]> Cypherpunks repositories - gostls13.git/commit
runtime: do not use PowerRegisterSuspendResumeNotification on systems with "program...
authorJason A. Donenfeld <Jason@zx2c4.com>
Thu, 21 Nov 2019 15:16:56 +0000 (16:16 +0100)
committerJason A. Donenfeld <Jason@zx2c4.com>
Mon, 16 Dec 2019 17:37:20 +0000 (17:37 +0000)
commit056a3d1c6f6f92b095f88b01d004eb2656a688c5
treec1a9b84a45ff37306f4c8e898c1b052cc70476e7
parent499dc1c5d583a2a0735d4e408078819b84697e2e
runtime: do not use PowerRegisterSuspendResumeNotification on systems with "program time" timer

Systems where PowerRegisterSuspendResumeNotification returns ERROR_
FILE_NOT_FOUND are also systems where nanotime() is on "program time"
rather than "real time".  The chain for this is:

powrprof.dll!PowerRegisterSuspendResumeNotification ->
  umpdc.dll!PdcPortOpen ->
    ntdll.dll!ZwAlpcConnectPort("\\PdcPort") ->
      syscall -> ntoskrnl.exe!AlpcpConnectPort

Opening \\.\PdcPort fails with STATUS_OBJECT_NAME_NOT_FOUND when pdc.sys
hasn't been initialized. Pdc.sys also provides the various hooks for
sleep resumption events, which means if it's not loaded, then our "real
time" timer is actually on "program time". Finally STATUS_OBJECT_NAME_
NOT_FOUND is passed through RtlNtStatusToDosError, which returns ERROR_
FILE_NOT_FOUND. Therefore, in the case where the function returns ERROR_
FILE_NOT_FOUND, we don't mind, since the timer we're using will
correspond fine with the lack of sleep resumption notifications. This
applies, for example, to Docker users.

Fixes #35447
Fixes #35482

Change-Id: I9e1ce5bbc54b9da55ff7a3918b5da28112647eee
Reviewed-on: https://go-review.googlesource.com/c/go/+/208317
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
src/runtime/os_windows.go