Mercurial > hg > graal-compiler
annotate src/share/vm/runtime/jniHandles.cpp @ 18096:ca6d25be853b jdk8u25-b13
8044269: Analysis of archive files.
Summary: Add checksum verification.
Reviewed-by: iklam, dholmes, mschoene
| author | jiangli |
|---|---|
| date | Tue, 12 Aug 2014 17:46:16 -0400 |
| parents | 78bbf4d43a14 |
| children | 52b4284cb496 |
| rev | line source |
|---|---|
| 0 | 1 /* |
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2 * Copyright (c) 1998, 2014, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 1972 | 25 #include "precompiled.hpp" |
| 26 #include "classfile/systemDictionary.hpp" | |
| 27 #include "oops/oop.inline.hpp" | |
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28 #include "prims/jvmtiExport.hpp" |
| 1972 | 29 #include "runtime/jniHandles.hpp" |
| 30 #include "runtime/mutexLocker.hpp" | |
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31 #include "runtime/thread.inline.hpp" |
| 0 | 32 |
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33 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC |
| 0 | 34 |
| 35 JNIHandleBlock* JNIHandles::_global_handles = NULL; | |
| 36 JNIHandleBlock* JNIHandles::_weak_global_handles = NULL; | |
| 37 oop JNIHandles::_deleted_handle = NULL; | |
| 38 | |
| 39 | |
| 40 jobject JNIHandles::make_local(oop obj) { | |
| 41 if (obj == NULL) { | |
| 42 return NULL; // ignore null handles | |
| 43 } else { | |
| 44 Thread* thread = Thread::current(); | |
| 45 assert(Universe::heap()->is_in_reserved(obj), "sanity check"); | |
| 46 return thread->active_handles()->allocate_handle(obj); | |
| 47 } | |
| 48 } | |
| 49 | |
| 50 | |
| 51 // optimized versions | |
| 52 | |
| 53 jobject JNIHandles::make_local(Thread* thread, oop obj) { | |
| 54 if (obj == NULL) { | |
| 55 return NULL; // ignore null handles | |
| 56 } else { | |
| 57 assert(Universe::heap()->is_in_reserved(obj), "sanity check"); | |
| 58 return thread->active_handles()->allocate_handle(obj); | |
| 59 } | |
| 60 } | |
| 61 | |
| 62 | |
| 63 jobject JNIHandles::make_local(JNIEnv* env, oop obj) { | |
| 64 if (obj == NULL) { | |
| 65 return NULL; // ignore null handles | |
| 66 } else { | |
| 67 JavaThread* thread = JavaThread::thread_from_jni_environment(env); | |
| 68 assert(Universe::heap()->is_in_reserved(obj), "sanity check"); | |
| 69 return thread->active_handles()->allocate_handle(obj); | |
| 70 } | |
| 71 } | |
| 72 | |
| 73 | |
| 74 jobject JNIHandles::make_global(Handle obj) { | |
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75 assert(!Universe::heap()->is_gc_active(), "can't extend the root set during GC"); |
| 0 | 76 jobject res = NULL; |
| 77 if (!obj.is_null()) { | |
| 78 // ignore null handles | |
| 79 MutexLocker ml(JNIGlobalHandle_lock); | |
| 80 assert(Universe::heap()->is_in_reserved(obj()), "sanity check"); | |
| 81 res = _global_handles->allocate_handle(obj()); | |
| 82 } else { | |
| 83 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops()); | |
| 84 } | |
| 85 | |
| 86 return res; | |
| 87 } | |
| 88 | |
| 89 | |
| 90 jobject JNIHandles::make_weak_global(Handle obj) { | |
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91 assert(!Universe::heap()->is_gc_active(), "can't extend the root set during GC"); |
| 0 | 92 jobject res = NULL; |
| 93 if (!obj.is_null()) { | |
| 94 // ignore null handles | |
| 95 MutexLocker ml(JNIGlobalHandle_lock); | |
| 96 assert(Universe::heap()->is_in_reserved(obj()), "sanity check"); | |
| 97 res = _weak_global_handles->allocate_handle(obj()); | |
| 98 } else { | |
| 99 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops()); | |
| 100 } | |
| 101 return res; | |
| 102 } | |
| 103 | |
| 104 | |
| 105 void JNIHandles::destroy_global(jobject handle) { | |
| 106 if (handle != NULL) { | |
