Add new thread class file

distrho/extra/d_thread.hpp

@@ -0,0 +1,291 @@
+/*
+ * 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_THREAD_HPP_INCLUDED
+#define DISTRHO_THREAD_HPP_INCLUDED
+
+#include "d_mutex.hpp"
+#include "d_sleep.hpp"
+#include "d_string.hpp"
+
+#if defined(__GLIBC__) && (__GLIBC__ * 1000 + __GLIBC_MINOR__) >= 2012
+// has pthread_setname_np
+#elif defined(DISTRHO_OS_LINUX)
+# include <sys/prctl.h>
+#endif
+
+START_NAMESPACE_DISTRHO
+
+// -----------------------------------------------------------------------
+// Thread class
+
+class Thread
+{
+protected:
+    /*
+     * Constructor.
+     */
+    Thread(const char* const threadName = nullptr) noexcept
+        : fLock(),
+          fName(threadName),
+#ifdef PTW32_DLLPORT
+          fHandle({nullptr, 0}),
+#else
+          fHandle(0),
+#endif
+          fShouldExit(false) {}
+
+    /*
+     * Destructor.
+     */
+    virtual ~Thread() /*noexcept*/
+    {
+        DISTRHO_SAFE_ASSERT(! isThreadRunning());
+
+        stopThread(-1);
+    }
+
+    /*
+     * Virtual function to be implemented by the subclass.
+     */
+    virtual void run() = 0;
+
+    // -------------------------------------------------------------------
+
+public:
+    /*
+     * Check if the thread is running.
+     */
+    bool isThreadRunning() const noexcept
+    {
+#ifdef PTW32_DLLPORT
+        return (fHandle.p != nullptr);
+#else
+        return (fHandle != 0);
+#endif
+    }
+
+    /*
+     * Check if the thread should exit.
+     */
+    bool shouldThreadExit() const noexcept
+    {
+        return fShouldExit;
+    }
+
+    /*
+     * Start the thread.
+     */
+    bool startThread() noexcept
+    {
+        // check if already running
+        DISTRHO_SAFE_ASSERT_RETURN(! isThreadRunning(), true);
+
+        const MutexLocker cml(fLock);
+
+        fShouldExit = false;
+
+        pthread_t handle;
+
+        if (pthread_create(&handle, nullptr, _entryPoint, this) == 0)
+        {
+#ifdef PTW32_DLLPORT
+            DISTRHO_SAFE_ASSERT_RETURN(handle.p != nullptr, false);
+#else
+            DISTRHO_SAFE_ASSERT_RETURN(handle != 0, false);
+#endif
+            pthread_detach(handle);
+            _copyFrom(handle);
+
+            // wait for thread to start
+            fLock.lock();
+
+            return true;
+        }
+
+        return false;
+    }
+
+    /*
+     * Stop the thread.
+     * In the 'timeOutMilliseconds':
+     * = 0 -> no wait
+     * > 0 -> wait timeout value
+     * < 0 -> wait forever
+     */
+    bool stopThread(const int timeOutMilliseconds) noexcept
+    {
+        const MutexLocker cml(fLock);
+
+        if (isThreadRunning())
+        {
+            signalThreadShouldExit();
+
+            if (timeOutMilliseconds != 0)
+            {
+                // Wait for the thread to stop
+                int timeOutCheck = (timeOutMilliseconds == 1 || timeOutMilliseconds == -1) ? timeOutMilliseconds : timeOutMilliseconds/2;
+
+                for (; isThreadRunning();)
+                {
+                    d_msleep(2);
+
+                    if (timeOutCheck < 0)
+                        continue;
+
+                    if (timeOutCheck > 0)
+                        timeOutCheck -= 1;
+                    else
+                        break;
+                }
+            }
+
+            if (isThreadRunning())
+            {
+                // should never happen!
+                d_stderr2("Carla assertion failure: \"! isThreadRunning()\" in file %s, line %i", __FILE__, __LINE__);
+
+                // copy thread id so we can clear our one
+                pthread_t threadId;
+                _copyTo(threadId);
+                _init();
+
+                try {
+                    pthread_cancel(threadId);
+                } DISTRHO_SAFE_EXCEPTION("pthread_cancel");
+
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    /*
+     * Tell the thread to stop as soon as possible.
+     */
+    void signalThreadShouldExit() noexcept
+    {
+        fShouldExit = true;
+    }
+
+    // -------------------------------------------------------------------
+
+    /*
+     * Returns the name of the thread.
+     * This is the name that gets set in the constructor.
+     */
+    const d_string& getThreadName() const noexcept
+    {
+        return fName;
+    }
+
+    /*
+     * Changes the name of the caller thread.
+     */
+    static void setCurrentThreadName(const char* const name) noexcept
+    {
+        DISTRHO_SAFE_ASSERT_RETURN(name != nullptr && name[0] != '\0',);
+
+#if defined(__GLIBC__) && (__GLIBC__ * 1000 + __GLIBC_MINOR__) >= 2012
+        pthread_setname_np(pthread_self(), name);
+#elif defined(DISTRHO_OS_LINUX)
+        prctl(PR_SET_NAME, name, 0, 0, 0);
+#endif
+    }
+
+    // -------------------------------------------------------------------
+
+private:
+    Mutex              fLock;       // Thread lock
+    const d_string     fName;       // Thread name
+    volatile pthread_t fHandle;     // Handle for this thread
+    volatile bool      fShouldExit; // true if thread should exit
+
+    /*
+     * Init pthread type.
+     */
+    void _init() noexcept
+    {
+#ifdef PTW32_DLLPORT
+        fHandle.p = nullptr;
+        fHandle.x = 0;
+#else
+        fHandle = 0;
+#endif
+    }
+
+    /*
+     * Copy our pthread type from another var.
+     */
+    void _copyFrom(const pthread_t& handle) noexcept
+    {
+#ifdef PTW32_DLLPORT
+        fHandle.p = handle.p;
+        fHandle.x = handle.x;
+#else
+        fHandle = handle;
+#endif
+    }
+
+    /*
+     * Copy our pthread type to another var.
+     */
+    void _copyTo(volatile pthread_t& handle) const noexcept
+    {
+#ifdef PTW32_DLLPORT
+        handle.p = fHandle.p;
+        handle.x = fHandle.x;
+#else
+        handle = fHandle;
+#endif
+    }
+
+    /*
+     * Thread entry point.
+     */
+    void _runEntryPoint() noexcept
+    {
+        // report ready
+        fLock.unlock();
+
+        setCurrentThreadName(fName);
+
+        try {
+            run();
+        } catch(...) {}
+
+        // done
+        _init();
+    }
+
+    /*
+     * Thread entry point.
+     */
+    static void* _entryPoint(void* userData) noexcept
+    {
+        static_cast<Thread*>(userData)->_runEntryPoint();
+        return nullptr;
+    }
+
+    DISTRHO_DECLARE_NON_COPY_CLASS(Thread)
+};
+
+// -----------------------------------------------------------------------
+
+END_NAMESPACE_DISTRHO
+
+#endif // DISTRHO_THREAD_HPP_INCLUDED