[GitHub] [incubator-nuttx] xiaoxiang781216 edited a comment on issue #4612: exit() and pthread_exit() limitations

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xiaoxiang781216 edited a comment on issue #4612:
URL: https://github.com/apache/incubator-nuttx/issues/4612#issuecomment-927301640


   > The main thread of a task should be able to call pthread_exit(), of course, calling pthread_self() first. Certainly this behavior is not prohibited by the specifications at OpenGroup.org and there are several posts that specifically claim that this is possible. See for example: https://programmer.help/blogs/the-use-of-pthread-exit-in-main-thread.html
   > 
   > In this case, the main thread of the process/task group will terminate, but the process/task group will persist and other threads will continue running. I believe that calling pthread_exit() from the main thread will currently lead to an assertion or crash due to the different forms of the main and pthread TCBs
   
   Yes, this is major reason why we can't handle main thread and pthread equally. The best fix could be unify two tcb struct into one and:
   
   1. Move main thread specific data to task_info_s
   2. Move pthread specific data to tls_info_s
   
   > and the fact that global data is retained in the main thread's stack.
   > 
   
   It's fixed by patch: https://github.com/apache/incubator-nuttx/pull/3992
   
   > Similarly, a pthread should be able to call exit() and terminate the entire process/ See for example https://www.informit.com/articles/article.aspx?p=2085690&seqNum=5. In fact, this is often the case when exit() is called from a signal handler in a multi-threaded task because we never know for sure which thread the signal handler will run on.
   > 
   > Again, a crash would be likely due to the same reasoning.
   
   


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