| 107 assert(is_global_handle(handle), "Invalid delete of global JNI handle"); | |
| 108 *((oop*)handle) = deleted_handle(); // Mark the handle as deleted, allocate will reuse it | |
| 109 } | |
| 110 } | |
| 111 | |
| 112 | |
| 113 void JNIHandles::destroy_weak_global(jobject handle) { | |
| 114 if (handle != NULL) { | |
| 115 assert(!CheckJNICalls || is_weak_global_handle(handle), "Invalid delete of weak global JNI handle"); | |
| 116 *((oop*)handle) = deleted_handle(); // Mark the handle as deleted, allocate will reuse it | |
| 117 } | |
| 118 } | |
| 119 | |
| 120 | |
| 121 void JNIHandles::oops_do(OopClosure* f) { | |
| 122 f->do_oop(&_deleted_handle); | |
| 123 _global_handles->oops_do(f); | |
| 124 } | |
| 125 | |
| 126 | |
| 127 void JNIHandles::weak_oops_do(BoolObjectClosure* is_alive, OopClosure* f) { | |
| 128 _weak_global_handles->weak_oops_do(is_alive, f); | |
| 129 } | |
| 130 | |
| 131 | |
| 132 void JNIHandles::initialize() { | |
| 133 _global_handles = JNIHandleBlock::allocate_block(); | |
| 134 _weak_global_handles = JNIHandleBlock::allocate_block(); | |
| 135 EXCEPTION_MARK; | |
| 136 // We will never reach the CATCH below since Exceptions::_throw will cause | |
| 137 // the VM to exit if an exception is thrown during initialization | |
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138 Klass* k = SystemDictionary::Object_klass(); |
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139 _deleted_handle = InstanceKlass::cast(k)->allocate_instance(CATCH); |
| 0 | 140 } |
| 141 | |
| 142 | |
| 143 bool JNIHandles::is_local_handle(Thread* thread, jobject handle) { | |
| 144 JNIHandleBlock* block = thread->active_handles(); | |
| 145 | |
| 146 // Look back past possible native calls to jni_PushLocalFrame. | |
| 147 while (block != NULL) { | |
| 148 if (block->chain_contains(handle)) { | |
| 149 return true; | |
| 150 } | |
| 151 block = block->pop_frame_link(); | |
| 152 } | |
| 153 return false; | |
| 154 } | |
| 155 | |
| 156 | |
| 157 // Determine if the handle is somewhere in the current thread's stack. | |
| 158 // We easily can't isolate any particular stack frame the handle might | |
| 159 // come from, so we'll check the whole stack. | |
| 160 | |
| 161 bool JNIHandles::is_frame_handle(JavaThread* thr, jobject obj) { | |
| 162 // If there is no java frame, then this must be top level code, such | |
| 163 // as the java command executable, in which case, this type of handle | |
| 164 // is not permitted. | |
| 165 return (thr->has_last_Java_frame() && | |
| 166 (void*)obj < (void*)thr->stack_base() && | |
| 167 (void*)obj >= (void*)thr->last_Java_sp()); | |
| 168 } | |
| 169 | |
| 170 | |
| 171 bool JNIHandles::is_global_handle(jobject handle) { | |
| 172 return _global_handles->chain_contains(handle); | |
| 173 } | |
| 174 | |
| 175 | |
| 176 bool JNIHandles::is_weak_global_handle(jobject handle) { | |
| 177 return _weak_global_handles->chain_contains(handle); | |
| 178 } | |
| 179 | |
| 180 long JNIHandles::global_handle_memory_usage() { | |
| 181 return _global_handles->memory_usage(); | |
| 182 } | |
| 183 | |
| 184 long JNIHandles::weak_global_handle_memory_usage() { | |
| 185 return _weak_global_handles->memory_usage(); | |
| 186 } | |
| 187 | |
| 188 | |
| 189 class AlwaysAliveClosure: public BoolObjectClosure { | |
| 190 public: | |
| 191 bool do_object_b(oop obj) { return true; } | |
| 192 }; | |
| 193 | |
| 194 class CountHandleClosure: public OopClosure { | |
| 195 private: | |
| 196 int _count; | |
| 197 public: | |
| 198 CountHandleClosure(): _count(0) {} | |
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199 virtual void do_oop(oop* unused) { |
| 0 | 200 _count++; |
| 201 } | |
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202 virtual void do_oop(narrowOop* unused) { ShouldNotReachHere(); } |
