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-rw-r--r--src/runtime/os_windows.go1388
1 files changed, 1388 insertions, 0 deletions
diff --git a/src/runtime/os_windows.go b/src/runtime/os_windows.go
new file mode 100644
index 0000000..6533b64
--- /dev/null
+++ b/src/runtime/os_windows.go
@@ -0,0 +1,1388 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package runtime
+
+import (
+ "internal/abi"
+ "internal/goarch"
+ "runtime/internal/atomic"
+ "unsafe"
+)
+
+// TODO(brainman): should not need those
+const (
+ _NSIG = 65
+)
+
+//go:cgo_import_dynamic runtime._AddVectoredContinueHandler AddVectoredContinueHandler%2 "kernel32.dll"
+//go:cgo_import_dynamic runtime._AddVectoredExceptionHandler AddVectoredExceptionHandler%2 "kernel32.dll"
+//go:cgo_import_dynamic runtime._CloseHandle CloseHandle%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._CreateEventA CreateEventA%4 "kernel32.dll"
+//go:cgo_import_dynamic runtime._CreateFileA CreateFileA%7 "kernel32.dll"
+//go:cgo_import_dynamic runtime._CreateIoCompletionPort CreateIoCompletionPort%4 "kernel32.dll"
+//go:cgo_import_dynamic runtime._CreateThread CreateThread%6 "kernel32.dll"
+//go:cgo_import_dynamic runtime._CreateWaitableTimerA CreateWaitableTimerA%3 "kernel32.dll"
+//go:cgo_import_dynamic runtime._CreateWaitableTimerExW CreateWaitableTimerExW%4 "kernel32.dll"
+//go:cgo_import_dynamic runtime._DuplicateHandle DuplicateHandle%7 "kernel32.dll"
+//go:cgo_import_dynamic runtime._ExitProcess ExitProcess%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._FreeEnvironmentStringsW FreeEnvironmentStringsW%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._GetConsoleMode GetConsoleMode%2 "kernel32.dll"
+//go:cgo_import_dynamic runtime._GetCurrentThreadId GetCurrentThreadId%0 "kernel32.dll"
+//go:cgo_import_dynamic runtime._GetEnvironmentStringsW GetEnvironmentStringsW%0 "kernel32.dll"
+//go:cgo_import_dynamic runtime._GetErrorMode GetErrorMode%0 "kernel32.dll"
+//go:cgo_import_dynamic runtime._GetProcAddress GetProcAddress%2 "kernel32.dll"
+//go:cgo_import_dynamic runtime._GetProcessAffinityMask GetProcessAffinityMask%3 "kernel32.dll"
+//go:cgo_import_dynamic runtime._GetQueuedCompletionStatusEx GetQueuedCompletionStatusEx%6 "kernel32.dll"
+//go:cgo_import_dynamic runtime._GetStdHandle GetStdHandle%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._GetSystemDirectoryA GetSystemDirectoryA%2 "kernel32.dll"
+//go:cgo_import_dynamic runtime._GetSystemInfo GetSystemInfo%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._GetThreadContext GetThreadContext%2 "kernel32.dll"
+//go:cgo_import_dynamic runtime._SetThreadContext SetThreadContext%2 "kernel32.dll"
+//go:cgo_import_dynamic runtime._LoadLibraryExW LoadLibraryExW%3 "kernel32.dll"
+//go:cgo_import_dynamic runtime._LoadLibraryW LoadLibraryW%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._PostQueuedCompletionStatus PostQueuedCompletionStatus%4 "kernel32.dll"
+//go:cgo_import_dynamic runtime._QueryPerformanceCounter QueryPerformanceCounter%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._RaiseFailFastException RaiseFailFastException%3 "kernel32.dll"
+//go:cgo_import_dynamic runtime._ResumeThread ResumeThread%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._RtlLookupFunctionEntry RtlLookupFunctionEntry%3 "kernel32.dll"
+//go:cgo_import_dynamic runtime._RtlVirtualUnwind RtlVirtualUnwind%8 "kernel32.dll"
+//go:cgo_import_dynamic runtime._SetConsoleCtrlHandler SetConsoleCtrlHandler%2 "kernel32.dll"
+//go:cgo_import_dynamic runtime._SetErrorMode SetErrorMode%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._SetEvent SetEvent%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._SetProcessPriorityBoost SetProcessPriorityBoost%2 "kernel32.dll"
+//go:cgo_import_dynamic runtime._SetThreadPriority SetThreadPriority%2 "kernel32.dll"
+//go:cgo_import_dynamic runtime._SetUnhandledExceptionFilter SetUnhandledExceptionFilter%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._SetWaitableTimer SetWaitableTimer%6 "kernel32.dll"
+//go:cgo_import_dynamic runtime._SuspendThread SuspendThread%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._SwitchToThread SwitchToThread%0 "kernel32.dll"
+//go:cgo_import_dynamic runtime._TlsAlloc TlsAlloc%0 "kernel32.dll"
+//go:cgo_import_dynamic runtime._VirtualAlloc VirtualAlloc%4 "kernel32.dll"
+//go:cgo_import_dynamic runtime._VirtualFree VirtualFree%3 "kernel32.dll"
+//go:cgo_import_dynamic runtime._VirtualQuery VirtualQuery%3 "kernel32.dll"
+//go:cgo_import_dynamic runtime._WaitForSingleObject WaitForSingleObject%2 "kernel32.dll"
+//go:cgo_import_dynamic runtime._WaitForMultipleObjects WaitForMultipleObjects%4 "kernel32.dll"
+//go:cgo_import_dynamic runtime._WerGetFlags WerGetFlags%2 "kernel32.dll"
+//go:cgo_import_dynamic runtime._WerSetFlags WerSetFlags%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._WriteConsoleW WriteConsoleW%5 "kernel32.dll"
+//go:cgo_import_dynamic runtime._WriteFile WriteFile%5 "kernel32.dll"
+
+type stdFunction unsafe.Pointer
+
+var (
+ // Following syscalls are available on every Windows PC.
+ // All these variables are set by the Windows executable
+ // loader before the Go program starts.
+ _AddVectoredContinueHandler,
+ _AddVectoredExceptionHandler,
+ _CloseHandle,
+ _CreateEventA,
+ _CreateFileA,
+ _CreateIoCompletionPort,
+ _CreateThread,
+ _CreateWaitableTimerA,
+ _CreateWaitableTimerExW,
+ _DuplicateHandle,
+ _ExitProcess,
+ _FreeEnvironmentStringsW,
+ _GetConsoleMode,
+ _GetCurrentThreadId,
+ _GetEnvironmentStringsW,
+ _GetErrorMode,
+ _GetProcAddress,
+ _GetProcessAffinityMask,
+ _GetQueuedCompletionStatusEx,
+ _GetStdHandle,
+ _GetSystemDirectoryA,
+ _GetSystemInfo,
+ _GetThreadContext,
+ _SetThreadContext,
+ _LoadLibraryExW,
+ _LoadLibraryW,
+ _PostQueuedCompletionStatus,
+ _QueryPerformanceCounter,
+ _RaiseFailFastException,
+ _ResumeThread,
+ _RtlLookupFunctionEntry,
+ _RtlVirtualUnwind,
+ _SetConsoleCtrlHandler,
+ _SetErrorMode,
+ _SetEvent,
+ _SetProcessPriorityBoost,
+ _SetThreadPriority,
+ _SetUnhandledExceptionFilter,
+ _SetWaitableTimer,
+ _SuspendThread,
+ _SwitchToThread,
+ _TlsAlloc,
+ _VirtualAlloc,
+ _VirtualFree,
+ _VirtualQuery,
+ _WaitForSingleObject,
+ _WaitForMultipleObjects,
+ _WerGetFlags,
+ _WerSetFlags,
+ _WriteConsoleW,
+ _WriteFile,
+ _ stdFunction
+
+ // Use ProcessPrng to generate cryptographically random data.
