README
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fslock 
fslock provides a cross-process mutex based on file locks that works on windows and *nix platforms.
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fslock relies on LockFileEx on Windows and flock on *nix systems. The timed and context-bounded calls (LockWithTimeout and LockWithContext) use overlapped IO on Windows. On *nix systems a blocking flock cannot be interrupted once it parks, so these calls instead poll with a non-blocking flock until the lock is acquired or the deadline or cancellation fires.
Variables
var ErrInvalidName error = errors.New("fslock: lock name must be a single path component")
ErrInvalidName indicates that the name passed to NewInRoot was not a single path component within the root: it was empty, ".", "..", or contained a path separator.
var ErrLocked error = trylockError("fslock is already locked")
ErrLocked indicates TryLock failed because the lock was already locked.
var ErrTimeout error = timeoutError("lock timeout exceeded")
ErrTimeout indicates that the lock attempt timed out.
type Lock
type Lock struct {
// contains filtered or unexported fields
}
Lock implements cross-process locks using syscalls.
func New
func New(filename string) (*Lock, error)
New returns a new lock around the given file. It opens a handle to the file's parent directory and returns an error if that directory cannot be opened.
func NewInRoot
func NewInRoot(root *os.Root, name string) (*Lock, error)
NewInRoot returns a new lock around the file named name within root. name must be a single path component: it may not be empty, ".", "..", or contain a path separator, and otherwise NewInRoot returns ErrInvalidName. To lock a file in a subdirectory, pass a sub-root obtained from root.OpenRoot. The lock file is resolved relative to a directory handle, so it can never escape root via symlinks or "..".
The lock borrows root only for the duration of this call: it opens its own independent handle to root's directory, which it owns and which Close releases. The caller retains ownership of root and may close it independently of the returned Lock.
func (*Lock) Close
func (l *Lock) Close() error
Close releases the directory handle held by the lock. It does not release a held lock; call Unlock first. The lock must not be used after Close.
func (*Lock) Lock
func (l *Lock) Lock() error
Lock locks the lock. This call will block until the lock is available.
func (*Lock) LockWithContext
func (l *Lock) LockWithContext(ctx context.Context) error
LockWithContext tries to lock the lock until the context is canceled or its deadline is exceeded. If the context is canceled before the lock is acquired, this method returns ctx.Err().
func (*Lock) LockWithTimeout
func (l *Lock) LockWithTimeout(timeout time.Duration) error
LockWithTimeout tries to lock the lock until the timeout expires. If the timeout expires, this method will return ErrTimeout.
func (*Lock) TryLock
func (l *Lock) TryLock() error
TryLock attempts to lock the lock. This method will return ErrLocked immediately if the lock cannot be acquired.
func (*Lock) Unlock
func (l *Lock) Unlock() error
Unlock unlocks the lock.
Documentation
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Overview ¶
Package fslock provides a cross-process mutex based on file locks.
It is built on top of flock for linux and darwin, and LockFileEx on Windows.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ErrInvalidName error = errors.New("fslock: lock name must be a single path component")
ErrInvalidName indicates that the name passed to NewInRoot was not a single path component within the root: it was empty, ".", "..", or contained a path separator.
var ErrLocked error = trylockError("fslock is already locked")
ErrLocked indicates TryLock failed because the lock was already locked.
var ErrTimeout error = timeoutError("lock timeout exceeded")
ErrTimeout indicates that the lock attempt timed out.
Functions ¶
This section is empty.
Types ¶
type Lock ¶
type Lock struct {
// contains filtered or unexported fields
}
Lock implements cross-process locks using syscalls. This implementation is based on flock syscall.
func New ¶
New returns a new lock around the given file. It opens a handle to the file's parent directory and returns an error if that directory cannot be opened.
func NewInRoot ¶ added in v0.0.5
NewInRoot returns a new lock around the file named name within root. name must be a single path component: it may not be empty, ".", "..", or contain a path separator, and otherwise NewInRoot returns ErrInvalidName. To lock a file in a subdirectory, pass a sub-root obtained from root.OpenRoot. All access to the lock file goes through a directory handle, so it can never escape root via symlinks or "..".
The lock borrows root only for the duration of this call: it opens its own independent handle to root's directory, which it owns and which Close releases. The caller retains ownership of root and may close it independently of the returned Lock.
func (*Lock) Close ¶ added in v0.0.5
Close releases the directory handle held by the lock. It does not release a held lock; call Unlock first. The lock must not be used after Close.
func (*Lock) LockWithContext ¶ added in v0.0.4
LockWithContext tries to lock the lock until the context is canceled or its deadline is exceeded. If the context is canceled before the lock is acquired, this method returns ctx.Err().
func (*Lock) LockWithTimeout ¶
LockWithTimeout tries to lock the lock until the timeout expires. If the timeout expires, this method will return ErrTimeout.
Source Files