]> Cypherpunks repositories - gostls13.git/commit
[release-branch.go1.13] runtime: do not use PowerRegisterSuspendResumeNotification...
authorJason A. Donenfeld <Jason@zx2c4.com>
Thu, 21 Nov 2019 15:16:56 +0000 (16:16 +0100)
committerDmitri Shuralyov <dmitshur@golang.org>
Fri, 3 Jan 2020 23:38:58 +0000 (23:38 +0000)
commitb570a4147dae9efd28b48cec5b0500f599a2a99e
treea1573867b749564a4bde75940a63a3d565407260
parentb0a2a817571c52341603d7d089c4138b048c67c3
[release-branch.go1.13] 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.

Updates #35447
Updates #35482
Fixes #35746

Change-Id: I9e1ce5bbc54b9da55ff7a3918b5da28112647eee
Reviewed-on: https://go-review.googlesource.com/c/go/+/211280
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
src/runtime/os_windows.go