| 0 | 203 int count() { return _count; } |
| 204 }; | |
| 205 | |
| 206 // We assume this is called at a safepoint: no lock is needed. | |
| 207 void JNIHandles::print_on(outputStream* st) { | |
| 208 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); | |
| 209 assert(_global_handles != NULL && _weak_global_handles != NULL, | |
| 210 "JNIHandles not initialized"); | |
| 211 | |
| 212 CountHandleClosure global_handle_count; | |
| 213 AlwaysAliveClosure always_alive; | |
| 214 oops_do(&global_handle_count); | |
| 215 weak_oops_do(&always_alive, &global_handle_count); | |
| 216 | |
| 217 st->print_cr("JNI global references: %d", global_handle_count.count()); | |
| 218 st->cr(); | |
| 219 st->flush(); | |
| 220 } | |
| 221 | |
| 222 class VerifyHandleClosure: public OopClosure { | |
| 223 public: | |
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224 virtual void do_oop(oop* root) { |
| 0 | 225 (*root)->verify(); |
| 226 } | |
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227 virtual void do_oop(narrowOop* root) { ShouldNotReachHere(); } |
| 0 | 228 }; |
| 229 | |
| 230 void JNIHandles::verify() { | |
| 231 VerifyHandleClosure verify_handle; | |
| 232 AlwaysAliveClosure always_alive; | |
| 233 | |
| 234 oops_do(&verify_handle); | |
| 235 weak_oops_do(&always_alive, &verify_handle); | |
| 236 } | |
| 237 | |
| 238 | |
| 239 | |
| 240 void jni_handles_init() { | |
| 241 JNIHandles::initialize(); | |
| 242 } | |
| 243 | |
| 244 | |
| 245 int JNIHandleBlock::_blocks_allocated = 0; | |
| 246 JNIHandleBlock* JNIHandleBlock::_block_free_list = NULL; | |
| 247 #ifndef PRODUCT | |
| 248 JNIHandleBlock* JNIHandleBlock::_block_list = NULL; | |
| 249 #endif | |
| 250 | |
| 251 | |
| 252 void JNIHandleBlock::zap() { | |
| 253 // Zap block values | |
| 254 _top = 0; | |
| 255 for (int index = 0; index < block_size_in_oops; index++) { | |
| 256 _handles[index] = badJNIHandle; | |
| 257 } | |
| 258 } | |
| 259 | |
| 260 JNIHandleBlock* JNIHandleBlock::allocate_block(Thread* thread) { | |
| 261 assert(thread == NULL || thread == Thread::current(), "sanity check"); | |
| 262 JNIHandleBlock* block; | |
| 263 // Check the thread-local free list for a block so we don't | |
| 264 // have to acquire a mutex. | |
| 265 if (thread != NULL && thread->free_handle_block() != NULL) { | |
| 266 block = thread->free_handle_block(); | |
| 267 thread->set_free_handle_block(block->_next); | |
| 268 } | |
| 269 else { | |
| 270 // locking with safepoint checking introduces a potential deadlock: | |
| 271 // - we would hold JNIHandleBlockFreeList_lock and then Threads_lock | |
| 272 // - another would hold Threads_lock (jni_AttachCurrentThread) and then | |
| 273 // JNIHandleBlockFreeList_lock (JNIHandleBlock::allocate_block) | |
| 274 MutexLockerEx ml(JNIHandleBlockFreeList_lock, | |
| 275 Mutex::_no_safepoint_check_flag); | |
| 276 if (_block_free_list == NULL) { | |
| 277 // Allocate new block | |
| 278 block = new JNIHandleBlock(); | |
| 279 _blocks_allocated++; | |
| 280 if (TraceJNIHandleAllocation) { | |
| 281 tty->print_cr("JNIHandleBlock " INTPTR_FORMAT " allocated (%d total blocks)", | |
| 282 block, _blocks_allocated); | |
| 283 } | |
| 284 if (ZapJNIHandleArea) block->zap(); | |
| 285 #ifndef PRODUCT | |
| 286 // Link new block to list of all allocated blocks | |
| 287 block->_block_list_link = _block_list; | |
| 288 _block_list = block; | |
| 289 #endif | |
| 290 } else { | |
| 291 // Get block from free list | |
| 292 block = _block_free_list; | |
| 293 _block_free_list = _block_free_list->_next; | |
| 294 } | |
| 295 } | |
| 296 block->_top = 0; | |
| 297 block->_next = NULL; | |
| 298 block->_pop_frame_link = NULL; | |
| 299 // _last, _free_list & _allocate_before_rebuild initialized in allocate_handle | |
| 300 debug_only(block->_last = NULL); | |
