Kevin Fleming: So, you want to be an Asterisk Developer?
Kevin Fleming discussed the task of becoming an Asterisk Developer:
Discussed Libraries Required
Debugging
-Easier to debug post-mortem
-Threading models differ by platform
-use make dont-optimize
-check makefiles for debugging defines
-ensure that 'debug' is listed for the console
-always use the -g parameter
-use 'thread apply all bt full' in gdb
-use 'ast_grab_core' (helpful for solving deadlocks)
Patches
-always run 'make update'
-use 'cvs diff -u' (or add 'diff -u' to your .cvsrc file)
-read the patch before submitting
-Watch for new/removed files
keeping out of tree patches up to date can be hard work
Licencing
-Asterisk, Zaptel and LibPRI are dual licenced (GPL and to Digium for commercial distribution)
-Contributions must be disclaimed
-Code can not violate patents etc
-If you make changes you are not required to distribute them
-You are not required to submit changes to Asterisk, although it is recommended
-If your code is committed it will be maintained by Asterisk crew
-The code you have is GPL forever
-The word Asterisk is trademarked
-Always disclaim your code
-You do not lose copyright on the code when you disclaim
Misc
-Prototypes are in module.h
-Use Use Count Tracking - needed for dynamically loadable modules
-usecount function is called by the loader
-Use the macros to implement basic usecount management
-Module has to tell Asterisk what they can do
-Application Modules are supposed to work on a channel that they are provided on
-Applications MUST keep use counts
-Channel modules are probably the most complicated part of Asterisk (allow connection to the outside world). Contains usecount again. Provide approx 25 methods that channels may provide
-Codec Modules are the means of converting from one format of audio to another. Quite simple. Many codecs keep internal state from one frame to another.
Format Modules - provide means to read and write audio formats in all of the formats Asterisk supports
Function Modules - look like variables. Currently only in CVS HEAD. They provide dialplan functions. Most of these are built into pbx_functions.so
CDR Modules - these provide CDR backends to post CDRs into storage systems (DB/txt etc)
Discussed Libraries Required
Debugging
-Easier to debug post-mortem
-Threading models differ by platform
-use make dont-optimize
-check makefiles for debugging defines
-ensure that 'debug' is listed for the console
-always use the -g parameter
-use 'thread apply all bt full' in gdb
-use 'ast_grab_core' (helpful for solving deadlocks)
Patches
-always run 'make update'
-use 'cvs diff -u' (or add 'diff -u' to your .cvsrc file)
-read the patch before submitting
-Watch for new/removed files
keeping out of tree patches up to date can be hard work
Licencing
-Asterisk, Zaptel and LibPRI are dual licenced (GPL and to Digium for commercial distribution)
-Contributions must be disclaimed
-Code can not violate patents etc
-If you make changes you are not required to distribute them
-You are not required to submit changes to Asterisk, although it is recommended
-If your code is committed it will be maintained by Asterisk crew
-The code you have is GPL forever
-The word Asterisk is trademarked
-Always disclaim your code
-You do not lose copyright on the code when you disclaim
Misc
-Prototypes are in module.h
-Use Use Count Tracking - needed for dynamically loadable modules
-usecount function is called by the loader
-Use the macros to implement basic usecount management
-Module has to tell Asterisk what they can do
-Application Modules are supposed to work on a channel that they are provided on
-Applications MUST keep use counts
-Channel modules are probably the most complicated part of Asterisk (allow connection to the outside world). Contains usecount again. Provide approx 25 methods that channels may provide
-Codec Modules are the means of converting from one format of audio to another. Quite simple. Many codecs keep internal state from one frame to another.
Format Modules - provide means to read and write audio formats in all of the formats Asterisk supports
Function Modules - look like variables. Currently only in CVS HEAD. They provide dialplan functions. Most of these are built into pbx_functions.so
CDR Modules - these provide CDR backends to post CDRs into storage systems (DB/txt etc)
posted by Dal at
11:14 AM
