1 /*
   2  * Copyright (c) 2012, 2014, 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/stringTable.hpp"
  31 #include "classfile/classLoaderData.hpp"
  32 
  33 #include "prims/whitebox.hpp"
  34 #include "prims/wbtestmethods/parserTests.hpp"
  35 
  36 #include "runtime/thread.hpp"
  37 #include "runtime/arguments.hpp"
  38 #include "runtime/interfaceSupport.hpp"
  39 #include "runtime/os.hpp"
  40 
  41 #include "utilities/debug.hpp"
  42 #include "utilities/macros.hpp"
  43 #include "utilities/exceptions.hpp"
  44 
  45 #if INCLUDE_ALL_GCS
  46 #include "gc_implementation/g1/concurrentMark.hpp"
  47 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  48 #include "gc_implementation/g1/heapRegionRemSet.hpp"
  49 #endif // INCLUDE_ALL_GCS
  50 
  51 #ifdef INCLUDE_NMT
  52 #include "services/memTracker.hpp"
  53 #endif // INCLUDE_NMT
  54 
  55 #include "compiler/compileBroker.hpp"
  56 #include "runtime/compilationPolicy.hpp"
  57 
  58 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  59 
  60 #define SIZE_T_MAX_VALUE ((size_t) -1)
  61 
  62 bool WhiteBox::_used = false;
  63 
  64 WB_ENTRY(jlong, WB_GetObjectAddress(JNIEnv* env, jobject o, jobject obj))
  65   return (jlong)(void*)JNIHandles::resolve(obj);
  66 WB_END
  67 
  68 WB_ENTRY(jint, WB_GetHeapOopSize(JNIEnv* env, jobject o))
  69   return heapOopSize;
  70 WB_END
  71 
  72 
  73 class WBIsKlassAliveClosure : public KlassClosure {
  74     Symbol* _name;
  75     bool _found;
  76 public:
  77     WBIsKlassAliveClosure(Symbol* name) : _name(name), _found(false) {}
  78 
  79     void do_klass(Klass* k) {
  80       if (_found) return;
  81       Symbol* ksym = k->name();
  82       if (ksym->fast_compare(_name) == 0) {
  83         _found = true;
  84       }
  85     }
  86 
  87     bool found() const {
  88         return _found;
  89     }
  90 };
  91 
  92 WB_ENTRY(jboolean, WB_IsClassAlive(JNIEnv* env, jobject target, jstring name))
  93   Handle h_name = JNIHandles::resolve(name);
  94   if (h_name.is_null()) return false;
  95   Symbol* sym = java_lang_String::as_symbol(h_name, CHECK_false);
  96   TempNewSymbol tsym(sym); // Make sure to decrement reference count on sym on return
  97 
  98   WBIsKlassAliveClosure closure(sym);
  99   ClassLoaderDataGraph::classes_do(&closure);
 100 
 101   return closure.found();
 102 WB_END
 103 
 104 WB_ENTRY(jlong, WB_GetCompressedOopsMaxHeapSize(JNIEnv* env, jobject o)) {
 105   return (jlong)Arguments::max_heap_for_compressed_oops();
 106 }
 107 WB_END
 108 
 109 WB_ENTRY(void, WB_PrintHeapSizes(JNIEnv* env, jobject o)) {
 110   CollectorPolicy * p = Universe::heap()->collector_policy();
 111   gclog_or_tty->print_cr("Minimum heap "SIZE_FORMAT" Initial heap "
 112     SIZE_FORMAT" Maximum heap "SIZE_FORMAT" Space alignment "SIZE_FORMAT" Heap alignment "SIZE_FORMAT,
 113     p->min_heap_byte_size(), p->initial_heap_byte_size(), p->max_heap_byte_size(),
 114     p->space_alignment(), p->heap_alignment());
 115 }
 116 WB_END
 117 
 118 #ifndef PRODUCT
 119 // Forward declaration
 120 void TestReservedSpace_test();
 121 void TestReserveMemorySpecial_test();
 122 void TestVirtualSpace_test();
 123 void TestMetaspaceAux_test();
 124 #endif
 125 
 126 WB_ENTRY(void, WB_RunMemoryUnitTests(JNIEnv* env, jobject o))
 127 #ifndef PRODUCT
 128   TestReservedSpace_test();
 129   TestReserveMemorySpecial_test();