| 301 debug_only(block->_free_list = NULL); | |
| 302 debug_only(block->_allocate_before_rebuild = -1); | |
| 303 return block; | |
| 304 } | |
| 305 | |
| 306 | |
| 307 void JNIHandleBlock::release_block(JNIHandleBlock* block, Thread* thread) { | |
| 308 assert(thread == NULL || thread == Thread::current(), "sanity check"); | |
| 309 JNIHandleBlock* pop_frame_link = block->pop_frame_link(); | |
| 310 // Put returned block at the beginning of the thread-local free list. | |
| 311 // Note that if thread == NULL, we use it as an implicit argument that | |
| 312 // we _don't_ want the block to be kept on the free_handle_block. | |
| 313 // See for instance JavaThread::exit(). | |
| 314 if (thread != NULL ) { | |
| 315 if (ZapJNIHandleArea) block->zap(); | |
| 316 JNIHandleBlock* freelist = thread->free_handle_block(); | |
| 317 block->_pop_frame_link = NULL; | |
| 318 thread->set_free_handle_block(block); | |
| 319 | |
| 320 // Add original freelist to end of chain | |
| 321 if ( freelist != NULL ) { | |
| 322 while ( block->_next != NULL ) block = block->_next; | |
| 323 block->_next = freelist; | |
| 324 } | |
| 325 block = NULL; | |
| 326 } | |
| 327 if (block != NULL) { | |
| 328 // Return blocks to free list | |
| 329 // locking with safepoint checking introduces a potential deadlock: | |
| 330 // - we would hold JNIHandleBlockFreeList_lock and then Threads_lock | |
| 331 // - another would hold Threads_lock (jni_AttachCurrentThread) and then | |
| 332 // JNIHandleBlockFreeList_lock (JNIHandleBlock::allocate_block) | |
| 333 MutexLockerEx ml(JNIHandleBlockFreeList_lock, | |
| 334 Mutex::_no_safepoint_check_flag); | |
| 335 while (block != NULL) { | |
| 336 if (ZapJNIHandleArea) block->zap(); | |
| 337 JNIHandleBlock* next = block->_next; | |
| 338 block->_next = _block_free_list; | |
| 339 _block_free_list = block; | |
| 340 block = next; | |
| 341 } | |
| 342 } | |
| 343 if (pop_frame_link != NULL) { | |
| 344 // As a sanity check we release blocks pointed to by the pop_frame_link. | |
| 345 // This should never happen (only if PopLocalFrame is not called the | |
| 346 // correct number of times). | |
| 347 release_block(pop_frame_link, thread); | |
| 348 } | |
| 349 } | |
| 350 | |
| 351 | |
| 352 void JNIHandleBlock::oops_do(OopClosure* f) { | |
| 353 JNIHandleBlock* current_chain = this; | |
| 354 // Iterate over chain of blocks, followed by chains linked through the | |
| 355 // pop frame links. | |
| 356 while (current_chain != NULL) { | |
| 357 for (JNIHandleBlock* current = current_chain; current != NULL; | |
| 358 current = current->_next) { | |
| 359 assert(current == current_chain || current->pop_frame_link() == NULL, | |
| 360 "only blocks first in chain should have pop frame link set"); | |
| 361 for (int index = 0; index < current->_top; index++) { | |
| 362 oop* root = &(current->_handles)[index]; | |
| 363 oop value = *root; | |
| 364 // traverse heap pointers only, not deleted handles or free list | |
| 365 // pointers | |
| 366 if (value != NULL && Universe::heap()->is_in_reserved(value)) { | |
| 367 f->do_oop(root); | |
| 368 } | |
| 369 } | |
| 370 // the next handle block is valid only if current block is full | |
| 371 if (current->_top < block_size_in_oops) { | |
| 372 break; | |
| 373 } | |
| 374 } | |
| 375 current_chain = current_chain->pop_frame_link(); | |
| 376 } | |
| 377 } | |
| 378 | |
| 379 | |
| 380 void JNIHandleBlock::weak_oops_do(BoolObjectClosure* is_alive, | |
| 381 OopClosure* f) { | |
| 382 for (JNIHandleBlock* current = this; current != NULL; current = current->_next) { | |
| 383 assert(current->pop_frame_link() == NULL, | |
| 384 "blocks holding weak global JNI handles should not have pop frame link set"); | |
| 385 for (int index = 0; index < current->_top; index++) { | |