+ _ProcessPrng stdFunction
+
+ // Load ntdll.dll manually during startup, otherwise Mingw
+ // links wrong printf function to cgo executable (see issue
+ // 12030 for details).
+ _RtlGetCurrentPeb stdFunction
+ _RtlGetNtVersionNumbers stdFunction
+
+ // These are from non-kernel32.dll, so we prefer to LoadLibraryEx them.
+ _timeBeginPeriod,
+ _timeEndPeriod,
+ _WSAGetOverlappedResult,
+ _ stdFunction
+)
+
+var (
+ bcryptprimitivesdll = [...]uint16{'b', 'c', 'r', 'y', 'p', 't', 'p', 'r', 'i', 'm', 'i', 't', 'i', 'v', 'e', 's', '.', 'd', 'l', 'l', 0}
+ ntdlldll = [...]uint16{'n', 't', 'd', 'l', 'l', '.', 'd', 'l', 'l', 0}
+ powrprofdll = [...]uint16{'p', 'o', 'w', 'r', 'p', 'r', 'o', 'f', '.', 'd', 'l', 'l', 0}
+ winmmdll = [...]uint16{'w', 'i', 'n', 'm', 'm', '.', 'd', 'l', 'l', 0}
+ ws2_32dll = [...]uint16{'w', 's', '2', '_', '3', '2', '.', 'd', 'l', 'l', 0}
+)
+
+// Function to be called by windows CreateThread
+// to start new os thread.
+func tstart_stdcall(newm *m)
+
+// Init-time helper
+func wintls()
+
+type mOS struct {
+ threadLock mutex // protects "thread" and prevents closing
+ thread uintptr // thread handle
+
+ waitsema uintptr // semaphore for parking on locks
+ resumesema uintptr // semaphore to indicate suspend/resume
+
+ highResTimer uintptr // high resolution timer handle used in usleep
+
+ // preemptExtLock synchronizes preemptM with entry/exit from
+ // external C code.
+ //
+ // This protects against races between preemptM calling
+ // SuspendThread and external code on this thread calling
+ // ExitProcess. If these happen concurrently, it's possible to
+ // exit the suspending thread and suspend the exiting thread,
+ // leading to deadlock.
+ //
+ // 0 indicates this M is not being preempted or in external
+ // code. Entering external code CASes this from 0 to 1. If
+ // this fails, a preemption is in progress, so the thread must
+ // wait for the preemption. preemptM also CASes this from 0 to
+ // 1. If this fails, the preemption fails (as it would if the
+ // PC weren't in Go code). The value is reset to 0 when
+ // returning from external code or after a preemption is
+ // complete.
+ //
+ // TODO(austin): We may not need this if preemption were more
+ // tightly synchronized on the G/P status and preemption
+ // blocked transition into _Gsyscall/_Psyscall.
+ preemptExtLock uint32
+}
+
+// Stubs so tests can link correctly. These should never be called.
+func open(name *byte, mode, perm int32) int32 {
+ throw("unimplemented")
+ return -1
+}
+func closefd(fd int32) int32 {
+ throw("unimplemented")
+ return -1
+}
+func read(fd int32, p unsafe.Pointer, n int32) int32 {
+ throw("unimplemented")
+ return -1
+}
+
+type sigset struct{}
+
+// Call a Windows function with stdcall conventions,
+// and switch to os stack during the call.
+func asmstdcall(fn unsafe.Pointer)
+
+var asmstdcallAddr unsafe.Pointer
+
+func windowsFindfunc(lib uintptr, name []byte) stdFunction {
+ if name[len(name)-1] != 0 {
+ throw("usage")
+ }
+ f := stdcall2(_GetProcAddress, lib, uintptr(unsafe.Pointer(&name[0])))
+ return stdFunction(unsafe.Pointer(f))
+}
+
+const _MAX_PATH = 260 // https://docs.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation
+var sysDirectory [_MAX_PATH + 1]byte
+var sysDirectoryLen uintptr
+
+func initSysDirectory() {
+ l := stdcall2(_GetSystemDirectoryA, uintptr(unsafe.Pointer(&sysDirectory[0])), uintptr(len(sysDirectory)-1))
+ if l == 0 || l > uintptr(len(sysDirectory)-1) {
+ throw("Unable to determine system directory")
+ }
+ sysDirectory[l] = '\\'
+ sysDirectoryLen = l + 1
+}
+
+//go:linkname windows_GetSystemDirectory internal/syscall/windows.GetSystemDirectory
+func windows_GetSystemDirectory() string {
+ return unsafe.String(&sysDirectory[0], sysDirectoryLen)
+}
+
+func windowsLoadSystemLib(name []uint16) uintptr {
+ return stdcall3(_LoadLibraryExW, uintptr(unsafe.Pointer(&name[0])), 0, _LOAD_LIBRARY_SEARCH_SYSTEM32)
+}
+
+func loadOptionalSyscalls() {
+ bcryptPrimitives := windowsLoadSystemLib(bcryptprimitivesdll[:])
+ if bcryptPrimitives == 0 {
+ throw("bcryptprimitives.dll not found")
+ }
+ _ProcessPrng = windowsFindfunc(bcryptPrimitives, []byte("ProcessPrng\000"))
+
+ n32 := windowsLoadSystemLib(ntdlldll[:])
+ if n32 == 0 {
+ throw("ntdll.dll not found")
+ }
+ _RtlGetCurrentPeb = windowsFindfunc(n32, []byte("RtlGetCurrentPeb\000"))
+ _RtlGetNtVersionNumbers = windowsFindfunc(n32, []byte("RtlGetNtVersionNumbers\000"))
+
+ m32 := windowsLoadSystemLib(winmmdll[:])
+ if m32 == 0 {
+ throw("winmm.dll not found")
+ }
+ _timeBeginPeriod = windowsFindfunc(m32, []byte("timeBeginPeriod\000"))
+ _timeEndPeriod = windowsFindfunc(m32, []byte("timeEndPeriod\000"))
+ if _timeBeginPeriod == nil || _timeEndPeriod == nil {
+ throw("timeBegin/EndPeriod not found")
+ }
+
+ ws232 := windowsLoadSystemLib(ws2_32dll[:])
+ if ws232 == 0 {
+ throw("ws2_32.dll not found")
+ }
+ _WSAGetOverlappedResult = windowsFindfunc(ws232, []byte("WSAGetOverlappedResult\000"))
+ if _WSAGetOverlappedResult == nil {
+ throw("WSAGetOverlappedResult not found")
+ }
+}
+
+func monitorSuspendResume() {
+ const (
+ _DEVICE_NOTIFY_CALLBACK = 2
+ )
+ type _DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS struct {
+ callback uintptr
+ context uintptr
+ }
+
+ powrprof := windowsLoadSystemLib(powrprofdll[:])
+ if powrprof == 0 {
+ return // Running on Windows 7, where we don't need it anyway.
