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84d4150668
Greetings, We use libunwind just for stack traces (I suspect many others do as well). The use pattern is: GetStackTrace(void** result, int max_depth) { ... unw_getcontext(&uc); unw_init_local(&cursor, &uc); while (n < max_depth) { if (unw_get_reg(&cursor, UNW_REG_IP, (unw_word_t *) &ip) < 0) { break; } result[n++] = ip; if (unw_step(&cursor) <= 0) { break; } } Given this usage, it is quite convenient for us to block signals (or prevent signal handlers from re-entering libunwind by other means) at the "top level", which makes most of the sigprocmask calls performed by libunwind itself unneccessary. The second patch in this series adds a configure option which removes most of the sigprocmask calls. Attached patch is a preliminary for it -- consolidating all of the "sigprocmask; mutex_lock;" sequences into lock_acquire and "mutex_unlock; sigprocmask;" sequences into lock_release. Thanks, -- Paul Pluzhnikov commit 402d15b123d54a7669db7cf17a76dd315094e472 Author: Paul Pluzhnikov <ppluzhnikov@google.com> Date: Mon Sep 21 10:18:28 2009 -0700 Replace "sigprocmask + mutext_lock" with a single lock_acquire. Likewise, replace "mutext_unlock + sigprocmask" with lock_release.
55 lines
1.8 KiB
C
55 lines
1.8 KiB
C
/* libunwind - a platform-independent unwind library
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Copyright (c) 2004-2005 Hewlett-Packard Development Company, L.P.
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Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
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This file is part of libunwind.
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Permission is hereby granted, free of charge, to any person obtaining
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a copy of this software and associated documentation files (the
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"Software"), to deal in the Software without restriction, including
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without limitation the rights to use, copy, modify, merge, publish,
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distribute, sublicense, and/or sell copies of the Software, and to
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permit persons to whom the Software is furnished to do so, subject to
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the following conditions:
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The above copyright notice and this permission notice shall be
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included in all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
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#include "unwind_i.h"
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HIDDEN pthread_mutex_t hppa_lock = PTHREAD_MUTEX_INITIALIZER;
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HIDDEN int tdep_needs_initialization = 1;
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HIDDEN void
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tdep_init (void)
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{
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intrmask_t saved_mask;
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sigfillset (&unwi_full_mask);
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lock_acquire (&hppa_lock, saved_mask);
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{
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if (!tdep_needs_initialization)
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/* another thread else beat us to it... */
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goto out;
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mi_init ();
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dwarf_init ();
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#ifndef UNW_REMOTE_ONLY
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hppa_local_addr_space_init ();
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#endif
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tdep_needs_initialization = 0; /* signal that we're initialized... */
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}
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out:
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lock_release (&hppa_lock, saved_mask);
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}
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