diff options
Diffstat (limited to 'libguile/posix.c')
-rw-r--r-- | libguile/posix.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/libguile/posix.c b/libguile/posix.c index 4f8b8ac7a..25476e513 100644 --- a/libguile/posix.c +++ b/libguile/posix.c @@ -1,4 +1,4 @@ -/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. +/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License @@ -1248,6 +1248,19 @@ SCM_DEFINE (scm_fork, "primitive-fork", 0, 0, 0, #define FUNC_NAME s_scm_fork { int pid; + scm_i_finalizer_pre_fork (); + if (scm_ilength (scm_all_threads ()) != 1) + /* Other threads may be holding on to resources that Guile needs -- + it is not safe to permit one thread to fork while others are + running. + + In addition, POSIX clearly specifies that if a multi-threaded + program forks, the child must only call functions that are + async-signal-safe. We can't guarantee that in general. The best + we can do is to allow forking only very early, before any call to + sigaction spawns the signal-handling thread. */ + SCM_MISC_ERROR ("attempt to fork while multiple threads are running", + SCM_EOL); pid = fork (); if (pid == -1) SCM_SYSERROR; |