Initial Vexta Core v0.1.0 release

src/threadsafety.h

@@ -0,0 +1,78 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2020 The Bitcoin Core developers
+// Copyright (c) 2014-2020 The DigiByte Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef DIGIBYTE_THREADSAFETY_H
+#define DIGIBYTE_THREADSAFETY_H
+
+#include <mutex>
+
+#ifdef __clang__
+// TL;DR Add GUARDED_BY(mutex) to member variables. The others are
+// rarely necessary. Ex: int nFoo GUARDED_BY(cs_foo);
+//
+// See https://clang.llvm.org/docs/ThreadSafetyAnalysis.html
+// for documentation.  The clang compiler can do advanced static analysis
+// of locking when given the -Wthread-safety option.
+#define LOCKABLE __attribute__((lockable))
+#define SCOPED_LOCKABLE __attribute__((scoped_lockable))
+#define GUARDED_BY(x) __attribute__((guarded_by(x)))
+#define PT_GUARDED_BY(x) __attribute__((pt_guarded_by(x)))
+#define ACQUIRED_AFTER(...) __attribute__((acquired_after(__VA_ARGS__)))
+#define ACQUIRED_BEFORE(...) __attribute__((acquired_before(__VA_ARGS__)))
+#define EXCLUSIVE_LOCK_FUNCTION(...) __attribute__((exclusive_lock_function(__VA_ARGS__)))
+#define SHARED_LOCK_FUNCTION(...) __attribute__((shared_lock_function(__VA_ARGS__)))
+#define EXCLUSIVE_TRYLOCK_FUNCTION(...) __attribute__((exclusive_trylock_function(__VA_ARGS__)))
+#define SHARED_TRYLOCK_FUNCTION(...) __attribute__((shared_trylock_function(__VA_ARGS__)))
+#define UNLOCK_FUNCTION(...) __attribute__((unlock_function(__VA_ARGS__)))
+#define LOCK_RETURNED(x) __attribute__((lock_returned(x)))
+#define LOCKS_EXCLUDED(...) __attribute__((locks_excluded(__VA_ARGS__)))
+#define EXCLUSIVE_LOCKS_REQUIRED(...) __attribute__((exclusive_locks_required(__VA_ARGS__)))
+#define SHARED_LOCKS_REQUIRED(...) __attribute__((shared_locks_required(__VA_ARGS__)))
+#define NO_THREAD_SAFETY_ANALYSIS __attribute__((no_thread_safety_analysis))
+#define ASSERT_EXCLUSIVE_LOCK(...) __attribute__((assert_exclusive_lock(__VA_ARGS__)))
+#else
+#define LOCKABLE
+#define SCOPED_LOCKABLE
+#define GUARDED_BY(x)
+#define PT_GUARDED_BY(x)
+#define ACQUIRED_AFTER(...)
+#define ACQUIRED_BEFORE(...)
+#define EXCLUSIVE_LOCK_FUNCTION(...)
+#define SHARED_LOCK_FUNCTION(...)
+#define EXCLUSIVE_TRYLOCK_FUNCTION(...)
+#define SHARED_TRYLOCK_FUNCTION(...)
+#define UNLOCK_FUNCTION(...)
+#define LOCK_RETURNED(x)
+#define LOCKS_EXCLUDED(...)
+#define EXCLUSIVE_LOCKS_REQUIRED(...)
+#define SHARED_LOCKS_REQUIRED(...)
+#define NO_THREAD_SAFETY_ANALYSIS
+#define ASSERT_EXCLUSIVE_LOCK(...)
+#endif // __GNUC__
+
+// StdMutex provides an annotated version of std::mutex for us,
+// and should only be used when sync.h Mutex/LOCK/etc are not usable.
+class LOCKABLE StdMutex : public std::mutex
+{
+public:
+#ifdef __clang__
+    //! For negative capabilities in the Clang Thread Safety Analysis.
+    //! A negative requirement uses the EXCLUSIVE_LOCKS_REQUIRED attribute, in conjunction
+    //! with the ! operator, to indicate that a mutex should not be held.
+    const StdMutex& operator!() const { return *this; }
+#endif // __clang__
+};
+
+// StdLockGuard provides an annotated version of std::lock_guard for us,
+// and should only be used when sync.h Mutex/LOCK/etc are not usable.
+class SCOPED_LOCKABLE StdLockGuard : public std::lock_guard<StdMutex>
+{
+public:
+    explicit StdLockGuard(StdMutex& cs) EXCLUSIVE_LOCK_FUNCTION(cs) : std::lock_guard<StdMutex>(cs) {}
+    ~StdLockGuard() UNLOCK_FUNCTION() {}
+};
+
+#endif // DIGIBYTE_THREADSAFETY_H