C Media Driver

Here you will find the source for the C Media Driver for Aeron. The build process builds a binary for the driver and places it in the following location

${CMAKE_CURRENT_BINARY_DIR}/binaries/aeronmd

Dependencies

The driver binary requires the following dependencies.

• Aeron C Driver Library, source of which is included here and built and placed in ${CMAKE_CURRENT_BINARY_DIR}/lib
• Linux Dependencies:
  • C Library (for the system built on)
  • -lpthread - pthread Library
  • -ldl - DL Library
  • -lbsd - BSD Library (optional - will use /dev/urandom directly instead of arc4random if not available)
  • -luuid - UUID Library (optional - will use pure random Receiver ID if not available)
  • -lm - Math Library
• Windows Dependencies:
  • Windows Version >= Vista
  • MSVC >= v141 (Visual Studio 2017)

Configuration

All configuration for the C media driver is done, currently, via environment variables. The variables are directly related to the Java properties for the Java media driver. The environment variables simply have _ in the place of .. For example, setting the environment variable AERON_TERM_BUFFER_LENGTH is equivalent to setting aeron.term.buffer.length in the Java media driver.

Operation

The driver can be started simply by executing aeronmd.

$ aeronmd

The driver can be stopped gracefully via Control-C or SIGINT just like the Java media driver.

Embedding the Driver

The C media driver may be embedded quite easily. An example is the driver main itself, aeronmd.c, and the API is documented in aeronmd.h.

Driver Logging

The C media driver uses DL interception for logging. To use this logging, add the Aeron C Driver Agent Library to LD_PRELOAD or DYLD_INSERT_LIBRARIES (for Mac. Also requires flat namespace) and set the environment variable, AERON_EVENT_LOG to a numeric mask for the events of interest. The following script may be used for convenience.