From 5640acb77be751509c5d2eee4703046dcaa05b57 Mon Sep 17 00:00:00 2001
From: Brian Burkhalter <brian.burkhalter@oracle.com>
Date: Fri, 22 Nov 2024 14:06:01 -0800
Subject: [PATCH 1/7] 8344882: (bf) Temporary direct buffers should not count
 against the upper limit on direct buffer memory

---
 .../share/classes/java/nio/Buffer.java        |  5 ++++
 .../java/nio/Direct-X-Buffer.java.template    | 30 ++++++++++++++-----
 .../jdk/internal/access/JavaNioAccess.java    |  5 ++++
 .../share/classes/sun/nio/ch/Util.java        | 12 +++++---
 test/jdk/ProblemList-Virtual.txt              |  3 --
 5 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/src/java.base/share/classes/java/nio/Buffer.java b/src/java.base/share/classes/java/nio/Buffer.java
index 39e0ff642a44a..5eac72274de6e 100644
--- a/src/java.base/share/classes/java/nio/Buffer.java
+++ b/src/java.base/share/classes/java/nio/Buffer.java
@@ -847,6 +847,11 @@ public ByteBuffer newHeapByteBuffer(byte[] hb, int offset, int capacity, MemoryS
                     return new HeapByteBuffer(hb, -1, 0, capacity, capacity, offset, segment);
                 }
 
+                @Override
+                public ByteBuffer allocateDirectTemporary(int cap) {
+                    return new DirectByteBuffer(cap, true);
+                }
+
                 @ForceInline
                 @Override
                 public Object getBufferBase(Buffer buffer) {
diff --git a/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template b/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
index dac9abbf620a6..4476087440800 100644
--- a/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
+++ b/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
@@ -39,7 +39,9 @@ import jdk.internal.misc.ScopedMemoryAccess.ScopedAccessError;
 import jdk.internal.misc.VM;
 import jdk.internal.ref.Cleaner;
 import sun.nio.ch.DirectBuffer;
-
+#if[byte]
+import jdk.internal.vm.annotation.Stable;
+#end[byte]
 
 #if[rw]
 sealed
@@ -72,14 +74,18 @@ class Direct$Type$Buffer$RW$$BO$
     // Cached unaligned-access capability
     static final boolean UNALIGNED = Bits.unaligned();
 
-    private record Deallocator(long address, long size, int capacity) implements Runnable {
+    private @Stable boolean temporary; // defaults to false
+
+    private record Deallocator(long address, long size, int capacity,
+                               boolean temporary) implements Runnable {
         private Deallocator {
             assert address != 0;
         }
 
         public void run() {
             UNSAFE.freeMemory(address);
-            Bits.unreserveMemory(size, capacity);
+            if (!temporary)
+                Bits.unreserveMemory(size, capacity);
         }
     }
 
@@ -99,19 +105,22 @@ class Direct$Type$Buffer$RW$$BO$
 
     // Primary constructor
     //
-    Direct$Type$Buffer$RW$(int cap) {                   // package-private
+    Direct$Type$Buffer$RW$(int cap, boolean temporary) { // package-private
 #if[rw]
         super(-1, 0, cap, cap, null);
+        this.temporary = temporary;
         boolean pa = VM.isDirectMemoryPageAligned();
         int ps = Bits.pageSize();
         long size = Math.max(1L, (long)cap + (pa ? ps : 0));
-        Bits.reserveMemory(size, cap);
+        if (!temporary)
+            Bits.reserveMemory(size, cap);
 
         long base = 0;
         try {
             base = UNSAFE.allocateMemory(size);
         } catch (OutOfMemoryError x) {
-            Bits.unreserveMemory(size, cap);
+            if (!temporary)
+                Bits.unreserveMemory(size, cap);
             throw x;
         }
         UNSAFE.setMemory(base, size, (byte) 0);
@@ -122,11 +131,12 @@ class Direct$Type$Buffer$RW$$BO$
             address = base;
         }
         try {
-            cleaner = Cleaner.create(this, new Deallocator(base, size, cap));
+            cleaner = Cleaner.create(this, new Deallocator(base, size, cap, temporary));
         } catch (Throwable t) {
             // Prevent leak if the Deallocator or Cleaner fail for any reason
             UNSAFE.freeMemory(base);
-            Bits.unreserveMemory(size, cap);
+            if (!temporary)
+                Bits.unreserveMemory(size, cap);
             throw t;
         }
         att = null;
@@ -136,6 +146,10 @@ class Direct$Type$Buffer$RW$$BO$
 #end[rw]
     }
 
