• Simon Marlow's avatar
    FIX part of #2301, and #1619 · addff19a
    Simon Marlow authored
    2301: Control-C now causes the new exception (AsyncException
    UserInterrupt) to be raised in the main thread.  The signal handler
    is set up by GHC.TopHandler.runMainIO, and can be overriden in the
    usual way by installing a new signal handler.  The advantage is that
    now all programs will get a chance to clean up on ^C.
    
    When UserInterrupt is caught by the topmost handler, we now exit the
    program via kill(getpid(),SIGINT), which tells the parent process that
    we exited as a result of ^C, so the parent can take appropriate action
    (it might want to exit too, for example).
    
    One subtlety is that we have to use a weak reference to the ThreadId
    for the main thread, so that the signal handler doesn't prevent the
    main thread from being subject to deadlock detection.
    
    1619: we now ignore SIGPIPE by default.  Although POSIX says that a
    SIGPIPE should terminate the process by default, I wonder if this
    decision was made because many C applications failed to check the exit
    code from write().  In Haskell a failed write due to a closed pipe
    will generate an exception anyway, so the main difference is that we
    now get a useful error message instead of silent program termination.
    See #1619 for more discussion.
    addff19a
RtsStartup.c 13.6 KB