README
¶
Package cloudeng.io/os/lockedfile/internal/filelock
import cloudeng.io/os/lockedfile/internal/filelock
Package filelock provides a platform-independent API for advisory file locking. Calls to functions in this package on platforms that do not support advisory locks will return errors for which IsNotSupported returns true.
Variables
ErrNotSupported
ErrNotSupported = errors.New("operation not supported")
Functions
Func IsNotSupported
func IsNotSupported(err error) bool
IsNotSupported returns a boolean indicating whether the error is known to report that a function is not supported (possibly for a specific input). It is satisfied by ErrNotSupported as well as some syscall errors.
Func Lock
func Lock(f File) error
Lock places an advisory write lock on the file, blocking until it can be locked.
If Lock returns nil, no other process will be able to place a read or write lock on the file until this process exits, closes f, or calls Unlock on it.
If f's descriptor is already read- or write-locked, the behavior of Lock is unspecified.
Closing the file may or may not release the lock promptly. Callers should ensure that Unlock is always called when Lock succeeds.
Func RLock
func RLock(f File) error
RLock places an advisory read lock on the file, blocking until it can be locked.
If RLock returns nil, no other process will be able to place a write lock on the file until this process exits, closes f, or calls Unlock on it.
If f is already read- or write-locked, the behavior of RLock is unspecified.
Closing the file may or may not release the lock promptly. Callers should ensure that Unlock is always called if RLock succeeds.
Func Unlock
func Unlock(f File) error
Unlock removes an advisory lock placed on f by this process.
The caller must not attempt to unlock a file that is not locked.
Types
Type File
type File interface {
// Name returns the name of the file.
Name() string
// Fd returns a valid file descriptor.
// (If the File is an *os.File, it must not be closed.)
Fd() uintptr
// Stat returns the FileInfo structure describing file.
Stat() (os.FileInfo, error)
}
A File provides the minimal set of methods required to lock an open file. File implementations must be usable as map keys. The usual implementation is *os.File.
Documentation
¶
Overview ¶
Package filelock provides a platform-independent API for advisory file locking. Calls to functions in this package on platforms that do not support advisory locks will return errors for which IsNotSupported returns true.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ErrNotSupported = errors.New("operation not supported")
Functions ¶
func IsNotSupported ¶
IsNotSupported returns a boolean indicating whether the error is known to report that a function is not supported (possibly for a specific input). It is satisfied by ErrNotSupported as well as some syscall errors.
func Lock ¶
Lock places an advisory write lock on the file, blocking until it can be locked.
If Lock returns nil, no other process will be able to place a read or write lock on the file until this process exits, closes f, or calls Unlock on it.
If f's descriptor is already read- or write-locked, the behavior of Lock is unspecified.
Closing the file may or may not release the lock promptly. Callers should ensure that Unlock is always called when Lock succeeds.
func RLock ¶
RLock places an advisory read lock on the file, blocking until it can be locked.
If RLock returns nil, no other process will be able to place a write lock on the file until this process exits, closes f, or calls Unlock on it.
If f is already read- or write-locked, the behavior of RLock is unspecified.
Closing the file may or may not release the lock promptly. Callers should ensure that Unlock is always called if RLock succeeds.
Types ¶
type File ¶
type File interface {
// Name returns the name of the file.
Name() string
// Fd returns a valid file descriptor.
// (If the File is an *os.File, it must not be closed.)
Fd() uintptr
// Stat returns the FileInfo structure describing file.
Stat() (os.FileInfo, error)
}
A File provides the minimal set of methods required to lock an open file. File implementations must be usable as map keys. The usual implementation is *os.File.
Source Files