+ }
+ powerRegisterSuspendResumeNotification := windowsFindfunc(powrprof, []byte("PowerRegisterSuspendResumeNotification\000"))
+ if powerRegisterSuspendResumeNotification == nil {
+ return // Running on Windows 7, where we don't need it anyway.
+ }
+ var fn any = func(context uintptr, changeType uint32, setting uintptr) uintptr {
+ for mp := (*m)(atomic.Loadp(unsafe.Pointer(&allm))); mp != nil; mp = mp.alllink {
+ if mp.resumesema != 0 {
+ stdcall1(_SetEvent, mp.resumesema)
+ }
+ }
+ return 0
+ }
+ params := _DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS{
+ callback: compileCallback(*efaceOf(&fn), true),
+ }
+ handle := uintptr(0)
+ stdcall3(powerRegisterSuspendResumeNotification, _DEVICE_NOTIFY_CALLBACK,
+ uintptr(unsafe.Pointer(&params)), uintptr(unsafe.Pointer(&handle)))
+}
+
+//go:nosplit
+func getLoadLibrary() uintptr {
+ return uintptr(unsafe.Pointer(_LoadLibraryW))
+}
+
+//go:nosplit
+func getLoadLibraryEx() uintptr {
+ return uintptr(unsafe.Pointer(_LoadLibraryExW))
+}
+
+//go:nosplit
+func getGetProcAddress() uintptr {
+ return uintptr(unsafe.Pointer(_GetProcAddress))
+}
+
+func getproccount() int32 {
+ var mask, sysmask uintptr
+ ret := stdcall3(_GetProcessAffinityMask, currentProcess, uintptr(unsafe.Pointer(&mask)), uintptr(unsafe.Pointer(&sysmask)))
+ if ret != 0 {
+ n := 0
+ maskbits := int(unsafe.Sizeof(mask) * 8)
+ for i := 0; i < maskbits; i++ {
+ if mask&(1<<uint(i)) != 0 {
+ n++
+ }
+ }
+ if n != 0 {
+ return int32(n)
+ }
+ }
+ // use GetSystemInfo if GetProcessAffinityMask fails
+ var info systeminfo
+ stdcall1(_GetSystemInfo, uintptr(unsafe.Pointer(&info)))
+ return int32(info.dwnumberofprocessors)
+}
+
+func getPageSize() uintptr {
+ var info systeminfo
+ stdcall1(_GetSystemInfo, uintptr(unsafe.Pointer(&info)))
+ return uintptr(info.dwpagesize)
+}
+
+const (
+ currentProcess = ^uintptr(0) // -1 = current process
+ currentThread = ^uintptr(1) // -2 = current thread
+)
+
+// in sys_windows_386.s and sys_windows_amd64.s:
+func getlasterror() uint32
+
+var timeBeginPeriodRetValue uint32
+
+// osRelaxMinNS indicates that sysmon shouldn't osRelax if the next
+// timer is less than 60 ms from now. Since osRelaxing may reduce
+// timer resolution to 15.6 ms, this keeps timer error under roughly 1
+// part in 4.
+const osRelaxMinNS = 60 * 1e6
+
+// osRelax is called by the scheduler when transitioning to and from
+// all Ps being idle.
+//
+// Some versions of Windows have high resolution timer. For those
+// versions osRelax is noop.
+// For Windows versions without high resolution timer, osRelax
+// adjusts the system-wide timer resolution. Go needs a
+// high resolution timer while running and there's little extra cost
+// if we're already using the CPU, but if all Ps are idle there's no
+// need to consume extra power to drive the high-res timer.
+func osRelax(relax bool) uint32 {
+ if haveHighResTimer {
+ // If the high resolution timer is available, the runtime uses the timer
+ // to sleep for short durations. This means there's no need to adjust
+ // the global clock frequency.
+ return 0
+ }
+
+ if relax {
+ return uint32(stdcall1(_timeEndPeriod, 1))
+ } else {
+ return uint32(stdcall1(_timeBeginPeriod, 1))
+ }
+}
+
+// haveHighResTimer indicates that the CreateWaitableTimerEx
+// CREATE_WAITABLE_TIMER_HIGH_RESOLUTION flag is available.
+var haveHighResTimer = false
+
+// createHighResTimer calls CreateWaitableTimerEx with
+// CREATE_WAITABLE_TIMER_HIGH_RESOLUTION flag to create high
+// resolution timer. createHighResTimer returns new timer
+// handle or 0, if CreateWaitableTimerEx failed.
+func createHighResTimer() uintptr {
+ const (
+ // As per @jstarks, see
+ // https://github.com/golang/go/issues/8687#issuecomment-656259353
+ _CREATE_WAITABLE_TIMER_HIGH_RESOLUTION = 0x00000002
+
+ _SYNCHRONIZE = 0x00100000
+ _TIMER_QUERY_STATE = 0x0001
+ _TIMER_MODIFY_STATE = 0x0002
+ )
+ return stdcall4(_CreateWaitableTimerExW, 0, 0,
+ _CREATE_WAITABLE_TIMER_HIGH_RESOLUTION,
+ _SYNCHRONIZE|_TIMER_QUERY_STATE|_TIMER_MODIFY_STATE)
+}
+
+func initHighResTimer() {
+ h := createHighResTimer()
+ if h != 0 {
+ haveHighResTimer = true
+ stdcall1(_CloseHandle, h)
+ }
+}
+
+//go:linkname canUseLongPaths os.canUseLongPaths
+var canUseLongPaths bool
+
+// We want this to be large enough to hold the contents of sysDirectory, *plus*
+// a slash and another component that itself is greater than MAX_PATH.
+var longFileName [(_MAX_PATH+1)*2 + 1]byte
+
+// initLongPathSupport initializes the canUseLongPaths variable, which is
+// linked into os.canUseLongPaths for determining whether or not long paths
+// need to be fixed up. In the best case, this function is running on newer
+// Windows 10 builds, which have a bit field member of the PEB called
+// "IsLongPathAwareProcess." When this is set, we don't need to go through the
+// error-prone fixup function in order to access long paths. So this init
+// function first checks the Windows build number, sets the flag, and then
+// tests to see if it's actually working. If everything checks out, then
+// canUseLongPaths is set to true, and later when called, os.fixLongPath
+// returns early without doing work.
