runtime: revert "do not call timeBeginPeriod on windows"

This reverts commit ab4c9298b8185a056ff1152f2c7bd9b38d3d06f3.

Sysmon critically depends on system timer resolution for retaking
of Ps blocked in system calls. See #14790 for an example
of a program where execution time goes from 2ms to 30ms if
timeBeginPeriod(1) is not used.

We can remove timeBeginPeriod(1) when we support UMS (#7876).

Update #14790

Change-Id: I362b56154359b2c52d47f9f2468fe012b481cf6d
Reviewed-on: https://go-review.googlesource.com/20834
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

diff --git a/misc/cgo/testcarchive/carchive_test.go b/misc/cgo/testcarchive/carchive_test.go
index 47e0ceb5c90a55b09c8652a67b03b2331955a822..72e9ef1d591c0488272408aba5104fe3c30ba785 100644 (file)
--- a/misc/cgo/testcarchive/carchive_test.go
+++ b/misc/cgo/testcarchive/carchive_test.go
@@ -120,7 +120,7 @@ func goEnv(key string) string {
 func compilemain(t *testing.T, libgo string) {
        ccArgs := append(cc, "-o", "testp"+exeSuffix, "main.c")
        if GOOS == "windows" {
-               ccArgs = append(ccArgs, "main_windows.c", libgo, "-lntdll", "-lws2_32")
+               ccArgs = append(ccArgs, "main_windows.c", libgo, "-lntdll", "-lws2_32", "-lwinmm")
        } else {
                ccArgs = append(ccArgs, "main_unix.c", libgo)
        }

diff --git a/src/runtime/export_windows_test.go b/src/runtime/export_windows_test.go
index 66c103709c6cc97c0c9029505157e4f299505fba..536b398fd7a077802aa5a65a328237c049171afa 100644 (file)
--- a/src/runtime/export_windows_test.go
+++ b/src/runtime/export_windows_test.go
@@ -8,8 +8,11 @@ package runtime
 
 import "unsafe"
 
-var TestingWER = &testingWER
-var OsYield = osyield
+var (
+       TestingWER              = &testingWER
+       OsYield                 = osyield
+       TimeBeginPeriodRetValue = &timeBeginPeriodRetValue
+)
 
 func NumberOfProcessors() int32 {
        var info systeminfo

diff --git a/src/runtime/os_windows.go b/src/runtime/os_windows.go
index 7244706b92c9ca048c611c9569a4532a87e12d22..9147091a497c7824df377b19374443cffc42f550 100644 (file)
--- a/src/runtime/os_windows.go
+++ b/src/runtime/os_windows.go
@@ -53,6 +53,7 @@ const (
 //go:cgo_import_dynamic runtime._WaitForSingleObject WaitForSingleObject%2 "kernel32.dll"
 //go:cgo_import_dynamic runtime._WriteConsoleW WriteConsoleW%5 "kernel32.dll"
 //go:cgo_import_dynamic runtime._WriteFile WriteFile%5 "kernel32.dll"
+//go:cgo_import_dynamic runtime._timeBeginPeriod timeBeginPeriod%1 "winmm.dll"
 
 type stdFunction unsafe.Pointer
 
@@ -98,7 +99,9 @@ var (
        _WSAGetOverlappedResult,
        _WaitForSingleObject,
        _WriteConsoleW,
-       _WriteFile stdFunction
+       _WriteFile,
+       _timeBeginPeriod,
+       _ stdFunction
 
        // Following syscalls are only available on some Windows PCs.
        // We will load syscalls, if available, before using them.
@@ -228,6 +231,8 @@ func setlasterror(err uint32)
 // flags can be used with LoadLibraryEx."
 var useLoadLibraryEx bool
 
+var timeBeginPeriodRetValue uint32
+
 func osinit() {
        asmstdcallAddr = unsafe.Pointer(funcPC(asmstdcall))
        usleep2Addr = unsafe.Pointer(funcPC(usleep2))
@@ -247,6 +252,8 @@ func osinit() {
 
        stdcall2(_SetConsoleCtrlHandler, funcPC(ctrlhandler), 1)
 
+       timeBeginPeriodRetValue = uint32(stdcall1(_timeBeginPeriod, 1))
+
        ncpu = getproccount()
 