+    Direct$Type$Buffer$RW$(int cap) { // package-private
+        this(cap, false);
+    }
+
 #if[rw]
 
     // Invoked to construct a direct ByteBuffer referring to the block of
diff --git a/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java b/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java
index f2d2b7b5b65e6..0faed1808e603 100644
--- a/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java
+++ b/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java
@@ -67,6 +67,11 @@ public interface JavaNioAccess {
      */
     ByteBuffer newHeapByteBuffer(byte[] hb, int offset, int capacity, MemorySegment segment);
 
+    /**
+     * Used by {@code sun.nio.ch.Util}.
+     */
+    ByteBuffer allocateDirectTemporary(int cap);
+
     /**
      * Used by {@code jdk.internal.foreign.Utils}.
      */
diff --git a/src/java.base/share/classes/sun/nio/ch/Util.java b/src/java.base/share/classes/sun/nio/ch/Util.java
index cf411008e43b8..4c57d292b5014 100644
--- a/src/java.base/share/classes/sun/nio/ch/Util.java
+++ b/src/java.base/share/classes/sun/nio/ch/Util.java
@@ -36,11 +36,15 @@
 import java.util.Iterator;
 import java.util.Set;
 
+import jdk.internal.access.JavaNioAccess;
+import jdk.internal.access.SharedSecrets;
 import jdk.internal.misc.TerminatingThreadLocal;
 import jdk.internal.misc.Unsafe;
 
 public class Util {
 
+    private static final JavaNioAccess NIO_ACCESS = SharedSecrets.getJavaNioAccess();
+
     // -- Caches --
 
     // The number of temp buffers in our pool
@@ -221,7 +225,7 @@ public static ByteBuffer getTemporaryDirectBuffer(int size) {
         // to remove the buffer from the cache (as this method does
         // below) given that we won't put the new buffer in the cache.
         if (isBufferTooLarge(size)) {
-            return ByteBuffer.allocateDirect(size);
+            return NIO_ACCESS.allocateDirectTemporary(size);
         }
 
         BufferCache cache = bufferCache.get();
@@ -236,7 +240,7 @@ public static ByteBuffer getTemporaryDirectBuffer(int size) {
                 buf = cache.removeFirst();
                 free(buf);
             }
-            return ByteBuffer.allocateDirect(size);
+            return NIO_ACCESS.allocateDirectTemporary(size);
         }
     }
 
@@ -247,7 +251,7 @@ public static ByteBuffer getTemporaryDirectBuffer(int size) {
     public static ByteBuffer getTemporaryAlignedDirectBuffer(int size,
                                                              int alignment) {
         if (isBufferTooLarge(size)) {
-            return ByteBuffer.allocateDirect(size + alignment - 1)
+            return NIO_ACCESS.allocateDirectTemporary(size + alignment - 1)
                     .alignedSlice(alignment);
         }
 
@@ -263,7 +267,7 @@ public static ByteBuffer getTemporaryAlignedDirectBuffer(int size,
                 free(buf);
             }
         }
-        return ByteBuffer.allocateDirect(size + alignment - 1)
+        return NIO_ACCESS.allocateDirectTemporary(size + alignment - 1)
                 .alignedSlice(alignment);
     }
 
diff --git a/test/jdk/ProblemList-Virtual.txt b/test/jdk/ProblemList-Virtual.txt
index b97e444ab367b..d7692b578cd04 100644
--- a/test/jdk/ProblemList-Virtual.txt
+++ b/test/jdk/ProblemList-Virtual.txt
@@ -69,6 +69,3 @@ java/util/Properties/StoreReproducibilityTest.java 0000000 generic-all
 java/util/Properties/StoreReproducibilityTest.java 0000000 generic-all
 javax/management/ImplementationVersion/ImplVersionTest.java 0000000 generic-all
 javax/management/remote/mandatory/version/ImplVersionTest.java 0000000 generic-all
-
-# Direct buffer memory allocated before test launch
-java/nio/Buffer/LimitDirectMemory.java 8342849 generic-all

From b68ee5f0fca6d11c9c630c0d2cfd8a69d5891018 Mon Sep 17 00:00:00 2001
From: Brian Burkhalter <brian.burkhalter@oracle.com>
Date: Mon, 25 Nov 2024 10:47:56 -0800
Subject: [PATCH 2/7] 8344882: Do not create Cleaner for temporary buffers

