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| author | ferrieux <ferrieux@users.sourceforge.net> | 2010-10-29 16:42:00 (GMT) |
|---|---|---|
| committer | ferrieux <ferrieux@users.sourceforge.net> | 2010-10-29 16:42:00 (GMT) |
| commit | 72988bdcda9f9395061389a6ed8147bdade46278 (patch) | |
| tree | bb78b28bd4acce1248673ffc9ee16fcc7b902962 /generic/tclTimer.c | |
| parent | f8239ece999da4a053812ab0a374c8b7cf094236 (diff) | |
| download | tcl-72988bdcda9f9395061389a6ed8147bdade46278.zip tcl-72988bdcda9f9395061389a6ed8147bdade46278.tar.gz tcl-72988bdcda9f9395061389a6ed8147bdade46278.tar.bz2 | |
Stop small [afters] from wasting CPU [Bug 2905784] while keeping accuracy.
Diffstat (limited to 'generic/tclTimer.c')
| -rw-r--r-- | generic/tclTimer.c | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/generic/tclTimer.c b/generic/tclTimer.c index aaa3493..c5974da 100644 --- a/generic/tclTimer.c +++ b/generic/tclTimer.c @@ -9,7 +9,7 @@ * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclTimer.c,v 1.42 2010/02/24 10:32:17 dkf Exp $ + * RCS: @(#) $Id: tclTimer.c,v 1.43 2010/10/29 16:42:01 ferrieux Exp $ */ #include "tclInt.h" @@ -129,6 +129,17 @@ static Tcl_ThreadDataKey dataKey; (1000*((Tcl_WideInt)(t1).sec - (Tcl_WideInt)(t2).sec) + \ ((long)(t1).usec - (long)(t2).usec)/1000) +#define TCL_TIME_DIFF_MS_CEILING(t1, t2) \ + (1000*((Tcl_WideInt)(t1).sec - (Tcl_WideInt)(t2).sec) + \ + ((long)(t1).usec - (long)(t2).usec + 999)/1000) + +/* + * Sleeps under that number of milliseconds don't get double-checked + * and are done in exactly one Tcl_Sleep(). This to limit gettimeofday()s. + */ + +#define SLEEP_OFFLOAD_GETTIMEOFDAY 20 + /* * The maximum number of milliseconds for each Tcl_Sleep call in AfterDelay. * This is used to limit the maximum lag between interp limit and script @@ -1002,7 +1013,8 @@ AfterDelay( Tcl_Time endTime, now; Tcl_WideInt diff; - Tcl_GetTime(&endTime); + Tcl_GetTime(&now); + endTime = now; endTime.sec += (long)(ms/1000); endTime.usec += ((int)(ms%1000))*1000; if (endTime.usec >= 1000000) { @@ -1011,7 +1023,6 @@ AfterDelay( } do { - Tcl_GetTime(&now); if (Tcl_AsyncReady()) { if (Tcl_AsyncInvoke(interp, TCL_OK) != TCL_OK) { return TCL_ERROR; @@ -1029,7 +1040,7 @@ AfterDelay( } if (iPtr->limit.timeEvent == NULL || TCL_TIME_BEFORE(endTime, iPtr->limit.time)) { - diff = TCL_TIME_DIFF_MS(endTime, now); + diff = TCL_TIME_DIFF_MS_CEILING(endTime, now); #ifndef TCL_WIDE_INT_IS_LONG if (diff > LONG_MAX) { diff = LONG_MAX; @@ -1038,9 +1049,11 @@ AfterDelay( if (diff > TCL_TIME_MAXIMUM_SLICE) { diff = TCL_TIME_MAXIMUM_SLICE; } + if (diff == 0 && TCL_TIME_BEFORE(now, endTime)) diff = 1; if (diff > 0) { Tcl_Sleep((long) diff); - } + if (diff < SLEEP_OFFLOAD_GETTIMEOFDAY) break; + } else break; } else { diff = TCL_TIME_DIFF_MS(iPtr->limit.time, now); #ifndef TCL_WIDE_INT_IS_LONG @@ -1066,6 +1079,7 @@ AfterDelay( return TCL_ERROR; } } + Tcl_GetTime(&now); } while (TCL_TIME_BEFORE(now, endTime)); return TCL_OK; } @@ -1269,5 +1283,7 @@ AfterCleanupProc( * mode: c * c-basic-offset: 4 * fill-column: 78 + * tab-width: 8 + * indent-tabs-mode: nil * End: */ |