Made use of clang's Thread Safety Analysis

mutex.hpp

@@ -0,0 +1,106 @@
+// Based on https://clang.llvm.org/docs/ThreadSafetyAnalysis.html
+#ifndef SIMPLE_WEB_MUTEX_HPP
+#define SIMPLE_WEB_MUTEX_HPP
+
+#include <mutex>
+
+// Enable thread safety attributes only with clang.
+#if defined(__clang__) && (!defined(SWIG))
+#define THREAD_ANNOTATION_ATTRIBUTE__(x) __attribute__((x))
+#else
+#define THREAD_ANNOTATION_ATTRIBUTE__(x) // no-op
+#endif
+
+#define CAPABILITY(x) \
+  THREAD_ANNOTATION_ATTRIBUTE__(capability(x))
+
+#define SCOPED_CAPABILITY \
+  THREAD_ANNOTATION_ATTRIBUTE__(scoped_lockable)
+
+#define GUARDED_BY(x) \
+  THREAD_ANNOTATION_ATTRIBUTE__(guarded_by(x))
+
+#define PT_GUARDED_BY(x) \
+  THREAD_ANNOTATION_ATTRIBUTE__(pt_guarded_by(x))
+
+#define ACQUIRED_BEFORE(...) \
+  THREAD_ANNOTATION_ATTRIBUTE__(acquired_before(__VA_ARGS__))
+
+#define ACQUIRED_AFTER(...) \
+  THREAD_ANNOTATION_ATTRIBUTE__(acquired_after(__VA_ARGS__))
+
+#define REQUIRES(...) \
+  THREAD_ANNOTATION_ATTRIBUTE__(requires_capability(__VA_ARGS__))
+
+#define REQUIRES_SHARED(...) \
+  THREAD_ANNOTATION_ATTRIBUTE__(requires_shared_capability(__VA_ARGS__))
+
+#define ACQUIRE(...) \
+  THREAD_ANNOTATION_ATTRIBUTE__(acquire_capability(__VA_ARGS__))
+
+#define ACQUIRE_SHARED(...) \
+  THREAD_ANNOTATION_ATTRIBUTE__(acquire_shared_capability(__VA_ARGS__))
+
+#define RELEASE(...) \
+  THREAD_ANNOTATION_ATTRIBUTE__(release_capability(__VA_ARGS__))
+
+#define RELEASE_SHARED(...) \
+  THREAD_ANNOTATION_ATTRIBUTE__(release_shared_capability(__VA_ARGS__))
+
+#define TRY_ACQUIRE(...) \
+  THREAD_ANNOTATION_ATTRIBUTE__(try_acquire_capability(__VA_ARGS__))
+
+#define TRY_ACQUIRE_SHARED(...) \
+  THREAD_ANNOTATION_ATTRIBUTE__(try_acquire_shared_capability(__VA_ARGS__))
+
+#define EXCLUDES(...) \
+  THREAD_ANNOTATION_ATTRIBUTE__(locks_excluded(__VA_ARGS__))
+
+#define ASSERT_CAPABILITY(x) \
+  THREAD_ANNOTATION_ATTRIBUTE__(assert_capability(x))
+
+#define ASSERT_SHARED_CAPABILITY(x) \
+  THREAD_ANNOTATION_ATTRIBUTE__(assert_shared_capability(x))
+
+#define RETURN_CAPABILITY(x) \
+  THREAD_ANNOTATION_ATTRIBUTE__(lock_returned(x))
+
+#define NO_THREAD_SAFETY_ANALYSIS \
+  THREAD_ANNOTATION_ATTRIBUTE__(no_thread_safety_analysis)
+
+namespace SimpleWeb {
+  /// Defines an annotated interface for mutexes.
+  class CAPABILITY("mutex") Mutex {
+    std::mutex mutex;
+
+  public:
+    void lock() ACQUIRE() {
+      mutex.lock();
+    }
+
+    void unlock() RELEASE() {
+      mutex.unlock();
+    }
+  };
+
+  class SCOPED_CAPABILITY LockGuard {
+    Mutex &mutex;
+    bool locked = true;
+
+  public:
+    LockGuard(Mutex &mutex_) ACQUIRE(mutex_) : mutex(mutex_) {
+      mutex.lock();
+    }
+    void unlock() RELEASE() {
+      mutex.unlock();
+      locked = false;
+    }
+    ~LockGuard() RELEASE() {
+      if(locked)
+        mutex.unlock();
+    }
+  };
+
+} // namespace SimpleWeb
+
+#endif // SIMPLE_WEB_MUTEX_HPP