xpcom/threads/nsTimerImpl.h

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  17  * The Original Code is mozilla.org code.
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  21  * Portions created by the Initial Developer are Copyright (C) 2001
  22  * the Initial Developer. All Rights Reserved.
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  24  * Contributor(s):
  25  *   Stuart Parmenter <pavlov@netscape.com>
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  39  * ***** END LICENSE BLOCK ***** */
  40
  41 #ifndef nsTimerImpl_h___
  42 #define nsTimerImpl_h___
  43
  44 //#define FORCE_PR_LOG /* Allow logging in the release build */
  45
  46 #include "nsITimer.h"
  47 #include "nsVoidArray.h"
  48 #include "nsIThread.h"
  49 #include "nsIObserver.h"
  50
  51 #include "nsCOMPtr.h"
  52
  53 #include "prlog.h"
  54
  55 #if defined(PR_LOGGING)
  56 static PRLogModuleInfo *gTimerLog = PR_NewLogModule("nsTimerImpl");
  57 #define DEBUG_TIMERS 1
  58 #else
  59 #undef DEBUG_TIMERS
  60 #endif
  61
  62 #define NS_TIMER_CLASSNAME "Timer"
  63 #define NS_TIMER_CID \
  64 { /* 5ff24248-1dd2-11b2-8427-fbab44f29bc8 */         \
  65      0x5ff24248,                                     \
  66      0x1dd2,                                         \
  67      0x11b2,                                         \
  68     {0x84, 0x27, 0xfb, 0xab, 0x44, 0xf2, 0x9b, 0xc8} \
  69 }
  70
  71 enum {
  72   CALLBACK_TYPE_UNKNOWN   = 0,
  73   CALLBACK_TYPE_INTERFACE = 1,
  74   CALLBACK_TYPE_FUNC      = 2,
  75   CALLBACK_TYPE_OBSERVER  = 3
  76 };
  77
  78 // Two timer deadlines must differ by less than half the PRIntervalTime domain.
  79 #define DELAY_INTERVAL_LIMIT    PR_BIT(8 * sizeof(PRIntervalTime) - 1)
  80
  81 // Maximum possible delay (XXX rework to use ms rather than interval ticks).
  82 #define DELAY_INTERVAL_MAX      (DELAY_INTERVAL_LIMIT - 1)
  83
  84 // Is interval-time t less than u, even if t has wrapped PRIntervalTime?
  85 #define TIMER_LESS_THAN(t, u)   ((t) - (u) > DELAY_INTERVAL_LIMIT)
  86
  87 class nsTimerImpl : public nsITimer
  88 {
  89 public:
  90
  91   nsTimerImpl();
  92
  93   static NS_HIDDEN_(nsresult) Startup();
  94   static NS_HIDDEN_(void) Shutdown();
  95
  96   friend class TimerThread;
  97
  98   void Fire();
  99   void PostTimerEvent();
 100   void SetDelayInternal(PRUint32 aDelay);
 101
 102   NS_DECL_ISUPPORTS
 103   NS_DECL_NSITIMER
 104
 105   PRInt32 GetGeneration() { return mGeneration; }
 106
 107 private:
 108   ~nsTimerImpl();
 109   nsresult InitCommon(PRUint32 aType, PRUint32 aDelay);
 110
 111   void ReleaseCallback()
 112   {
 113     if (mCallbackType == CALLBACK_TYPE_INTERFACE)
 114       NS_RELEASE(mCallback.i);
 115     else if (mCallbackType == CALLBACK_TYPE_OBSERVER)
 116       NS_RELEASE(mCallback.o);
 117   }
 118
 119   nsCOMPtr<nsIThread>   mCallingThread;
 120
 121   void *                mClosure;
 122
 123   union {
 124     nsTimerCallbackFunc c;
 125     nsITimerCallback *  i;
 126     nsIObserver *       o;
 127   } mCallback;
 128
 129   // These members are set by Init (called from NS_NewTimer) and never reset.
 130   PRUint8               mCallbackType;
 131
 132   // These members are set by the initiating thread, when the timer's type is
 133   // changed and during the period where it fires on that thread.
 134   PRUint8               mType;
 135   PRPackedBool          mFiring;
 136
 137
 138   // Use a PRBool (int) here to isolate loads and stores of these two members
 139   // done on various threads under the protection of TimerThread::mLock, from
 140   // loads and stores done on the initiating/type-changing/timer-firing thread
 141   // to the above PRUint8/PRPackedBool members.
 142   PRBool                mArmed;
 143   PRBool                mCanceled;
 144
 145   // The generation number of this timer, re-generated each time the timer is
 146   // initialized so one-shot timers can be canceled and re-initialized by the
 147   // arming thread without any bad race conditions.
 148   PRInt32               mGeneration;
 149
 150   PRUint32              mDelay;
 151   PRIntervalTime        mTimeout;
 152
 153 #ifdef DEBUG_TIMERS
 154   PRIntervalTime        mStart, mStart2;
 155   static double         sDeltaSum;
 156   static double         sDeltaSumSquared;
 157   static double         sDeltaNum;
 158 #endif
 159
 160 };
 161
 162 #endif /* nsTimerImpl_h___ */