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bitmovin / libdash

MPEG-DASH Access Library - Official ISO/IEC MPEG-DASH Reference Implementation
https://bitmovin.com/
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Fix pthread resource leak #14

Closed mikkoau closed 5 years ago

mikkoau commented 7 years ago

We're using libdash's default segment download implementation on Linux to download 10+ adaptationsets simultaneously with 1 second segment length. The default implementation creates a new pthread instance for each segment but doesn't release thread resources (and stack 1-2MB/each?) when the download finishes. This resource leak killed our application in 3-5 minutes when testing with a machine with 2GB of RAM.

This fix creates pthreads as detached so they'll free resources automatically when thread function finishes.

More info: http://man7.org/linux/man-pages/man3/pthread_detach.3.html " Either pthread_join(3) or pthread_detach() should be called for each thread that an application creates, so that system resources for the thread can be released. "

schellkenig commented 7 years ago

Did you join the thread or is the join missing somewhere in the implementation?

mikkoau commented 7 years ago

libdash library uses pthreads internally through MultiThreading abstraction (and thread handle is private in AbstractChunk class). So threads are not revealed through public interface's include files.

Internal implementation (~AbstractChunk) calls DestroyThreadPortable() but that only releases thread handle variable. There's no pthread_join() call in MultiThreading.cpp. Detaching is better approach imho since thread's return value is not needed.