---
 .../java/nio/Direct-X-Buffer.java.template    | 24 +++++++++----------
 .../share/classes/sun/nio/ch/Util.java        |  2 +-
 2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template b/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
index 4476087440800..4de087a01df2f 100644
--- a/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
+++ b/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
@@ -76,16 +76,14 @@ class Direct$Type$Buffer$RW$$BO$
 
     private @Stable boolean temporary; // defaults to false
 
-    private record Deallocator(long address, long size, int capacity,
-                               boolean temporary) implements Runnable {
+    private record Deallocator(long address, long size, int capacity) implements Runnable {
         private Deallocator {
             assert address != 0;
         }
 
         public void run() {
             UNSAFE.freeMemory(address);
-            if (!temporary)
-                Bits.unreserveMemory(size, capacity);
+            Bits.unreserveMemory(size, capacity);
         }
     }
 
@@ -130,14 +128,16 @@ class Direct$Type$Buffer$RW$$BO$
         } else {
             address = base;
         }
-        try {
-            cleaner = Cleaner.create(this, new Deallocator(base, size, cap, temporary));
-        } catch (Throwable t) {
-            // Prevent leak if the Deallocator or Cleaner fail for any reason
-            UNSAFE.freeMemory(base);
-            if (!temporary)
-                Bits.unreserveMemory(size, cap);
-            throw t;
+        if (!temporary) {
+            try {
+                cleaner = Cleaner.create(this, new Deallocator(base, size, cap));
+            } catch (Throwable t) {
+                // Prevent leak if the Deallocator or Cleaner fail for any reason
+                UNSAFE.freeMemory(base);
+                throw t;
+            }
+        } else { // temporary
+            cleaner = null;
         }
         att = null;
 #else[rw]
diff --git a/src/java.base/share/classes/sun/nio/ch/Util.java b/src/java.base/share/classes/sun/nio/ch/Util.java
index 4c57d292b5014..10aaa8bc95a0d 100644
--- a/src/java.base/share/classes/sun/nio/ch/Util.java
+++ b/src/java.base/share/classes/sun/nio/ch/Util.java
@@ -325,7 +325,7 @@ static void offerLastTemporaryDirectBuffer(ByteBuffer buf) {
      * Frees the memory for the given direct buffer
      */
     private static void free(ByteBuffer buf) {
-        ((DirectBuffer)buf).cleaner().clean();
+        unsafe.freeMemory(((DirectBuffer)buf).address());
     }
 
 

From 9d84aa9cfd718265c72e26eff9434f8817d25d80 Mon Sep 17 00:00:00 2001
From: Brian Burkhalter <brian.burkhalter@oracle.com>
Date: Mon, 25 Nov 2024 11:17:06 -0800
Subject: [PATCH 3/7] 8344882: Remove DirectBuffer.temporary; rename
 JavaNioAccess temporary direct buffer allocation method

---
 src/java.base/share/classes/java/nio/Buffer.java          | 2 +-
 .../share/classes/java/nio/Direct-X-Buffer.java.template  | 3 ---
 .../share/classes/jdk/internal/access/JavaNioAccess.java  | 2 +-
 src/java.base/share/classes/sun/nio/ch/Util.java          | 8 ++++----
 4 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/src/java.base/share/classes/java/nio/Buffer.java b/src/java.base/share/classes/java/nio/Buffer.java
index 5eac72274de6e..95f9464396cfa 100644
--- a/src/java.base/share/classes/java/nio/Buffer.java
+++ b/src/java.base/share/classes/java/nio/Buffer.java
@@ -848,7 +848,7 @@ public ByteBuffer newHeapByteBuffer(byte[] hb, int offset, int capacity, MemoryS
                 }
 
                 @Override
-                public ByteBuffer allocateDirectTemporary(int cap) {
+                public ByteBuffer allocateTemporaryDirectBuffer(int cap) {
                     return new DirectByteBuffer(cap, true);
                 }
 
diff --git a/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template b/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
index 4de087a01df2f..a370834dd1bc1 100644
--- a/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
+++ b/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
@@ -74,8 +74,6 @@ class Direct$Type$Buffer$RW$$BO$
     // Cached unaligned-access capability
     static final boolean UNALIGNED = Bits.unaligned();
 
