libs/qm-dsp/thread/Thread.h

   1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
   2
   3 /*
   4     QM DSP Library
   5
   6     Centre for Digital Music, Queen Mary, University of London.
   7     This file copyright Chris Cannam, used with permission.
   8 */
   9
  10 #ifndef _THREAD_H_
  11 #define _THREAD_H_
  12
  13 #ifdef _WIN32
  14 #include <windows.h>
  15 #else /* !_WIN32 */
  16 #ifdef USE_PTHREADS
  17 #include <pthread.h>
  18 #endif /* USE_PTHREADS */
  19 #endif /* !_WIN32 */
  20
  21 #include <string>
  22
  23 //#define DEBUG_THREAD 1
  24 //#define DEBUG_MUTEX 1
  25 //#define DEBUG_CONDITION 1
  26
  27 class Thread
  28 {
  29 public:
  30 #ifdef _WIN32
  31     typedef HANDLE Id;
  32 #else
  33 #ifdef USE_PTHREADS
  34     typedef pthread_t Id;
  35 #endif
  36 #endif
  37
  38     Thread();
  39     virtual ~Thread();
  40
  41     Id id();
  42
  43     void start();
  44     void wait();
  45
  46     static bool threadingAvailable();
  47
  48 protected:
  49     virtual void run() = 0;
  50
  51 private:
  52 #ifdef _WIN32
  53     HANDLE m_id;
  54     bool m_extant;
  55     static DWORD WINAPI staticRun(LPVOID lpParam);
  56 #else
  57 #ifdef USE_PTHREADS
  58     pthread_t m_id;
  59     bool m_extant;
  60     static void *staticRun(void *);
  61 #endif
  62 #endif
  63 };
  64
  65 class Mutex
  66 {
  67 public:
  68     Mutex();
  69     ~Mutex();
  70
  71     void lock();
  72     void unlock();
  73     bool trylock();
  74
  75 private:
  76 #ifdef _WIN32
  77     HANDLE m_mutex;
  78 #ifndef NO_THREAD_CHECKS
  79     DWORD m_lockedBy;
  80 #endif
  81 #else
  82 #ifdef USE_PTHREADS
  83     pthread_mutex_t m_mutex;
  84 #ifndef NO_THREAD_CHECKS
  85     pthread_t m_lockedBy;
  86     bool m_locked;
  87 #endif
  88 #endif
  89 #endif
  90 };
  91
  92 class MutexLocker
  93 {
  94 public:
  95     MutexLocker(Mutex *);
  96     ~MutexLocker();
  97
  98 private:
  99     Mutex *m_mutex;
 100 };
 101
 102 class Condition
 103 {
 104 public:
 105     Condition(std::string name);
 106     ~Condition();
 107
 108     // Condition bundles a pthread-style condition variable and mutex
 109     // into one class.
 110
 111     // To wait on a condition, call lock(), test termination variables
 112     // as appropriate, and then wait().  The condition will be
 113     // unlocked for the duration of the wait() call, which will end
 114     // when the condition is signalled.  The condition will be locked
 115     // again when wait() returns.
 116     //
 117     // To signal a condition, call signal().  If the waiting thread
 118     // will be performing tests between its own lock() and wait(),
 119     // then the signalling thread should also lock() before it signals
 120     // (and then unlock afterwards).  If the signalling thread always
 121     // locks the mutex during signalling, then the waiting thread
 122     // knows that signals will only happen during wait() and not be
 123     // missed at other times.
 124
 125     void lock();
 126     void unlock();
 127     void wait(int us = 0);
 128
 129     void signal();
 130
 131 private:
 132
 133 #ifdef _WIN32
 134     HANDLE m_mutex;
 135     HANDLE m_condition;
 136     bool m_locked;
 137 #else
 138 #ifdef USE_PTHREADS
 139     pthread_mutex_t m_mutex;
 140     pthread_cond_t m_condition;
 141     bool m_locked;
 142 #endif
 143 #endif
 144 #ifdef DEBUG_CONDITION
 145     std::string m_name;
 146 #endif
 147 };
 148
 149 #endif