Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2012 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #include "src/optimizing-compile-dispatcher.h" |
| 6 | |
| 7 | #include "src/base/atomicops.h" |
| 8 | #include "src/full-codegen/full-codegen.h" |
| 9 | #include "src/isolate.h" |
| 10 | #include "src/v8.h" |
| 11 | |
| 12 | namespace v8 { |
| 13 | namespace internal { |
| 14 | |
| 15 | namespace { |
| 16 | |
| 17 | void DisposeOptimizedCompileJob(OptimizedCompileJob* job, |
| 18 | bool restore_function_code) { |
| 19 | // The recompile job is allocated in the CompilationInfo's zone. |
| 20 | CompilationInfo* info = job->info(); |
| 21 | if (restore_function_code) { |
| 22 | if (info->is_osr()) { |
| 23 | if (!job->IsWaitingForInstall()) { |
| 24 | // Remove stack check that guards OSR entry on original code. |
| 25 | Handle<Code> code = info->unoptimized_code(); |
| 26 | uint32_t offset = code->TranslateAstIdToPcOffset(info->osr_ast_id()); |
| 27 | BackEdgeTable::RemoveStackCheck(code, offset); |
| 28 | } |
| 29 | } else { |
| 30 | Handle<JSFunction> function = info->closure(); |
| 31 | function->ReplaceCode(function->shared()->code()); |
| 32 | } |
| 33 | } |
| 34 | delete info; |
| 35 | } |
| 36 | |
| 37 | } // namespace |
| 38 | |
| 39 | |
| 40 | class OptimizingCompileDispatcher::CompileTask : public v8::Task { |
| 41 | public: |
| 42 | explicit CompileTask(Isolate* isolate) : isolate_(isolate) { |
| 43 | OptimizingCompileDispatcher* dispatcher = |
| 44 | isolate_->optimizing_compile_dispatcher(); |
| 45 | base::LockGuard<base::Mutex> lock_guard(&dispatcher->ref_count_mutex_); |
| 46 | ++dispatcher->ref_count_; |
| 47 | } |
| 48 | |
| 49 | virtual ~CompileTask() {} |
| 50 | |
| 51 | private: |
| 52 | // v8::Task overrides. |
| 53 | void Run() override { |
| 54 | DisallowHeapAllocation no_allocation; |
| 55 | DisallowHandleAllocation no_handles; |
| 56 | DisallowHandleDereference no_deref; |
| 57 | |
| 58 | OptimizingCompileDispatcher* dispatcher = |
| 59 | isolate_->optimizing_compile_dispatcher(); |
| 60 | { |
| 61 | TimerEventScope<TimerEventRecompileConcurrent> timer(isolate_); |
| 62 | |
| 63 | if (dispatcher->recompilation_delay_ != 0) { |
| 64 | base::OS::Sleep(base::TimeDelta::FromMilliseconds( |
| 65 | dispatcher->recompilation_delay_)); |
| 66 | } |
| 67 | |
| 68 | dispatcher->CompileNext(dispatcher->NextInput(true)); |
| 69 | } |
| 70 | { |
| 71 | base::LockGuard<base::Mutex> lock_guard(&dispatcher->ref_count_mutex_); |
| 72 | if (--dispatcher->ref_count_ == 0) { |
| 73 | dispatcher->ref_count_zero_.NotifyOne(); |
| 74 | } |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | Isolate* isolate_; |
| 79 | |
| 80 | DISALLOW_COPY_AND_ASSIGN(CompileTask); |
| 81 | }; |
| 82 | |
| 83 | |
| 84 | OptimizingCompileDispatcher::~OptimizingCompileDispatcher() { |
| 85 | #ifdef DEBUG |
| 86 | { |
| 87 | base::LockGuard<base::Mutex> lock_guard(&ref_count_mutex_); |
| 88 | DCHECK_EQ(0, ref_count_); |
| 89 | } |
| 90 | #endif |
| 91 | DCHECK_EQ(0, input_queue_length_); |
| 92 | DeleteArray(input_queue_); |
| 93 | if (FLAG_concurrent_osr) { |
| 94 | #ifdef DEBUG |
| 95 | for (int i = 0; i < osr_buffer_capacity_; i++) { |
| 96 | CHECK_NULL(osr_buffer_[i]); |
| 97 | } |
| 98 | #endif |
| 99 | DeleteArray(osr_buffer_); |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | |
