1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ART_RUNTIME_GC_SCOPED_GC_CRITICAL_SECTION_H_ 18 #define ART_RUNTIME_GC_SCOPED_GC_CRITICAL_SECTION_H_ 19 20 #include "base/locks.h" 21 #include "collector_type.h" 22 #include "gc_cause.h" 23 24 namespace art { 25 26 class Thread; 27 28 namespace gc { 29 30 // The use of ScopedGCCriticalSection should be preferred whenever possible. 31 class GCCriticalSection { 32 public: GCCriticalSection(Thread * self,const char * name)33 GCCriticalSection(Thread* self, const char* name) 34 : self_(self), section_name_(name) {} ~GCCriticalSection()35 ~GCCriticalSection() {} 36 37 // Starts a GCCriticalSection. Returns the previous no-suspension reason. 38 const char* Enter(GcCause cause, CollectorType type) ACQUIRE(Roles::uninterruptible_); 39 40 // Ends a GCCriticalSection. Takes the old no-suspension reason. 41 void Exit(const char* old_reason) RELEASE(Roles::uninterruptible_); 42 43 private: 44 Thread* const self_; 45 const char* section_name_; 46 }; 47 48 // Wait until the GC is finished and then prevent the GC from starting until the destructor. Used 49 // to prevent deadlocks in places where we call ClassLinker::VisitClass with all the threads 50 // suspended. 51 class ScopedGCCriticalSection { 52 public: 53 ScopedGCCriticalSection(Thread* self, GcCause cause, CollectorType collector_type) 54 ACQUIRE(Roles::uninterruptible_); 55 ~ScopedGCCriticalSection() RELEASE(Roles::uninterruptible_); 56 57 private: 58 GCCriticalSection critical_section_; 59 const char* old_no_suspend_reason_; 60 }; 61 62 // The use of ScopedGCCriticalSection should be preferred whenever possible. 63 // This class allows thread suspension but should never be used with allocations because of the 64 // deadlock risk. TODO: Add a new thread role for "no allocations" that still allows suspension. 65 class ScopedInterruptibleGCCriticalSection { 66 public: 67 ScopedInterruptibleGCCriticalSection(Thread* self, GcCause cause, CollectorType type); 68 ~ScopedInterruptibleGCCriticalSection(); 69 70 private: 71 Thread* const self_; 72 }; 73 74 75 } // namespace gc 76 } // namespace art 77 78 #endif // ART_RUNTIME_GC_SCOPED_GC_CRITICAL_SECTION_H_ 79