 130   TestVirtualSpace_test();
 131   TestMetaspaceAux_test();
 132 #endif
 133 WB_END
 134 
 135 WB_ENTRY(void, WB_ReadFromNoaccessArea(JNIEnv* env, jobject o))
 136   size_t granularity = os::vm_allocation_granularity();
 137   ReservedHeapSpace rhs(100 * granularity, granularity, false, NULL);
 138   VirtualSpace vs;
 139   vs.initialize(rhs, 50 * granularity);
 140 
 141   //Check if constraints are complied
 142   if (!( UseCompressedOops && rhs.base() != NULL &&
 143          Universe::narrow_oop_base() != NULL &&
 144          Universe::narrow_oop_use_implicit_null_checks() )) {
 145     tty->print_cr("WB_ReadFromNoaccessArea method is useless:\n "
 146                   "\tUseCompressedOops is %d\n"
 147                   "\trhs.base() is "PTR_FORMAT"\n"
 148                   "\tUniverse::narrow_oop_base() is "PTR_FORMAT"\n"
 149                   "\tUniverse::narrow_oop_use_implicit_null_checks() is %d",
 150                   UseCompressedOops,
 151                   rhs.base(),
 152                   Universe::narrow_oop_base(),
 153                   Universe::narrow_oop_use_implicit_null_checks());
 154     return;
 155   }
 156   tty->print_cr("Reading from no access area... ");
 157   tty->print_cr("*(vs.low_boundary() - rhs.noaccess_prefix() / 2 ) = %c",
 158                 *(vs.low_boundary() - rhs.noaccess_prefix() / 2 ));
 159 WB_END
 160 
 161 static jint wb_stress_virtual_space_resize(size_t reserved_space_size,
 162                                            size_t magnitude, size_t iterations) {
 163   size_t granularity = os::vm_allocation_granularity();
 164   ReservedHeapSpace rhs(reserved_space_size * granularity, granularity, false, NULL);
 165   VirtualSpace vs;
 166   if (!vs.initialize(rhs, 0)) {
 167     tty->print_cr("Failed to initialize VirtualSpace. Can't proceed.");
 168     return 3;
 169   }
 170 
 171   long seed = os::random();
 172   tty->print_cr("Random seed is %ld", seed);
 173   os::init_random(seed);
 174 
 175   for (size_t i = 0; i < iterations; i++) {
 176 
 177     // Whether we will shrink or grow
 178     bool shrink = os::random() % 2L == 0;
 179 
 180     // Get random delta to resize virtual space
 181     size_t delta = (size_t)os::random() % magnitude;
 182 
 183     // If we are about to shrink virtual space below zero, then expand instead
 184     if (shrink && vs.committed_size() < delta) {
 185       shrink = false;
 186     }
 187 
 188     // Resizing by delta
 189     if (shrink) {
 190       vs.shrink_by(delta);
 191     } else {
 192       // If expanding fails expand_by will silently return false
 193       vs.expand_by(delta, true);
 194     }
 195   }
 196   return 0;
 197 }
 198 
 199 WB_ENTRY(jint, WB_StressVirtualSpaceResize(JNIEnv* env, jobject o,
 200         jlong reserved_space_size, jlong magnitude, jlong iterations))
 201   tty->print_cr("reservedSpaceSize="JLONG_FORMAT", magnitude="JLONG_FORMAT", "
 202                 "iterations="JLONG_FORMAT"\n", reserved_space_size, magnitude,
 203                 iterations);
 204   if (reserved_space_size < 0 || magnitude < 0 || iterations < 0) {
 205     tty->print_cr("One of variables printed above is negative. Can't proceed.\n");
 206     return 1;
 207   }
 208 
 209   // sizeof(size_t) depends on whether OS is 32bit or 64bit. sizeof(jlong) is
 210   // always 8 byte. That's why we should avoid overflow in case of 32bit platform.
