topical media & game development

topical media & game development

[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

lib-of-vs-libs-Poco-include-Poco-Pipe.h / h


  //
  // Pipe.h
  //
  //  $Id: //poco/1.3/Foundation/include/Poco/Pipe.h#1$ 
  //
  // Library: Foundation
  // Package: Processes
  // Module:  Pipe
  //
  // Definition of the Pipe class.
  //
  // Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
  // and Contributors.
  //
  // Permission is hereby granted, free of charge, to any person or organization
  // obtaining a copy of the software and accompanying documentation covered by
  // this license (the "Software") to use, reproduce, display, distribute,
  // execute, and transmit the Software, and to prepare derivative works of the
  // Software, and to permit third-parties to whom the Software is furnished to
  // do so, all subject to the following:
  // 
  // The copyright notices in the Software and this entire statement, including
  // the above license grant, this restriction and the following disclaimer,
  // must be included in all copies of the Software, in whole or in part, and
  // all derivative works of the Software, unless such copies or derivative
  // works are solely in the form of machine-executable object code generated by
  // a source language processor.
  // 
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
  // SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
  // FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
  // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  // DEALINGS IN THE SOFTWARE.
  //
  
  ifndef Foundation_Pipe_INCLUDED
  define Foundation_Pipe_INCLUDED
  
  include "Poco/Foundation.h"
  include "Poco/PipeImpl.h"
  
  namespace Poco {
  
  class Foundation_API Pipe

This class implements an anonymous pipe. Pipes are a common method of inter-process communication - on Unix, pipes are the oldest form of IPC. A pipe is a half-duplex communication channel, which means that data only flows in one direction. Pipes have a read-end and a write-end. One process writes to the pipe and another process reads the data written by its peer. Read and write operations are always synchronous. A read will block until data is available and a write will block until the reader reads the data. The sendBytes() and readBytes() methods of Pipe are usually used through a PipeOutputStream or PipeInputStream and are not called directly. Pipe objects have value semantics; the actual work is delegated to a reference-counted PipeImpl object. { public: typedef PipeImpl::Handle Handle;

The read/write handle or file descriptor.

enum CloseMode

used by close()

{ CLOSE_READ = 0x01,

Close reading end of pipe.

CLOSE_WRITE = 0x02,

Close writing end of pipe.

CLOSE_BOTH = 0x03

Close both ends of pipe.

}; Pipe(); Creates the Pipe. Throws a CreateFileException if the pipe cannot be created. Pipe(const Pipe& pipe); Creates the Pipe using the PipeImpl from another one.


          ~Pipe();

Closes and destroys the Pipe.


          Pipe& operator = (const Pipe& pipe);

Releases the Pipe's PipeImpl and assigns another one.


          int writeBytes(const void* buffer, int length);

Sends the contents of the given buffer through the pipe. Blocks until the receiver is ready to read the data. Returns the number of bytes sent. Throws a WriteFileException if the data cannot be written.


          int readBytes(void* buffer, int length);

Receives data from the pipe and stores it in buffer. Up to length bytes are received. Blocks until data becomes available. Returns the number of bytes received, or 0 if the pipe has been closed. Throws a ReadFileException if nothing can be read.


          Handle readHandle() const;

Returns the read handle or file descriptor for the Pipe. For internal use only. Handle writeHandle() const; Returns the write handle or file descriptor for the Pipe. For internal use only.


          void close(CloseMode mode = CLOSE_BOTH);

Depending on the argument, closes either the reading end, the writing end, or both ends of the Pipe. private: PipeImpl* _pImpl; };


  //
  // inlines
  //
  inline int Pipe::writeBytes(const void* buffer, int length)
  {
          return _pImpl->writeBytes(buffer, length);
  }
  
  inline int Pipe::readBytes(void* buffer, int length)
  {
          return _pImpl->readBytes(buffer, length);
  }
  
  inline Pipe::Handle Pipe::readHandle() const
  {
          return _pImpl->readHandle();
  }
  
  inline Pipe::Handle Pipe::writeHandle() const
  {
          return _pImpl->writeHandle();
  }
  
  } // namespace Poco
  
  endif // Foundation_Pipe_INCLUDED

[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

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