README
¶
lockfile
Handle locking via pid files.
Attention: This is a fork of Ingo Oeser's amazing work whose behavior differs a bit. While the original package allows a process to obtain the same lock twice, this fork forbids this behavior.
install
Install Go 1, either from source or with a prepackaged binary. For Windows suport, Go 1.4 or newer is required.
Then run
go get gopkg.in/Acconut/lockfile.v1
LICENSE
BSD
documentation
package documentation at godoc.org
contributing
Contributions are welcome. Please open an issue or send me a pull request for a dedicated branch. Make sure the git commit hooks show it works.
git commit hooks
enable commit hooks via
cd .git ; rm -rf hooks; ln -s ../git-hooks hooks ; cd ..
Documentation
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Overview ¶
Package lockfile handles pid file based locking. While a sync.Mutex helps against concurrency issues within a single process, this package is designed to help against concurrency issues between cooperating processes or serializing multiple invocations of the same process.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ( ErrBusy = TemporaryError("Locked by other process") // If you get this, retry after a short sleep might help ErrNotExist = TemporaryError("Lockfile created, but doesn't exist") // If you get this, retry after a short sleep might help ErrNeedAbsPath = errors.New("Lockfiles must be given as absolute path names") ErrInvalidPid = errors.New("Lockfile contains invalid pid for system") ErrDeadOwner = errors.New("Lockfile contains pid of process not existent on this system anymore") ErrRogueDeletion = errors.New("Lockfile owned by me has been removed unexpectedly") )
Various errors returned by this package
Functions ¶
This section is empty.
Types ¶
type Lockfile ¶
type Lockfile string
Lockfile is a pid file which can be locked
Example ¶
lock, err := New(filepath.Join(os.TempDir(), "lock.me.now.lck"))
if err != nil {
fmt.Printf("Cannot init lock. reason: %v", err)
panic(err) // handle properly please!
}
err = lock.TryLock()
// Error handling is essential, as we only try to get the lock.
if err != nil {
fmt.Printf("Cannot lock %q, reason: %v", lock, err)
panic(err) // handle properly please!
}
defer lock.Unlock()
fmt.Println("Do stuff under lock")
Output: Do stuff under lock
type TemporaryError ¶ added in v1.1.0
type TemporaryError string
TemporaryError is a type of error where a retry after a random amount of sleep should help to mitigate it.
func (TemporaryError) Error ¶ added in v1.1.0
func (t TemporaryError) Error() string
func (TemporaryError) Temporary ¶ added in v1.1.0
func (t TemporaryError) Temporary() bool
Temporary returns always true. It exists, so you can detect it via
if te, ok := err.(interface{ Temporary() bool }); ok {
fmt.Println("I am a temporay error situation, so wait and retry")
}
Source Files