# HG changeset patch
# User bpb
# Date 1552500742 25200
# Node ID 1d7aec80147a6d92b101a76aef92f3ddc88bedf4
# Parent  9a90236ab64c34aefddc5335e31e75ebcbfc793e
8219597: (bf) Heap buffer state changes could provoke unexpected exceptions
Reviewed-by: alanb, rriggs

diff -r 9a90236ab64c -r 1d7aec80147a src/java.base/share/classes/java/nio/Heap-X-Buffer.java.template
--- a/src/java.base/share/classes/java/nio/Heap-X-Buffer.java.template	Wed Mar 13 14:10:18 2019 -0400
+++ b/src/java.base/share/classes/java/nio/Heap-X-Buffer.java.template	Wed Mar 13 11:12:22 2019 -0700
@@ -104,11 +104,12 @@
     }
 
     public $Type$Buffer slice() {
+        int rem = this.remaining();
         return new Heap$Type$Buffer$RW$(hb,
                                         -1,
                                         0,
-                                        this.remaining(),
-                                        this.remaining(),
+                                        rem,
+                                        rem,
                                         this.position() + offset);
     }
 
@@ -174,10 +175,11 @@
 
     public $Type$Buffer get($type$[] dst, int offset, int length) {
         checkBounds(offset, length, dst.length);
-        if (length > remaining())
+        int pos = position();
+        if (length > limit() - pos)
             throw new BufferUnderflowException();
-        System.arraycopy(hb, ix(position()), dst, offset, length);
-        position(position() + length);
+        System.arraycopy(hb, ix(pos), dst, offset, length);
+        position(pos + length);
         return this;
     }
 
@@ -219,10 +221,11 @@
     public $Type$Buffer put($type$[] src, int offset, int length) {
 #if[rw]
         checkBounds(offset, length, src.length);
-        if (length > remaining())
+        int pos = position();
+        if (length > limit() - pos)
             throw new BufferOverflowException();
-        System.arraycopy(src, offset, hb, ix(position()), length);
-        position(position() + length);
+        System.arraycopy(src, offset, hb, ix(pos), length);
+        position(pos + length);
         return this;
 #else[rw]
         throw new ReadOnlyBufferException();
@@ -235,19 +238,22 @@
             if (src == this)
                 throw createSameBufferException();
             Heap$Type$Buffer sb = (Heap$Type$Buffer)src;
-            int n = sb.remaining();
-            if (n > remaining())
+            int pos = position();
+            int sbpos = sb.position();
+            int n = sb.limit() - sbpos;
+            if (n > limit() - pos)
                 throw new BufferOverflowException();
-            System.arraycopy(sb.hb, sb.ix(sb.position()),
-                             hb, ix(position()), n);
-            sb.position(sb.position() + n);
-            position(position() + n);
+            System.arraycopy(sb.hb, sb.ix(sbpos),
+                             hb, ix(pos), n);
+            sb.position(sbpos + n);
+            position(pos + n);
         } else if (src.isDirect()) {
             int n = src.remaining();
-            if (n > remaining())
+            int pos = position();
+            if (n > limit() - pos)
                 throw new BufferOverflowException();
-            src.get(hb, ix(position()), n);
-            position(position() + n);
+            src.get(hb, ix(pos), n);
+            position(pos + n);
         } else {
             super.put(src);
         }
@@ -289,8 +295,10 @@
 
     public $Type$Buffer compact() {
 #if[rw]
-        System.arraycopy(hb, ix(position()), hb, ix(0), remaining());
-        position(remaining());
+        int pos = position();
+        int rem = limit() - pos;
+        System.arraycopy(hb, ix(pos), hb, ix(0), rem);
+        position(rem);
         limit(capacity());
         discardMark();
         return this;
@@ -348,8 +356,9 @@
     }
 
     public CharBuffer asCharBuffer() {
-        int size = this.remaining() >> 1;
-        long addr = address + position();
+        int pos = position();
+        int size = (limit() - pos) >> 1;
+        long addr = address + pos;
         return (bigEndian
                 ? (CharBuffer)(new ByteBufferAsCharBuffer$RW$B(this,
                                                                -1,
@@ -399,8 +408,9 @@
     }
 
     public ShortBuffer asShortBuffer() {
-        int size = this.remaining() >> 1;
-        long addr = address + position();
+        int pos = position();
+        int size = (limit() - pos) >> 1;
+        long addr = address + pos;
         return (bigEndian
                 ? (ShortBuffer)(new ByteBufferAsShortBuffer$RW$B(this,
                                                                  -1,
@@ -450,8 +460,9 @@
     }
 
     public IntBuffer asIntBuffer() {
-        int size = this.remaining() >> 2;
-        long addr = address + position();
+        int pos = position();
+        int size = (limit() - pos) >> 2;
+        long addr = address + pos;
         return (bigEndian
                 ? (IntBuffer)(new ByteBufferAsIntBuffer$RW$B(this,
                                                              -1,
@@ -501,8 +512,9 @@
     }
 
     public LongBuffer asLongBuffer() {
-        int size = this.remaining() >> 3;
-        long addr = address + position();
+        int pos = position();
+        int size = (limit() - pos) >> 3;
+        long addr = address + pos;
         return (bigEndian
                 ? (LongBuffer)(new ByteBufferAsLongBuffer$RW$B(this,
                                                                -1,
@@ -556,8 +568,9 @@
     }
 
     public FloatBuffer asFloatBuffer() {
-        int size = this.remaining() >> 2;
-        long addr = address + position();
+        int pos = position();
+        int size = (limit() - pos) >> 2;
+        long addr = address + pos;
         return (bigEndian
                 ? (FloatBuffer)(new ByteBufferAsFloatBuffer$RW$B(this,
                                                                  -1,
@@ -611,8 +624,9 @@
     }
 
     public DoubleBuffer asDoubleBuffer() {
-        int size = this.remaining() >> 3;
-        long addr = address + position();
+        int pos = position();
+        int size = (limit() - pos) >> 3;
+        long addr = address + pos;
         return (bigEndian
                 ? (DoubleBuffer)(new ByteBufferAsDoubleBuffer$RW$B(this,
                                                                    -1,