+func initLongPathSupport() {
+ const (
+ IsLongPathAwareProcess = 0x80
+ PebBitFieldOffset = 3
+ OPEN_EXISTING = 3
+ ERROR_PATH_NOT_FOUND = 3
+ )
+
+ // Check that we're ≥ 10.0.15063.
+ var maj, min, build uint32
+ stdcall3(_RtlGetNtVersionNumbers, uintptr(unsafe.Pointer(&maj)), uintptr(unsafe.Pointer(&min)), uintptr(unsafe.Pointer(&build)))
+ if maj < 10 || (maj == 10 && min == 0 && build&0xffff < 15063) {
+ return
+ }
+
+ // Set the IsLongPathAwareProcess flag of the PEB's bit field.
+ bitField := (*byte)(unsafe.Pointer(stdcall0(_RtlGetCurrentPeb) + PebBitFieldOffset))
+ originalBitField := *bitField
+ *bitField |= IsLongPathAwareProcess
+
+ // Check that this actually has an effect, by constructing a large file
+ // path and seeing whether we get ERROR_PATH_NOT_FOUND, rather than
+ // some other error, which would indicate the path is too long, and
+ // hence long path support is not successful. This whole section is NOT
+ // strictly necessary, but is a nice validity check for the near to
+ // medium term, when this functionality is still relatively new in
+ // Windows.
+ targ := longFileName[len(longFileName)-33 : len(longFileName)-1]
+ if readRandom(targ) != len(targ) {
+ readTimeRandom(targ)
+ }
+ start := copy(longFileName[:], sysDirectory[:sysDirectoryLen])
+ const dig = "0123456789abcdef"
+ for i := 0; i < 32; i++ {
+ longFileName[start+i*2] = dig[longFileName[len(longFileName)-33+i]>>4]
+ longFileName[start+i*2+1] = dig[longFileName[len(longFileName)-33+i]&0xf]
+ }
+ start += 64
+ for i := start; i < len(longFileName)-1; i++ {
+ longFileName[i] = 'A'
+ }
+ stdcall7(_CreateFileA, uintptr(unsafe.Pointer(&longFileName[0])), 0, 0, 0, OPEN_EXISTING, 0, 0)
+ // The ERROR_PATH_NOT_FOUND error value is distinct from
+ // ERROR_FILE_NOT_FOUND or ERROR_INVALID_NAME, the latter of which we
+ // expect here due to the final component being too long.
+ if getlasterror() == ERROR_PATH_NOT_FOUND {
+ *bitField = originalBitField
+ println("runtime: warning: IsLongPathAwareProcess failed to enable long paths; proceeding in fixup mode")
+ return
+ }
+
+ canUseLongPaths = true
+}
+
+func osinit() {
+ asmstdcallAddr = unsafe.Pointer(abi.FuncPCABI0(asmstdcall))
+
+ loadOptionalSyscalls()
+
+ preventErrorDialogs()
+
+ initExceptionHandler()
+
+ initHighResTimer()
+ timeBeginPeriodRetValue = osRelax(false)
+
+ initSysDirectory()
+ initLongPathSupport()
+
+ ncpu = getproccount()
+
+ physPageSize = getPageSize()
+
+ // Windows dynamic priority boosting assumes that a process has different types
+ // of dedicated threads -- GUI, IO, computational, etc. Go processes use
+ // equivalent threads that all do a mix of GUI, IO, computations, etc.
+ // In such context dynamic priority boosting does nothing but harm, so we turn it off.
+ stdcall2(_SetProcessPriorityBoost, currentProcess, 1)
+}
+
+//go:nosplit
+func readRandom(r []byte) int {
+ n := 0
+ if stdcall2(_ProcessPrng, uintptr(unsafe.Pointer(&r[0])), uintptr(len(r)))&0xff != 0 {
+ n = len(r)
+ }
+ return n
+}
+
+func goenvs() {
+ // strings is a pointer to environment variable pairs in the form:
+ // "envA=valA\x00envB=valB\x00\x00" (in UTF-16)
+ // Two consecutive zero bytes end the list.
+ strings := unsafe.Pointer(stdcall0(_GetEnvironmentStringsW))
+ p := (*[1 << 24]uint16)(strings)[:]
+
+ n := 0
+ for from, i := 0, 0; true; i++ {
+ if p[i] == 0 {
+ // empty string marks the end
+ if i == from {
+ break
+ }
+ from = i + 1
+ n++
+ }
+ }
+ envs = make([]string, n)
+
+ for i := range envs {
+ envs[i] = gostringw(&p[0])
+ for p[0] != 0 {
+ p = p[1:]
+ }
+ p = p[1:] // skip nil byte
+ }
+
+ stdcall1(_FreeEnvironmentStringsW, uintptr(strings))
+
+ // We call these all the way here, late in init, so that malloc works
+ // for the callback functions these generate.
+ var fn any = ctrlHandler
+ ctrlHandlerPC := compileCallback(*efaceOf(&fn), true)
+ stdcall2(_SetConsoleCtrlHandler, ctrlHandlerPC, 1)
+
+ monitorSuspendResume()
+}
+
+// exiting is set to non-zero when the process is exiting.
+var exiting uint32
+
+//go:nosplit
+func exit(code int32) {
+ // Disallow thread suspension for preemption. Otherwise,
+ // ExitProcess and SuspendThread can race: SuspendThread
+ // queues a suspension request for this thread, ExitProcess
+ // kills the suspending thread, and then this thread suspends.
+ lock(&suspendLock)
+ atomic.Store(&exiting, 1)
+ stdcall1(_ExitProcess, uintptr(code))
+}
+
+// write1 must be nosplit because it's used as a last resort in
+// functions like badmorestackg0. In such cases, we'll always take the
+// ASCII path.
+//
+//go:nosplit
+func write1(fd uintptr, buf unsafe.Pointer, n int32) int32 {
+ const (
+ _STD_OUTPUT_HANDLE = ^uintptr(10) // -11
+ _STD_ERROR_HANDLE = ^uintptr(11) // -12
+ )
+ var handle uintptr
+ switch fd {
+ case 1:
+ handle = stdcall1(_GetStdHandle, _STD_OUTPUT_HANDLE)
+ case 2:
+ handle = stdcall1(_GetStdHandle, _STD_ERROR_HANDLE)
+ default:
+ // assume fd is real windows handle.
+ handle = fd
+ }
+ isASCII := true
+ b := (*[1 << 30]byte)(buf)[:n]
+ for _, x := range b {
+ if x >= 0x80 {
+ isASCII = false
+ break
+ }
+ }
+
+ if !isASCII {
+ var m uint32
+ isConsole := stdcall2(_GetConsoleMode, handle, uintptr(unsafe.Pointer(&m))) != 0
+ // If this is a console output, various non-unicode code pages can be in use.
+ // Use the dedicated WriteConsole call to ensure unicode is printed correctly.