| 104 | OptimizedCompileJob* OptimizingCompileDispatcher::NextInput( |
| 105 | bool check_if_flushing) { |
| 106 | base::LockGuard<base::Mutex> access_input_queue_(&input_queue_mutex_); |
| 107 | if (input_queue_length_ == 0) return NULL; |
| 108 | OptimizedCompileJob* job = input_queue_[InputQueueIndex(0)]; |
| 109 | DCHECK_NOT_NULL(job); |
| 110 | input_queue_shift_ = InputQueueIndex(1); |
| 111 | input_queue_length_--; |
| 112 | if (check_if_flushing) { |
| 113 | if (static_cast<ModeFlag>(base::Acquire_Load(&mode_)) == FLUSH) { |
| 114 | if (!job->info()->is_osr()) { |
| 115 | AllowHandleDereference allow_handle_dereference; |
| 116 | DisposeOptimizedCompileJob(job, true); |
| 117 | } |
| 118 | return NULL; |
| 119 | } |
| 120 | } |
| 121 | return job; |
| 122 | } |
| 123 | |
| 124 | |
| 125 | void OptimizingCompileDispatcher::CompileNext(OptimizedCompileJob* job) { |
| 126 | if (!job) return; |
| 127 | |
| 128 | // The function may have already been optimized by OSR. Simply continue. |
| 129 | OptimizedCompileJob::Status status = job->OptimizeGraph(); |
| 130 | USE(status); // Prevent an unused-variable error in release mode. |
| 131 | DCHECK(status != OptimizedCompileJob::FAILED); |
| 132 | |
| 133 | // The function may have already been optimized by OSR. Simply continue. |
| 134 | // Use a mutex to make sure that functions marked for install |
| 135 | // are always also queued. |
| 136 | base::LockGuard<base::Mutex> access_output_queue_(&output_queue_mutex_); |
| 137 | output_queue_.push(job); |
| 138 | isolate_->stack_guard()->RequestInstallCode(); |
| 139 | } |
| 140 | |
| 141 | |
| 142 | void OptimizingCompileDispatcher::FlushOutputQueue(bool restore_function_code) { |
| 143 | for (;;) { |
| 144 | OptimizedCompileJob* job = NULL; |
| 145 | { |
| 146 | base::LockGuard<base::Mutex> access_output_queue_(&output_queue_mutex_); |
| 147 | if (output_queue_.empty()) return; |
| 148 | job = output_queue_.front(); |
| 149 | output_queue_.pop(); |
| 150 | } |
| 151 | |
| 152 | // OSR jobs are dealt with separately. |
| 153 | if (!job->info()->is_osr()) { |
| 154 | DisposeOptimizedCompileJob(job, restore_function_code); |
| 155 | } |
| 156 | } |
| 157 | } |
| 158 | |
| 159 | |
| 160 | void OptimizingCompileDispatcher::FlushOsrBuffer(bool restore_function_code) { |
| 161 | for (int i = 0; i < osr_buffer_capacity_; i++) { |
| 162 | if (osr_buffer_[i] != NULL) { |
| 163 | DisposeOptimizedCompileJob(osr_buffer_[i], restore_function_code); |
| 164 | osr_buffer_[i] = NULL; |
| 165 | } |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | |
| 170 | void OptimizingCompileDispatcher::Flush() { |
| 171 | base::Release_Store(&mode_, static_cast<base::AtomicWord>(FLUSH)); |
| 172 | if (FLAG_block_concurrent_recompilation) Unblock(); |
| 173 | { |
| 174 | base::LockGuard<base::Mutex> lock_guard(&ref_count_mutex_); |
| 175 | while (ref_count_ > 0) ref_count_zero_.Wait(&ref_count_mutex_); |
| 176 | base::Release_Store(&mode_, static_cast<base::AtomicWord>(COMPILE)); |
| 177 | } |
| 178 | FlushOutputQueue(true); |
| 179 | if (FLAG_concurrent_osr) FlushOsrBuffer(true); |
| 180 | if (FLAG_trace_concurrent_recompilation) { |
| 181 | PrintF(" ** Flushed concurrent recompilation queues.\n"); |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | |
| 186 | void OptimizingCompileDispatcher::Stop() { |
| 187 | base::Release_Store(&mode_, static_cast<base::AtomicWord>(FLUSH)); |
