1 /*
   2  * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 
  27 #include "jni.h"
  28 
  29 #include "memory/universe.hpp"
  30 #include "oops/oop.inline.hpp"
  31 #include "prims/whitebox.hpp"
  32 #include "runtime/interfaceSupport.hpp"
  33 #include "runtime/os.hpp"
  34 #include "utilities/debug.hpp"
  35 
  36 #ifndef SERIALGC
  37 #include "gc_implementation/g1/concurrentMark.hpp"
  38 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  39 #include "gc_implementation/g1/heapRegionRemSet.hpp"
  40 #endif // !SERIALGC
  41 
  42 bool WhiteBox::_used = false;
  43 
  44 // Entry macro to transition from JNI to VM state.
  45 
  46 #define WB_ENTRY(result_type, header) JNI_ENTRY(result_type, header)
  47 #define WB_END JNI_END
  48 
  49 // Definitions of functions exposed via Whitebox API
  50 
  51 WB_ENTRY(jlong, WB_GetObjectAddress(JNIEnv* env, jobject o, jobject obj))
  52   return (jlong)(void*)JNIHandles::resolve(obj);
  53 WB_END
  54 
  55 WB_ENTRY(jint, WB_GetHeapOopSize(JNIEnv* env, jobject o))
  56   return heapOopSize;
  57 WB_END
  58 
  59 #ifndef SERIALGC
  60 WB_ENTRY(jboolean, WB_G1IsHumongous(JNIEnv* env, jobject o, jobject obj))
  61   G1CollectedHeap* g1 = G1CollectedHeap::heap();
  62   oop result = JNIHandles::resolve(obj);
  63   const HeapRegion* hr = g1->heap_region_containing(result);
  64   return hr->isHumongous();
  65 WB_END
  66 
  67 WB_ENTRY(jlong, WB_G1NumFreeRegions(JNIEnv* env, jobject o))
  68   G1CollectedHeap* g1 = G1CollectedHeap::heap();
  69   size_t nr = g1->free_regions();
  70   return (jlong)nr;
  71 WB_END
  72 
  73 WB_ENTRY(jboolean, WB_G1InConcurrentMark(JNIEnv* env, jobject o))
  74   G1CollectedHeap* g1 = G1CollectedHeap::heap();
  75   ConcurrentMark* cm = g1->concurrent_mark();
  76   return cm->concurrent_marking_in_progress();
  77 WB_END
  78 
  79 WB_ENTRY(jint, WB_G1RegionSize(JNIEnv* env, jobject o))
  80   return (jint)HeapRegion::GrainBytes;
  81 WB_END
  82 #endif // !SERIALGC
  83 
  84 #define CC (char*)
  85 
  86 static JNINativeMethod methods[] = {
  87   {CC"getObjectAddress",   CC"(Ljava/lang/Object;)J", (void*)&WB_GetObjectAddress  },
  88   {CC"getHeapOopSize",     CC"()I",                   (void*)&WB_GetHeapOopSize    },
  89 #ifndef SERIALGC
  90   {CC"g1InConcurrentMark", CC"()Z",                   (void*)&WB_G1InConcurrentMark},
  91   {CC"g1IsHumongous",      CC"(Ljava/lang/Object;)Z", (void*)&WB_G1IsHumongous     },
  92   {CC"g1NumFreeRegions",   CC"()J",                   (void*)&WB_G1NumFreeRegions  },
  93   {CC"g1RegionSize",       CC"()I",                   (void*)&WB_G1RegionSize      },
  94 #endif // !SERIALGC
  95 };
  96 
  97 #undef CC
  98 
  99 JVM_ENTRY(void, JVM_RegisterWhiteBoxMethods(JNIEnv* env, jclass wbclass))
 100   {
 101     if (WhiteBoxAPI) {
 102       // Make sure that wbclass is loaded by the null classloader
 103       instanceKlassHandle ikh = instanceKlassHandle(JNIHandles::resolve(wbclass)->klass());
 104       Handle loader(ikh->class_loader());
 105       if (loader.is_null()) {
 106         ThreadToNativeFromVM ttnfv(thread); // can't be in VM when we call JNI
 107         jint result = env->RegisterNatives(wbclass, methods, sizeof(methods)/sizeof(methods[0]));
 108         if (result == 0) {
 109           WhiteBox::set_used();
 110         }
 111       }
 112     }
 113   }
 114 JVM_END