bdls_pipeutil

Detailed Description

Outline

• Purpose
• Classes
• Description
  • Pipe Atomicity

Purpose

Provide basic portable named-pipe utilities.

Classes

• bdls::PipeUtil: Portable utility methods for naming and accessing pipes

See also

balb_pipecontrolchannel

Description

This component, bdls::PipeUtil, provides portable utility methods for named pipes.

Pipe Atomicity

Applications that expect multiple writers to a single pipe must should be aware that message content might be corrupted (interleaved) unless:

1. Each message is written to the pipe in a single write system call.
2. The length of each message is less than PIPE_BUF (the limit for guaranteed atomicity).

The value PIPE_BUF depends on the platform:

 +------------------------------+------------------+
 | Platform                     | PIPE_BUF (bytes) |
 +------------------------------+------------------+
 | POSIX (minimum requirement)) |    512           |
 | IBM                          | 32,768           |
 | SUN                          | 32,768           |
 | Linux                        | 65,536           |
 | Windows                      | 65,536           |
 +------------------------------+------------------+

Also note that Linux allows the PIPE_BUF size to be changed via the fcntl system call.