/** winTimer()
*
* The classic Rexx external function, WinTimer() was documented prior to 4.0.0
* and therefore needs to be retained for backward compatibility.
*
* The original implementation was poor, using SetTimer() / KillTimer(). For
* the wait mode, it used this loop:
*
* else if ( stricmp("WAIT", mode) == 0 )
* {
* while ( !PeekMessage(&msg, NULL, WM_TIMER, WM_TIMER, PM_REMOVE)
* {
* ; // do nothing
* }
* return 0;
* }
*
* PeekMessage() returns immediately if there are no messages. Since there
* were probably no windows on the thread, the WAIT function spun in a busy
* loop consuming 100% of the CPU.
*
* svn revision 8968 and previous contains the original implementation if there
* is a need to review that code.
*
* The original implmentation was replaced in ooDialog 4.2.2 with this
* implementation using waitable timers instead. It is backwards compatible
* with the original implementation, and needs to remain that way.
*
* For very small periods, SetTimer replaces the specified time with
* USER_TIMER_MINIMUM. So when Rexx programmers specified 1 or 2 or 6
* milliseconds, the got USER_TIMER_MINIMUM instead. We mimic that behaviour
* here, otherwise programs using a delay of 1 millisecond do not work the
* same. We actually use 1.5 times USER_TIMER_MINIMUM because it seems to work
* the best.
*
* @param mode Keyword for what is to be done. START creates the timer and
* starts it. WAIT waits on the timer. STOP destroys the
* timer.
*
* @param msOrId Either the period of the timer, in miliseconds, if mode is
* START, or the timer ID for the other modes.
*
* @return The timer ID for the START mode, or success / error return code for
* the other modes.
*
* @notes Sets the .SystemErrorCode. For the STOP and WAIT modes the system
* error code value is returned in addition to setting the
* .SystemErrorCode.
*
* @remarks If this routine was being implemented from scratch, it would be
* done differently. However since it is being used to preserve
* backwards compatibility, this implementation serves best. An
* enhancement creating a new Waitable object class would be nice.
*/
RexxRoutine2(uintptr_t, winTimer_rtn, CSTRING, mode, uintptr_t, msOrId)
{
oodResetSysErrCode(context->threadContext);
if ( stricmp("START", mode) == 0 )
{
HANDLE hTimer = NULL;
LARGE_INTEGER liDueTime;
if ( msOrId < USER_TIMER_MINIMUM + 5 )
{
msOrId = USER_TIMER_MINIMUM + 5;
}
liDueTime.QuadPart = msOrId * -10000;
hTimer = CreateWaitableTimer(NULL, FALSE, NULL);
if ( hTimer == NULL )
{
oodSetSysErrCode(context->threadContext);
return 0;
}
if ( ! SetWaitableTimer(hTimer, &liDueTime, (int32_t)msOrId, NULL, NULL, FALSE) )
{
oodSetSysErrCode(context->threadContext);
return 0;
}
return (uintptr_t)hTimer;
}
else if ( stricmp("STOP", mode) == 0 )
{
if ( CancelWaitableTimer((HANDLE)msOrId) == 0 )
{
uint32_t rc = GetLastError();
oodSetSysErrCode(context->threadContext, rc);
return rc;
}
return 0;
}
else if ( stricmp("WAIT", mode) == 0 )
{
if ( WaitForSingleObject((HANDLE)msOrId, INFINITE) != WAIT_OBJECT_0 )
{
uint32_t rc = GetLastError();
oodSetSysErrCode(context->threadContext, rc);
return rc;
}
return 0;
}
wrongArgValueException(context->threadContext, 1, "START, STOP, WAIT", mode);
return 0;
}
RexxObjectPtr wrongArgValueException(RexxThreadContext *c, size_t pos, const char *list, const char *actual)
{
return wrongArgValueException(c, pos, list, c->String(actual));
}
