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 "memory/universe.hpp"
  28 #include "oops/oop.inline.hpp"
  29 
  30 #include "classfile/symbolTable.hpp"
  31 
  32 #include "prims/whitebox.hpp"
  33 #include "prims/wbtestmethods/parserTests.hpp"
  34 
  35 #include "runtime/interfaceSupport.hpp"
  36 #include "runtime/os.hpp"
  37 #include "utilities/debug.hpp"
  38 
  39 #ifndef SERIALGC
  40 #include "gc_implementation/g1/concurrentMark.hpp"
  41 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  42 #include "gc_implementation/g1/heapRegionRemSet.hpp"
  43 #endif // !SERIALGC
  44 
  45 bool WhiteBox::_used = false;
  46 
  47 WB_ENTRY(jlong, WB_GetObjectAddress(JNIEnv* env, jobject o, jobject obj))
  48   return (jlong)(void*)JNIHandles::resolve(obj);
  49 WB_END
  50 
  51 WB_ENTRY(jint, WB_GetHeapOopSize(JNIEnv* env, jobject o))
  52   return heapOopSize;
  53 WB_END
  54 
  55 #ifndef SERIALGC
  56 WB_ENTRY(jboolean, WB_G1IsHumongous(JNIEnv* env, jobject o, jobject obj))
  57   G1CollectedHeap* g1 = G1CollectedHeap::heap();
  58   oop result = JNIHandles::resolve(obj);
  59   const HeapRegion* hr = g1->heap_region_containing(result);
  60   return hr->isHumongous();
  61 WB_END
  62 
  63 WB_ENTRY(jlong, WB_G1NumFreeRegions(JNIEnv* env, jobject o))
  64   G1CollectedHeap* g1 = G1CollectedHeap::heap();
  65   size_t nr = g1->free_regions();
  66   return (jlong)nr;
  67 WB_END
  68 
  69 WB_ENTRY(jboolean, WB_G1InConcurrentMark(JNIEnv* env, jobject o))
  70   G1CollectedHeap* g1 = G1CollectedHeap::heap();
  71   ConcurrentMark* cm = g1->concurrent_mark();
  72   return cm->concurrent_marking_in_progress();
  73 WB_END
  74 
  75 WB_ENTRY(jint, WB_G1RegionSize(JNIEnv* env, jobject o))
  76   return (jint)HeapRegion::GrainBytes;
  77 WB_END
  78 #endif // !SERIALGC
  79 
  80 //Some convenience methods to deal with objects from java
  81 int WhiteBox::offset_for_field(const char* field_name, oop object,
  82     Symbol* signature_symbol)
  83 {
  84   assert(field_name != NULL && strlen(field_name) > 0, "Field name not valid");
  85   Thread* THREAD = Thread::current();
  86 
  87   //Get the class of our object
  88   klassOop arg_klass = object->klass();
  89   //Turn it into an instance-klass
  90   instanceKlass* ik = instanceKlass::cast(arg_klass);
  91 
  92   //Create symbols to look for in the class
  93   TempNewSymbol name_symbol = SymbolTable::lookup(field_name, (int) strlen(field_name),
  94       THREAD);
  95 
  96   //To be filled in with an offset of the field we're looking for
  97   fieldDescriptor fd;
  98 
  99   klassOop res = ik->find_field(name_symbol, signature_symbol, &fd);
 100   if (res == NULL)
 101   {
 102     tty->print_cr("Invalid layout of %s at %s", ik->external_name(),
 103         name_symbol->as_C_string());
 104     fatal("Invalid layout of preloaded class");
 105   }
 106 
 107   //fetch the field at the offset we've found
 108   int dest_offset = fd.offset();
 109 
 110   return dest_offset;
 111 }
 112 
 113 
 114 const char* WhiteBox::lookup_jstring(const char* field_name, oop object)
 115 {
 116   int offset = offset_for_field(field_name, object,
 117       vmSymbols::string_signature());
 118   oop string = object->obj_field(offset);
 119   const char* ret = java_lang_String::as_utf8_string(string);
 120   return ret;
 121 }
 122 
 123 bool WhiteBox::lookup_bool(const char* field_name, oop object)
 124 {
 125   int offset =
 126       offset_for_field(field_name, object, vmSymbols::bool_signature());
 127   bool ret = (object->bool_field(offset) == JNI_TRUE);
 128   return ret;
 129 }
 130 
 131 
 132 #define CC (char*)
 133 
 134 static JNINativeMethod methods[] = {
 135   {CC"getObjectAddress",   CC"(Ljava/lang/Object;)J", (void*)&WB_GetObjectAddress  },
 136   {CC"getHeapOopSize",     CC"()I",                   (void*)&WB_GetHeapOopSize    },
 137   {CC "parseCommandLine",
 138       CC "(Ljava/lang/String;[Lsun/hotspot/parser/DiagnosticCommand;)[Ljava/lang/Object;",
 139       (void*) &WB_ParseCommandLine
 140   },
 141 #ifndef SERIALGC
 142   {CC"g1InConcurrentMark", CC"()Z",                   (void*)&WB_G1InConcurrentMark},
 143   {CC"g1IsHumongous",      CC"(Ljava/lang/Object;)Z", (void*)&WB_G1IsHumongous     },
 144   {CC"g1NumFreeRegions",   CC"()J",                   (void*)&WB_G1NumFreeRegions  },
 145   {CC"g1RegionSize",       CC"()I",                   (void*)&WB_G1RegionSize      },
 146 #endif // !SERIALGC
 147 };
 148 
 149 #undef CC
 150 
 151 JVM_ENTRY(void, JVM_RegisterWhiteBoxMethods(JNIEnv* env, jclass wbclass))
 152   {
 153     if (WhiteBoxAPI) {
 154       // Make sure that wbclass is loaded by the null classloader
 155       instanceKlassHandle ikh = instanceKlassHandle(JNIHandles::resolve(wbclass)->klass());
 156       Handle loader(ikh->class_loader());
 157       if (loader.is_null()) {
 158         ThreadToNativeFromVM ttnfv(thread); // can't be in VM when we call JNI
 159         jint result = env->RegisterNatives(wbclass, methods, sizeof(methods)/sizeof(methods[0]));
 160         if (result == 0) {
 161           WhiteBox::set_used();
 162         }
 163       }
 164     }
 165   }
 166 JVM_END