| 188 | if (FLAG_block_concurrent_recompilation) Unblock(); |
| 189 | { |
| 190 | base::LockGuard<base::Mutex> lock_guard(&ref_count_mutex_); |
| 191 | while (ref_count_ > 0) ref_count_zero_.Wait(&ref_count_mutex_); |
| 192 | base::Release_Store(&mode_, static_cast<base::AtomicWord>(COMPILE)); |
| 193 | } |
| 194 | |
| 195 | if (recompilation_delay_ != 0) { |
| 196 | // At this point the optimizing compiler thread's event loop has stopped. |
| 197 | // There is no need for a mutex when reading input_queue_length_. |
| 198 | while (input_queue_length_ > 0) CompileNext(NextInput()); |
| 199 | InstallOptimizedFunctions(); |
| 200 | } else { |
| 201 | FlushOutputQueue(false); |
| 202 | } |
| 203 | |
| 204 | if (FLAG_concurrent_osr) FlushOsrBuffer(false); |
| 205 | |
| 206 | if ((FLAG_trace_osr || FLAG_trace_concurrent_recompilation) && |
| 207 | FLAG_concurrent_osr) { |
| 208 | PrintF("[COSR hit rate %d / %d]\n", osr_hits_, osr_attempts_); |
| 209 | } |
| 210 | } |
| 211 | |
| 212 | |
| 213 | void OptimizingCompileDispatcher::InstallOptimizedFunctions() { |
| 214 | HandleScope handle_scope(isolate_); |
| 215 | |
| 216 | for (;;) { |
| 217 | OptimizedCompileJob* job = NULL; |
| 218 | { |
| 219 | base::LockGuard<base::Mutex> access_output_queue_(&output_queue_mutex_); |
| 220 | if (output_queue_.empty()) return; |
| 221 | job = output_queue_.front(); |
| 222 | output_queue_.pop(); |
| 223 | } |
| 224 | CompilationInfo* info = job->info(); |
| 225 | Handle<JSFunction> function(*info->closure()); |
| 226 | if (info->is_osr()) { |
| 227 | if (FLAG_trace_osr) { |
| 228 | PrintF("[COSR - "); |
| 229 | function->ShortPrint(); |
| 230 | PrintF(" is ready for install and entry at AST id %d]\n", |
| 231 | info->osr_ast_id().ToInt()); |
| 232 | } |
| 233 | job->WaitForInstall(); |
| 234 | // Remove stack check that guards OSR entry on original code. |
| 235 | Handle<Code> code = info->unoptimized_code(); |
| 236 | uint32_t offset = code->TranslateAstIdToPcOffset(info->osr_ast_id()); |
| 237 | BackEdgeTable::RemoveStackCheck(code, offset); |
| 238 | } else { |
| 239 | if (function->IsOptimized()) { |
| 240 | if (FLAG_trace_concurrent_recompilation) { |
| 241 | PrintF(" ** Aborting compilation for "); |
| 242 | function->ShortPrint(); |
| 243 | PrintF(" as it has already been optimized.\n"); |
| 244 | } |
| 245 | DisposeOptimizedCompileJob(job, false); |
| 246 | } else { |
| 247 | Handle<Code> code = Compiler::GetConcurrentlyOptimizedCode(job); |
| 248 | function->ReplaceCode(code.is_null() ? function->shared()->code() |
| 249 | : *code); |
| 250 | } |
| 251 | } |
| 252 | } |
| 253 | } |
| 254 | |
| 255 | |
| 256 | void OptimizingCompileDispatcher::QueueForOptimization( |
| 257 | OptimizedCompileJob* job) { |
| 258 | DCHECK(IsQueueAvailable()); |
| 259 | CompilationInfo* info = job->info(); |
| 260 | if (info->is_osr()) { |
| 261 | osr_attempts_++; |
| 262 | AddToOsrBuffer(job); |
| 263 | // Add job to the front of the input queue. |
| 264 | base::LockGuard<base::Mutex> access_input_queue(&input_queue_mutex_); |
| 265 | DCHECK_LT(input_queue_length_, input_queue_capacity_); |
| 266 | // Move shift_ back by one. |
| 267 | input_queue_shift_ = InputQueueIndex(input_queue_capacity_ - 1); |
| 268 | input_queue_[InputQueueIndex(0)] = job; |
| 269 | input_queue_length_++; |
| 270 | } else { |
| 271 | // Add job to the back of the input queue. |