 211   if (sizeof(size_t) < sizeof(jlong)) {
 212     jlong size_t_max_value = (jlong) SIZE_T_MAX_VALUE;
 213     if (reserved_space_size > size_t_max_value || magnitude > size_t_max_value
 214         || iterations > size_t_max_value) {
 215       tty->print_cr("One of variables printed above overflows size_t. Can't proceed.\n");
 216       return 2;
 217     }
 218   }
 219 
 220   return wb_stress_virtual_space_resize((size_t) reserved_space_size,
 221                                         (size_t) magnitude, (size_t) iterations);
 222 WB_END
 223 
 224 #if INCLUDE_ALL_GCS
 225 WB_ENTRY(jboolean, WB_G1IsHumongous(JNIEnv* env, jobject o, jobject obj))
 226   G1CollectedHeap* g1 = G1CollectedHeap::heap();
 227   oop result = JNIHandles::resolve(obj);
 228   const HeapRegion* hr = g1->heap_region_containing(result);
 229   return hr->isHumongous();
 230 WB_END
 231 
 232 WB_ENTRY(jlong, WB_G1NumFreeRegions(JNIEnv* env, jobject o))
 233   G1CollectedHeap* g1 = G1CollectedHeap::heap();
 234   size_t nr = g1->free_regions();
 235   return (jlong)nr;
 236 WB_END
 237 
 238 WB_ENTRY(jboolean, WB_G1InConcurrentMark(JNIEnv* env, jobject o))
 239   G1CollectedHeap* g1 = G1CollectedHeap::heap();
 240   ConcurrentMark* cm = g1->concurrent_mark();
 241   return cm->concurrent_marking_in_progress();
 242 WB_END
 243 
 244 WB_ENTRY(jint, WB_G1RegionSize(JNIEnv* env, jobject o))
 245   return (jint)HeapRegion::GrainBytes;
 246 WB_END
 247 #endif // INCLUDE_ALL_GCS
 248 
 249 #if INCLUDE_NMT
 250 // Alloc memory using the test memory type so that we can use that to see if
 251 // NMT picks it up correctly
 252 WB_ENTRY(jlong, WB_NMTMalloc(JNIEnv* env, jobject o, jlong size))
 253   jlong addr = 0;
 254 
 255   if (MemTracker::is_on() && !MemTracker::shutdown_in_progress()) {
 256     addr = (jlong)(uintptr_t)os::malloc(size, mtTest);
 257   }
 258 
 259   return addr;
 260 WB_END
 261 
 262 // Free the memory allocated by NMTAllocTest
 263 WB_ENTRY(void, WB_NMTFree(JNIEnv* env, jobject o, jlong mem))
 264   os::free((void*)(uintptr_t)mem, mtTest);
 265 WB_END
 266 
 267 WB_ENTRY(jlong, WB_NMTReserveMemory(JNIEnv* env, jobject o, jlong size))
 268   jlong addr = 0;
 269 
 270   if (MemTracker::is_on() && !MemTracker::shutdown_in_progress()) {
 271     addr = (jlong)(uintptr_t)os::reserve_memory(size);
 272     MemTracker::record_virtual_memory_type((address)addr, mtTest);
 273   }
 274 
 275   return addr;
 276 WB_END
 277 
 278 
 279 WB_ENTRY(void, WB_NMTCommitMemory(JNIEnv* env, jobject o, jlong addr, jlong size))
 280   os::commit_memory((char *)(uintptr_t)addr, size, !ExecMem);
 281   MemTracker::record_virtual_memory_type((address)(uintptr_t)addr, mtTest);
 282 WB_END
 283 
 284 WB_ENTRY(void, WB_NMTUncommitMemory(JNIEnv* env, jobject o, jlong addr, jlong size))
 285   os::uncommit_memory((char *)(uintptr_t)addr, size);
 286 WB_END
 287 
 288 WB_ENTRY(void, WB_NMTReleaseMemory(JNIEnv* env, jobject o, jlong addr, jlong size))
 289   os::release_memory((char *)(uintptr_t)addr, size);
 290 WB_END
 291 
 292 // Block until the current generation of NMT data to be merged, used to reliably test the NMT feature
 293 WB_ENTRY(jboolean, WB_NMTWaitForDataMerge(JNIEnv* env))
 294 
 295   if (!MemTracker::is_on() || MemTracker::shutdown_in_progress()) {
 296     return false;
 297   }
 298 
 299   return MemTracker::wbtest_wait_for_data_merge();
 300 WB_END
 301 
 302 WB_ENTRY(jboolean, WB_NMTIsDetailSupported(JNIEnv* env))
 303   return MemTracker::tracking_level() == MemTracker::NMT_detail;
 304 WB_END
 305 
 306 #endif // INCLUDE_NMT
 307 
 308 static jmethodID reflected_method_to_jmid(JavaThread* thread, JNIEnv* env, jobject method) {
 309   assert(method != NULL, "method should not be null");
 310   ThreadToNativeFromVM ttn(thread);
 311   return env->FromReflectedMethod(method);
 312 }
 313 
 314 WB_ENTRY(void, WB_DeoptimizeAll(JNIEnv* env, jobject o))
 315   MutexLockerEx mu(Compile_lock);
 316   CodeCache::mark_all_nmethods_for_deoptimization();
