On 02/10/2011 08:29 AM, Oliver Kowalke wrote:
Am 10.02.2011 17:11, schrieb Artyom:
Small notes:
1. waitpid should be done for specific pid I waiting for to allow other threads to use wait 2. You need to use WNOHANG so it would not be blocking, and allow to check specific ids.
You would create for each child process you want to wait for a separat thread? Wouldn't this degrade the performance of the system if you have to wait for many processes? Why not using only one thread which handles SIGCHLD and catches all child stati?
This is ultimately the best (and only reasonable) approach (where the use of a dedicated thread, as opposed to no additional threads and just letting the signal handler be called in an arbitrary thread, would be optional). However, it does place a high burden on Boost.Process: since under this method Boost.Process will need exclusive control over SIGCHLD and all waiting on child processes, it must provide appropriate interfaces to interoperate will all other application and library code that may wish to deal with child processes. I believe it should be possible to make Boost.Process itself not depend on a dedicated signal handling thread, but potentially other application/library code that wants to deal with child proceses/sigchld might need the signal handler to run in a dedicated thread. (And potentially, the application or some other library may wish to handle SIGCHLD and call wait directly, in which case there should be some interface by which this code can notify boost.process appropriately.)