Author: mturk
Date: Fri Apr 24 09:24:37 2009
New Revision: 768233
URL: http://svn.apache.org/viewvc?rev=768233&view=rev
Log:
Add null Pointer Memory.malloc
Modified:
commons/sandbox/runtime/trunk/src/main/java/org/apache/commons/runtime/Memory.java
commons/sandbox/runtime/trunk/src/main/native/shared/memory.c
commons/sandbox/runtime/trunk/src/test/org/apache/commons/runtime/TestMemory.java
Modified:
commons/sandbox/runtime/trunk/src/main/java/org/apache/commons/runtime/Memory.java
URL:
http://svn.apache.org/viewvc/commons/sandbox/runtime/trunk/src/main/java/org/apache/commons/runtime/Memory.java?rev=768233&r1=768232&r2=768233&view=diff
==============================================================================
---
commons/sandbox/runtime/trunk/src/main/java/org/apache/commons/runtime/Memory.java
(original)
+++
commons/sandbox/runtime/trunk/src/main/java/org/apache/commons/runtime/Memory.java
Fri Apr 24 09:24:37 2009
@@ -32,6 +32,70 @@
// No Instance
}
+ private static native Pointer nullp0();
+
+ /**
+ * Create a new {...@code null Pointer}.
+ *
+ * <p>
+ * Creating new {...@code null} pointers make sense only for
+ * using that object as a reference for methods that
+ * require a {...@code Pointer} whose size is unknown at the
+ * time of the call. The method will usually fill the pointer
+ * with the valid memory block area. A typical usage of such
+ * a {code Pointer} can be explained as this:
+ * <pre>
+ *
+ * void *pointer;
+ *
+ * int method(void **pointer, int size)
+ * {
+ * *pointer = malloc(size + something);
+ * return something;
+ * }
+ *
+ * ...
+ *
+ * free(pointer);
+ *
+ * </pre>
+ * The example code uses {...@code by-reference} concept to fill in
+ * the provided {...@code pointer} with the value unknown at the time
+ * {...@code pointer} was declared.
+ * </p>
+ * <p>
+ * Typical usage in Java code would be as follows:
+ * <pre>
+ *
+ * Pointer ptr = Memory.malloc();
+ *
+ * DirectByteBuffer b = DirectByteBuffer.allocate(ptr, size);
+ *
+ * ...
+ *
+ * ptr.free();
+ *
+ * </pre>
+ * The newly created {...@code DirectyByteBuffer} holds the memory
+ * area pointed by {...@code Pointer} object and {...@code Pointer}
+ * object holds a native pointer to a physical memory area location.
+ * When done the memory should be released by calling
+ * {...@code ptr.free()}.
+ * </p>
+ *
+ * @return {...@code null} pointer.
+ * @throws OutOfMemoryError if memory cannot be allocated.
+ */
+ public static Pointer malloc()
+ throws OutOfMemoryError
+ {
+ Pointer p = nullp0();
+ if (p == null)
+ throw new OutOfMemoryError("Memory alloc failed");
+ return p;
+ }
+
+
/**
* Allocates {...@code size} bytes and returns a {...@link Pointer}
* to the allocated memory. The memory is not cleared.
Modified: commons/sandbox/runtime/trunk/src/main/native/shared/memory.c
URL:
http://svn.apache.org/viewvc/commons/sandbox/runtime/trunk/src/main/native/shared/memory.c?rev=768233&r1=768232&r2=768233&view=diff
==============================================================================
--- commons/sandbox/runtime/trunk/src/main/native/shared/memory.c (original)
+++ commons/sandbox/runtime/trunk/src/main/native/shared/memory.c Fri Apr 24
09:24:37 2009
@@ -247,6 +247,12 @@
}
}
+ACR_JNI_EXPORT_DECLARE(jobject, Memory, nullp0)(ACR_JNISTDARGS)
+{
+ UNREFERENCED_O;
+ return ACR_PointerCreate(_E, NULL, 0, ptr_cleanup);
+}
+
ACR_JNI_EXPORT_DECLARE(jobject, Memory, malloc)(ACR_JNISTDARGS, jlong siz)
{
jobject ptr = NULL;
Modified:
commons/sandbox/runtime/trunk/src/test/org/apache/commons/runtime/TestMemory.java
URL:
http://svn.apache.org/viewvc/commons/sandbox/runtime/trunk/src/test/org/apache/commons/runtime/TestMemory.java?rev=768233&r1=768232&r2=768233&view=diff
==============================================================================
---
commons/sandbox/runtime/trunk/src/test/org/apache/commons/runtime/TestMemory.java
(original)
+++
commons/sandbox/runtime/trunk/src/test/org/apache/commons/runtime/TestMemory.java
Fri Apr 24 09:24:37 2009
@@ -41,6 +41,22 @@
}
+
+ public void testNull()
+ throws Throwable
+ {
+ Pointer p = Memory.malloc();
+ assertNotNull("Pointer", p);
+ assertTrue("Not null", p.IsNull());
+ try {
+ p.free();
+ fail("Not RuntimeException");
+ } catch (RuntimeException ex) {
+ // calling free() in null Pointer
+ // throws RuntimeException
+ }
+ }
+
public void testMalloc()
throws Throwable
{
@@ -185,7 +201,7 @@
p.free();
}
- public void testNull()
+ public void testPointerNull()
throws Throwable
{
assertTrue("Not null", Pointer.NULL.IsNull());