 317   VM_Deoptimize op;
 318   VMThread::execute(&op);
 319 WB_END
 320 
 321 WB_ENTRY(jint, WB_DeoptimizeMethod(JNIEnv* env, jobject o, jobject method, jboolean is_osr))
 322   jmethodID jmid = reflected_method_to_jmid(thread, env, method);
 323   int result = 0;
 324   CHECK_JNI_EXCEPTION_(env, result);
 325   MutexLockerEx mu(Compile_lock);
 326   methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
 327   nmethod* code;
 328   if (is_osr) {
 329     int bci = InvocationEntryBci;
 330     while ((code = mh->lookup_osr_nmethod_for(bci, CompLevel_none, false)) != NULL) {
 331       code->mark_for_deoptimization();
 332       ++result;
 333       bci = code->osr_entry_bci() + 1;
 334     }
 335   } else {
 336     code = mh->code();
 337   }
 338   if (code != NULL) {
 339     code->mark_for_deoptimization();
 340     ++result;
 341   }
 342   result += CodeCache::mark_for_deoptimization(mh());
 343   if (result > 0) {
 344     VM_Deoptimize op;
 345     VMThread::execute(&op);
 346   }
 347   return result;
 348 WB_END
 349 
 350 WB_ENTRY(jboolean, WB_IsMethodCompiled(JNIEnv* env, jobject o, jobject method, jboolean is_osr))
 351   jmethodID jmid = reflected_method_to_jmid(thread, env, method);
 352   CHECK_JNI_EXCEPTION_(env, JNI_FALSE);
 353   MutexLockerEx mu(Compile_lock);
 354   methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
 355   nmethod* code = is_osr ? mh->lookup_osr_nmethod_for(InvocationEntryBci, CompLevel_none, false) : mh->code();
 356   if (code == NULL) {
 357     return JNI_FALSE;
 358   }
 359   return (code->is_alive() && !code->is_marked_for_deoptimization());
 360 WB_END
 361 
 362 WB_ENTRY(jboolean, WB_IsMethodCompilable(JNIEnv* env, jobject o, jobject method, jint comp_level, jboolean is_osr))
 363   jmethodID jmid = reflected_method_to_jmid(thread, env, method);
 364   CHECK_JNI_EXCEPTION_(env, JNI_FALSE);
 365   MutexLockerEx mu(Compile_lock);
 366   methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
 367   if (is_osr) {
 368     return CompilationPolicy::can_be_osr_compiled(mh, comp_level);
 369   } else {
 370     return CompilationPolicy::can_be_compiled(mh, comp_level);
 371   }
 372 WB_END
 373 
 374 WB_ENTRY(jboolean, WB_IsMethodQueuedForCompilation(JNIEnv* env, jobject o, jobject method))
 375   jmethodID jmid = reflected_method_to_jmid(thread, env, method);
 376   CHECK_JNI_EXCEPTION_(env, JNI_FALSE);
 377   MutexLockerEx mu(Compile_lock);
 378   methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
 379   return mh->queued_for_compilation();
 380 WB_END
 381 
 382 WB_ENTRY(jint, WB_GetMethodCompilationLevel(JNIEnv* env, jobject o, jobject method, jboolean is_osr))
 383   jmethodID jmid = reflected_method_to_jmid(thread, env, method);
 384   CHECK_JNI_EXCEPTION_(env, CompLevel_none);
 385   methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
 386   nmethod* code = is_osr ? mh->lookup_osr_nmethod_for(InvocationEntryBci, CompLevel_none, false) : mh->code();
 387   return (code != NULL ? code->comp_level() : CompLevel_none);
 388 WB_END
 389 
 390 WB_ENTRY(void, WB_MakeMethodNotCompilable(JNIEnv* env, jobject o, jobject method, jint comp_level, jboolean is_osr))
 391   jmethodID jmid = reflected_method_to_jmid(thread, env, method);
 392   CHECK_JNI_EXCEPTION(env);
 393   methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
 394   if (is_osr) {
 395     mh->set_not_osr_compilable(comp_level, true /* report */, "WhiteBox");
 396   } else {
 397     mh->set_not_compilable(comp_level, true /* report */, "WhiteBox");
 398   }
 399 WB_END
 400 
 401 WB_ENTRY(jint, WB_GetMethodEntryBci(JNIEnv* env, jobject o, jobject method))
 402   jmethodID jmid = reflected_method_to_jmid(thread, env, method);
 403   CHECK_JNI_EXCEPTION_(env, InvocationEntryBci);
 404   methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
 405   nmethod* code = mh->lookup_osr_nmethod_for(InvocationEntryBci, CompLevel_none, false);
