diff options
Diffstat (limited to 'vendor/github.com/gofrs/flock/flock_winapi.go')
| -rw-r--r-- | vendor/github.com/gofrs/flock/flock_winapi.go | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/vendor/github.com/gofrs/flock/flock_winapi.go b/vendor/github.com/gofrs/flock/flock_winapi.go new file mode 100644 index 00000000..fe405a25 --- /dev/null +++ b/vendor/github.com/gofrs/flock/flock_winapi.go @@ -0,0 +1,76 @@ +// Copyright 2015 Tim Heckman. All rights reserved. +// Use of this source code is governed by the BSD 3-Clause +// license that can be found in the LICENSE file. + +// +build windows + +package flock + +import ( + "syscall" + "unsafe" +) + +var ( + kernel32, _ = syscall.LoadLibrary("kernel32.dll") + procLockFileEx, _ = syscall.GetProcAddress(kernel32, "LockFileEx") + procUnlockFileEx, _ = syscall.GetProcAddress(kernel32, "UnlockFileEx") +) + +const ( + winLockfileFailImmediately = 0x00000001 + winLockfileExclusiveLock = 0x00000002 + winLockfileSharedLock = 0x00000000 +) + +// Use of 0x00000000 for the shared lock is a guess based on some the MS Windows +// `LockFileEX` docs, which document the `LOCKFILE_EXCLUSIVE_LOCK` flag as: +// +// > The function requests an exclusive lock. Otherwise, it requests a shared +// > lock. +// +// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365203(v=vs.85).aspx + +func lockFileEx(handle syscall.Handle, flags uint32, reserved uint32, numberOfBytesToLockLow uint32, numberOfBytesToLockHigh uint32, offset *syscall.Overlapped) (bool, syscall.Errno) { + r1, _, errNo := syscall.Syscall6( + uintptr(procLockFileEx), + 6, + uintptr(handle), + uintptr(flags), + uintptr(reserved), + uintptr(numberOfBytesToLockLow), + uintptr(numberOfBytesToLockHigh), + uintptr(unsafe.Pointer(offset))) + + if r1 != 1 { + if errNo == 0 { + return false, syscall.EINVAL + } + + return false, errNo + } + + return true, 0 +} + +func unlockFileEx(handle syscall.Handle, reserved uint32, numberOfBytesToLockLow uint32, numberOfBytesToLockHigh uint32, offset *syscall.Overlapped) (bool, syscall.Errno) { + r1, _, errNo := syscall.Syscall6( + uintptr(procUnlockFileEx), + 5, + uintptr(handle), + uintptr(reserved), + uintptr(numberOfBytesToLockLow), + uintptr(numberOfBytesToLockHigh), + uintptr(unsafe.Pointer(offset)), + 0) + + if r1 != 1 { + if errNo == 0 { + return false, syscall.EINVAL + } + + return false, errNo + } + + return true, 0 +} |
