8053995: Add method to WhiteBox to get vm pagesize.
Summary: Unsafe is not recommended and may deprecated in future. Added a WhiteBox API to get VM page size.
Reviewed-by: dholmes, ccheung, mseledtsov
Contributed-by: yumin.qi@oracle.com
--- a/hotspot/src/share/vm/prims/whitebox.cpp Tue Nov 25 14:16:32 2014 +0300
+++ b/hotspot/src/share/vm/prims/whitebox.cpp Wed Nov 26 10:32:21 2014 -0800
@@ -82,6 +82,9 @@
return heapOopSize;
WB_END
+WB_ENTRY(jint, WB_GetVMPageSize(JNIEnv* env, jobject o))
+ return os::vm_page_size();
+WB_END
class WBIsKlassAliveClosure : public KlassClosure {
Symbol* _name;
@@ -1121,6 +1124,7 @@
{CC"getObjectSize", CC"(Ljava/lang/Object;)J", (void*)&WB_GetObjectSize },
{CC"isObjectInOldGen", CC"(Ljava/lang/Object;)Z", (void*)&WB_isObjectInOldGen },
{CC"getHeapOopSize", CC"()I", (void*)&WB_GetHeapOopSize },
+ {CC"getVMPageSize", CC"()I", (void*)&WB_GetVMPageSize },
{CC"isClassAlive0", CC"(Ljava/lang/String;)Z", (void*)&WB_IsClassAlive },
{CC"parseCommandLine",
CC"(Ljava/lang/String;[Lsun/hotspot/parser/DiagnosticCommand;)[Ljava/lang/Object;",
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/memory/ReadVMPageSize.java Wed Nov 26 10:32:21 2014 -0800
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @summary Using WhiteBox to get VM page size
+ * @library /testlibrary /testlibrary/whitebox
+ * @build ReadVMPageSize
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI ReadVMPageSize
+ */
+
+import com.oracle.java.testlibrary.*;
+import sun.hotspot.WhiteBox;
+
+public class ReadVMPageSize {
+ public static void main(String args[]) throws Exception {
+ WhiteBox wb = WhiteBox.getWhiteBox();
+ int pageSize = wb.getVMPageSize();
+ if (pageSize < 0) {
+ throw new Exception("pageSize < 0");
+ } else {
+ System.out.println("Page size = " + pageSize);
+ }
+ }
+}
--- a/hotspot/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java Tue Nov 25 14:16:32 2014 +0300
+++ b/hotspot/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java Wed Nov 26 10:32:21 2014 -0800
@@ -74,6 +74,7 @@
// Memory
public native long getObjectAddress(Object o);
public native int getHeapOopSize();
+ public native int getVMPageSize();
public native boolean isObjectInOldGen(Object o);
public native long getObjectSize(Object o);