 406   return (code != NULL && code->is_osr_method() ? code->osr_entry_bci() : InvocationEntryBci);
 407 WB_END
 408 
 409 WB_ENTRY(jboolean, WB_TestSetDontInlineMethod(JNIEnv* env, jobject o, jobject method, jboolean value))
 410   jmethodID jmid = reflected_method_to_jmid(thread, env, method);
 411   CHECK_JNI_EXCEPTION_(env, JNI_FALSE);
 412   methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
 413   bool result = mh->dont_inline();
 414   mh->set_dont_inline(value == JNI_TRUE);
 415   return result;
 416 WB_END
 417 
 418 WB_ENTRY(jint, WB_GetCompileQueueSize(JNIEnv* env, jobject o, jint comp_level))
 419   if (comp_level == CompLevel_any) {
 420     return CompileBroker::queue_size(CompLevel_full_optimization) /* C2 */ +
 421         CompileBroker::queue_size(CompLevel_full_profile) /* C1 */;
 422   } else {
 423     return CompileBroker::queue_size(comp_level);
 424   }
 425 WB_END
 426 
 427 WB_ENTRY(jboolean, WB_TestSetForceInlineMethod(JNIEnv* env, jobject o, jobject method, jboolean value))
 428   jmethodID jmid = reflected_method_to_jmid(thread, env, method);
 429   CHECK_JNI_EXCEPTION_(env, JNI_FALSE);
 430   methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
 431   bool result = mh->force_inline();
 432   mh->set_force_inline(value == JNI_TRUE);
 433   return result;
 434 WB_END
 435 
 436 WB_ENTRY(jboolean, WB_EnqueueMethodForCompilation(JNIEnv* env, jobject o, jobject method, jint comp_level, jint bci))
 437   jmethodID jmid = reflected_method_to_jmid(thread, env, method);
 438   CHECK_JNI_EXCEPTION_(env, JNI_FALSE);
 439   methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
 440   nmethod* nm = CompileBroker::compile_method(mh, bci, comp_level, mh, mh->invocation_count(), "WhiteBox", THREAD);
 441   MutexLockerEx mu(Compile_lock);
 442   return (mh->queued_for_compilation() || nm != NULL);
 443 WB_END
 444 
 445 class VM_WhiteBoxOperation : public VM_Operation {
 446  public:
 447   VM_WhiteBoxOperation()                         { }
 448   VMOp_Type type()                  const        { return VMOp_WhiteBoxOperation; }
 449   bool allow_nested_vm_operations() const        { return true; }
 450 };
 451 
 452 class AlwaysFalseClosure : public BoolObjectClosure {
 453  public:
 454   bool do_object_b(oop p) { return false; }
 455 };
 456 
 457 static AlwaysFalseClosure always_false;
 458 
 459 class VM_WhiteBoxCleanMethodData : public VM_WhiteBoxOperation {
 460  public:
 461   VM_WhiteBoxCleanMethodData(MethodData* mdo) : _mdo(mdo) { }
 462   void doit() {
 463     _mdo->clean_method_data(&always_false);
 464   }
 465  private:
 466   MethodData* _mdo;
 467 };
 468 
 469 WB_ENTRY(void, WB_ClearMethodState(JNIEnv* env, jobject o, jobject method))
 470   jmethodID jmid = reflected_method_to_jmid(thread, env, method);
 471   CHECK_JNI_EXCEPTION(env);
 472   methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
 473   MutexLockerEx mu(Compile_lock);
 474   MethodData* mdo = mh->method_data();
 475   MethodCounters* mcs = mh->method_counters();
 476 
 477   if (mdo != NULL) {
 478     mdo->init();
 479     ResourceMark rm;
 480     int arg_count = mdo->method()->size_of_parameters();
 481     for (int i = 0; i < arg_count; i++) {
 482       mdo->set_arg_modified(i, 0);
 483     }
 484     VM_WhiteBoxCleanMethodData op(mdo);
 485     VMThread::execute(&op);
 486   }
 487 
 488   mh->clear_not_c1_compilable();
 489   mh->clear_not_c2_compilable();
 490   mh->clear_not_c2_osr_compilable();
 491   NOT_PRODUCT(mh->set_compiled_invocation_count(0));
 492   if (mcs != NULL) {
 493     mcs->backedge_counter()->init();
 494     mcs->invocation_counter()->init();
 495     mcs->set_interpreter_invocation_count(0);
 496     mcs->set_interpreter_throwout_count(0);
 497 
 498 #ifdef TIERED
 499     mcs->set_rate(0.0F);
 500     mh->set_prev_event_count(0);
 501     mh->set_prev_time(0);
 502 #endif
 503   }
 504 WB_END
 505 
 506 WB_ENTRY(jboolean, WB_IsInStringTable(JNIEnv* env, jobject o, jstring javaString))
