windows: add mutex management functions

Indeed Go has mutexes of its own, but these are considerably
different from the native Windows ones, that can work across processes
and be put in various namespaces. They're an essential part of Windows
systems programming and important for interfacing with various external
interfaces.

Change-Id: I03987800ed1c134442321678c2c7d7aa359ecb36
Reviewed-on: https://go-review.googlesource.com/c/sys/+/192497
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

windows/syscall_windows.go

@@ -257,6 +257,10 @@ func NewCallbackCDecl(fn interface{}) uintptr {
 //sys	SetEvent(event Handle) (err error) = kernel32.SetEvent
 //sys	ResetEvent(event Handle) (err error) = kernel32.ResetEvent
 //sys	PulseEvent(event Handle) (err error) = kernel32.PulseEvent
+//sys	CreateMutex(mutexAttrs *SecurityAttributes, initialOwner bool, name *uint16) (handle Handle, err error) = kernel32.CreateMutexW
+//sys	CreateMutexEx(mutexAttrs *SecurityAttributes, name *uint16, flags uint32, desiredAccess uint32) (handle Handle, err error) = kernel32.CreateMutexExW
+//sys	OpenMutex(desiredAccess uint32, inheritHandle bool, name *uint16) (handle Handle, err error) = kernel32.OpenMutexW
+//sys	ReleaseMutex(mutex Handle) (err error) = kernel32.ReleaseMutex
 //sys	SleepEx(milliseconds uint32, alertable bool) (ret uint32) = kernel32.SleepEx
 //sys	CreateJobObject(jobAttr *SecurityAttributes, name *uint16) (handle Handle, err error) = kernel32.CreateJobObjectW
 //sys	AssignProcessToJobObject(job Handle, process Handle) (err error) = kernel32.AssignProcessToJobObject

windows/types_windows.go

@@ -1190,6 +1190,28 @@ const (
 	REG_QWORD = REG_QWORD_LITTLE_ENDIAN
 )
 
+const (
+	EVENT_MODIFY_STATE = 0x0002
+	EVENT_ALL_ACCESS   = STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | 0x3
+
+	MUTANT_QUERY_STATE = 0x0001
+	MUTANT_ALL_ACCESS  = STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | MUTANT_QUERY_STATE
+
+	SEMAPHORE_MODIFY_STATE = 0x0002
+	SEMAPHORE_ALL_ACCESS   = STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | 0x3
+
+	TIMER_QUERY_STATE  = 0x0001
+	TIMER_MODIFY_STATE = 0x0002
+	TIMER_ALL_ACCESS   = STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | TIMER_QUERY_STATE | TIMER_MODIFY_STATE
+
+	MUTEX_MODIFY_STATE = MUTANT_QUERY_STATE
+	MUTEX_ALL_ACCESS   = MUTANT_ALL_ACCESS
+
+	CREATE_EVENT_MANUAL_RESET  = 0x1
+	CREATE_EVENT_INITIAL_SET   = 0x2
+	CREATE_MUTEX_INITIAL_OWNER = 0x1
+)
+
 type AddrinfoW struct {
 	Flags     int32
 	Family    int32

windows/zsyscall_windows.go

@@ -197,6 +197,10 @@ var (
 	procSetEvent                           = modkernel32.NewProc("SetEvent")
 	procResetEvent                         = modkernel32.NewProc("ResetEvent")
 	procPulseEvent                         = modkernel32.NewProc("PulseEvent")
+	procCreateMutexW                       = modkernel32.NewProc("CreateMutexW")
+	procCreateMutexExW                     = modkernel32.NewProc("CreateMutexExW")
+	procOpenMutexW                         = modkernel32.NewProc("OpenMutexW")
+	procReleaseMutex                       = modkernel32.NewProc("ReleaseMutex")
 	procSleepEx                            = modkernel32.NewProc("SleepEx")
 	procCreateJobObjectW                   = modkernel32.NewProc("CreateJobObjectW")
 	procAssignProcessToJobObject           = modkernel32.NewProc("AssignProcessToJobObject")
@@ -2109,6 +2113,69 @@ func PulseEvent(event Handle) (err error) {
 	return
 }
 
+func CreateMutex(mutexAttrs *SecurityAttributes, initialOwner bool, name *uint16) (handle Handle, err error) {
+	var _p0 uint32
+	if initialOwner {
+		_p0 = 1
+	} else {
+		_p0 = 0
+	}
+	r0, _, e1 := syscall.Syscall(procCreateMutexW.Addr(), 3, uintptr(unsafe.Pointer(mutexAttrs)), uintptr(_p0), uintptr(unsafe.Pointer(name)))
+	handle = Handle(r0)
+	if handle == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func CreateMutexEx(mutexAttrs *SecurityAttributes, name *uint16, flags uint32, desiredAccess uint32) (handle Handle, err error) {
+	r0, _, e1 := syscall.Syscall6(procCreateMutexExW.Addr(), 4, uintptr(unsafe.Pointer(mutexAttrs)), uintptr(unsafe.Pointer(name)), uintptr(flags), uintptr(desiredAccess), 0, 0)
+	handle = Handle(r0)
+	if handle == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func OpenMutex(desiredAccess uint32, inheritHandle bool, name *uint16) (handle Handle, err error) {
+	var _p0 uint32
+	if inheritHandle {
+		_p0 = 1
+	} else {
+		_p0 = 0
+	}
+	r0, _, e1 := syscall.Syscall(procOpenMutexW.Addr(), 3, uintptr(desiredAccess), uintptr(_p0), uintptr(unsafe.Pointer(name)))
+	handle = Handle(r0)
+	if handle == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func ReleaseMutex(mutex Handle) (err error) {
+	r1, _, e1 := syscall.Syscall(procReleaseMutex.Addr(), 1, uintptr(mutex), 0, 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
 func SleepEx(milliseconds uint32, alertable bool) (ret uint32) {
 	var _p0 uint32
 	if alertable {