+ if isConsole {
+ return int32(writeConsole(handle, buf, n))
+ }
+ }
+ var written uint32
+ stdcall5(_WriteFile, handle, uintptr(buf), uintptr(n), uintptr(unsafe.Pointer(&written)), 0)
+ return int32(written)
+}
+
+var (
+ utf16ConsoleBack [1000]uint16
+ utf16ConsoleBackLock mutex
+)
+
+// writeConsole writes bufLen bytes from buf to the console File.
+// It returns the number of bytes written.
+func writeConsole(handle uintptr, buf unsafe.Pointer, bufLen int32) int {
+ const surr2 = (surrogateMin + surrogateMax + 1) / 2
+
+ // Do not use defer for unlock. May cause issues when printing a panic.
+ lock(&utf16ConsoleBackLock)
+
+ b := (*[1 << 30]byte)(buf)[:bufLen]
+ s := *(*string)(unsafe.Pointer(&b))
+
+ utf16tmp := utf16ConsoleBack[:]
+
+ total := len(s)
+ w := 0
+ for _, r := range s {
+ if w >= len(utf16tmp)-2 {
+ writeConsoleUTF16(handle, utf16tmp[:w])
+ w = 0
+ }
+ if r < 0x10000 {
+ utf16tmp[w] = uint16(r)
+ w++
+ } else {
+ r -= 0x10000
+ utf16tmp[w] = surrogateMin + uint16(r>>10)&0x3ff
+ utf16tmp[w+1] = surr2 + uint16(r)&0x3ff
+ w += 2
+ }
+ }
+ writeConsoleUTF16(handle, utf16tmp[:w])
+ unlock(&utf16ConsoleBackLock)
+ return total
+}
+
+// writeConsoleUTF16 is the dedicated windows calls that correctly prints
+// to the console regardless of the current code page. Input is utf-16 code points.
+// The handle must be a console handle.
+func writeConsoleUTF16(handle uintptr, b []uint16) {
+ l := uint32(len(b))
+ if l == 0 {
+ return
+ }
+ var written uint32
+ stdcall5(_WriteConsoleW,
+ handle,
+ uintptr(unsafe.Pointer(&b[0])),
+ uintptr(l),
+ uintptr(unsafe.Pointer(&written)),
+ 0,
+ )
+ return
+}
+
+//go:nosplit
+func semasleep(ns int64) int32 {
+ const (
+ _WAIT_ABANDONED = 0x00000080
+ _WAIT_OBJECT_0 = 0x00000000
+ _WAIT_TIMEOUT = 0x00000102
+ _WAIT_FAILED = 0xFFFFFFFF
+ )
+
+ var result uintptr
+ if ns < 0 {
+ result = stdcall2(_WaitForSingleObject, getg().m.waitsema, uintptr(_INFINITE))
+ } else {
+ start := nanotime()
+ elapsed := int64(0)
+ for {
+ ms := int64(timediv(ns-elapsed, 1000000, nil))
+ if ms == 0 {
+ ms = 1
+ }
+ result = stdcall4(_WaitForMultipleObjects, 2,
+ uintptr(unsafe.Pointer(&[2]uintptr{getg().m.waitsema, getg().m.resumesema})),
+ 0, uintptr(ms))
+ if result != _WAIT_OBJECT_0+1 {
+ // Not a suspend/resume event
+ break
+ }
+ elapsed = nanotime() - start
+ if elapsed >= ns {
+ return -1
+ }
+ }
+ }
+ switch result {
+ case _WAIT_OBJECT_0: // Signaled
+ return 0
+
+ case _WAIT_TIMEOUT:
+ return -1
+
+ case _WAIT_ABANDONED:
+ systemstack(func() {
+ throw("runtime.semasleep wait_abandoned")
+ })
+
+ case _WAIT_FAILED:
+ systemstack(func() {
+ print("runtime: waitforsingleobject wait_failed; errno=", getlasterror(), "\n")
+ throw("runtime.semasleep wait_failed")
+ })
+
+ default:
+ systemstack(func() {
+ print("runtime: waitforsingleobject unexpected; result=", result, "\n")
+ throw("runtime.semasleep unexpected")
+ })
+ }
+
+ return -1 // unreachable
+}
+
+//go:nosplit
+func semawakeup(mp *m) {
+ if stdcall1(_SetEvent, mp.waitsema) == 0 {
+ systemstack(func() {
+ print("runtime: setevent failed; errno=", getlasterror(), "\n")
+ throw("runtime.semawakeup")
+ })
+ }
+}
+
+//go:nosplit
+func semacreate(mp *m) {
+ if mp.waitsema != 0 {
+ return
+ }
+ mp.waitsema = stdcall4(_CreateEventA, 0, 0, 0, 0)
+ if mp.waitsema == 0 {
+ systemstack(func() {
+ print("runtime: createevent failed; errno=", getlasterror(), "\n")
+ throw("runtime.semacreate")
+ })
+ }
+ mp.resumesema = stdcall4(_CreateEventA, 0, 0, 0, 0)
+ if mp.resumesema == 0 {
+ systemstack(func() {
+ print("runtime: createevent failed; errno=", getlasterror(), "\n")
+ throw("runtime.semacreate")
+ })
+ stdcall1(_CloseHandle, mp.waitsema)
+ mp.waitsema = 0
+ }
+}
+
+// May run with m.p==nil, so write barriers are not allowed. This
+// function is called by newosproc0, so it is also required to
+// operate without stack guards.
+//
+//go:nowritebarrierrec
+//go:nosplit
+func newosproc(mp *m) {
+ // We pass 0 for the stack size to use the default for this binary.
+ thandle := stdcall6(_CreateThread, 0, 0,
+ abi.FuncPCABI0(tstart_stdcall), uintptr(unsafe.Pointer(mp)),
+ 0, 0)
+
+ if thandle == 0 {
+ if atomic.Load(&exiting) != 0 {
+ // CreateThread may fail if called
+ // concurrently with ExitProcess. If this
+ // happens, just freeze this thread and let
+ // the process exit. See issue #18253.
+ lock(&deadlock)
+ lock(&deadlock)
+ }
+ print("runtime: failed to create new OS thread (have ", mcount(), " already; errno=", getlasterror(), ")\n")
+ throw("runtime.newosproc")
+ }
+
+ // Close thandle to avoid leaking the thread object if it exits.
+ stdcall1(_CloseHandle, thandle)
+}
+
+// Used by the C library build mode. On Linux this function would allocate a
+// stack, but that's not necessary for Windows. No stack guards are present
+// and the GC has not been initialized, so write barriers will fail.
+//
+//go:nowritebarrierrec
+//go:nosplit
+func newosproc0(mp *m, stk unsafe.Pointer) {
+ // TODO: this is completely broken. The args passed to newosproc0 (in asm_amd64.s)
+ // are stacksize and function, not *m and stack.
+ // Check os_linux.go for an implementation that might actually work.
+ throw("bad newosproc0")
+}
+
+func exitThread(wait *atomic.Uint32) {
+ // We should never reach exitThread on Windows because we let
+ // the OS clean up threads.
+ throw("exitThread")
+}
+
+// Called to initialize a new m (including the bootstrap m).
+// Called on the parent thread (main thread in case of bootstrap), can allocate memory.