 507   ResourceMark rm(THREAD);
 508   int len;
 509   jchar* name = java_lang_String::as_unicode_string(JNIHandles::resolve(javaString), len, CHECK_false);
 510   return (StringTable::lookup(name, len) != NULL);
 511 WB_END
 512 
 513 WB_ENTRY(void, WB_FullGC(JNIEnv* env, jobject o))
 514   Universe::heap()->collector_policy()->set_should_clear_all_soft_refs(true);
 515   Universe::heap()->collect(GCCause::_last_ditch_collection);
 516 WB_END
 517 
 518 
 519 WB_ENTRY(void, WB_ReadReservedMemory(JNIEnv* env, jobject o))
 520   // static+volatile in order to force the read to happen
 521   // (not be eliminated by the compiler)
 522   static char c;
 523   static volatile char* p;
 524 
 525   p = os::reserve_memory(os::vm_allocation_granularity(), NULL, 0);
 526   if (p == NULL) {
 527     THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), "Failed to reserve memory");
 528   }
 529 
 530   c = *p;
 531 WB_END
 532 
 533 WB_ENTRY(jstring, WB_GetCPUFeatures(JNIEnv* env, jobject o))
 534   const char* cpu_features = VM_Version::cpu_features();
 535   ThreadToNativeFromVM ttn(thread);
 536   jstring features_string = env->NewStringUTF(cpu_features);
 537 
 538   CHECK_JNI_EXCEPTION_(env, NULL);
 539 
 540   return features_string;
 541 WB_END
 542 
 543 
 544 WB_ENTRY(jobjectArray, WB_GetNMethod(JNIEnv* env, jobject o, jobject method, jboolean is_osr))
 545   ResourceMark rm(THREAD);
 546   jmethodID jmid = reflected_method_to_jmid(thread, env, method);
 547   CHECK_JNI_EXCEPTION_(env, NULL);
 548   methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
 549   nmethod* code = is_osr ? mh->lookup_osr_nmethod_for(InvocationEntryBci, CompLevel_none, false) : mh->code();
 550   jobjectArray result = NULL;
 551   if (code == NULL) {
 552     return result;
 553   }
 554   int insts_size = code->insts_size();
 555 
 556   ThreadToNativeFromVM ttn(thread);
 557   jclass clazz = env->FindClass(vmSymbols::java_lang_Object()->as_C_string());
 558   CHECK_JNI_EXCEPTION_(env, NULL);
 559   result = env->NewObjectArray(2, clazz, NULL);
 560   if (result == NULL) {
 561     return result;
 562   }
 563 
 564   clazz = env->FindClass(vmSymbols::java_lang_Integer()->as_C_string());
 565   CHECK_JNI_EXCEPTION_(env, NULL);
 566   jmethodID constructor = env->GetMethodID(clazz, vmSymbols::object_initializer_name()->as_C_string(), vmSymbols::int_void_signature()->as_C_string());
 567   CHECK_JNI_EXCEPTION_(env, NULL);
 568   jobject obj = env->NewObject(clazz, constructor, code->comp_level());
 569   CHECK_JNI_EXCEPTION_(env, NULL);
 570   env->SetObjectArrayElement(result, 0, obj);
 571 
 572   jbyteArray insts = env->NewByteArray(insts_size);
 573   CHECK_JNI_EXCEPTION_(env, NULL);
 574   env->SetByteArrayRegion(insts, 0, insts_size, (jbyte*) code->insts_begin());
 575   env->SetObjectArrayElement(result, 1, insts);
 576 
 577   return result;
 578 WB_END
 579 
 580 
 581 WB_ENTRY(jlong, WB_GetThreadFullStackSize(JNIEnv* env, jobject o))
 582   return (jlong) Thread::current()->stack_size();
 583 WB_END
 584 
 585 WB_ENTRY(jlong, WB_GetThreadRemainingStackSize(JNIEnv* env, jobject o))
 586   JavaThread* t = JavaThread::current();
 587   return (jlong) t->stack_available(os::current_stack_pointer()) - (jlong) StackShadowPages * os::vm_page_size();
 588 WB_END
 589 
 590 //Some convenience methods to deal with objects from java
 591 int WhiteBox::offset_for_field(const char* field_name, oop object,
 592     Symbol* signature_symbol) {
 593   assert(field_name != NULL && strlen(field_name) > 0, "Field name not valid");
 594   Thread* THREAD = Thread::current();
 595 
 596   //Get the class of our object
 597   Klass* arg_klass = object->klass();
 598   //Turn it into an instance-klass
 599   InstanceKlass* ik = InstanceKlass::cast(arg_klass);
 600 
 601   //Create symbols to look for in the class
 602   TempNewSymbol name_symbol = SymbolTable::lookup(field_name, (int) strlen(field_name),
 603       THREAD);
