WindowsXP-SP1/enduser/netmeeting/t120/mst123/timer.h
2020-09-30 16:53:49 +02:00

239 lines
7.8 KiB
C++

/* Timer.h
*
* Copyright (c) 1993-1995 by DataBeam Corporation, Lexington, KY
*
* Abstract:
* This class maintains the current time and dispathes function calls
* when timers expire. If a routine wants to be called in X amount of
* time, it creates a timer event with this class. When the time expires,
* the function is called. If the user wants to cancel the timer before
* it expires, he can use the DeleteTimerEvent() function.
*
* When a person creates a timer event, one of the parameters is the
* control flags. The user can set the flag so that the event is a
* one-time thing or a constant event that occurs every X milliseconds.
*
* This timer has a millisecond granularity. The time passed into the
* CreateEventTimer() function is assumed to be in milliseconds.
*
* The ProcessTimerEvents() function must be called frequently and
* regularly so that the timeouts occur promptly.
*
* Caveats:
* None.
*
* Author:
* James P. Galvin
* James W. Lawwill
*/
#ifndef _TIMER_
#define _TIMER_
/*
** Possible Error values
*/
typedef enum
{
TIMER_NO_ERROR,
TIMER_NO_TIMERS_AVAILABLE,
TIMER_NO_TIMER_MEMORY,
TIMER_INVALID_TIMER_HANDLE
}
TimerError, * PTimerError;
/*
** These defines are used in the control_flags variable in the TimerEvent
** structure. TIMER_EVENT_IN_USE is a flag used internal to the timer
** procedure. TIMER_EVENT_ONE_SHOT can be passed in by the user to
** signify that the timer should only occur once.
*/
#define TIMER_EVENT_IN_USE 0x0001
#define TIMER_EVENT_ONE_SHOT 0x0002
#define TRANSPORT_HASHING_BUCKETS 3
typedef USHORT TimerEventHandle;
typedef TimerEventHandle *PTimerEventHandle;
typedef void (IObject::*PTimerFunction) (TimerEventHandle);
/*
** Each timer event has a TimerEvent structure associated with it.
*/
typedef struct TimerEventStruct
{
TimerEventHandle event_handle;
ULong timer_duration;
ULong total_duration;
IObject *object_ptr;
PTimerFunction timer_func_ptr;
USHORT control_flags;
TimerEventStruct *next_timer_event;
TimerEventStruct *previous_timer_event;
}
TimerEvent, * PTimerEvent;
class Timer
{
public:
Timer (
Void);
~Timer (
Void);
TimerEventHandle CreateTimerEvent (
ULong timer_duration,
USHORT control_flags,
IObject * object_ptr,
PTimerFunction timer_function);
TimerError DeleteTimerEvent (
TimerEventHandle timer_event);
Void ProcessTimerEvents (
Void);
private:
USHORT Maximum_Timer_Events;
USHORT Timer_Event_Count;
SListClass Timer_Event_Free_Stack;
PTimerEvent First_Timer_Event_In_Chain;
DWORD Last_Timer_Value;
DictionaryClass Timer_List;
};
typedef Timer * PTimer;
extern PTimer System_Timer;
#define InstallTimerEvent(duration, control, func) \
(g_pSystemTimer->CreateTimerEvent((duration),(control),this,(PTimerFunction)(func)))
#endif
/*
* Timer (Void)
*
* Functional Description:
* This is the constructor for the timer class. This procedure gets
* thc current Windows system time.
*
* Formal Parameters:
* None
*
* Return Value:
* None
*
* Side Effects:
* None
*
* Caveats:
* None
*/
/*
* ~Timer (Void)
*
* Functional Description:
* This is the destructor for the timer class. This routine frees all
* memory associated with timer events.
*
* Formal Parameters:
* None
*
* Return Value:
* None
*
* Side Effects:
* None
*
* Caveats:
* None
*/
/*
* TimerEventHandle CreateTimerEvent (
* ULong timer_duration,
* USHORT control_flags,
* IObject * object_ptr,
* PTimerFunction timer_function);
*
* Functional Description:
* This routine is called to create a timer event. The routine stores the
* information passed-in in a TimerEvent structure. When the timer expires
* the function will be called.
*
* Formal Parameters:
* timer_duration - (i) Amount of time to wait before calling the
* function. The granularity of the timer
* is milliseconds.
* control_flags - (i) This is a USHORT but currently we only
* look at one of the bits. The
* TIMER_EVENT_ONE_SHOT can be passed-in by
* the user if they only want this timeout
* to occur once. If this value is 0, the
* event will occur time after time.
* object_ptr - (i) This is the data address of the object. It
* is the 'this' pointer of the calling object.
* timer_function - (i) This is the address of the function to
* call after the timer expires.
*
* Return Value:
* TimerEventHandle - This is a handle to the timer event. If you
* need to delete the timer event, pass this
* handle to the DeleteTimer() function. A NULL
* handle is returned if the create failed.
*
* Side Effects:
* None
*
* Caveats:
* None
*/
/*
* TimerError DeleteTimerEvent (TimerEventHandle timer_event)
*
* Functional Description:
* This routine is called by the user to delete a timer event that is
* currently active.
*
* Formal Parameters:
* timer_event - (i) Handle to a timer event
*
* Return Value:
* TIMER_NO_ERROR - Successful Delete
* TIMER_NO_TIMER_MEMORY - The timer_event can't exist because
* there was never any Timer memory
* TIMER_INVALID_TIMER_HANDLE - timer_event is not in our list
* of timers
*
* Side Effects:
* None
*
* Caveats:
* None
*/
/*
* Void ProcessTimerEvents (Void)
*
* Functional Description:
* This routine MUST be called frequently and regularly so that we can
* manage our timers. This function gets the current system time and
* goes through each of the timers to see which have expired. If a timer
* has expired, we call the function associated with it. Upon return,
* if the timer was marked as a one-shot event, we remove it from our
* list of timers.
*
* Formal Parameters:
* None
*
* Return Value:
* None
*
* Side Effects:
* None
*
* Caveats:
* None
*/