+func mpreinit(mp *m) {
+}
+
+//go:nosplit
+func sigsave(p *sigset) {
+}
+
+//go:nosplit
+func msigrestore(sigmask sigset) {
+}
+
+//go:nosplit
+//go:nowritebarrierrec
+func clearSignalHandlers() {
+}
+
+//go:nosplit
+func sigblock(exiting bool) {
+}
+
+// Called to initialize a new m (including the bootstrap m).
+// Called on the new thread, cannot allocate memory.
+func minit() {
+ var thandle uintptr
+ if stdcall7(_DuplicateHandle, currentProcess, currentThread, currentProcess, uintptr(unsafe.Pointer(&thandle)), 0, 0, _DUPLICATE_SAME_ACCESS) == 0 {
+ print("runtime.minit: duplicatehandle failed; errno=", getlasterror(), "\n")
+ throw("runtime.minit: duplicatehandle failed")
+ }
+
+ mp := getg().m
+ lock(&mp.threadLock)
+ mp.thread = thandle
+ mp.procid = uint64(stdcall0(_GetCurrentThreadId))
+
+ // Configure usleep timer, if possible.
+ if mp.highResTimer == 0 && haveHighResTimer {
+ mp.highResTimer = createHighResTimer()
+ if mp.highResTimer == 0 {
+ print("runtime: CreateWaitableTimerEx failed; errno=", getlasterror(), "\n")
+ throw("CreateWaitableTimerEx when creating timer failed")
+ }
+ }
+ unlock(&mp.threadLock)
+
+ // Query the true stack base from the OS. Currently we're
+ // running on a small assumed stack.
+ var mbi memoryBasicInformation
+ res := stdcall3(_VirtualQuery, uintptr(unsafe.Pointer(&mbi)), uintptr(unsafe.Pointer(&mbi)), unsafe.Sizeof(mbi))
+ if res == 0 {
+ print("runtime: VirtualQuery failed; errno=", getlasterror(), "\n")
+ throw("VirtualQuery for stack base failed")
+ }
+ // The system leaves an 8K PAGE_GUARD region at the bottom of
+ // the stack (in theory VirtualQuery isn't supposed to include
+ // that, but it does). Add an additional 8K of slop for
+ // calling C functions that don't have stack checks and for
+ // lastcontinuehandler. We shouldn't be anywhere near this
+ // bound anyway.
+ base := mbi.allocationBase + 16<<10
+ // Sanity check the stack bounds.
+ g0 := getg()
+ if base > g0.stack.hi || g0.stack.hi-base > 64<<20 {
+ print("runtime: g0 stack [", hex(base), ",", hex(g0.stack.hi), ")\n")
+ throw("bad g0 stack")
+ }
+ g0.stack.lo = base
+ g0.stackguard0 = g0.stack.lo + stackGuard
+ g0.stackguard1 = g0.stackguard0
+ // Sanity check the SP.
+ stackcheck()
+}
+
+// Called from dropm to undo the effect of an minit.
+//
+//go:nosplit
+func unminit() {
+ mp := getg().m
+ lock(&mp.threadLock)
+ if mp.thread != 0 {
+ stdcall1(_CloseHandle, mp.thread)
+ mp.thread = 0
+ }
+ unlock(&mp.threadLock)
+
+ mp.procid = 0
+}
+
+// Called from exitm, but not from drop, to undo the effect of thread-owned
+// resources in minit, semacreate, or elsewhere. Do not take locks after calling this.
+//
+//go:nosplit
+func mdestroy(mp *m) {
+ if mp.highResTimer != 0 {
+ stdcall1(_CloseHandle, mp.highResTimer)
+ mp.highResTimer = 0
+ }
+ if mp.waitsema != 0 {
+ stdcall1(_CloseHandle, mp.waitsema)
+ mp.waitsema = 0
+ }
+ if mp.resumesema != 0 {
+ stdcall1(_CloseHandle, mp.resumesema)
+ mp.resumesema = 0
+ }
+}
+
+// asmstdcall_trampoline calls asmstdcall converting from Go to C calling convention.
+func asmstdcall_trampoline(args unsafe.Pointer)
+
+// stdcall_no_g calls asmstdcall on os stack without using g.
+//
+//go:nosplit
+func stdcall_no_g(fn stdFunction, n int, args uintptr) uintptr {
+ libcall := libcall{
+ fn: uintptr(unsafe.Pointer(fn)),
+ n: uintptr(n),
+ args: args,
+ }
+ asmstdcall_trampoline(noescape(unsafe.Pointer(&libcall)))
+ return libcall.r1
+}
+
+// Calling stdcall on os stack.
+// May run during STW, so write barriers are not allowed.
+//
+//go:nowritebarrier
+//go:nosplit
+func stdcall(fn stdFunction) uintptr {
+ gp := getg()
+ mp := gp.m
+ mp.libcall.fn = uintptr(unsafe.Pointer(fn))
+ resetLibcall := false
+ if mp.profilehz != 0 && mp.libcallsp == 0 {
+ // leave pc/sp for cpu profiler
+ mp.libcallg.set(gp)
+ mp.libcallpc = getcallerpc()
+ // sp must be the last, because once async cpu profiler finds
+ // all three values to be non-zero, it will use them
+ mp.libcallsp = getcallersp()
+ resetLibcall = true // See comment in sys_darwin.go:libcCall
+ }
+ asmcgocall(asmstdcallAddr, unsafe.Pointer(&mp.libcall))
+ if resetLibcall {
+ mp.libcallsp = 0
+ }
+ return mp.libcall.r1
+}
+
+//go:nosplit
+func stdcall0(fn stdFunction) uintptr {
+ mp := getg().m
+ mp.libcall.n = 0
+ mp.libcall.args = 0
+ return stdcall(fn)
+}
+
+//go:nosplit
+//go:cgo_unsafe_args
+func stdcall1(fn stdFunction, a0 uintptr) uintptr {
+ mp := getg().m
+ mp.libcall.n = 1
+ mp.libcall.args = uintptr(noescape(unsafe.Pointer(&a0)))
+ return stdcall(fn)
+}
+
+//go:nosplit
+//go:cgo_unsafe_args
+func stdcall2(fn stdFunction, a0, a1 uintptr) uintptr {
+ mp := getg().m
+ mp.libcall.n = 2
+ mp.libcall.args = uintptr(noescape(unsafe.Pointer(&a0)))
+ return stdcall(fn)
+}
+
+//go:nosplit
+//go:cgo_unsafe_args
+func stdcall3(fn stdFunction, a0, a1, a2 uintptr) uintptr {
+ mp := getg().m
+ mp.libcall.n = 3
+ mp.libcall.args = uintptr(noescape(unsafe.Pointer(&a0)))
+ return stdcall(fn)
+}
+
+//go:nosplit
+//go:cgo_unsafe_args
+func stdcall4(fn stdFunction, a0, a1, a2, a3 uintptr) uintptr {
+ mp := getg().m
+ mp.libcall.n = 4
+ mp.libcall.args = uintptr(noescape(unsafe.Pointer(&a0)))
+ return stdcall(fn)
+}
+
+//go:nosplit
+//go:cgo_unsafe_args
+func stdcall5(fn stdFunction, a0, a1, a2, a3, a4 uintptr) uintptr {
+ mp := getg().m
+ mp.libcall.n = 5
+ mp.libcall.args = uintptr(noescape(unsafe.Pointer(&a0)))
+ return stdcall(fn)
+}
+
+//go:nosplit
+//go:cgo_unsafe_args
+func stdcall6(fn stdFunction, a0, a1, a2, a3, a4, a5 uintptr) uintptr {
+ mp := getg().m
+ mp.libcall.n = 6
+ mp.libcall.args = uintptr(noescape(unsafe.Pointer(&a0)))
+ return stdcall(fn)
+}
+
+//go:nosplit
+//go:cgo_unsafe_args
+func stdcall7(fn stdFunction, a0, a1, a2, a3, a4, a5, a6 uintptr) uintptr {
+ mp := getg().m
+ mp.libcall.n = 7
+ mp.libcall.args = uintptr(noescape(unsafe.Pointer(&a0)))
+ return stdcall(fn)
+}
+
+//go:nosplit
+//go:cgo_unsafe_args
+func stdcall8(fn stdFunction, a0, a1, a2, a3, a4, a5, a6, a7 uintptr) uintptr {
+ mp := getg().m
+ mp.libcall.n = 8
+ mp.libcall.args = uintptr(noescape(unsafe.Pointer(&a0)))
+ return stdcall(fn)
+}
+
+// These must run on the system stack only.
