michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:  * OS/2 interval timers
michael@0:  *
michael@0:  */
michael@0: 
michael@0: #include "primpl.h"
michael@0: 
michael@0: static PRBool useHighResTimer = PR_FALSE;
michael@0: PRIntervalTime _os2_ticksPerSec = -1;
michael@0: PRIntn _os2_bitShift = 0;
michael@0: PRInt32 _os2_highMask = 0;
michael@0:    
michael@0: void
michael@0: _PR_MD_INTERVAL_INIT()
michael@0: {
michael@0:     char *envp;
michael@0:     ULONG timerFreq;
michael@0:     APIRET rc;
michael@0: 
michael@0:     if ((envp = getenv("NSPR_OS2_NO_HIRES_TIMER")) != NULL) {
michael@0:         if (atoi(envp) == 1)
michael@0:            return;
michael@0:     }
michael@0: 
michael@0:     timerFreq = 0; /* OS/2 high-resolution timer frequency in Hz */
michael@0:     rc = DosTmrQueryFreq(&timerFreq);
michael@0:     if (NO_ERROR == rc) {
michael@0:         useHighResTimer = PR_TRUE;
michael@0:         PR_ASSERT(timerFreq != 0);
michael@0:         while (timerFreq > PR_INTERVAL_MAX) {
michael@0:             timerFreq >>= 1;
michael@0:             _os2_bitShift++;
michael@0:             _os2_highMask = (_os2_highMask << 1)+1;
michael@0:         }
michael@0: 
michael@0:         _os2_ticksPerSec = timerFreq;
michael@0:         PR_ASSERT(_os2_ticksPerSec > PR_INTERVAL_MIN);
michael@0:     }
michael@0: }
michael@0: 
michael@0: PRIntervalTime
michael@0: _PR_MD_GET_INTERVAL()
michael@0: {
michael@0:     if (useHighResTimer) {
michael@0:         QWORD timestamp;
michael@0:         PRInt32 top;
michael@0:         APIRET rc = DosTmrQueryTime(&timestamp);
michael@0:         if (NO_ERROR != rc) {
michael@0:             return -1;
michael@0:         }
michael@0:         /* Sadly, nspr requires the interval to range from 1000 ticks per
michael@0:          * second to only 100000 ticks per second. DosTmrQueryTime is too
michael@0:          * high resolution...
michael@0:          */
michael@0:         top = timestamp.ulHi & _os2_highMask;
michael@0:         top = top << (32 - _os2_bitShift);
michael@0:         timestamp.ulLo = timestamp.ulLo >> _os2_bitShift;   
michael@0:         timestamp.ulLo = timestamp.ulLo + top; 
michael@0:         return (PRUint32)timestamp.ulLo;
michael@0:     } else {
michael@0:         ULONG msCount = -1;
michael@0:         DosQuerySysInfo(QSV_MS_COUNT, QSV_MS_COUNT, &msCount, sizeof(msCount));
michael@0:         return msCount;
michael@0:     }
michael@0: }
michael@0: 
michael@0: PRIntervalTime
michael@0: _PR_MD_INTERVAL_PER_SEC()
michael@0: {
michael@0:     if (useHighResTimer) {
michael@0:         return _os2_ticksPerSec;
michael@0:     } else {
michael@0:         return 1000;
michael@0:     }
michael@0: }