On Nov 26 19:07, Houder wrote: > On Mon, 26 Nov 2018 18:01:40, Corinna Vinschen wrote: > > > > On Nov 23 11:27, James E. King III wrote: > [snip] > > > > I found that a call to > > > clock_gettime(CLOCK_MONOTONIC, ..) has a one-time initialization that > > > is not thread-safe. If two threads call this at the same time, they > > > will race. The results I am seeing are typically that one of the two > > > callers get a timespec structure with zero values, and no error return > > > code from the call. > > > > Thanks for the testcase, but I can't reproduce the problem, neither on > > 32 bit nor on 64 bit. I tweaked your makefile to have a 100K loop I > > started multiple times with differently optimzed code, but to no avail. > > > > To account for that, I inspected the code doing the initialization and > > found that it uses REALTIME priority when trying to make sure multiple > > threads don't collide. This is a bit on the dangerous side, apparently. > > > > I tweaked the code to use a spinlock instead. > > > > I'm just about to upload new developer snapshots to > > https://cygwin.com/snapshots/ > > > > Should be up in 10 mins or so. Can you please try if this fixes the > > problem for you? > > - only replaced the cygwin1.dll ... > > Henri > > 64-@@ uname -a > CYGWIN_NT-6.1 Seven 2.11.3(0.329/5/3) x86_64 Cygwin > 64-@@ ls -l /bin/cygwin1* > -rwxr-xr-x 1 Henri None 3339661 Nov 8 14:36 /bin/cygwin1-2.11.2.X > -rwxr-xr-x 1 Henri None 3337995 Nov 26 18:43 /bin/cygwin1-64-20181126.X > -rwxr-xr-x 1 Henri None 3337995 Nov 26 18:43 /bin/cygwin1.dll > 64-@@ cd threads > 64-@@ make test > 64-@@ make test > 64-@@ make test > 64-@@ make test > 64-@@ make test > 64-@@ make test > 64-@@ make test > 64-@@ make test > 64-@@ vi Makefile > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ #... wait a while ... > 64-@@ for loop in {1..100}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..1000}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..1000}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..1000}; do ./cyg_hires_clock_race.exe; done > 64-@@ for loop in {1..10000}; do ./cyg_hires_clock_race.exe; done > 64-@@# That is enough!
Thanks a lot for testing! (Particulary since I couldn't even reproduce this on W7) Corinna -- Corinna Vinschen Cygwin Maintainer
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