Mercurial > gnulib
view lib/i-ring.c @ 37246:5cfb3a67238d
regex: avoid glibc deadlock during configure
glibc has a known bug where certain corruptions of the heap can
cause malloc to default to printing a debug message that includes
a backtrace, but the act of getting the backtrace uses dlopen
which in turn calls into malloc, causing a recursive lock ending
in deadlock. Thus, when configure is probing for a known glibc
heap corruption bug, the overall configure would hang.
The solution suggested by glibc developers is to force malloc
to quit printing debug messages, which avoids recursive malloc.
* m4/regex.m4 (gl_REGEX): Avoid recursive malloc deadlock when
glibc bug 15078 in turn triggers bug 16159.
Reported by Michal Privoznik.
Signed-off-by: Eric Blake <eblake@redhat.com>
author | Eric Blake <eblake@redhat.com> |
---|---|
date | Tue, 03 Dec 2013 10:34:13 -0700 |
parents | c741bc27922a |
children | 344018b6e5d7 |
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/* a simple ring buffer Copyright (C) 2006, 2009-2013 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ /* written by Jim Meyering */ #include <config.h> #include "i-ring.h" #include <stdlib.h> void i_ring_init (I_ring *ir, int default_val) { int i; ir->ir_empty = true; ir->ir_front = 0; ir->ir_back = 0; for (i = 0; i < I_RING_SIZE; i++) ir->ir_data[i] = default_val; ir->ir_default_val = default_val; } bool i_ring_empty (I_ring const *ir) { return ir->ir_empty; } int i_ring_push (I_ring *ir, int val) { unsigned int dest_idx = (ir->ir_front + !ir->ir_empty) % I_RING_SIZE; int old_val = ir->ir_data[dest_idx]; ir->ir_data[dest_idx] = val; ir->ir_front = dest_idx; if (dest_idx == ir->ir_back) ir->ir_back = (ir->ir_back + !ir->ir_empty) % I_RING_SIZE; ir->ir_empty = false; return old_val; } int i_ring_pop (I_ring *ir) { int top_val; if (i_ring_empty (ir)) abort (); top_val = ir->ir_data[ir->ir_front]; ir->ir_data[ir->ir_front] = ir->ir_default_val; if (ir->ir_front == ir->ir_back) ir->ir_empty = true; else ir->ir_front = ((ir->ir_front + I_RING_SIZE - 1) % I_RING_SIZE); return top_val; }