions(+), 33 deletions(-)

diff --git a/src/notzed.zcl/classes/au/notzed/zcl/CLCommandQueue.java b/src/notzed.zcl/classes/au/notzed/zcl/CLCommandQueue.java
index f878bb8..063b480 100644
--- a/src/notzed.zcl/classes/au/notzed/zcl/CLCommandQueue.java
+++ b/src/notzed.zcl/classes/au/notzed/zcl/CLCommandQueue.java
@@ -1343,22 +1343,6 @@ public class CLCommandQueue extends CLExtendable {
 		}
 	}
 
-	private MemoryAddress getMap(ByteBuffer bb) {
-		synchronized (maps) {
-			// Note this can't use a hashtable as ByteBuffer
-			// hashes on state like position.
-			for (int i=0;i<maps.size();i++) {
-				MapData d = maps.get(i);
-
-				if (d.buffer == bb) {
-					maps.remove(i);
-					return d.raw;
-				}
-			}
-		}
-		throw new IllegalArgumentException();
-	}
-
 	public ByteBuffer enqueueMapBuffer(CLBuffer buffer, boolean blocking,
 					   long flags,
 					   long offset,
@@ -1379,14 +1363,7 @@ public class CLCommandQueue extends CLExtendable {
 			if (res != 0)
 				throw new CLException(res);
 
-			// Need to map the segment and track it separately
-			ByteBuffer bb = Memory.ofNative(cmap, size).asByteBuffer();
-
-			addMap(cmap, bb);
-
-			info.post(event);
-
-			return bb;
+			return Memory.ofNative(cmap, size).asByteBuffer();
 		} catch (CLException | RuntimeException | Error t) {
 			throw t;
 		} catch (Throwable t) {
@@ -1443,14 +1420,7 @@ public class CLCommandQueue extends CLExtendable {
 				    ?                     stride * region[1] + region[0] // 2D
 				    : slice * region[2] + stride * region[1] + region[0]; // 3D
 
-			// Need to map the segment and track it separately
-			ByteBuffer bb = Memory.ofNative(cmap, size).asByteBuffer();
-
-			addMap(cmap, bb);
-
-			info.post(event);
-
-			return bb;
+			return Memory.ofNative(cmap, size).asByteBuffer();
 		} catch (CLException | RuntimeException | Error t) {
 			throw t;
 		} catch (Throwable t) {
@@ -1461,7 +1431,7 @@ public class CLCommandQueue extends CLExtendable {
 	public void enqueueUnmapMemObject(CLMemory mem, ByteBuffer mapped,
 					  CLEventList wait,
 					  CLEventList event) throws CLException {
-		MemoryAddress cmap = getMap(mapped);
+		MemoryAddress cmap = MemorySegment.ofByteBuffer(mapped).baseAddress();
 
 		try (Allocator frame = Memory.stack()) {
 			EventInfo info = new EventInfo(frame, wait, event);
diff --git a/src/notzed.zcl/tests/au/notzed/zcl/CLBufferTest.java b/src/notzed.zcl/tests/au/notzed/zcl/CLBufferTest.java
index 6cf19a7..2359ee0 100644
--- a/src/notzed.zcl/tests/au/notzed/zcl/CLBufferTest.java
+++ b/src/notzed.zcl/tests/au/notzed/zcl/CLBufferTest.java
@@ -247,6 +247,8 @@ public class CLBufferTest {
 		}
 	}
 
+	// clcommandqueue no longer tracks the memory so double-free is at your own risk.
+	@Ignore
 	@Test
 	public void testMap2() throws Exception {
 		System.out.println("mapBuffer double unmap");
-- 
2.39.2