 604 
 605   //To be filled in with an offset of the field we're looking for
 606   fieldDescriptor fd;
 607 
 608   Klass* res = ik->find_field(name_symbol, signature_symbol, &fd);
 609   if (res == NULL) {
 610     tty->print_cr("Invalid layout of %s at %s", ik->external_name(),
 611         name_symbol->as_C_string());
 612     fatal("Invalid layout of preloaded class");
 613   }
 614 
 615   //fetch the field at the offset we've found
 616   int dest_offset = fd.offset();
 617 
 618   return dest_offset;
 619 }
 620 
 621 
 622 const char* WhiteBox::lookup_jstring(const char* field_name, oop object) {
 623   int offset = offset_for_field(field_name, object,
 624       vmSymbols::string_signature());
 625   oop string = object->obj_field(offset);
 626   if (string == NULL) {
 627     return NULL;
 628   }
 629   const char* ret = java_lang_String::as_utf8_string(string);
 630   return ret;
 631 }
 632 
 633 bool WhiteBox::lookup_bool(const char* field_name, oop object) {
 634   int offset =
 635       offset_for_field(field_name, object, vmSymbols::bool_signature());
 636   bool ret = (object->bool_field(offset) == JNI_TRUE);
 637   return ret;
 638 }
 639 
 640 
 641 #define CC (char*)
 642 
 643 static JNINativeMethod methods[] = {
 644   {CC"getObjectAddress",   CC"(Ljava/lang/Object;)J", (void*)&WB_GetObjectAddress  },
 645   {CC"getHeapOopSize",     CC"()I",                   (void*)&WB_GetHeapOopSize    },
 646   {CC"isClassAlive0",      CC"(Ljava/lang/String;)Z", (void*)&WB_IsClassAlive      },
 647   {CC"parseCommandLine",
 648       CC"(Ljava/lang/String;[Lsun/hotspot/parser/DiagnosticCommand;)[Ljava/lang/Object;",
 649       (void*) &WB_ParseCommandLine
 650   },
 651   {CC"getCompressedOopsMaxHeapSize", CC"()J",
 652       (void*)&WB_GetCompressedOopsMaxHeapSize},
 653   {CC"printHeapSizes",     CC"()V",                   (void*)&WB_PrintHeapSizes    },
 654   {CC"runMemoryUnitTests", CC"()V",                   (void*)&WB_RunMemoryUnitTests},
 655   {CC"readFromNoaccessArea",CC"()V",                  (void*)&WB_ReadFromNoaccessArea},
 656   {CC"stressVirtualSpaceResize",CC"(JJJ)I",           (void*)&WB_StressVirtualSpaceResize},
 657 #if INCLUDE_ALL_GCS
 658   {CC"g1InConcurrentMark", CC"()Z",                   (void*)&WB_G1InConcurrentMark},
 659   {CC"g1IsHumongous",      CC"(Ljava/lang/Object;)Z", (void*)&WB_G1IsHumongous     },
 660   {CC"g1NumFreeRegions",   CC"()J",                   (void*)&WB_G1NumFreeRegions  },
 661   {CC"g1RegionSize",       CC"()I",                   (void*)&WB_G1RegionSize      },
 662 #endif // INCLUDE_ALL_GCS
 663 #if INCLUDE_NMT
 664   {CC"NMTMalloc",           CC"(J)J",                 (void*)&WB_NMTMalloc          },
 665   {CC"NMTFree",             CC"(J)V",                 (void*)&WB_NMTFree            },
 666   {CC"NMTReserveMemory",    CC"(J)J",                 (void*)&WB_NMTReserveMemory   },
 667   {CC"NMTCommitMemory",     CC"(JJ)V",                (void*)&WB_NMTCommitMemory    },
 668   {CC"NMTUncommitMemory",   CC"(JJ)V",                (void*)&WB_NMTUncommitMemory  },
 669   {CC"NMTReleaseMemory",    CC"(JJ)V",                (void*)&WB_NMTReleaseMemory   },
 670   {CC"NMTWaitForDataMerge", CC"()Z",                  (void*)&WB_NMTWaitForDataMerge},
 671   {CC"NMTIsDetailSupported",CC"()Z",                  (void*)&WB_NMTIsDetailSupported},
 672 #endif // INCLUDE_NMT
 673   {CC"deoptimizeAll",      CC"()V",                   (void*)&WB_DeoptimizeAll     },
 674   {CC"deoptimizeMethod",   CC"(Ljava/lang/reflect/Executable;Z)I",
 675                                                       (void*)&WB_DeoptimizeMethod  },
 676   {CC"isMethodCompiled",   CC"(Ljava/lang/reflect/Executable;Z)Z",
 677                                                       (void*)&WB_IsMethodCompiled  },
 678   {CC"isMethodCompilable", CC"(Ljava/lang/reflect/Executable;IZ)Z",
 679                                                       (void*)&WB_IsMethodCompilable},
