diff options
Diffstat (limited to 'src/sync.h')
| -rw-r--r-- | src/sync.h | 55 |
1 files changed, 45 insertions, 10 deletions
diff --git a/src/sync.h b/src/sync.h index 85000a9151..7ec4b668ac 100644 --- a/src/sync.h +++ b/src/sync.h @@ -6,8 +6,11 @@ #ifndef BITCOIN_SYNC_H #define BITCOIN_SYNC_H +#ifdef DEBUG_LOCKCONTENTION #include <logging.h> #include <logging/timer.h> +#endif + #include <threadsafety.h> #include <util/macros.h> @@ -80,8 +83,6 @@ void AssertLockNotHeldInternal(const char* pszName, const char* pszFile, int nLi inline void DeleteLock(void* cs) {} inline bool LockStackEmpty() { return true; } #endif -#define AssertLockHeld(cs) AssertLockHeldInternal(#cs, __FILE__, __LINE__, &cs) -#define AssertLockNotHeld(cs) AssertLockNotHeldInternal(#cs, __FILE__, __LINE__, &cs) /** * Template mixin that adds -Wthread-safety locking annotations and lock order @@ -126,7 +127,25 @@ public: using RecursiveMutex = AnnotatedMixin<std::recursive_mutex>; /** Wrapped mutex: supports waiting but not recursive locking */ -typedef AnnotatedMixin<std::mutex> Mutex; +using Mutex = AnnotatedMixin<std::mutex>; + +/** Different type to mark Mutex at global scope + * + * Thread safety analysis can't handle negative assertions about mutexes + * with global scope well, so mark them with a separate type, and + * eventually move all the mutexes into classes so they are not globally + * visible. + * + * See: https://github.com/bitcoin/bitcoin/pull/20272#issuecomment-720755781 + */ +class GlobalMutex : public Mutex { }; + +#define AssertLockHeld(cs) AssertLockHeldInternal(#cs, __FILE__, __LINE__, &cs) + +inline void AssertLockNotHeldInline(const char* name, const char* file, int line, Mutex* cs) EXCLUSIVE_LOCKS_REQUIRED(!cs) { AssertLockNotHeldInternal(name, file, line, cs); } +inline void AssertLockNotHeldInline(const char* name, const char* file, int line, RecursiveMutex* cs) LOCKS_EXCLUDED(cs) { AssertLockNotHeldInternal(name, file, line, cs); } +inline void AssertLockNotHeldInline(const char* name, const char* file, int line, GlobalMutex* cs) LOCKS_EXCLUDED(cs) { AssertLockNotHeldInternal(name, file, line, cs); } +#define AssertLockNotHeld(cs) AssertLockNotHeldInline(#cs, __FILE__, __LINE__, &cs) /** Wrapper around std::unique_lock style lock for Mutex. */ template <typename Mutex, typename Base = typename Mutex::UniqueLock> @@ -136,8 +155,10 @@ private: void Enter(const char* pszName, const char* pszFile, int nLine) { EnterCritical(pszName, pszFile, nLine, Base::mutex()); +#ifdef DEBUG_LOCKCONTENTION if (Base::try_lock()) return; LOG_TIME_MICROS_WITH_CATEGORY(strprintf("lock contention %s, %s:%d", pszName, pszFile, nLine), BCLog::LOCK); +#endif Base::lock(); } @@ -218,17 +239,31 @@ public: friend class reverse_lock; }; -#define REVERSE_LOCK(g) typename std::decay<decltype(g)>::type::reverse_lock PASTE2(revlock, __COUNTER__)(g, #g, __FILE__, __LINE__) +#define REVERSE_LOCK(g) typename std::decay<decltype(g)>::type::reverse_lock UNIQUE_NAME(revlock)(g, #g, __FILE__, __LINE__) template<typename MutexArg> using DebugLock = UniqueLock<typename std::remove_reference<typename std::remove_pointer<MutexArg>::type>::type>; -#define LOCK(cs) DebugLock<decltype(cs)> PASTE2(criticalblock, __COUNTER__)(cs, #cs, __FILE__, __LINE__) +// When locking a Mutex, require negative capability to ensure the lock +// is not already held +inline Mutex& MaybeCheckNotHeld(Mutex& cs) EXCLUSIVE_LOCKS_REQUIRED(!cs) LOCK_RETURNED(cs) { return cs; } +inline Mutex* MaybeCheckNotHeld(Mutex* cs) EXCLUSIVE_LOCKS_REQUIRED(!cs) LOCK_RETURNED(cs) { return cs; } + +// When locking a GlobalMutex, just check it is not locked in the surrounding scope +inline GlobalMutex& MaybeCheckNotHeld(GlobalMutex& cs) LOCKS_EXCLUDED(cs) LOCK_RETURNED(cs) { return cs; } +inline GlobalMutex* MaybeCheckNotHeld(GlobalMutex* cs) LOCKS_EXCLUDED(cs) LOCK_RETURNED(cs) { return cs; } + +// When locking a RecursiveMutex, it's okay to already hold the lock +// but check that it is not known to be locked in the surrounding scope anyway +inline RecursiveMutex& MaybeCheckNotHeld(RecursiveMutex& cs) LOCKS_EXCLUDED(cs) LOCK_RETURNED(cs) { return cs; } +inline RecursiveMutex* MaybeCheckNotHeld(RecursiveMutex* cs) LOCKS_EXCLUDED(cs) LOCK_RETURNED(cs) { return cs; } + +#define LOCK(cs) DebugLock<decltype(cs)> UNIQUE_NAME(criticalblock)(MaybeCheckNotHeld(cs), #cs, __FILE__, __LINE__) #define LOCK2(cs1, cs2) \ - DebugLock<decltype(cs1)> criticalblock1(cs1, #cs1, __FILE__, __LINE__); \ - DebugLock<decltype(cs2)> criticalblock2(cs2, #cs2, __FILE__, __LINE__); -#define TRY_LOCK(cs, name) DebugLock<decltype(cs)> name(cs, #cs, __FILE__, __LINE__, true) -#define WAIT_LOCK(cs, name) DebugLock<decltype(cs)> name(cs, #cs, __FILE__, __LINE__) + DebugLock<decltype(cs1)> criticalblock1(MaybeCheckNotHeld(cs1), #cs1, __FILE__, __LINE__); \ + DebugLock<decltype(cs2)> criticalblock2(MaybeCheckNotHeld(cs2), #cs2, __FILE__, __LINE__); +#define TRY_LOCK(cs, name) DebugLock<decltype(cs)> name(MaybeCheckNotHeld(cs), #cs, __FILE__, __LINE__, true) +#define WAIT_LOCK(cs, name) DebugLock<decltype(cs)> name(MaybeCheckNotHeld(cs), #cs, __FILE__, __LINE__) #define ENTER_CRITICAL_SECTION(cs) \ { \ @@ -267,7 +302,7 @@ using DebugLock = UniqueLock<typename std::remove_reference<typename std::remove //! //! The above is detectable at compile-time with the -Wreturn-local-addr flag in //! gcc and the -Wreturn-stack-address flag in clang, both enabled by default. -#define WITH_LOCK(cs, code) [&]() -> decltype(auto) { LOCK(cs); code; }() +#define WITH_LOCK(cs, code) (MaybeCheckNotHeld(cs), [&]() -> decltype(auto) { LOCK(cs); code; }()) class CSemaphore { |