From 1494f895d69a33df2f8d855f73943faec5c6858e Mon Sep 17 00:00:00 2001 From: Simon Marlow Date: Thu, 6 Apr 2006 14:48:36 +0000 Subject: [PATCH 1/1] Add SA_RESTART flag to the timer signal handler. This seems to be necessary to prevent readline being confused by our SIGALRM handler. --- ghc/rts/posix/Itimer.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/ghc/rts/posix/Itimer.c b/ghc/rts/posix/Itimer.c index 06d0e6c..83ed84d 100644 --- a/ghc/rts/posix/Itimer.c +++ b/ghc/rts/posix/Itimer.c @@ -84,7 +84,18 @@ install_vtalrm_handler(TickProc handle_tick) action.sa_handler = handle_tick; sigemptyset(&action.sa_mask); + +#ifdef SA_RESTART + // specify SA_RESTART. One consequence if we don't do this is + // that readline gets confused by the -threaded RTS. It seems + // that if a SIGALRM handler is installed without SA_RESTART, + // readline installs its own SIGALRM signal handler (see + // readline's signals.c), and this somehow causes readline to go + // wrong when the input exceeds a single line (try it). + action.sa_flags = SA_RESTART; +#else action.sa_flags = 0; +#endif return sigaction(ITIMER_SIGNAL, &action, NULL); } -- 1.7.10.4