-    private @Stable boolean temporary; // defaults to false
-
     private record Deallocator(long address, long size, int capacity) implements Runnable {
         private Deallocator {
             assert address != 0;
@@ -106,7 +104,6 @@ class Direct$Type$Buffer$RW$$BO$
     Direct$Type$Buffer$RW$(int cap, boolean temporary) { // package-private
 #if[rw]
         super(-1, 0, cap, cap, null);
-        this.temporary = temporary;
         boolean pa = VM.isDirectMemoryPageAligned();
         int ps = Bits.pageSize();
         long size = Math.max(1L, (long)cap + (pa ? ps : 0));
diff --git a/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java b/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java
index 0faed1808e603..e526ec91667b6 100644
--- a/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java
+++ b/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java
@@ -70,7 +70,7 @@ public interface JavaNioAccess {
     /**
      * Used by {@code sun.nio.ch.Util}.
      */
-    ByteBuffer allocateDirectTemporary(int cap);
+    ByteBuffer allocateTemporaryDirectBuffer(int cap);
 
     /**
      * Used by {@code jdk.internal.foreign.Utils}.
diff --git a/src/java.base/share/classes/sun/nio/ch/Util.java b/src/java.base/share/classes/sun/nio/ch/Util.java
index 10aaa8bc95a0d..448081e72936c 100644
--- a/src/java.base/share/classes/sun/nio/ch/Util.java
+++ b/src/java.base/share/classes/sun/nio/ch/Util.java
@@ -225,7 +225,7 @@ public static ByteBuffer getTemporaryDirectBuffer(int size) {
         // to remove the buffer from the cache (as this method does
         // below) given that we won't put the new buffer in the cache.
         if (isBufferTooLarge(size)) {
-            return NIO_ACCESS.allocateDirectTemporary(size);
+            return NIO_ACCESS.allocateTemporaryDirectBuffer(size);
         }
 
         BufferCache cache = bufferCache.get();
@@ -240,7 +240,7 @@ public static ByteBuffer getTemporaryDirectBuffer(int size) {
                 buf = cache.removeFirst();
                 free(buf);
             }
-            return NIO_ACCESS.allocateDirectTemporary(size);
+            return NIO_ACCESS.allocateTemporaryDirectBuffer(size);
         }
     }
 
@@ -251,7 +251,7 @@ public static ByteBuffer getTemporaryDirectBuffer(int size) {
     public static ByteBuffer getTemporaryAlignedDirectBuffer(int size,
                                                              int alignment) {
         if (isBufferTooLarge(size)) {
-            return NIO_ACCESS.allocateDirectTemporary(size + alignment - 1)
+            return NIO_ACCESS.allocateTemporaryDirectBuffer(size + alignment - 1)
                     .alignedSlice(alignment);
         }
 
@@ -267,7 +267,7 @@ public static ByteBuffer getTemporaryAlignedDirectBuffer(int size,
                 free(buf);
             }
         }
-        return NIO_ACCESS.allocateDirectTemporary(size + alignment - 1)
+        return NIO_ACCESS.allocateTemporaryDirectBuffer(size + alignment - 1)
                 .alignedSlice(alignment);
     }
 

From 4e4cdbb3887db3df462aed2592b851bb2ddb2f76 Mon Sep 17 00:00:00 2001
From: Brian Burkhalter <brian.burkhalter@oracle.com>
Date: Mon, 25 Nov 2024 11:52:49 -0800
Subject: [PATCH 4/7] 8344882: Remove vestigial import of Stable annotation

---
 .../share/classes/java/nio/Direct-X-Buffer.java.template       | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template b/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
index a370834dd1bc1..846363acdf2ba 100644
--- a/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
+++ b/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
@@ -39,9 +39,6 @@ import jdk.internal.misc.ScopedMemoryAccess.ScopedAccessError;
 import jdk.internal.misc.VM;
 import jdk.internal.ref.Cleaner;
 import sun.nio.ch.DirectBuffer;
-#if[byte]
-import jdk.internal.vm.annotation.Stable;
-#end[byte]
 
 #if[rw]
 sealed

From 1d7588a5144e9b449c8b030a94bba885fa52c1e0 Mon Sep 17 00:00:00 2001
From: Brian Burkhalter <brian.burkhalter@oracle.com>
Date: Tue, 26 Nov 2024 08:35:41 -0800
Subject: [PATCH 5/7] 8344882: Remove local field "temporary" by using an
 alternate constructor

