Add d_mutex.hpp file, for a Mutex class

distrho/extra/d_mutex.hpp

@@ -0,0 +1,221 @@
+/*
+ * DISTRHO Plugin Framework (DPF)
+ * Copyright (C) 2012-2014 Filipe Coelho <falktx@falktx.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any purpose with
+ * or without fee is hereby granted, provided that the above copyright notice and this
+ * permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
+ * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef DISTRHO_MUTEX_HPP_INCLUDED
+#define DISTRHO_MUTEX_HPP_INCLUDED
+
+#include "../DistrhoUtils.hpp"
+
+#include <pthread.h>
+
+// -----------------------------------------------------------------------
+// Mutex class
+
+class Mutex
+{
+public:
+    /*
+     * Constructor.
+     */
+    Mutex() noexcept
+    {
+        pthread_mutex_init(&fMutex, nullptr);
+    }
+
+    /*
+     * Destructor.
+     */
+    ~Mutex() noexcept
+    {
+        pthread_mutex_destroy(&fMutex);
+    }
+
+    /*
+     * Lock the mutex.
+     */
+    void lock() const noexcept
+    {
+        pthread_mutex_lock(&fMutex);
+    }
+
+    /*
+     * Try to lock the mutex.
+     * Returns true if successful.
+     */
+    bool tryLock() const noexcept
+    {
+        return (pthread_mutex_trylock(&fMutex) == 0);
+    }
+
+    /*
+     * Unlock the mutex.
+     */
+    void unlock() const noexcept
+    {
+        pthread_mutex_unlock(&fMutex);
+    }
+
+private:
+    mutable pthread_mutex_t fMutex;
+
+    DISTRHO_PREVENT_HEAP_ALLOCATION
+    DISTRHO_DECLARE_NON_COPY_CLASS(Mutex)
+};
+
+// -----------------------------------------------------------------------
+// RecursiveMutex class
+
+class RecursiveMutex
+{
+public:
+    /*
+     * Constructor.
+     */
+    RecursiveMutex() noexcept
+    {
+#ifdef DISTRHO_OS_WINDOWS
+        InitializeCriticalSection(&fSection);
+#else
+        pthread_mutexattr_t atts;
+        pthread_mutexattr_init(&atts);
+        pthread_mutexattr_settype(&atts, PTHREAD_MUTEX_RECURSIVE);
+        pthread_mutex_init(&fMutex, &atts);
+        pthread_mutexattr_destroy(&atts);
+#endif
+    }
+
+    /*
+     * Destructor.
+     */
+    ~RecursiveMutex() noexcept
+    {
+#ifdef DISTRHO_OS_WINDOWS
+        DeleteCriticalSection(&fSection);
+#else
+        pthread_mutex_destroy(&fMutex);
+#endif
+    }
+
+    /*
+     * Lock the mutex.
+     */
+    void lock() const noexcept
+    {
+#ifdef DISTRHO_OS_WINDOWS
+        EnterCriticalSection(&fSection);
+#else
+        pthread_mutex_lock(&fMutex);
+#endif
+    }
+
+    /*
+     * Try to lock the mutex.
+     * Returns true if successful.
+     */
+    bool tryLock() const noexcept
+    {
+#ifdef DISTRHO_OS_WINDOWS
+        return (TryEnterCriticalSection(&fSection) != FALSE);
+#else
+        return (pthread_mutex_trylock(&fMutex) == 0);
+#endif
+    }
+
+    /*
+     * Unlock the mutex.
+     */
+    void unlock() const noexcept
+    {
+#ifdef DISTRHO_OS_WINDOWS
+        LeaveCriticalSection(&fSection);
+#else
+        pthread_mutex_unlock(&fMutex);
+#endif
+    }
+
+private:
+#ifdef DISTRHO_OS_WINDOWS
+    mutable CRITICAL_SECTION fSection;
+#else
+    mutable pthread_mutex_t fMutex;
+#endif
+
+    DISTRHO_PREVENT_HEAP_ALLOCATION
+    DISTRHO_DECLARE_NON_COPY_CLASS(RecursiveMutex)
+};
+
+// -----------------------------------------------------------------------
+// Helper class to lock&unlock a mutex during a function scope.
+
+template <class Mutex>
+class ScopedLocker
+{
+public:
+    ScopedLocker(const Mutex& mutex) noexcept
+        : fMutex(mutex)
+    {
+        fMutex.lock();
+    }
+
+    ~ScopedLocker() noexcept
+    {
+        fMutex.unlock();
+    }
+
+private:
+    const Mutex& fMutex;
+
+    DISTRHO_PREVENT_HEAP_ALLOCATION
+    DISTRHO_DECLARE_NON_COPY_CLASS(ScopedLocker)
+};
+
+// -----------------------------------------------------------------------
+// Helper class to unlock&lock a mutex during a function scope.
+
+template <class Mutex>
+class ScopedUnlocker
+{
+public:
+    ScopedUnlocker(const Mutex& mutex) noexcept
+        : fMutex(mutex)
+    {
+        fMutex.unlock();
+    }
+
+    ~ScopedUnlocker() noexcept
+    {
+        fMutex.lock();
+    }
+
+private:
+    const Mutex& fMutex;
+
+    DISTRHO_PREVENT_HEAP_ALLOCATION
+    DISTRHO_DECLARE_NON_COPY_CLASS(ScopedUnlocker)
+};
+
+// -----------------------------------------------------------------------
+// Define types
+
+typedef ScopedLocker<Mutex>          MutexLocker;
+typedef ScopedLocker<RecursiveMutex> RecursiveMutexLocker;
+
+typedef ScopedUnlocker<Mutex>          MutexUnlocker;
+typedef ScopedUnlocker<RecursiveMutex> RecursiveMutexUnlocker;
+
+// -----------------------------------------------------------------------
+
+#endif // DISTRHO_MUTEX_HPP_INCLUDED