--- a/hotspot/src/share/vm/prims/whitebox.cpp Tue May 21 16:17:51 2013 -0700
+++ b/hotspot/src/share/vm/prims/whitebox.cpp Tue May 21 19:52:01 2013 -0700
@@ -37,6 +37,7 @@
#include "runtime/os.hpp"
#include "utilities/debug.hpp"
#include "utilities/macros.hpp"
+#include "utilities/exceptions.hpp"
#if INCLUDE_ALL_GCS
#include "gc_implementation/g1/concurrentMark.hpp"
@@ -330,8 +331,18 @@
WB_END
-WB_ENTRY(jlong, WB_ReserveMemory(JNIEnv* env, jobject o, jlong size))
- return (jlong)os::reserve_memory(size, NULL, 0);
+WB_ENTRY(void, WB_ReadReservedMemory(JNIEnv* env, jobject o))
+ // static+volatile in order to force the read to happen
+ // (not be eliminated by the compiler)
+ static char c;
+ static volatile char* p;
+
+ p = os::reserve_memory(os::vm_allocation_granularity(), NULL, 0);
+ if (p == NULL) {
+ THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), "Failed to reserve memory");
+ }
+
+ c = *p;
WB_END
//Some convenience methods to deal with objects from java
@@ -437,7 +448,7 @@
{CC"isInStringTable", CC"(Ljava/lang/String;)Z", (void*)&WB_IsInStringTable },
{CC"fullGC", CC"()V", (void*)&WB_FullGC },
- {CC"reserveMemory", CC"(J)J", (void*)&WB_ReserveMemory },
+ {CC"readReservedMemory", CC"()V", (void*)&WB_ReadReservedMemory },
};
#undef CC
--- a/hotspot/test/runtime/memory/ReserveMemory.java Tue May 21 16:17:51 2013 -0700
+++ b/hotspot/test/runtime/memory/ReserveMemory.java Tue May 21 19:52:01 2013 -0700
@@ -34,29 +34,20 @@
import com.oracle.java.testlibrary.*;
-import java.lang.reflect.Field;
import sun.hotspot.WhiteBox;
-import sun.misc.Unsafe;
public class ReserveMemory {
- private static Unsafe getUnsafe() throws Exception {
- Field f = Unsafe.class.getDeclaredField("theUnsafe");
- f.setAccessible(true);
- return (Unsafe)f.get(null);
- }
-
private static boolean isWindows() {
return System.getProperty("os.name").toLowerCase().startsWith("win");
}
+ private static boolean isOsx() {
+ return System.getProperty("os.name").toLowerCase().startsWith("mac");
+ }
+
public static void main(String args[]) throws Exception {
if (args.length > 0) {
- long address = WhiteBox.getWhiteBox().reserveMemory(4096);
-
- System.out.println("Reserved memory at address: 0x" + Long.toHexString(address));
- System.out.println("Will now read from the address, expecting a crash!");
-
- int x = getUnsafe().getInt(address);
+ WhiteBox.getWhiteBox().readReservedMemory();
throw new Exception("Read of reserved/uncommitted memory unexpectedly succeeded, expected crash!");
}
@@ -71,6 +62,8 @@
OutputAnalyzer output = new OutputAnalyzer(pb.start());
if (isWindows()) {
output.shouldContain("EXCEPTION_ACCESS_VIOLATION");
+ } else if (isOsx()) {
+ output.shouldContain("SIGBUS");
} else {
output.shouldContain("SIGSEGV");
}
--- a/hotspot/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java Tue May 21 16:17:51 2013 -0700
+++ b/hotspot/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java Tue May 21 19:52:01 2013 -0700
@@ -115,7 +115,7 @@
public native boolean isInStringTable(String str);
// Memory
- public native long reserveMemory(long size);
+ public native void readReservedMemory();
// force Full GC
public native void fullGC();