ucommon
Data Structures | Public Member Functions | Static Public Member Functions | Protected Member Functions | Protected Attributes
ucommon::ThreadLock Class Reference

A generic and portable implimentation of Read/Write locking. More...

#include <thread.h>

Inheritance diagram for ucommon::ThreadLock:
Inheritance graph
[legend]
Collaboration diagram for ucommon::ThreadLock:
Collaboration graph
[legend]

Data Structures

class  guard_reader
 Guard class to apply scope based access locking to objects. More...
class  guard_writer
 Guard class to apply scope based exclusive locking to objects. More...

Public Member Functions

bool access (timeout_t timeout=Timer::inf)
 Request shared (read) access through the lock.
bool modify (timeout_t timeout=Timer::inf)
 Request modify (write) access through the lock.
void release (void)
 Release the lock.
 ThreadLock ()
 Create an instance of a rwlock.

Static Public Member Functions

static void indexing (unsigned size)
 Specify hash table size for guard protection.
static bool reader (const void *object, timeout_t timeout=Timer::inf)
 Shared access to an arbitrary object.
static void release (const void *object)
 Release an arbitrary object that has been protected by a rwlock.
static bool writer (const void *object, timeout_t timeout=Timer::inf)
 Write protect access to an arbitrary object.

Protected Member Functions

virtual void _lock (void)
virtual void _share (void)
 Access interface to share lock the object.
virtual void _unlock (void)

Protected Attributes

pthread_t writeid
unsigned writers

Detailed Description

A generic and portable implimentation of Read/Write locking.

This class impliments classical read/write locking, including "timed" locks. Support for scheduling threads to avoid writer starvation is also provided for. By building read/write locks from a conditional, we make them available on pthread implimetations and other platforms which do not normally include optional pthread rwlock's. We also do not restrict the number of threads that may use the lock. Finally, both the exclusive and shared protocols are implimented to support exclusive_lock and shared_lock referencing.

Author:
David Sugar <dyfet@gnutelephony.org>

Definition at line 498 of file thread.h.


Member Function Documentation

Request shared (read) access through the lock.

Parameters:
timeoutin milliseconds to wait for lock.
Returns:
true if locked, false if timeout.
static void ucommon::ThreadLock::indexing ( unsigned  size) [static]

Specify hash table size for guard protection.

The default is 1. This should be called at initialization time from the main thread of the application before any other threads are created.

Parameters:
sizeof hash table used for guarding.

Request modify (write) access through the lock.

Parameters:
timeoutin milliseconds to wait for lock.
Returns:
true if locked, false if timeout.
static bool ucommon::ThreadLock::reader ( const void *  object,
timeout_t  timeout = Timer::inf 
) [static]

Shared access to an arbitrary object.

This is based on the protect function of mutex.

Parameters:
objectto share.
timeoutin milliseconds to wait for lock.
Returns:
true if shared, false if timeout.
static void ucommon::ThreadLock::release ( const void *  object) [static]

Release an arbitrary object that has been protected by a rwlock.

Parameters:
objectto release.
static bool ucommon::ThreadLock::writer ( const void *  object,
timeout_t  timeout = Timer::inf 
) [static]

Write protect access to an arbitrary object.

This is like the protect function of mutex.

Parameters:
objectto protect.
timeoutin milliseconds to wait for lock.
Returns:
true if locked, false if timeout.

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