---
 .../share/classes/java/nio/Buffer.java        |  5 +--
 .../java/nio/Direct-X-Buffer.java.template    | 33 ++++++++-----------
 .../jdk/internal/access/JavaNioAccess.java    |  2 +-
 .../share/classes/sun/nio/ch/Util.java        |  8 ++---
 4 files changed, 21 insertions(+), 27 deletions(-)

diff --git a/src/java.base/share/classes/java/nio/Buffer.java b/src/java.base/share/classes/java/nio/Buffer.java
index 95f9464396cfa..c1e37aef35cba 100644
--- a/src/java.base/share/classes/java/nio/Buffer.java
+++ b/src/java.base/share/classes/java/nio/Buffer.java
@@ -848,8 +848,9 @@ public ByteBuffer newHeapByteBuffer(byte[] hb, int offset, int capacity, MemoryS
                 }
 
                 @Override
-                public ByteBuffer allocateTemporaryDirectBuffer(int cap) {
-                    return new DirectByteBuffer(cap, true);
+                public ByteBuffer newDirectByteBuffer(int cap) {
+                    long addr = UNSAFE.allocateMemory(cap);
+                    return new DirectByteBuffer(addr, cap);
                 }
 
                 @ForceInline
diff --git a/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template b/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
index 846363acdf2ba..0da1dc66a9a37 100644
--- a/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
+++ b/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
@@ -40,6 +40,7 @@ import jdk.internal.misc.VM;
 import jdk.internal.ref.Cleaner;
 import sun.nio.ch.DirectBuffer;
 
+
 #if[rw]
 sealed
 #else[rw]
@@ -98,21 +99,19 @@ class Direct$Type$Buffer$RW$$BO$
 
     // Primary constructor
     //
-    Direct$Type$Buffer$RW$(int cap, boolean temporary) { // package-private
+    Direct$Type$Buffer$RW$(int cap) {                   // package-private
 #if[rw]
         super(-1, 0, cap, cap, null);
         boolean pa = VM.isDirectMemoryPageAligned();
         int ps = Bits.pageSize();
         long size = Math.max(1L, (long)cap + (pa ? ps : 0));
-        if (!temporary)
-            Bits.reserveMemory(size, cap);
+        Bits.reserveMemory(size, cap);
 
         long base = 0;
         try {
             base = UNSAFE.allocateMemory(size);
         } catch (OutOfMemoryError x) {
-            if (!temporary)
-                Bits.unreserveMemory(size, cap);
+            Bits.unreserveMemory(size, cap);
             throw x;
         }
         UNSAFE.setMemory(base, size, (byte) 0);
@@ -122,16 +121,13 @@ class Direct$Type$Buffer$RW$$BO$
         } else {
             address = base;
         }
-        if (!temporary) {
-            try {
-                cleaner = Cleaner.create(this, new Deallocator(base, size, cap));
-            } catch (Throwable t) {
-                // Prevent leak if the Deallocator or Cleaner fail for any reason
-                UNSAFE.freeMemory(base);
-                throw t;
-            }
-        } else { // temporary
-            cleaner = null;
+        try {
+            cleaner = Cleaner.create(this, new Deallocator(base, size, cap));
+        } catch (Throwable t) {
+            // Prevent leak if the Deallocator or Cleaner fail for any reason
+            UNSAFE.freeMemory(base);
+            Bits.unreserveMemory(size, cap);
+            throw t;
         }
         att = null;
 #else[rw]
@@ -140,10 +136,6 @@ class Direct$Type$Buffer$RW$$BO$
 #end[rw]
     }
 
-    Direct$Type$Buffer$RW$(int cap) { // package-private
-        this(cap, false);
-    }
-
 #if[rw]
 
     // Invoked to construct a direct ByteBuffer referring to the block of
@@ -167,9 +159,10 @@ class Direct$Type$Buffer$RW$$BO$
     }
 
     // Invoked only by JNI: NewDirectByteBuffer(void*, long)
+    // and JavaNioAccess.newDirectByteBuffer(int).
     // The long-valued capacity is restricted to int range.
     //
-    private Direct$Type$Buffer(long addr, long cap) {
+    Direct$Type$Buffer(long addr, long cap) {
         super(-1, 0, checkCapacity(cap), (int)cap, null);
         address = addr;
         cleaner = null;
diff --git a/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java b/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java
index e526ec91667b6..e1668b4dec8f5 100644
--- a/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java
+++ b/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java
@@ -70,7 +70,7 @@ public interface JavaNioAccess {
     /**
      * Used by {@code sun.nio.ch.Util}.
      */
-    ByteBuffer allocateTemporaryDirectBuffer(int cap);
+    ByteBuffer newDirectByteBuffer(int cap);
 
