- * The segment will feature all access modes, unless the given - * buffer is {@linkplain ByteBuffer#isReadOnly() read-only} in which case the segment will + * The segment will feature all access modes (see {@link #ALL_ACCESS}), + * unless the given buffer is {@linkplain ByteBuffer#isReadOnly() read-only} in which case the segment will * not feature the {@link #WRITE} access mode. *
* The resulting memory segment keeps a reference to the backing buffer, to ensure it remains reachable @@ -414,7 +414,8 @@ static MemorySegment ofByteBuffer(ByteBuffer bb) { * Creates a new array memory segment that models the memory associated with a given heap-allocated byte array. *
* The resulting memory segment keeps a reference to the backing array, to ensure it remains reachable - * for the life-time of the segment. The segment will feature all access modes. + * for the life-time of the segment. The segment will feature all access modes + * (see {@link #ALL_ACCESS}). * * @param arr the primitive array backing the array memory segment. * @return a new array memory segment. @@ -427,7 +428,8 @@ static MemorySegment ofArray(byte[] arr) { * Creates a new array memory segment that models the memory associated with a given heap-allocated char array. *
* The resulting memory segment keeps a reference to the backing array, to ensure it remains reachable - * for the life-time of the segment. The segment will feature all access modes. + * for the life-time of the segment. The segment will feature all access modes + * (see {@link #ALL_ACCESS}). * * @param arr the primitive array backing the array memory segment. * @return a new array memory segment. @@ -440,7 +442,8 @@ static MemorySegment ofArray(char[] arr) { * Creates a new array memory segment that models the memory associated with a given heap-allocated short array. *
* The resulting memory segment keeps a reference to the backing array, to ensure it remains reachable - * for the life-time of the segment. The segment will feature all access modes. + * for the life-time of the segment. The segment will feature all access modes + * (see {@link #ALL_ACCESS}). * * @param arr the primitive array backing the array memory segment. * @return a new array memory segment. @@ -466,7 +469,8 @@ static MemorySegment ofArray(int[] arr) { * Creates a new array memory segment that models the memory associated with a given heap-allocated float array. *
* The resulting memory segment keeps a reference to the backing array, to ensure it remains reachable - * for the life-time of the segment. The segment will feature all access modes. + * for the life-time of the segment. The segment will feature all access modes + * (see {@link #ALL_ACCESS}). * * @param arr the primitive array backing the array memory segment. * @return a new array memory segment. @@ -479,7 +483,8 @@ static MemorySegment ofArray(float[] arr) { * Creates a new array memory segment that models the memory associated with a given heap-allocated long array. *
* The resulting memory segment keeps a reference to the backing array, to ensure it remains reachable - * for the life-time of the segment. The segment will feature all access modes. + * for the life-time of the segment. The segment will feature all access modes + * (see {@link #ALL_ACCESS}). * * @param arr the primitive array backing the array memory segment. * @return a new array memory segment. @@ -492,7 +497,8 @@ static MemorySegment ofArray(long[] arr) { * Creates a new array memory segment that models the memory associated with a given heap-allocated double array. *
* The resulting memory segment keeps a reference to the backing array, to ensure it remains reachable - * for the life-time of the segment. The segment will feature all access modes. + * for the life-time of the segment. The segment will feature all access modes + * (see {@link #ALL_ACCESS}). * * @param arr the primitive array backing the array memory segment. * @return a new array memory segment. @@ -544,9 +550,9 @@ static MemorySegment allocateNative(long bytesSize) { /** * Creates a new mapped memory segment that models a memory-mapped region of a file from a given path. *
- * The segment will feature all access modes, unless the given mapping mode - * is {@linkplain FileChannel.MapMode#READ_ONLY READ_ONLY}, in which case the segment will not feature - * the {@link #WRITE} access mode. + * The segment will feature all access modes (see {@link #ALL_ACCESS}), + * unless the given mapping mode is {@linkplain FileChannel.MapMode#READ_ONLY READ_ONLY}, in which case + * the segment will not feature the {@link #WRITE} access mode. * * @implNote When obtaining a mapped segment from a newly created file, the initialization state of the contents of the block * of mapped memory associated with the returned mapped memory segment is unspecified and should not be relied upon. @@ -568,7 +574,8 @@ static MappedMemorySegment mapFromPath(Path path, long bytesOffset, long bytesSi /** * Creates a new native memory segment that models a newly allocated block of off-heap memory with given size and - * alignment constraint (in bytes). The segment will feature all access modes. + * alignment constraint (in bytes). The segment will feature all access modes + * (see {@link #ALL_ACCESS}). * * @implNote The block of off-heap memory associated with the returned native memory segment is initialized to zero. * Moreover, a client is responsible to call the {@link MemorySegment#close()} on a native memory segment, @@ -598,7 +605,8 @@ static MemorySegment allocateNative(long bytesSize, long alignmentBytes) { * bounds, and can therefore be closed; closing such a segment can optionally result in calling an user-provided cleanup * action. This method can be very useful when interacting with custom native memory sources (e.g. custom allocators, * GPU memory, etc.), where an address to some underlying memory region is typically obtained from native code - * (often as a plain {@code long} value). The segment will feature all access modes. + * (often as a plain {@code long} value). The segment will feature all access modes + * (see {@link #ALL_ACCESS}). *
* This method is restricted. Restricted method are unsafe, and, if used incorrectly, their use might crash
* the JVM crash or, worse, silently result in memory corruption. Thus, clients should refrain from depending on
@@ -666,4 +674,11 @@ static MemorySegment ofNativeRestricted(MemoryAddress addr, long bytesSize, Thre
* @see MemorySegment#withAccessModes(int)
*/
int HANDOFF = ACQUIRE << 1;
+
+ /**
+ * Default access mode; this is a union of all the access modes supported by memory segments.
