platform_system_core/libbacktrace/BacktraceLog.h
Christopher Ferris 2d09171758 Modify the code to avoid potential deadlocks.
If the signal to dump a thread is never delivered, then it's
possible for a deadlock. The signal handler is responsible for
unlocking and deleting the ThreadEntry created for the pid/tid
combination. This means if the signal is lost, the ThreadEntry
gets stuck locked and never deleted. If a second attempt to get
a backtrace of this thread occurs, there is a deadlock.

Also, decrease the timeout from 10 seconds to 5 seconds. The original
10 seconds was because the unwind was actually done in the signal
handler. Now the signal handler does nothing but copy the ucontext
structure and let the caller do the unwind.

Bug: 21086132
Change-Id: Idc735dbf6147ec879d35bd4f034c5d227e26a98d
2015-06-01 13:51:51 -07:00

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C

/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef _LIBBACKTRACE_BACKTRACE_LOG_H
#define _LIBBACKTRACE_BACKTRACE_LOG_H
#define LOG_TAG "libbacktrace"
#include <log/log.h>
// Macro to log the function name along with the warning message.
#define BACK_LOGW(format, ...) \
ALOGW("%s: " format, __PRETTY_FUNCTION__, ##__VA_ARGS__)
#define BACK_LOGE(format, ...) \
ALOGE("%s: " format, __PRETTY_FUNCTION__, ##__VA_ARGS__)
#endif // _LIBBACKTRACE_BACKTRACE_LOG_H