isc::log::interprocess::InterprocessSyncFile Class Reference

File-based Interprocess Sync Class. More...

#include <interprocess_sync_file.h>

Inheritance diagram for isc::log::interprocess::InterprocessSyncFile:

Public Member Functions
	InterprocessSyncFile (const std::string &task_name)
	Constructor.
virtual	~InterprocessSyncFile ()
	Destructor.
Public Member Functions inherited from isc::log::interprocess::InterprocessSync
	InterprocessSync (const std::string &task_name)
	Constructor.
virtual	~InterprocessSync ()
	Destructor.

Protected Member Functions
bool	lock ()
	Acquire the lock (blocks if something else has acquired a lock on the same task name)
bool	tryLock ()
	Try to acquire a lock (doesn't block)
bool	unlock ()
	Release the lock.
virtual bool	lock ()=0
	Acquire the lock (blocks if something else has acquired a lock on the same task name)
virtual bool	tryLock ()=0
	Try to acquire a lock (doesn't block)
virtual bool	unlock ()=0
	Release the lock.

Additional Inherited Members
Protected Attributes inherited from isc::log::interprocess::InterprocessSync
bool	is_locked_
	Is the lock taken?
const std::string	task_name_
	The task name.

Detailed Description

File-based Interprocess Sync Class.

This class specifies a concrete implementation for a file-based interprocess synchronization mechanism. Please see the InterprocessSync class documentation for usage.

An InterprocessSyncFileError exception may be thrown if there is an issue opening the lock file.

Lock files are created typically in the local state directory (var). They are typically named like "<task_name>_lockfile". This implementation opens lock files lazily (only when necessary). It also leaves the lock files lying around as multiple processes may have locks on them.

Definition at line 42 of file interprocess_sync_file.h.

Constructor & Destructor Documentation

InterprocessSyncFile()

isc::log::interprocess::InterprocessSyncFile::InterprocessSyncFile ( const std::string &  task_name )

inline

Constructor.

Creates a file-based interprocess synchronization object

Parameters

task_name

Name of the synchronization task. This has to be identical among the various processes that need to be synchronized for the same task.

Definition at line 51 of file interprocess_sync_file.h.

~InterprocessSyncFile()

isc::log::interprocess::InterprocessSyncFile::~InterprocessSyncFile ( )

virtual

Destructor.

Definition at line 31 of file interprocess_sync_file.cc.

Member Function Documentation

lock()

bool isc::log::interprocess::InterprocessSyncFile::lock ( )

protectedvirtual

Acquire the lock (blocks if something else has acquired a lock on the same task name)

Returns

Returns true if the lock was acquired, false otherwise.

Implements isc::log::interprocess::InterprocessSync.

Definition at line 89 of file interprocess_sync_file.cc.

References isc::log::interprocess::InterprocessSync::is_locked_.

tryLock()

bool isc::log::interprocess::InterprocessSyncFile::tryLock ( )

protectedvirtual

Try to acquire a lock (doesn't block)

Returns

Returns true if the lock was acquired, false otherwise.

Implements isc::log::interprocess::InterprocessSync.

Definition at line 103 of file interprocess_sync_file.cc.

References isc::log::interprocess::InterprocessSync::is_locked_.

unlock()

bool isc::log::interprocess::InterprocessSyncFile::unlock ( )

protectedvirtual

Release the lock.

Returns

Returns true if the lock was released, false otherwise.

Implements isc::log::interprocess::InterprocessSync.

Definition at line 117 of file interprocess_sync_file.cc.

References isc::log::interprocess::InterprocessSync::is_locked_.

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

• interprocess_sync_file.h
• interprocess_sync_file.cc