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 #include "classfile/classLoaderData.hpp"
  32 
  33 #include "prims/whitebox.hpp"
  34 #include "prims/wbtestmethods/parserTests.hpp"
  35 
  36 #include "runtime/interfaceSupport.hpp"
  37 #include "runtime/os.hpp"
  38 #include "utilities/debug.hpp"
  39 
  40 #ifndef SERIALGC
  41 #include "gc_implementation/g1/concurrentMark.hpp"
  42 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  43 #include "gc_implementation/g1/heapRegionRemSet.hpp"
  44 #endif // !SERIALGC
  45 
  46 bool WhiteBox::_used = false;
  47 
  48 WB_ENTRY(jlong, WB_GetObjectAddress(JNIEnv* env, jobject o, jobject obj))
  49   return (jlong)(void*)JNIHandles::resolve(obj);
  50 WB_END
  51 
  52 WB_ENTRY(jint, WB_GetHeapOopSize(JNIEnv* env, jobject o))
  53   return heapOopSize;
  54 WB_END
  55 
  56 
  57 class WBIsKlassAliveClosure : public KlassClosure {
  58     Symbol* _name;
  59     bool _found;
  60 public:
  61     WBIsKlassAliveClosure(Symbol* name) : _name(name), _found(false) {}
  62 
  63     void do_klass(Klass* k) {
  64       if (_found) return;
  65       Symbol* ksym = k->name();
  66       if (ksym->fast_compare(_name) == 0) {
  67         _found = true;
  68       }
  69     }
  70 
  71     bool found() const {
  72         return _found;
  73     }
  74 };
  75 
  76 WB_ENTRY(jboolean, WB_IsClassAlive(JNIEnv* env, jobject target, jstring name))
  77   Handle h_name = JNIHandles::resolve(name);
  78   if (h_name.is_null()) return false;
  79   Symbol* sym = java_lang_String::as_symbol(h_name, CHECK_false);
  80   TempNewSymbol tsym(sym); // Make sure to decrement reference count on sym on return
  81 
  82   WBIsKlassAliveClosure closure(sym);
  83   ClassLoaderDataGraph::classes_do(&closure);
  84 
  85   return closure.found();
  86 WB_END
  87 
  88 #ifndef SERIALGC
  89 WB_ENTRY(jboolean, WB_G1IsHumongous(JNIEnv* env, jobject o, jobject obj))
  90   G1CollectedHeap* g1 = G1CollectedHeap::heap();
  91   oop result = JNIHandles::resolve(obj);
  92   const HeapRegion* hr = g1->heap_region_containing(result);
  93   return hr->isHumongous();
  94 WB_END
  95 
  96 WB_ENTRY(jlong, WB_G1NumFreeRegions(JNIEnv* env, jobject o))
  97   G1CollectedHeap* g1 = G1CollectedHeap::heap();
  98   size_t nr = g1->free_regions();
  99   return (jlong)nr;
 100 WB_END
 101 
 102 WB_ENTRY(jboolean, WB_G1InConcurrentMark(JNIEnv* env, jobject o))
 103   G1CollectedHeap* g1 = G1CollectedHeap::heap();
 104   ConcurrentMark* cm = g1->concurrent_mark();
 105   return cm->concurrent_marking_in_progress();
 106 WB_END
 107 
 108 WB_ENTRY(jint, WB_G1RegionSize(JNIEnv* env, jobject o))
 109   return (jint)HeapRegion::GrainBytes;
 110 WB_END
 111 #endif // !SERIALGC
 112 
 113 //Some convenience methods to deal with objects from java
 114 int WhiteBox::offset_for_field(const char* field_name, oop object,
 115     Symbol* signature_symbol) {
 116   assert(field_name != NULL && strlen(field_name) > 0, "Field name not valid");
 117   Thread* THREAD = Thread::current();
 118 
 119   //Get the class of our object
 120   Klass* arg_klass = object->klass();
 121   //Turn it into an instance-klass
 122   InstanceKlass* ik = InstanceKlass::cast(arg_klass);
 123 
 124   //Create symbols to look for in the class
 125   TempNewSymbol name_symbol = SymbolTable::lookup(field_name, (int) strlen(field_name),
 126       THREAD);
 127 
 128   //To be filled in with an offset of the field we're looking for
 129   fieldDescriptor fd;
 130 
 131   Klass* res = ik->find_field(name_symbol, signature_symbol, &fd);
 132   if (res == NULL) {
 133     tty->print_cr("Invalid layout of %s at %s", ik->external_name(),
 134         name_symbol->as_C_string());
 135     fatal("Invalid layout of preloaded class");
 136   }
 137 
 138   //fetch the field at the offset we've found
 139   int dest_offset = fd.offset();
 140 
 141   return dest_offset;
 142 }
 143 
 144 
 145 const char* WhiteBox::lookup_jstring(const char* field_name, oop object) {
 146   int offset = offset_for_field(field_name, object,
 147       vmSymbols::string_signature());
 148   oop string = object->obj_field(offset);
 149   if (string == NULL) {
 150     return NULL;
 151   }
 152   const char* ret = java_lang_String::as_utf8_string(string);
 153   return ret;
 154 }
 155 
 156 bool WhiteBox::lookup_bool(const char* field_name, oop object) {
 157   int offset =
 158       offset_for_field(field_name, object, vmSymbols::bool_signature());
 159   bool ret = (object->bool_field(offset) == JNI_TRUE);
 160   return ret;
 161 }
 162 
 163 
 164 #define CC (char*)
 165 
 166 static JNINativeMethod methods[] = {
 167   {CC"getObjectAddress",   CC"(Ljava/lang/Object;)J", (void*)&WB_GetObjectAddress  },
 168   {CC"getHeapOopSize",     CC"()I",                   (void*)&WB_GetHeapOopSize    },
 169   {CC"isClassAlive0",       CC"(Ljava/lang/String;)Z", (void*)&WB_IsClassAlive      },
 170   {CC "parseCommandLine",
 171       CC "(Ljava/lang/String;[Lsun/hotspot/parser/DiagnosticCommand;)[Ljava/lang/Object;",
 172       (void*) &WB_ParseCommandLine
 173   },
 174 #ifndef SERIALGC
 175   {CC"g1InConcurrentMark", CC"()Z",                   (void*)&WB_G1InConcurrentMark},
 176   {CC"g1IsHumongous",      CC"(Ljava/lang/Object;)Z", (void*)&WB_G1IsHumongous     },
 177   {CC"g1NumFreeRegions",   CC"()J",                   (void*)&WB_G1NumFreeRegions  },
 178   {CC"g1RegionSize",       CC"()I",                   (void*)&WB_G1RegionSize      },
 179 #endif // !SERIALGC
 180 };
 181 
 182 #undef CC
 183 
 184 JVM_ENTRY(void, JVM_RegisterWhiteBoxMethods(JNIEnv* env, jclass wbclass))
 185   {
 186     if (WhiteBoxAPI) {
 187       // Make sure that wbclass is loaded by the null classloader
 188       instanceKlassHandle ikh = instanceKlassHandle(JNIHandles::resolve(wbclass)->klass());
 189       Handle loader(ikh->class_loader());
 190       if (loader.is_null()) {
 191         ThreadToNativeFromVM ttnfv(thread); // can't be in VM when we call JNI
 192         jint result = env->RegisterNatives(wbclass, methods, sizeof(methods)/sizeof(methods[0]));
 193         if (result == 0) {
 194           WhiteBox::set_used();
 195         }
 196       }
 197     }
 198   }
 199 JVM_END