diff options
| -rw-r--r-- | winsup/cygwin/ChangeLog | 11 | ||||
| -rw-r--r-- | winsup/cygwin/hires.h | 3 | ||||
| -rw-r--r-- | winsup/cygwin/times.cc | 39 |
3 files changed, 26 insertions, 27 deletions
diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog index 3ad68f67a..36b87e67f 100644 --- a/winsup/cygwin/ChangeLog +++ b/winsup/cygwin/ChangeLog @@ -1,3 +1,14 @@ +2012-03-26 Corinna Vinschen <corinna@vinschen.de> + + * hires.h (hires_ms::dmsecs): Drop unused method. + * times.cc (JITTER): Remove. + (gtod): Revert to process-local variable. + (hires_ms::nsecs): Just return system time to disallow discrepancy with + the OS. + (hires_ms::resolution): Return coarsest timer value from OS. Add + comment to explain why. + (clock_setres): Ditto. + 2012-03-21 Christopher Faylor <me.cygwin2012@cgf.cx> * child_info.h: Reset magic number. diff --git a/winsup/cygwin/hires.h b/winsup/cygwin/hires.h index 7d84a52cd..c9a4def38 100644 --- a/winsup/cygwin/hires.h +++ b/winsup/cygwin/hires.h @@ -1,6 +1,6 @@ /* hires.h: Definitions for hires clock calculations - Copyright 2002, 2003, 2004, 2005, 2009, 2010, 2011 Red Hat, Inc. + Copyright 2002, 2003, 2004, 2005, 2009, 2010, 2011, 2012 Red Hat, Inc. This file is part of Cygwin. @@ -62,7 +62,6 @@ class hires_ms : public hires_base LONGLONG nsecs (); LONGLONG usecs () {return nsecs () / 10LL;} LONGLONG msecs () {return nsecs () / 10000LL;} - UINT dmsecs () { return timeGetTime_ns () / 10000LL; } UINT resolution (); LONGLONG uptime () {return (nsecs () - initime_ns) / 10000LL;} }; diff --git a/winsup/cygwin/times.cc b/winsup/cygwin/times.cc index 4f4c39c92..051be82ba 100644 --- a/winsup/cygwin/times.cc +++ b/winsup/cygwin/times.cc @@ -1,7 +1,7 @@ /* times.cc Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, - 2005, 2006, 2007, 2008, 2009, 2010, 2011 Red Hat, Inc. + 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Red Hat, Inc. This file is part of Cygwin. @@ -27,17 +27,7 @@ details. */ #include "cygtls.h" #include "ntdll.h" -/* Max allowed diversion in 100ns of internal timer from system time. If - this difference is exceeded, the internal timer gets re-primed. */ -#define JITTER (40 * 10000LL) - -/* TODO: Putting this variable in the shared cygwin region partially solves - the problem of cygwin processes not recognizing date changes when other - cygwin processes set the date. There is still an additional problem of - long-running cygwin processes becoming confused when a non-cygwin process - sets the date. Unfortunately, it looks like a minor redesign is required - to handle that case. */ -hires_ms gtod __attribute__((section (".cygwin_dll_common"), shared)); +hires_ms NO_COPY gtod; hires_ns NO_COPY ntod; @@ -575,16 +565,7 @@ hires_ms::nsecs () { if (!inited) prime (); - - LONGLONG t = systime_ns (); - LONGLONG res = initime_ns + timeGetTime_ns (); - if (llabs (res - t) > JITTER) - { - inited = false; - prime (); - res = initime_ns + timeGetTime_ns (); - } - return res; + return systime_ns (); } extern "C" int @@ -731,10 +712,15 @@ hires_ms::resolution () status = NtQueryTimerResolution (&coarsest, &finest, &actual); if (NT_SUCCESS (status)) - minperiod = (DWORD) actual; + /* The actual resolution of the OS timer is a system-wide setting which + can be changed any time, by any process. The only fixed value we + can rely on is the coarsest value. */ + minperiod = coarsest; else { - /* Try to empirically determine current timer resolution */ + /* There's no good reason that NtQueryTimerResolution should fail + at all, but let's play it safe. Try to empirically determine + current timer resolution */ int priority = GetThreadPriority (GetCurrentThread ()); SetThreadPriority (GetCurrentThread (), THREAD_PRIORITY_TIME_CRITICAL); @@ -837,7 +823,10 @@ clock_setres (clockid_t clk_id, struct timespec *tp) __seterrno_from_nt_status (status); return -1; } - minperiod = actual; + /* The actual resolution of the OS timer is a system-wide setting which + can be changed any time, by any process. The only fixed value we can + rely on is the coarsest value. */ + minperiod = coarsest; period_set = true; return 0; } |