public abstract class Lock extends Object
Typical use might look like:
new Lock.With(directory.makeLock("my.lock")) { public Object doBody() { ... code to execute while locked ... } }.run();
Directory.makeLock(String)
Modifier and Type | Class and Description |
---|---|
static class |
Lock.With
Utility class for executing code with exclusive access.
|
Modifier and Type | Field and Description |
---|---|
protected Throwable |
failureReason
If a lock obtain called, this failureReason may be set
with the "root cause" Exception as to why the lock was
not obtained.
|
static long |
LOCK_OBTAIN_WAIT_FOREVER
Pass this value to
obtain(long) to try
forever to obtain the lock. |
static long |
LOCK_POLL_INTERVAL
How long
obtain(long) waits, in milliseconds,
in between attempts to acquire the lock. |
Constructor and Description |
---|
Lock() |
Modifier and Type | Method and Description |
---|---|
abstract boolean |
isLocked()
Returns true if the resource is currently locked.
|
abstract boolean |
obtain()
Attempts to obtain exclusive access and immediately return
upon success or failure.
|
boolean |
obtain(long lockWaitTimeout)
Attempts to obtain an exclusive lock within amount of
time given.
|
abstract void |
release()
Releases exclusive access.
|
public static long LOCK_POLL_INTERVAL
obtain(long)
waits, in milliseconds,
in between attempts to acquire the lock.public static final long LOCK_OBTAIN_WAIT_FOREVER
obtain(long)
to try
forever to obtain the lock.protected Throwable failureReason
public abstract boolean obtain() throws IOException
IOException
public boolean obtain(long lockWaitTimeout) throws IOException
LOCK_POLL_INTERVAL
(currently 1000) milliseconds until lockWaitTimeout is
passed.lockWaitTimeout
- length of time to wait in
milliseconds or LOCK_OBTAIN_WAIT_FOREVER
to retry foreverLockObtainFailedException
- if lock wait times outIllegalArgumentException
- if lockWaitTimeout is
out of boundsIOException
- if obtain() throws IOExceptionpublic abstract void release() throws IOException
IOException
public abstract boolean isLocked() throws IOException
obtain()
before using the resource.IOException
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