Provided by: libbobcat-dev_5.02.00-1build1_amd64 bug


       FBB::Sharedpos - Shared Memory offset controller


       #include <bobcat/sharedpos>
       Linking option: -lbobcat


       The  class  SharedPos  is  a support class for Bobcat’s shared memory handling classes. It
       controls the shared memory read/write ofset and  ensures  that  shared  memory  operations
       never exceed the shared memory’s maximum offset.

       The  class  SharedPos  has several public members, but they are primarily useful for other
       Shared* classes offered by  Bobcat.  There  is  probably  little  use  for  a  stand-alone
       SharedPos object.

       In the descriptions of the class’s member functions offset refers to the read/write offset
       within  a  FBB::SharedSegment(3bobcat)   object   for   which   SharedPos   performs   the


       All  constructors,  members,  operators  and manipulators, mentioned in this man-page, are
       defined in the namespace FBB.





       Default, copy and move constructors as well as the copy and move assignment operators  are
       available.   The   default   constructor   does   not   yet   monitor  the  offset  of  an
       FBB::SharedSegment object. The member reset is used to start monitoring offsets.


       o      void operator++():
              The offset is incremented. If this member is called when the offset is equal to the
              shared memory’s maximum offset an FBB::Exception is thrown.

       o      void operator+=(size_t len):
              The  offset  is  incremented  by  len.  If offset + len exceeds the shared memory’s
              maximum offset then the offset is set to the maximum offset and  an  FBB::Exception
              is thrown.

       o      std::ostream &operator<<(std::ostream &out, SharedPos const &pos):
              Inserts information about the SharedPos object into out.


       Note:  the  behavior of member functions returning values which refer to information of an
       FBB::SharedSegment is undefined until the member reset has been called.

       o      bool atMaxOffset() const:
              Returns true if offset  equals  the  maximum  offset  that  can  be  used  for  the
              configured FBB::SharedSegment object.

       o      size_t blockIdx() const:
              The  index  of the configured FBB::SharedSegment object’s shared segment data block
              to which offset refers is returned.

       o      size_t blockOffset() const:
              The offset within the shared segment data block matching the member offset’s return
              value is returned.

       o      bool eof() const:
              Returns  true if offset exceeds the maximum offset of any character ever written to
              the shared memory to which the SharedPos object interfaces.  If  eof  returns  true
              information  may  still  be written to the shared memory: writing is possible until
              the maximum shared memory segment offset has been reached.

       o      std::streamsize eos() const:
              The offset just beyond the maximum offset for the current shared segment data block
              is  returned.  E.g., if blockIdx returns 5, and the size of the shared segment data
              blocks equals 2000, then eos returns 12000 (the first offset of segment 6).

       o      std::streamsize maxOffset() const:
              The  maximum  possible  offset  that  can  be  used  for  the  currently  monitored
              FBB::SharedSegment is returned.

       o      std::streamsize offset() const:
              The offset within the currently monitored shared memory segment is returned.

       o      void reset(SharedSegment *sharedData):
              The  SharedPos  object  is  reset  to  monitor the offset of the FBB::SharedSegment
              object whose address is passed as argument to reset. The address must  point  to  a
              sharedsegment(3bobcat)  object  that  must  exist  until  the  end of the SharedPos
              object’s lifetime or until its next reset call.  Immediately  after  calling  reset
              offset is reset to 0.

       o      std::streamsize showmanyc() const:
              The  number  of  characters  that  can be read from the current shared segment data
              block is returned.  This member interrogates the number of readable  characters  in
              the  shared  memory  segment.  This  number  may  change while this member is being
              executed. In order to receive a stable return value, calling functions should  have
              obtained a lock on the FBB::SharedSegment data before calling this member. See also
              the sharedsegment(3bobcat) man-page.

       o      std::ios::pos_type  seek(std::ios::off_type  offset,  std::ios::seekdir  origin   =
              The  monitored  offset  is  changed  to  this member’s offset argument, relative to
              origin. Seeking beyond eof is OK. However,  -1  is  returned  when  seeking  beyond
              maxOffset or seeking before the shared segment’s offset 0.


       See the sharedstream(3bobcat) man page.


       bobcat/sharedpos - defines the class interface


       bobcat(7),     isharedstream(3bobcat),    osharedstream(3bobcat),    sharedblock(3bobcat),
       sharedcondition(3bobcat),           sharedmemory(3bobcat),           sharedmutex(3bobcat),
       sharedreadme(7bobcat), sharedsegment(3bobcat), sharedstream(3bobcat), sharedbuf(3bobcat)


       None Reported.


       o      bobcat_5.02.00-x.dsc: detached signature;

       o      bobcat_5.02.00-x.tar.gz: source archive;

       o      bobcat_5.02.00-x_i386.changes: change log;

       o      libbobcat1_5.02.00-x_*.deb: debian package holding the libraries;

       o      libbobcat1-dev_5.02.00-x_*.deb:  debian  package holding the libraries, headers and
              manual pages;

       o public archive location;


       Bobcat is an acronym of `Brokken’s Own Base Classes And Templates’.


       This is free software, distributed under the terms  of  the  GNU  General  Public  License


       Frank B. Brokken (