| 272 | base::LockGuard<base::Mutex> access_input_queue(&input_queue_mutex_); |
| 273 | DCHECK_LT(input_queue_length_, input_queue_capacity_); |
| 274 | input_queue_[InputQueueIndex(input_queue_length_)] = job; |
| 275 | input_queue_length_++; |
| 276 | } |
| 277 | if (FLAG_block_concurrent_recompilation) { |
| 278 | blocked_jobs_++; |
| 279 | } else { |
| 280 | V8::GetCurrentPlatform()->CallOnBackgroundThread( |
| 281 | new CompileTask(isolate_), v8::Platform::kShortRunningTask); |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | |
| 286 | void OptimizingCompileDispatcher::Unblock() { |
| 287 | while (blocked_jobs_ > 0) { |
| 288 | V8::GetCurrentPlatform()->CallOnBackgroundThread( |
| 289 | new CompileTask(isolate_), v8::Platform::kShortRunningTask); |
| 290 | blocked_jobs_--; |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | |
| 295 | OptimizedCompileJob* OptimizingCompileDispatcher::FindReadyOSRCandidate( |
| 296 | Handle<JSFunction> function, BailoutId osr_ast_id) { |
| 297 | for (int i = 0; i < osr_buffer_capacity_; i++) { |
| 298 | OptimizedCompileJob* current = osr_buffer_[i]; |
| 299 | if (current != NULL && current->IsWaitingForInstall() && |
| 300 | current->info()->HasSameOsrEntry(function, osr_ast_id)) { |
| 301 | osr_hits_++; |
| 302 | osr_buffer_[i] = NULL; |
| 303 | return current; |
| 304 | } |
| 305 | } |
| 306 | return NULL; |
| 307 | } |
| 308 | |
| 309 | |
| 310 | bool OptimizingCompileDispatcher::IsQueuedForOSR(Handle<JSFunction> function, |
| 311 | BailoutId osr_ast_id) { |
| 312 | for (int i = 0; i < osr_buffer_capacity_; i++) { |
| 313 | OptimizedCompileJob* current = osr_buffer_[i]; |
| 314 | if (current != NULL && |
| 315 | current->info()->HasSameOsrEntry(function, osr_ast_id)) { |
| 316 | return !current->IsWaitingForInstall(); |
| 317 | } |
| 318 | } |
| 319 | return false; |
| 320 | } |
| 321 | |
| 322 | |
| 323 | bool OptimizingCompileDispatcher::IsQueuedForOSR(JSFunction* function) { |
| 324 | for (int i = 0; i < osr_buffer_capacity_; i++) { |
| 325 | OptimizedCompileJob* current = osr_buffer_[i]; |
| 326 | if (current != NULL && *current->info()->closure() == function) { |
| 327 | return !current->IsWaitingForInstall(); |
| 328 | } |
| 329 | } |
| 330 | return false; |
| 331 | } |
| 332 | |
| 333 | |
| 334 | void OptimizingCompileDispatcher::AddToOsrBuffer(OptimizedCompileJob* job) { |
| 335 | // Find the next slot that is empty or has a stale job. |
| 336 | OptimizedCompileJob* stale = NULL; |
| 337 | while (true) { |
| 338 | stale = osr_buffer_[osr_buffer_cursor_]; |
| 339 | if (stale == NULL || stale->IsWaitingForInstall()) break; |
| 340 | osr_buffer_cursor_ = (osr_buffer_cursor_ + 1) % osr_buffer_capacity_; |
| 341 | } |
| 342 | |
| 343 | // Add to found slot and dispose the evicted job. |
| 344 | if (stale != NULL) { |
| 345 | DCHECK(stale->IsWaitingForInstall()); |
| 346 | CompilationInfo* info = stale->info(); |
| 347 | if (FLAG_trace_osr) { |
| 348 | PrintF("[COSR - Discarded "); |
| 349 | info->closure()->PrintName(); |
| 350 | PrintF(", AST id %d]\n", info->osr_ast_id().ToInt()); |
| 351 | } |
| 352 | DisposeOptimizedCompileJob(stale, false); |
| 353 | } |
| 354 | osr_buffer_[osr_buffer_cursor_] = job; |
| 355 | osr_buffer_cursor_ = (osr_buffer_cursor_ + 1) % osr_buffer_capacity_; |
| 356 | } |
| 357 | } // namespace internal |
| 358 | } // namespace v8 |