Oracle Fusion Middleware C++ API Reference for Oracle Coherence
12c (12.1.2)

E26041-01

ConcurrentMap Class Reference

#include <coherence/util/ConcurrentMap.hpp>

Inherits Map.

Inherited by NamedCache [virtual], and ConverterCollections::ConverterConcurrentMap [virtual].

List of all members.


Detailed Description

Map with additional concurrency features.

Author:
jh 2008.03.05

Public Types

typedef spec::Handle Handle
 ConcurrentMap Handle definition.
typedef spec::View View
 ConcurrentMap View definition.
typedef spec::Holder Holder
 ConcurrentMap Holder definition.
typedef this_spec::Handle Handle
 Map Handle definition.
typedef this_spec::View View
 Map View definition.
typedef this_spec::Holder Holder
 Map Holder definition.

Public Member Functions

virtual bool lock (Object::View vKey, int64_t cWait) const =0
 Attempt to lock the specified item within the specified period of time.
virtual bool lock (Object::View vKey) const =0
 Attempt to lock the specified item and return immediately.
virtual bool unlock (Object::View vKey) const =0
 Unlock the specified item.

Static Public Member Functions

static Object::View getLockAll ()
 Special key value indicating an intent to lock the entire map.

Classes

class  LockBlock
 The LockBlock allows for easy creation of ConcurrentMap::lock code. More...

Member Function Documentation

virtual bool lock ( Object::View  vKey,
int64_t  cWait 
) const [pure virtual]

Attempt to lock the specified item within the specified period of time.

The item doesn't have to exist to be locked. While the item is locked there is known to be a lock holder which has an exclusive right to modify (calling put and remove methods) that item.

Lock holder is an abstract concept that depends on the ConcurrentMap implementation. For example, holder could be a process or a thread (or both).

Locking strategy may vary for concrete implementations as well. Lock could have an expiration time (this lock is sometimes called a "lease") or be held indefinitely (until the lock holder terminates).

Some implementations may allow the entire map to be locked. If the map is locked in such a way, then only a lock holder is allowed to perform any of the "put" or "remove" operations. Pass the special constant getLockAll() as the vKey parameter to indicate the map lock.

Parameters:
vKey key being locked
cWait the number of milliseconds to continue trying to obtain a lock; pass zero to return immediately; pass -1 to block the calling thread until the lock could be obtained
Returns:
true if the item was successfully locked within the specified time; false otherwise

Implemented in ContinuousQueryCache, NearCache, WrapperNamedCache, ConverterCollections::ConverterConcurrentMap, and ConverterCollections::ConverterNamedCache.

virtual bool lock ( Object::View  vKey  )  const [pure virtual]

Attempt to lock the specified item and return immediately.

This method behaves exactly as if it simply performs the call lock(vKey, 0).

Parameters:
vKey key being locked
Returns:
true if the item was successfully locked; false otherwise

Implemented in ContinuousQueryCache, NearCache, WrapperNamedCache, ConverterCollections::ConverterConcurrentMap, and ConverterCollections::ConverterNamedCache.

virtual bool unlock ( Object::View  vKey  )  const [pure virtual]

Unlock the specified item.

The item doesn't have to exist to be unlocked. If the item is currently locked, only the holder of the lock could successfully unlock it.

Parameters:
vKey key being unlocked
Returns:
true if the item was successfully unlocked; false otherwise

Implemented in ContinuousQueryCache, NearCache, WrapperNamedCache, ConverterCollections::ConverterConcurrentMap, and ConverterCollections::ConverterNamedCache.


The documentation for this class was generated from the following file:
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