//------------------------------------------------------------------------------ /* This file is part of Beast: https://github.com/vinniefalco/Beast Copyright 2013, Vinnie Falco Portions of this file are from JUCE. Copyright (c) 2013 - Raw Material Software Ltd. Please visit http://www.juce.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 BEAST_THREADS_THREAD_H_INCLUDED #define BEAST_THREADS_THREAD_H_INCLUDED #include #include #include #include namespace beast { //============================================================================== /** Encapsulates a thread. Subclasses derive from Thread and implement the run() method, in which they do their business. The thread can then be started with the startThread() method and controlled with various other methods. This class also contains some thread-related static methods, such as sleep(), yield(), getCurrentThreadId() etc. @see CriticalSection, WaitableEvent, Process, ThreadWithProgressWindow, MessageManagerLock */ class Thread : LeakChecked , public Uncopyable { public: //============================================================================== /** Creates a thread. When first created, the thread is not running. Use the startThread() method to start it. */ explicit Thread (const String& threadName); /** Destructor. If the thread has not been stopped first, this will generate a fatal error. */ virtual ~Thread(); //============================================================================== /** Must be implemented to perform the thread's actual code. Remember that the thread must regularly check the threadShouldExit() method whilst running, and if this returns true it should return from the run() method as soon as possible to avoid being forcibly killed. @see threadShouldExit, startThread */ virtual void run() = 0; //============================================================================== // Thread control functions.. /** Starts the thread running. This will start the thread's run() method. (if it's already started, startThread() won't do anything). @see stopThread */ void startThread(); /** Starts the thread with a given priority. Launches the thread with a given priority, where 0 = lowest, 10 = highest. If the thread is already running, its priority will be changed. @see startThread, setPriority */ void startThread (int priority); /** Attempts to stop the thread running. This method will cause the threadShouldExit() method to return true and call notify() in case the thread is currently waiting. Hopefully the thread will then respond to this by exiting cleanly, and the stopThread method will wait for a given time-period for this to happen. If the thread is stuck and fails to respond after the time-out, it gets forcibly killed, which is a very bad thing to happen, as it could still be holding locks, etc. which are needed by other parts of your program. @param timeOutMilliseconds The number of milliseconds to wait for the thread to finish before killing it by force. A negative value in here will wait forever. @see signalThreadShouldExit, threadShouldExit, waitForThreadToExit, isThreadRunning @returns true if the thread exits, or false if the timeout expires first. */ bool stopThread (int timeOutMilliseconds = -1); /** Stop the thread without blocking. This calls signalThreadShouldExit followed by notify. */ void stopThreadAsync (); //============================================================================== /** Returns true if the thread is currently active */ bool isThreadRunning() const; /** Sets a flag to tell the thread it should stop. Calling this means that the threadShouldExit() method will then return true. The thread should be regularly checking this to see whether it should exit. If your thread makes use of wait(), you might want to call notify() after calling this method, to interrupt any waits that might be in progress, and allow it to reach a point where it can exit. @see threadShouldExit @see waitForThreadToExit */ void signalThreadShouldExit(); /** Checks whether the thread has been told to stop running. Threads need to check this regularly, and if it returns true, they should return from their run() method at the first possible opportunity. @see signalThreadShouldExit */ inline bool threadShouldExit() const { return shouldExit; } /** Waits for the thread to stop. This will waits until isThreadRunning() is false or until a timeout expires. @param timeOutMilliseconds the time to wait, in milliseconds. If this value is less than zero, it will wait forever. @returns true if the thread exits, or false if the timeout expires first. */ bool waitForThreadToExit (int timeOutMilliseconds = -1) const; //============================================================================== /** Changes the thread's priority. May return false if for some reason the priority can't be changed. @param priority the new priority, in the range 0 (lowest) to 10 (highest). A priority of 5 is normal. */ bool setPriority (int priority); /** Changes the priority of the caller thread. Similar to setPriority(), but this static method acts on the caller thread. May return false if for some reason the priority can't be changed. @see setPriority */ static bool setCurrentThreadPriority (int priority); //============================================================================== /** Sets the affinity mask for the thread. This will only have an effect next time the thread is started - i.e. if the thread is already running when called, it'll have no effect. @see setCurrentThreadAffinityMask */ void setAffinityMask (std::uint32_t affinityMask); /** Changes the affinity mask for the caller thread. This will change the affinity mask for the thread that calls this static method. @see setAffinityMask */ static void setCurrentThreadAffinityMask (std::uint32_t affinityMask); //============================================================================== // this can be called from any thread that needs to pause.. static void sleep (int milliseconds); /** Yields the calling thread's current time-slot. */ static void yield(); //============================================================================== /** Makes the thread wait for a notification. This puts the thread to sleep until either the timeout period expires, or another thread calls the notify() method to wake it up. A negative time-out value means that the method will wait indefinitely. @returns true if the event has been signalled, false if the timeout expires. */ bool wait (int timeOutMilliseconds = -1) const; /** Wakes up the thread. If the thread has called the wait() method, this will wake it up. @see wait */ void notify() const; //============================================================================== /** A value type used for thread IDs. @see getCurrentThreadId(), getThreadId() */ typedef void* ThreadID; /** Returns an id that identifies the caller thread. To find the ID of a particular thread object, use getThreadId(). @returns a unique identifier that identifies the calling thread. @see getThreadId */ static ThreadID getCurrentThreadId(); /** Finds the thread object that is currently running. Note that the main UI thread (or other non-Beast threads) don't have a Thread object associated with them, so this will return 0. */ static Thread* getCurrentThread(); /** Returns the ID of this thread. That means the ID of this thread object - not of the thread that's calling the method. This can change when the thread is started and stopped, and will be invalid if the thread's not actually running. @see getCurrentThreadId */ ThreadID getThreadId() const noexcept { return threadId; } /** Returns the name of the thread. This is the name that gets set in the constructor. */ const String& getThreadName() const { return threadName; } /** Changes the name of the caller thread. Different OSes may place different length or content limits on this name. */ static void setCurrentThreadName (const String& newThreadName); private: //============================================================================== const String threadName; void* volatile threadHandle; ThreadID threadId; RecursiveMutex startStopLock; WaitableEvent startSuspensionEvent, defaultEvent; int threadPriority; std::uint32_t affinityMask; bool volatile shouldExit; #ifndef DOXYGEN friend void beast_threadEntryPoint (void*); #endif void launchThread(); void closeThreadHandle(); void killThread(); void threadEntryPoint(); static bool setThreadPriority (void*, int); }; } #endif