+
+//go:nosplit
+func osyield_no_g() {
+ stdcall_no_g(_SwitchToThread, 0, 0)
+}
+
+//go:nosplit
+func osyield() {
+ systemstack(func() {
+ stdcall0(_SwitchToThread)
+ })
+}
+
+//go:nosplit
+func usleep_no_g(us uint32) {
+ timeout := uintptr(us) / 1000 // ms units
+ args := [...]uintptr{_INVALID_HANDLE_VALUE, timeout}
+ stdcall_no_g(_WaitForSingleObject, len(args), uintptr(noescape(unsafe.Pointer(&args[0]))))
+}
+
+//go:nosplit
+func usleep(us uint32) {
+ systemstack(func() {
+ var h, timeout uintptr
+ // If the high-res timer is available and its handle has been allocated for this m, use it.
+ // Otherwise fall back to the low-res one, which doesn't need a handle.
+ if haveHighResTimer && getg().m.highResTimer != 0 {
+ h = getg().m.highResTimer
+ dt := -10 * int64(us) // relative sleep (negative), 100ns units
+ stdcall6(_SetWaitableTimer, h, uintptr(unsafe.Pointer(&dt)), 0, 0, 0, 0)
+ timeout = _INFINITE
+ } else {
+ h = _INVALID_HANDLE_VALUE
+ timeout = uintptr(us) / 1000 // ms units
+ }
+ stdcall2(_WaitForSingleObject, h, timeout)
+ })
+}
+
+func ctrlHandler(_type uint32) uintptr {
+ var s uint32
+
+ switch _type {
+ case _CTRL_C_EVENT, _CTRL_BREAK_EVENT:
+ s = _SIGINT
+ case _CTRL_CLOSE_EVENT, _CTRL_LOGOFF_EVENT, _CTRL_SHUTDOWN_EVENT:
+ s = _SIGTERM
+ default:
+ return 0
+ }
+
+ if sigsend(s) {
+ if s == _SIGTERM {
+ // Windows terminates the process after this handler returns.
+ // Block indefinitely to give signal handlers a chance to clean up,
+ // but make sure to be properly parked first, so the rest of the
+ // program can continue executing.
+ block()
+ }
+ return 1
+ }
+ return 0
+}
+
+// called from zcallback_windows_*.s to sys_windows_*.s
+func callbackasm1()
+
+var profiletimer uintptr
+
+func profilem(mp *m, thread uintptr) {
+ // Align Context to 16 bytes.
+ var c *context
+ var cbuf [unsafe.Sizeof(*c) + 15]byte
+ c = (*context)(unsafe.Pointer((uintptr(unsafe.Pointer(&cbuf[15]))) &^ 15))
+
+ c.contextflags = _CONTEXT_CONTROL
+ stdcall2(_GetThreadContext, thread, uintptr(unsafe.Pointer(c)))
+
+ gp := gFromSP(mp, c.sp())
+
+ sigprof(c.ip(), c.sp(), c.lr(), gp, mp)
+}
+
+func gFromSP(mp *m, sp uintptr) *g {
+ if gp := mp.g0; gp != nil && gp.stack.lo < sp && sp < gp.stack.hi {
+ return gp
+ }
+ if gp := mp.gsignal; gp != nil && gp.stack.lo < sp && sp < gp.stack.hi {
+ return gp
+ }
+ if gp := mp.curg; gp != nil && gp.stack.lo < sp && sp < gp.stack.hi {
+ return gp
+ }
+ return nil
+}
+
+func profileLoop() {
+ stdcall2(_SetThreadPriority, currentThread, _THREAD_PRIORITY_HIGHEST)
+
+ for {
+ stdcall2(_WaitForSingleObject, profiletimer, _INFINITE)
+ first := (*m)(atomic.Loadp(unsafe.Pointer(&allm)))
+ for mp := first; mp != nil; mp = mp.alllink {
+ if mp == getg().m {
+ // Don't profile ourselves.
+ continue
+ }
+
+ lock(&mp.threadLock)
+ // Do not profile threads blocked on Notes,
+ // this includes idle worker threads,
+ // idle timer thread, idle heap scavenger, etc.
+ if mp.thread == 0 || mp.profilehz == 0 || mp.blocked {
+ unlock(&mp.threadLock)
+ continue
+ }
+ // Acquire our own handle to the thread.
+ var thread uintptr
+ if stdcall7(_DuplicateHandle, currentProcess, mp.thread, currentProcess, uintptr(unsafe.Pointer(&thread)), 0, 0, _DUPLICATE_SAME_ACCESS) == 0 {
+ print("runtime: duplicatehandle failed; errno=", getlasterror(), "\n")
+ throw("duplicatehandle failed")
+ }
+ unlock(&mp.threadLock)
+
+ // mp may exit between the DuplicateHandle
+ // above and the SuspendThread. The handle
+ // will remain valid, but SuspendThread may
+ // fail.
+ if int32(stdcall1(_SuspendThread, thread)) == -1 {
+ // The thread no longer exists.
+ stdcall1(_CloseHandle, thread)
+ continue
+ }
+ if mp.profilehz != 0 && !mp.blocked {
+ // Pass the thread handle in case mp
+ // was in the process of shutting down.
