net_instaweb::PthreadSharedMem Class Reference

#include "pthread_shared_mem.h"

Inheritance diagram for net_instaweb::PthreadSharedMem:

Public Member Functions
virtual size_t	SharedMutexSize () const
	Size of mutexes inside shared memory segments.
virtual AbstractSharedMemSegment *	CreateSegment (const GoogleString &name, size_t size, MessageHandler *handler)
virtual AbstractSharedMemSegment *	AttachToSegment (const GoogleString &name, size_t size, MessageHandler *handler)
virtual void	DestroySegment (const GoogleString &name, MessageHandler *handler)
Public Member Functions inherited from net_instaweb::AbstractSharedMem
virtual bool	IsDummy ()

Static Public Member Functions
static void	Terminate ()
	Frees all lazy-initialized memory used to track shared-memory segments.

Detailed Description

POSIX shared memory support, using mmap/pthread_mutexattr_setpshared Supports both processes and threads, but processes that want to access it must be results of just fork (without exec), and all the CreateSegment calls must occur before the fork.

This implementation is also not capable of deallocating segments except at exit, so it should not be used when the set of segments may be dynamic.

Member Function Documentation

virtual AbstractSharedMemSegment* net_instaweb::PthreadSharedMem::AttachToSegment ( const GoogleString &  name, size_t  size, MessageHandler *  handler  )

virtual

Attaches to an existing segment, which must have been created already. May return NULL on failure

Implements net_instaweb::AbstractSharedMem.

virtual AbstractSharedMemSegment* net_instaweb::PthreadSharedMem::CreateSegment ( const GoogleString &  name, size_t  size, MessageHandler *  handler  )

virtual

This should be called upon main process/thread initialization to create a shared memory segment that will be accessed by other processes/threads as identified by a unique name (via AttachToSegment). It will remove any previous segment with the same name. The memory will be zeroed out.

May return NULL on failure.

Implements net_instaweb::AbstractSharedMem.

virtual void net_instaweb::PthreadSharedMem::DestroySegment ( const GoogleString &  name, MessageHandler *  handler  )

virtual

Cleans up the segment with given name. You should call this after there is no longer any need for AttachToSegment to succeed.

Implements net_instaweb::AbstractSharedMem.

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

• pagespeed/kernel/thread/pthread_shared_mem.h