        // Windows dynamic priority boosting assumes that a process has different types

diff --git a/src/runtime/syscall_windows_test.go b/src/runtime/syscall_windows_test.go
index ff045338c10ceee283dfaf8ca70e1d8491955cf5..4a10749682414f9c4d36fb872c3014ca9fa474ba 100644 (file)
--- a/src/runtime/syscall_windows_test.go
+++ b/src/runtime/syscall_windows_test.go
@@ -622,6 +622,13 @@ uintptr_t cfunc(callback f, uintptr_t n) {
        }
 }
 
+func TestTimeBeginPeriod(t *testing.T) {
+       const TIMERR_NOERROR = 0
+       if *runtime.TimeBeginPeriodRetValue != TIMERR_NOERROR {
+               t.Fatalf("timeBeginPeriod failed: it returned %d", *runtime.TimeBeginPeriodRetValue)
+       }
+}
+
 // removeOneCPU removes one (any) cpu from affinity mask.
 // It returns new affinity mask.
 func removeOneCPU(mask uintptr) (uintptr, error) {
@@ -874,21 +881,10 @@ var (
        modwinmm    = syscall.NewLazyDLL("winmm.dll")
        modkernel32 = syscall.NewLazyDLL("kernel32.dll")
 
-       proctimeBeginPeriod = modwinmm.NewProc("timeBeginPeriod")
-       proctimeEndPeriod   = modwinmm.NewProc("timeEndPeriod")
-
        procCreateEvent = modkernel32.NewProc("CreateEventW")
        procSetEvent    = modkernel32.NewProc("SetEvent")
 )
 
-func timeBeginPeriod(period uint32) {
-       syscall.Syscall(proctimeBeginPeriod.Addr(), 1, uintptr(period), 0, 0)
-}
-
-func timeEndPeriod(period uint32) {
-       syscall.Syscall(proctimeEndPeriod.Addr(), 1, uintptr(period), 0, 0)
-}
-
 func createEvent() (syscall.Handle, error) {
        r0, _, e0 := syscall.Syscall6(procCreateEvent.Addr(), 4, 0, 0, 0, 0, 0, 0)
        if r0 == 0 {
@@ -905,7 +901,7 @@ func setEvent(h syscall.Handle) error {
        return nil
 }
 
-func benchChanToSyscallPing(b *testing.B) {
+func BenchmarkChanToSyscallPing(b *testing.B) {
        n := b.N
        ch := make(chan int)
        event, err := createEvent()
@@ -927,17 +923,7 @@ func benchChanToSyscallPing(b *testing.B) {
        }
 }
 
-func BenchmarkChanToSyscallPing1ms(b *testing.B) {
-       timeBeginPeriod(1)
-       benchChanToSyscallPing(b)
-       timeEndPeriod(1)
-}
-
-func BenchmarkChanToSyscallPing15ms(b *testing.B) {
-       benchChanToSyscallPing(b)
-}
-
-func benchSyscallToSyscallPing(b *testing.B) {
+func BenchmarkSyscallToSyscallPing(b *testing.B) {
        n := b.N
        event1, err := createEvent()
        if err != nil {
@@ -965,17 +951,7 @@ func benchSyscallToSyscallPing(b *testing.B) {
        }
 }
 
-func BenchmarkSyscallToSyscallPing1ms(b *testing.B) {
-       timeBeginPeriod(1)
-       benchSyscallToSyscallPing(b)
-       timeEndPeriod(1)
-}
-
-func BenchmarkSyscallToSyscallPing15ms(b *testing.B) {
-       benchSyscallToSyscallPing(b)
-}
-
-func benchChanToChanPing(b *testing.B) {
+func BenchmarkChanToChanPing(b *testing.B) {
        n := b.N
        ch1 := make(chan int)
        ch2 := make(chan int)
@@ -991,28 +967,8 @@ func benchChanToChanPing(b *testing.B) {
        }
 }
 
-func BenchmarkChanToChanPing1ms(b *testing.B) {
-       timeBeginPeriod(1)
-       benchChanToChanPing(b)
-       timeEndPeriod(1)
-}
-
-func BenchmarkChanToChanPing15ms(b *testing.B) {
-       benchChanToChanPing(b)
-}
-
-func benchOsYield(b *testing.B) {
+func BenchmarkOsYield(b *testing.B) {
        for i := 0; i < b.N; i++ {
                runtime.OsYield()
        }
 }
-
-func BenchmarkOsYield1ms(b *testing.B) {
-       timeBeginPeriod(1)
-       benchOsYield(b)
-       timeEndPeriod(1)
-}
-
-func BenchmarkOsYield15ms(b *testing.B) {
-       benchOsYield(b)
-}