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WvMagicCircle Class Reference

#include <wvmagiccircle.h>

Inheritance diagram for WvMagicCircle:

Inheritance graph
[legend]
List of all members.

Detailed Description

A circular queue that can be accessed across fork().


Public Member Functions

 WvMagicCircle (size_t size)
 Creates a shared memory circular queue.
size_t used ()
size_t left ()
size_t put (const void *data, size_t len)
size_t get (void *data, size_t len)
size_t skip (size_t len)
virtual bool isok () const
 By default, returns true if geterr() == 0.
virtual int geterr () const
 If isok() is false, return the system error number corresponding to the error, -1 for a special error string (which you can obtain with errstr()) or 0 on end of file.
virtual WvString errstr () const
virtual void seterr (int _errnum)
 Set the errnum variable -- we have an error.
void seterr (WvStringParm specialerr)
void seterr (WVSTRING_FORMAT_DECL)
void seterr (const WvErrorBase &err)
void noerr ()
 Reset our error state - there's no error condition anymore.

Protected Attributes

WvShmZone shm
volatile int & head
volatile int & tail
int size
char * circle
int errnum
WvString errstring


Constructor & Destructor Documentation

WvMagicCircle::WvMagicCircle size_t  size  ) 
 

Creates a shared memory circular queue.

"size" is the number of elements to store


Member Function Documentation

virtual bool WvErrorBase::isok  )  const [inline, virtual, inherited]
 

By default, returns true if geterr() == 0.

Might be overridden so that isok() == false even though no error code has been specified.

Reimplemented in WvRSAKey, and WvX509Mgr.

virtual int WvErrorBase::geterr  )  const [inline, virtual, inherited]
 

If isok() is false, return the system error number corresponding to the error, -1 for a special error string (which you can obtain with errstr()) or 0 on end of file.

If isok() is true, returns an undefined number.

Reimplemented in WvX509Mgr.

void WvErrorBase::seterr int  _errnum  )  [virtual, inherited]
 

Set the errnum variable -- we have an error.

If called more than once, seterr() doesn't change the error code away from the previous one. That way, we remember the _original_ cause of our problems.

Subclasses may want to override seterr(int) to shut themselves down (eg. WvStream::close()) when an error condition is set.

Note that seterr(WvString) will call seterr(-1).


The documentation for this class was generated from the following files:
Generated on Sun Jul 10 16:29:07 2005 for WvStreams by  doxygen 1.4.0