| 386 oop* root = &(current->_handles)[index]; | |
| 387 oop value = *root; | |
| 388 // traverse heap pointers only, not deleted handles or free list pointers | |
| 389 if (value != NULL && Universe::heap()->is_in_reserved(value)) { | |
| 390 if (is_alive->do_object_b(value)) { | |
| 391 // The weakly referenced object is alive, update pointer | |
| 392 f->do_oop(root); | |
| 393 } else { | |
| 394 // The weakly referenced object is not alive, clear the reference by storing NULL | |
| 395 if (TraceReferenceGC) { | |
| 396 tty->print_cr("Clearing JNI weak reference (" INTPTR_FORMAT ")", root); | |
| 397 } | |
| 398 *root = NULL; | |
| 399 } | |
| 400 } | |
| 401 } | |
| 402 // the next handle block is valid only if current block is full | |
| 403 if (current->_top < block_size_in_oops) { | |
| 404 break; | |
| 405 } | |
| 406 } | |
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407 |
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408 /* |
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409 * JVMTI data structures may also contain weak oops. The iteration of them |
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410 * is placed here so that we don't need to add it to each of the collectors. |
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411 */ |
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412 JvmtiExport::weak_oops_do(is_alive, f); |
| 0 | 413 } |
| 414 | |
| 415 | |
| 416 jobject JNIHandleBlock::allocate_handle(oop obj) { | |
| 417 assert(Universe::heap()->is_in_reserved(obj), "sanity check"); | |
| 418 if (_top == 0) { | |
| 419 // This is the first allocation or the initial block got zapped when | |
| 420 // entering a native function. If we have any following blocks they are | |
| 421 // not valid anymore. | |
| 422 for (JNIHandleBlock* current = _next; current != NULL; | |
| 423 current = current->_next) { | |
| 424 assert(current->_last == NULL, "only first block should have _last set"); | |
| 425 assert(current->_free_list == NULL, | |
| 426 "only first block should have _free_list set"); | |
| 427 current->_top = 0; | |
| 428 if (ZapJNIHandleArea) current->zap(); | |
| 429 } | |
| 430 // Clear initial block | |
| 431 _free_list = NULL; | |
| 432 _allocate_before_rebuild = 0; | |
| 433 _last = this; | |
| 434 if (ZapJNIHandleArea) zap(); | |
| 435 } | |
| 436 | |
| 437 // Try last block | |
| 438 if (_last->_top < block_size_in_oops) { | |
| 439 oop* handle = &(_last->_handles)[_last->_top++]; | |
| 440 *handle = obj; | |
| 441 return (jobject) handle; | |
| 442 } | |
| 443 | |
| 444 // Try free list | |
| 445 if (_free_list != NULL) { | |
| 446 oop* handle = _free_list; | |
| 447 _free_list = (oop*) *_free_list; | |
| 448 *handle = obj; | |
| 449 return (jobject) handle; | |
| 450 } | |
| 451 // Check if unused block follow last | |
| 452 if (_last->_next != NULL) { | |
| 453 // update last and retry | |
| 454 _last = _last->_next; | |
| 455 return allocate_handle(obj); | |
| 456 } | |
| 457 | |
| 458 // No space available, we have to rebuild free list or expand | |
| 459 if (_allocate_before_rebuild == 0) { | |
| 460 rebuild_free_list(); // updates _allocate_before_rebuild counter | |
| 461 } else { | |
| 462 // Append new block | |
| 463 Thread* thread = Thread::current(); | |
| 464 Handle obj_handle(thread, obj); | |
| 465 // This can block, so we need to preserve obj accross call. | |
| 466 _last->_next = JNIHandleBlock::allocate_block(thread); | |
| 467 _last = _last->_next; | |
| 468 _allocate_before_rebuild--; | |
| 469 obj = obj_handle(); | |
| 470 } | |
| 471 return allocate_handle(obj); // retry | |
| 472 } | |
| 473 | |
| 474 | |
| 475 void JNIHandleBlock::rebuild_free_list() { | |
| 476 assert(_allocate_before_rebuild == 0 && _free_list == NULL, "just checking"); | |