 680   {CC"isMethodQueuedForCompilation",
 681       CC"(Ljava/lang/reflect/Executable;)Z",          (void*)&WB_IsMethodQueuedForCompilation},
 682   {CC"makeMethodNotCompilable",
 683       CC"(Ljava/lang/reflect/Executable;IZ)V",        (void*)&WB_MakeMethodNotCompilable},
 684   {CC"testSetDontInlineMethod",
 685       CC"(Ljava/lang/reflect/Executable;Z)Z",         (void*)&WB_TestSetDontInlineMethod},
 686   {CC"getMethodCompilationLevel",
 687       CC"(Ljava/lang/reflect/Executable;Z)I",         (void*)&WB_GetMethodCompilationLevel},
 688   {CC"getMethodEntryBci",
 689       CC"(Ljava/lang/reflect/Executable;)I",          (void*)&WB_GetMethodEntryBci},
 690   {CC"getCompileQueueSize",
 691       CC"(I)I",                                       (void*)&WB_GetCompileQueueSize},
 692   {CC"testSetForceInlineMethod",
 693       CC"(Ljava/lang/reflect/Executable;Z)Z",         (void*)&WB_TestSetForceInlineMethod},
 694   {CC"enqueueMethodForCompilation",
 695       CC"(Ljava/lang/reflect/Executable;II)Z",        (void*)&WB_EnqueueMethodForCompilation},
 696   {CC"clearMethodState",
 697       CC"(Ljava/lang/reflect/Executable;)V",          (void*)&WB_ClearMethodState},
 698   {CC"isInStringTable",   CC"(Ljava/lang/String;)Z",  (void*)&WB_IsInStringTable  },
 699   {CC"fullGC",   CC"()V",                             (void*)&WB_FullGC },
 700   {CC"readReservedMemory", CC"()V",                   (void*)&WB_ReadReservedMemory },
 701   {CC"getCPUFeatures",     CC"()Ljava/lang/String;",  (void*)&WB_GetCPUFeatures     },
 702   {CC"getNMethod",         CC"(Ljava/lang/reflect/Executable;Z)[Ljava/lang/Object;",
 703                                                       (void*)&WB_GetNMethod         },
 704   {CC"getThreadFullStackSize", CC"()J",               (void*)&WB_GetThreadFullStackSize },
 705   {CC"getThreadRemainingStackSize", CC"()J",          (void*)&WB_GetThreadRemainingStackSize },
 706 };
 707 
 708 #undef CC
 709 
 710 JVM_ENTRY(void, JVM_RegisterWhiteBoxMethods(JNIEnv* env, jclass wbclass))
 711   {
 712     if (WhiteBoxAPI) {
 713       // Make sure that wbclass is loaded by the null classloader
 714       instanceKlassHandle ikh = instanceKlassHandle(JNIHandles::resolve(wbclass)->klass());
 715       Handle loader(ikh->class_loader());
 716       if (loader.is_null()) {
 717         ResourceMark rm;
 718         ThreadToNativeFromVM ttnfv(thread); // can't be in VM when we call JNI
 719         bool result = true;
 720         //  one by one registration natives for exception catching
 721         jclass exceptionKlass = env->FindClass(vmSymbols::java_lang_NoSuchMethodError()->as_C_string());
 722         CHECK_JNI_EXCEPTION(env);
 723         for (int i = 0, n = sizeof(methods) / sizeof(methods[0]); i < n; ++i) {
 724           if (env->RegisterNatives(wbclass, methods + i, 1) != 0) {
 725             result = false;
 726             jthrowable throwable_obj = env->ExceptionOccurred();
 727             if (throwable_obj != NULL) {
 728               env->ExceptionClear();
 729               if (env->IsInstanceOf(throwable_obj, exceptionKlass)) {
 730                 // j.l.NoSuchMethodError is thrown when a method can't be found or a method is not native
 731                 // ignoring the exception
 732                 tty->print_cr("Warning: 'NoSuchMethodError' on register of sun.hotspot.WhiteBox::%s%s", methods[i].name, methods[i].signature);
 733               }
 734             } else {
 735               // register is failed w/o exception or w/ unexpected exception
 736               tty->print_cr("Warning: unexpected error on register of sun.hotspot.WhiteBox::%s%s. All methods will be unregistered", methods[i].name, methods[i].signature);
 737               env->UnregisterNatives(wbclass);
 738               break;
 739             }
 740           }
 741         }
 742 
 743         if (result) {
 744           WhiteBox::set_used();
 745         }
 746       }
 747     }
 748   }
 749 JVM_END