     /**
      * Used by {@code jdk.internal.foreign.Utils}.
diff --git a/src/java.base/share/classes/sun/nio/ch/Util.java b/src/java.base/share/classes/sun/nio/ch/Util.java
index 448081e72936c..719ae1c8e1e04 100644
--- a/src/java.base/share/classes/sun/nio/ch/Util.java
+++ b/src/java.base/share/classes/sun/nio/ch/Util.java
@@ -225,7 +225,7 @@ public static ByteBuffer getTemporaryDirectBuffer(int size) {
         // to remove the buffer from the cache (as this method does
         // below) given that we won't put the new buffer in the cache.
         if (isBufferTooLarge(size)) {
-            return NIO_ACCESS.allocateTemporaryDirectBuffer(size);
+            return NIO_ACCESS.newDirectByteBuffer(size);
         }
 
         BufferCache cache = bufferCache.get();
@@ -240,7 +240,7 @@ public static ByteBuffer getTemporaryDirectBuffer(int size) {
                 buf = cache.removeFirst();
                 free(buf);
             }
-            return NIO_ACCESS.allocateTemporaryDirectBuffer(size);
+            return NIO_ACCESS.newDirectByteBuffer(size);
         }
     }
 
@@ -251,7 +251,7 @@ public static ByteBuffer getTemporaryDirectBuffer(int size) {
     public static ByteBuffer getTemporaryAlignedDirectBuffer(int size,
                                                              int alignment) {
         if (isBufferTooLarge(size)) {
-            return NIO_ACCESS.allocateTemporaryDirectBuffer(size + alignment - 1)
+            return NIO_ACCESS.newDirectByteBuffer(size + alignment - 1)
                     .alignedSlice(alignment);
         }
 
@@ -267,7 +267,7 @@ public static ByteBuffer getTemporaryAlignedDirectBuffer(int size,
                 free(buf);
             }
         }
-        return NIO_ACCESS.allocateTemporaryDirectBuffer(size + alignment - 1)
+        return NIO_ACCESS.newDirectByteBuffer(size + alignment - 1)
                 .alignedSlice(alignment);
     }
 

From c27de5a36d4dbf9d57b26a3b910a0409654e8858 Mon Sep 17 00:00:00 2001
From: Brian Burkhalter <brian.burkhalter@oracle.com>
Date: Tue, 26 Nov 2024 08:55:55 -0800
Subject: [PATCH 6/7] 8344882: Make allocate+free be only in Util

---
 src/java.base/share/classes/java/nio/Buffer.java   |  3 +--
 .../classes/jdk/internal/access/JavaNioAccess.java |  2 +-
 src/java.base/share/classes/sun/nio/ch/Util.java   | 14 ++++++++------
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/src/java.base/share/classes/java/nio/Buffer.java b/src/java.base/share/classes/java/nio/Buffer.java
index c1e37aef35cba..c0c2cfe80e7f0 100644
--- a/src/java.base/share/classes/java/nio/Buffer.java
+++ b/src/java.base/share/classes/java/nio/Buffer.java
@@ -848,8 +848,7 @@ public ByteBuffer newHeapByteBuffer(byte[] hb, int offset, int capacity, MemoryS
                 }
 
                 @Override
-                public ByteBuffer newDirectByteBuffer(int cap) {
-                    long addr = UNSAFE.allocateMemory(cap);
+                public ByteBuffer newDirectByteBuffer(long addr, int cap) {
                     return new DirectByteBuffer(addr, cap);
                 }
 
diff --git a/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java b/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java
index e1668b4dec8f5..431ffbdab5378 100644
--- a/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java
+++ b/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java
@@ -70,7 +70,7 @@ public interface JavaNioAccess {
     /**
      * Used by {@code sun.nio.ch.Util}.
      */
-    ByteBuffer newDirectByteBuffer(int cap);
+    ByteBuffer newDirectByteBuffer(long addr, int cap);
 