+ * @see MemorySegment#accessModes()
+ * @see MemorySegment#withAccessModes(int)
+ */
+ int ALL_ACCESS = READ | WRITE | CLOSE | ACQUIRE | HANDOFF;
}
diff --git a/src/jdk.incubator.foreign/share/classes/jdk/internal/foreign/AbstractMemorySegmentImpl.java b/src/jdk.incubator.foreign/share/classes/jdk/internal/foreign/AbstractMemorySegmentImpl.java
index 2f804184494..2bfe7926e8d 100644
--- a/src/jdk.incubator.foreign/share/classes/jdk/internal/foreign/AbstractMemorySegmentImpl.java
+++ b/src/jdk.incubator.foreign/share/classes/jdk/internal/foreign/AbstractMemorySegmentImpl.java
@@ -64,11 +64,9 @@ public abstract class AbstractMemorySegmentImpl implements MemorySegment, Memory
private static final boolean enableSmallSegments =
Boolean.parseBoolean(GetPropertyAction.privilegedGetProperty("jdk.incubator.foreign.SmallSegments", "true"));
- final static int ACCESS_MASK = READ | WRITE | CLOSE | ACQUIRE | HANDOFF;
final static int FIRST_RESERVED_FLAG = 1 << 16; // upper 16 bits are reserved
final static int SMALL = FIRST_RESERVED_FLAG;
final static long NONCE = new Random().nextLong();
- final static int DEFAULT_MASK = READ | WRITE | CLOSE | ACQUIRE | HANDOFF;
final static JavaNioAccess nioAccess = SharedSecrets.getJavaNioAccess();
@@ -93,8 +91,8 @@ public abstract class AbstractMemorySegmentImpl implements MemorySegment, Memory
static int defaultAccessModes(long size) {
return (enableSmallSegments && size < Integer.MAX_VALUE) ?
- DEFAULT_MASK | SMALL :
- DEFAULT_MASK;
+ ALL_ACCESS | SMALL :
+ ALL_ACCESS;
}
@Override
@@ -192,7 +190,7 @@ public final ByteBuffer asByteBuffer() {
@Override
public final int accessModes() {
- return mask & ACCESS_MASK;
+ return mask & ALL_ACCESS;
}
@Override
@@ -216,7 +214,7 @@ public AbstractMemorySegmentImpl withAccessModes(int accessModes) {
if ((~accessModes() & accessModes) != 0) {
throw new IllegalArgumentException("Cannot acquire more access modes");
}
- return dup(0, length, (mask & ~ACCESS_MASK) | accessModes, scope);
+ return dup(0, length, (mask & ~ALL_ACCESS) | accessModes, scope);
}
@Override
@@ -226,7 +224,7 @@ public boolean hasAccessModes(int accessModes) {
}
private void checkAccessModes(int accessModes) {
- if ((accessModes & ~ACCESS_MASK) != 0) {
+ if ((accessModes & ~ALL_ACCESS) != 0) {
throw new IllegalArgumentException("Invalid access modes");
}
}
diff --git a/test/jdk/java/foreign/TestByteBuffer.java b/test/jdk/java/foreign/TestByteBuffer.java
index ef6b0098047..984763907a6 100644
--- a/test/jdk/java/foreign/TestByteBuffer.java
+++ b/test/jdk/java/foreign/TestByteBuffer.java
@@ -239,18 +239,16 @@ public void testChannel() throws Throwable {
}
}
- static final int ALL_ACCESS_MODES = READ | WRITE | CLOSE | ACQUIRE | HANDOFF;
-
@Test
public void testDefaultAccessModesMappedSegment() throws Throwable {
try (MappedMemorySegment segment = MemorySegment.mapFromPath(tempPath, 0L, 8, FileChannel.MapMode.READ_WRITE)) {
- assertTrue(segment.hasAccessModes(ALL_ACCESS_MODES));
- assertEquals(segment.accessModes(), ALL_ACCESS_MODES);
+ assertTrue(segment.hasAccessModes(ALL_ACCESS));
+ assertEquals(segment.accessModes(), ALL_ACCESS);
}
try (MappedMemorySegment segment = MemorySegment.mapFromPath(tempPath, 0L, 8, FileChannel.MapMode.READ_ONLY)) {
- assertTrue(segment.hasAccessModes(ALL_ACCESS_MODES & ~WRITE));
- assertEquals(segment.accessModes(), ALL_ACCESS_MODES& ~WRITE);
+ assertTrue(segment.hasAccessModes(ALL_ACCESS & ~WRITE));
+ assertEquals(segment.accessModes(), ALL_ACCESS & ~WRITE);
}
}
@@ -521,14 +519,14 @@ public void testCopyNativeToHeap(Consumer