+ profilem(mp, thread)
+ }
+ stdcall1(_ResumeThread, thread)
+ stdcall1(_CloseHandle, thread)
+ }
+ }
+}
+
+func setProcessCPUProfiler(hz int32) {
+ if profiletimer == 0 {
+ var timer uintptr
+ if haveHighResTimer {
+ timer = createHighResTimer()
+ } else {
+ timer = stdcall3(_CreateWaitableTimerA, 0, 0, 0)
+ }
+ atomic.Storeuintptr(&profiletimer, timer)
+ newm(profileLoop, nil, -1)
+ }
+}
+
+func setThreadCPUProfiler(hz int32) {
+ ms := int32(0)
+ due := ^int64(^uint64(1 << 63))
+ if hz > 0 {
+ ms = 1000 / hz
+ if ms == 0 {
+ ms = 1
+ }
+ due = int64(ms) * -10000
+ }
+ stdcall6(_SetWaitableTimer, profiletimer, uintptr(unsafe.Pointer(&due)), uintptr(ms), 0, 0, 0)
+ atomic.Store((*uint32)(unsafe.Pointer(&getg().m.profilehz)), uint32(hz))
+}
+
+const preemptMSupported = true
+
+// suspendLock protects simultaneous SuspendThread operations from
+// suspending each other.
+var suspendLock mutex
+
+func preemptM(mp *m) {
+ if mp == getg().m {
+ throw("self-preempt")
+ }
+
+ // Synchronize with external code that may try to ExitProcess.
+ if !atomic.Cas(&mp.preemptExtLock, 0, 1) {
+ // External code is running. Fail the preemption
+ // attempt.
+ mp.preemptGen.Add(1)
+ return
+ }
+
+ // Acquire our own handle to mp's thread.
+ lock(&mp.threadLock)
+ if mp.thread == 0 {
+ // The M hasn't been minit'd yet (or was just unminit'd).
+ unlock(&mp.threadLock)
+ atomic.Store(&mp.preemptExtLock, 0)
+ mp.preemptGen.Add(1)
+ return
+ }
+ var thread uintptr
+ if stdcall7(_DuplicateHandle, currentProcess, mp.thread, currentProcess, uintptr(unsafe.Pointer(&thread)), 0, 0, _DUPLICATE_SAME_ACCESS) == 0 {
+ print("runtime.preemptM: duplicatehandle failed; errno=", getlasterror(), "\n")
+ throw("runtime.preemptM: duplicatehandle failed")
+ }
+ unlock(&mp.threadLock)
+
+ // Prepare thread context buffer. This must be aligned to 16 bytes.
+ var c *context
+ var cbuf [unsafe.Sizeof(*c) + 15]byte
+ c = (*context)(unsafe.Pointer((uintptr(unsafe.Pointer(&cbuf[15]))) &^ 15))
+ c.contextflags = _CONTEXT_CONTROL
+
+ // Serialize thread suspension. SuspendThread is asynchronous,
+ // so it's otherwise possible for two threads to suspend each
+ // other and deadlock. We must hold this lock until after
+ // GetThreadContext, since that blocks until the thread is
+ // actually suspended.
+ lock(&suspendLock)
+
+ // Suspend the thread.
+ if int32(stdcall1(_SuspendThread, thread)) == -1 {
+ unlock(&suspendLock)
+ stdcall1(_CloseHandle, thread)
+ atomic.Store(&mp.preemptExtLock, 0)
+ // The thread no longer exists. This shouldn't be
+ // possible, but just acknowledge the request.
+ mp.preemptGen.Add(1)
+ return
+ }
+
+ // We have to be very careful between this point and once
+ // we've shown mp is at an async safe-point. This is like a
+ // signal handler in the sense that mp could have been doing
+ // anything when we stopped it, including holding arbitrary
+ // locks.
+
+ // We have to get the thread context before inspecting the M
+ // because SuspendThread only requests a suspend.
+ // GetThreadContext actually blocks until it's suspended.
+ stdcall2(_GetThreadContext, thread, uintptr(unsafe.Pointer(c)))
+
+ unlock(&suspendLock)
+
+ // Does it want a preemption and is it safe to preempt?
+ gp := gFromSP(mp, c.sp())
+ if gp != nil && wantAsyncPreempt(gp) {
+ if ok, newpc := isAsyncSafePoint(gp, c.ip(), c.sp(), c.lr()); ok {
+ // Inject call to asyncPreempt
+ targetPC := abi.FuncPCABI0(asyncPreempt)
+ switch GOARCH {
+ default:
+ throw("unsupported architecture")
+ case "386", "amd64":
+ // Make it look like the thread called targetPC.
+ sp := c.sp()
+ sp -= goarch.PtrSize
+ *(*uintptr)(unsafe.Pointer(sp)) = newpc
+ c.set_sp(sp)
+ c.set_ip(targetPC)
+
+ case "arm":
+ // Push LR. The injected call is responsible
+ // for restoring LR. gentraceback is aware of
+ // this extra slot. See sigctxt.pushCall in
+ // signal_arm.go, which is similar except we
+ // subtract 1 from IP here.
+ sp := c.sp()
+ sp -= goarch.PtrSize
+ c.set_sp(sp)
+ *(*uint32)(unsafe.Pointer(sp)) = uint32(c.lr())
+ c.set_lr(newpc - 1)
+ c.set_ip(targetPC)
+
+ case "arm64":
+ // Push LR. The injected call is responsible
+ // for restoring LR. gentraceback is aware of
+ // this extra slot. See sigctxt.pushCall in
+ // signal_arm64.go.
+ sp := c.sp() - 16 // SP needs 16-byte alignment
+ c.set_sp(sp)
+ *(*uint64)(unsafe.Pointer(sp)) = uint64(c.lr())
+ c.set_lr(newpc)
+ c.set_ip(targetPC)
+ }
+ stdcall2(_SetThreadContext, thread, uintptr(unsafe.Pointer(c)))
+ }
+ }
+
+ atomic.Store(&mp.preemptExtLock, 0)
+
+ // Acknowledge the preemption.
+ mp.preemptGen.Add(1)
+
+ stdcall1(_ResumeThread, thread)
+ stdcall1(_CloseHandle, thread)
+}
+
+// osPreemptExtEnter is called before entering external code that may
+// call ExitProcess.
+//
+// This must be nosplit because it may be called from a syscall with
+// untyped stack slots, so the stack must not be grown or scanned.
+//
+//go:nosplit
+func osPreemptExtEnter(mp *m) {
+ for !atomic.Cas(&mp.preemptExtLock, 0, 1) {
+ // An asynchronous preemption is in progress. It's not
+ // safe to enter external code because it may call
+ // ExitProcess and deadlock with SuspendThread.
+ // Ideally we would do the preemption ourselves, but
+ // can't since there may be untyped syscall arguments
+ // on the stack. Instead, just wait and encourage the
+ // SuspendThread APC to run. The preemption should be
+ // done shortly.
+ osyield()
+ }
+ // Asynchronous preemption is now blocked.
+}
+
+// osPreemptExtExit is called after returning from external code that
+// may call ExitProcess.
+//
+// See osPreemptExtEnter for why this is nosplit.
+//
+//go:nosplit
+func osPreemptExtExit(mp *m) {
+ atomic.Store(&mp.preemptExtLock, 0)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-29 12:58:36 +0000