     /**
      * Used by {@code jdk.internal.foreign.Utils}.
diff --git a/src/java.base/share/classes/sun/nio/ch/Util.java b/src/java.base/share/classes/sun/nio/ch/Util.java
index 719ae1c8e1e04..7736db11eede0 100644
--- a/src/java.base/share/classes/sun/nio/ch/Util.java
+++ b/src/java.base/share/classes/sun/nio/ch/Util.java
@@ -225,7 +225,8 @@ public static ByteBuffer getTemporaryDirectBuffer(int size) {
         // to remove the buffer from the cache (as this method does
         // below) given that we won't put the new buffer in the cache.
         if (isBufferTooLarge(size)) {
-            return NIO_ACCESS.newDirectByteBuffer(size);
+            long addr = unsafe.allocateMemory(size);
+            return NIO_ACCESS.newDirectByteBuffer(addr, size);
         }
 
         BufferCache cache = bufferCache.get();
@@ -240,7 +241,8 @@ public static ByteBuffer getTemporaryDirectBuffer(int size) {
                 buf = cache.removeFirst();
                 free(buf);
             }
-            return NIO_ACCESS.newDirectByteBuffer(size);
+            long addr = unsafe.allocateMemory(size);
+            return NIO_ACCESS.newDirectByteBuffer(addr, size);
         }
     }
 
@@ -251,8 +253,8 @@ public static ByteBuffer getTemporaryDirectBuffer(int size) {
     public static ByteBuffer getTemporaryAlignedDirectBuffer(int size,
                                                              int alignment) {
         if (isBufferTooLarge(size)) {
-            return NIO_ACCESS.newDirectByteBuffer(size + alignment - 1)
-                    .alignedSlice(alignment);
+            return getTemporaryDirectBuffer(size + alignment - 1)
+                .alignedSlice(alignment);
         }
 
         BufferCache cache = bufferCache.get();
@@ -267,8 +269,8 @@ public static ByteBuffer getTemporaryAlignedDirectBuffer(int size,
                 free(buf);
             }
         }
-        return NIO_ACCESS.newDirectByteBuffer(size + alignment - 1)
-                .alignedSlice(alignment);
+        return getTemporaryDirectBuffer(size + alignment - 1)
+            .alignedSlice(alignment);
     }
 
     /**

From 80d6551dcfd071dd6f86c4224f2d2be544735426 Mon Sep 17 00:00:00 2001
From: Brian Burkhalter <brian.burkhalter@oracle.com>
Date: Tue, 26 Nov 2024 10:48:19 -0800
Subject: [PATCH 7/7] 8344882: If the buffer is a slice, free it's parent's
 address

---
 src/java.base/share/classes/sun/nio/ch/Util.java | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/java.base/share/classes/sun/nio/ch/Util.java b/src/java.base/share/classes/sun/nio/ch/Util.java
index 7736db11eede0..24f1ee7d76901 100644
--- a/src/java.base/share/classes/sun/nio/ch/Util.java
+++ b/src/java.base/share/classes/sun/nio/ch/Util.java
@@ -280,12 +280,23 @@ public static void releaseTemporaryDirectBuffer(ByteBuffer buf) {
         offerFirstTemporaryDirectBuffer(buf);
     }
 
+    /**
+     * Return the underling byte buffer if the given byte buffer is
+     * an aligned slice.
+     */
+    private static ByteBuffer unwrapIfAlignedSlice(ByteBuffer buf) {
+        var parent = (ByteBuffer) ((DirectBuffer) buf).attachment();
+        return (parent != null) ? parent : buf;
+    }
+
     /**
      * Releases a temporary buffer by returning to the cache or freeing it. If
      * returning to the cache then insert it at the start so that it is
      * likely to be returned by a subsequent call to getTemporaryDirectBuffer.
      */
     static void offerFirstTemporaryDirectBuffer(ByteBuffer buf) {
+        buf = unwrapIfAlignedSlice(buf);
+
         // If the buffer is too large for the cache we don't have to
         // check the cache. We'll just free it.
         if (isBufferTooLarge(buf)) {
@@ -308,6 +319,8 @@ static void offerFirstTemporaryDirectBuffer(ByteBuffer buf) {
      * cache in same order that they were obtained.
      */
     static void offerLastTemporaryDirectBuffer(ByteBuffer buf) {
+        buf = unwrapIfAlignedSlice(buf);
+
         // If the buffer is too large for the cache we don't have to
         // check the cache. We'll just free it.
         if (isBufferTooLarge(buf)) {