diff options
Diffstat (limited to 'sysdeps/mach/hurd')
-rw-r--r-- | sysdeps/mach/hurd/jmp-unwind.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/jmp-unwind.c b/sysdeps/mach/hurd/jmp-unwind.c new file mode 100644 index 0000000000..f7540f0dde --- /dev/null +++ b/sysdeps/mach/hurd/jmp-unwind.c @@ -0,0 +1,62 @@ +/* _longjmp_unwind -- Clean up stack frames unwound by longjmp. Hurd version. +Copyright (C) 1995 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <setjmp.h> +#include <hurd/signal.h> +#include <hurd/userlink.h> +#include <assert.h> + +/* This function is called by `longjmp' (with its arguments) to restore + active resources to a sane state before the frames code using them are + jumped out of. */ + +void +_longjmp_unwind (jmp_buf env, int val) +{ + struct hurd_sigstate *ss = _hurd_self_sigstate (); + struct hurd_userlink *link; + + /* All access to SS->active_resources must take place inside a critical + section where signal handlers cannot run. */ + __spin_lock (&ss->lock); + assert (! ss->critical_section); + ss->critical_section = 1; + __spin_unlock (&ss->lock); + +#ifndef _JMPBUF_UNWINDS + #error "sysdeps/MACHINE/jmp_buf.h fails to define _JMPBUF_UNWINDS" +#endif + + /* Iterate over the current thread's list of active resources. + Process the head portion of the list whose links reside + in stack frames being unwound by this jump. */ + + for (link = ss->active_resources; + link && _JMPBUF_UNWINDS (env[0].__jmpbuf, link); + link = link->thread.next) + /* Remove this link from the resource's users list, + since the frame using the resource is being unwound. + This call returns nonzero if that was the last user. */ + if (_hurd_userlink_unlink (link)) + /* One of the frames being unwound by the longjmp was the last user + of its resource. Call the cleanup function to deallocate it. */ + (*link->cleanup) (link->cleanup_data, env, val); + + _hurd_critical_section_unlock (ss); +} |