| 1 | //===-- tsan_mutexset.h -----------------------------------------*- C++ -*-===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // This file is a part of ThreadSanitizer (TSan), a race detector. |
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| 10 | // |
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| 11 | // MutexSet holds the set of mutexes currently held by a thread. |
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| 12 | //===----------------------------------------------------------------------===// |
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| 13 | #ifndef TSAN_MUTEXSET_H |
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| 14 | #define TSAN_MUTEXSET_H |
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| 15 | |
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| 16 | #include "tsan_defs.h" |
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| 17 | |
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| 18 | namespace __tsan { |
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| 19 | |
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| 20 | class MutexSet { |
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| 21 | public: |
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| 22 | // Holds limited number of mutexes. |
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| 23 | // The oldest mutexes are discarded on overflow. |
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| 24 | static constexpr uptr kMaxSize = 16; |
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| 25 | struct Desc { |
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| 26 | uptr addr; |
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| 27 | StackID stack_id; |
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| 28 | u32 seq; |
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| 29 | u32 count; |
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| 30 | bool write; |
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| 31 | |
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| 32 | Desc() { internal_memset(s: this, c: 0, n: sizeof(*this)); } |
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| 33 | Desc(const Desc& other) { *this = other; } |
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| 34 | Desc& operator=(const MutexSet::Desc& other) { |
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| 35 | internal_memcpy(dest: this, src: &other, n: sizeof(*this)); |
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| 36 | return *this; |
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| 37 | } |
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| 38 | }; |
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| 39 | |
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| 40 | MutexSet(); |
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| 41 | void Reset(); |
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| 42 | void AddAddr(uptr addr, StackID stack_id, bool write); |
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| 43 | void DelAddr(uptr addr, bool destroy = false); |
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| 44 | uptr Size() const; |
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| 45 | Desc Get(uptr i) const; |
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| 46 | |
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| 47 | private: |
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| 48 | #if !SANITIZER_GO |
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| 49 | u32 seq_ = 0; |
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| 50 | uptr size_ = 0; |
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| 51 | Desc descs_[kMaxSize]; |
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| 52 | |
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| 53 | void RemovePos(uptr i); |
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| 54 | #endif |
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| 55 | }; |
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| 56 | |
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| 57 | // MutexSet is too large to live on stack. |
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| 58 | // DynamicMutexSet can be use used to create local MutexSet's. |
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| 59 | class DynamicMutexSet { |
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| 60 | public: |
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| 61 | DynamicMutexSet(); |
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| 62 | ~DynamicMutexSet(); |
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| 63 | MutexSet* operator->() { return ptr_; } |
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| 64 | operator MutexSet*() { return ptr_; } |
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| 65 | DynamicMutexSet(const DynamicMutexSet&) = delete; |
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| 66 | DynamicMutexSet& operator=(const DynamicMutexSet&) = delete; |
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| 67 | |
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| 68 | private: |
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| 69 | MutexSet* ptr_; |
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| 70 | #if SANITIZER_GO |
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| 71 | MutexSet set_; |
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| 72 | #endif |
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| 73 | }; |
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| 74 | |
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| 75 | // Go does not have mutexes, so do not spend memory and time. |
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| 76 | // (Go sync.Mutex is actually a semaphore -- can be unlocked |
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| 77 | // in different goroutine). |
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| 78 | #if SANITIZER_GO |
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| 79 | MutexSet::MutexSet() {} |
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| 80 | void MutexSet::Reset() {} |
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| 81 | void MutexSet::AddAddr(uptr addr, StackID stack_id, bool write) {} |
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| 82 | void MutexSet::DelAddr(uptr addr, bool destroy) {} |
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| 83 | uptr MutexSet::Size() const { return 0; } |
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| 84 | MutexSet::Desc MutexSet::Get(uptr i) const { return Desc(); } |
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| 85 | DynamicMutexSet::DynamicMutexSet() : ptr_(&set_) {} |
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| 86 | DynamicMutexSet::~DynamicMutexSet() {} |
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| 87 | #endif |
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| 88 | |
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| 89 | } // namespace __tsan |
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| 90 | |
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| 91 | #endif // TSAN_MUTEXSET_H |
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| 92 | |
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