| 477 int free = 0; | |
| 478 int blocks = 0; | |
| 479 for (JNIHandleBlock* current = this; current != NULL; current = current->_next) { | |
| 480 for (int index = 0; index < current->_top; index++) { | |
| 481 oop* handle = &(current->_handles)[index]; | |
| 482 if (*handle == JNIHandles::deleted_handle()) { | |
| 483 // this handle was cleared out by a delete call, reuse it | |
| 484 *handle = (oop) _free_list; | |
| 485 _free_list = handle; | |
| 486 free++; | |
| 487 } | |
| 488 } | |
| 489 // we should not rebuild free list if there are unused handles at the end | |
| 490 assert(current->_top == block_size_in_oops, "just checking"); | |
| 491 blocks++; | |
| 492 } | |
| 493 // Heuristic: if more than half of the handles are free we rebuild next time | |
| 494 // as well, otherwise we append a corresponding number of new blocks before | |
| 495 // attempting a free list rebuild again. | |
| 496 int total = blocks * block_size_in_oops; | |
| 497 int extra = total - 2*free; | |
| 498 if (extra > 0) { | |
| 499 // Not as many free handles as we would like - compute number of new blocks to append | |
| 500 _allocate_before_rebuild = (extra + block_size_in_oops - 1) / block_size_in_oops; | |
| 501 } | |
| 502 if (TraceJNIHandleAllocation) { | |
| 503 tty->print_cr("Rebuild free list JNIHandleBlock " INTPTR_FORMAT " blocks=%d used=%d free=%d add=%d", | |
| 504 this, blocks, total-free, free, _allocate_before_rebuild); | |
| 505 } | |
| 506 } | |
| 507 | |
| 508 | |
| 509 bool JNIHandleBlock::contains(jobject handle) const { | |
| 510 return ((jobject)&_handles[0] <= handle && handle<(jobject)&_handles[_top]); | |
| 511 } | |
| 512 | |
| 513 | |
| 514 bool JNIHandleBlock::chain_contains(jobject handle) const { | |
| 515 for (JNIHandleBlock* current = (JNIHandleBlock*) this; current != NULL; current = current->_next) { | |
| 516 if (current->contains(handle)) { | |
| 517 return true; | |
| 518 } | |
| 519 } | |
| 520 return false; | |
| 521 } | |
| 522 | |
| 523 | |
| 524 int JNIHandleBlock::length() const { | |
| 525 int result = 1; | |
| 526 for (JNIHandleBlock* current = _next; current != NULL; current = current->_next) { | |
| 527 result++; | |
| 528 } | |
| 529 return result; | |
| 530 } | |
| 531 | |
| 532 // This method is not thread-safe, i.e., must be called whule holding a lock on the | |
| 533 // structure. | |
| 534 long JNIHandleBlock::memory_usage() const { | |
| 535 return length() * sizeof(JNIHandleBlock); | |
| 536 } | |
| 537 | |
| 538 | |
| 539 #ifndef PRODUCT | |
| 540 | |
| 541 bool JNIHandleBlock::any_contains(jobject handle) { | |
| 542 for (JNIHandleBlock* current = _block_list; current != NULL; current = current->_block_list_link) { | |
| 543 if (current->contains(handle)) { | |
| 544 return true; | |
| 545 } | |
| 546 } | |
| 547 return false; | |
| 548 } | |
| 549 | |
| 550 void JNIHandleBlock::print_statistics() { | |
| 551 int used_blocks = 0; | |
| 552 int free_blocks = 0; | |
| 553 int used_handles = 0; | |
| 554 int free_handles = 0; | |
| 555 JNIHandleBlock* block = _block_list; | |
| 556 while (block != NULL) { | |
| 557 if (block->_top > 0) { | |
| 558 used_blocks++; | |
| 559 } else { | |
| 560 free_blocks++; | |
| 561 } | |
| 562 used_handles += block->_top; | |
| 563 free_handles += (block_size_in_oops - block->_top); | |
| 564 block = block->_block_list_link; | |
| 565 } | |
| 566 tty->print_cr("JNIHandleBlocks statistics"); | |
| 567 tty->print_cr("- blocks allocated: %d", used_blocks + free_blocks); | |
| 568 tty->print_cr("- blocks in use: %d", used_blocks); | |
| 569 tty->print_cr("- blocks free: %d", free_blocks); | |
| 570 tty->print_cr("- handles in use: %d", used_handles); | |
| 571 tty->print_cr("- handles free: %d", free_handles); | |
| 572 } | |
| 573 | |
| 574 #endif |