platform_system_core/libbacktrace/ThreadEntry.cpp

132 lines
3.5 KiB
C++

/*
* Copyright (C) 2015 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.
*/
#include <pthread.h>
#include <stdint.h>
#include <string.h>
#include <sys/types.h>
#include <time.h>
#include <ucontext.h>
#include "BacktraceAsyncSafeLog.h"
#include "ThreadEntry.h"
// Initialize static member variables.
ThreadEntry* ThreadEntry::list_ = nullptr;
pthread_mutex_t ThreadEntry::list_mutex_ = PTHREAD_MUTEX_INITIALIZER;
// Assumes that ThreadEntry::list_mutex_ has already been locked before
// creating a ThreadEntry object.
ThreadEntry::ThreadEntry(pid_t pid, pid_t tid)
: pid_(pid), tid_(tid), ref_count_(1), mutex_(PTHREAD_MUTEX_INITIALIZER),
wait_mutex_(PTHREAD_MUTEX_INITIALIZER), wait_value_(0),
next_(ThreadEntry::list_), prev_(nullptr) {
pthread_condattr_t attr;
pthread_condattr_init(&attr);
pthread_condattr_setclock(&attr, CLOCK_MONOTONIC);
pthread_cond_init(&wait_cond_, &attr);
// Add ourselves to the list.
if (ThreadEntry::list_) {
ThreadEntry::list_->prev_ = this;
}
ThreadEntry::list_ = this;
}
ThreadEntry* ThreadEntry::Get(pid_t pid, pid_t tid, bool create) {
pthread_mutex_lock(&ThreadEntry::list_mutex_);
ThreadEntry* entry = list_;
while (entry != nullptr) {
if (entry->Match(pid, tid)) {
break;
}
entry = entry->next_;
}
if (!entry) {
if (create) {
entry = new ThreadEntry(pid, tid);
}
} else {
entry->ref_count_++;
}
pthread_mutex_unlock(&ThreadEntry::list_mutex_);
return entry;
}
void ThreadEntry::Remove(ThreadEntry* entry) {
entry->Unlock();
pthread_mutex_lock(&ThreadEntry::list_mutex_);
if (--entry->ref_count_ == 0) {
delete entry;
}
pthread_mutex_unlock(&ThreadEntry::list_mutex_);
}
// Assumes that ThreadEntry::list_mutex_ has already been locked before
// deleting a ThreadEntry object.
ThreadEntry::~ThreadEntry() {
if (list_ == this) {
list_ = next_;
} else {
if (next_) {
next_->prev_ = prev_;
}
prev_->next_ = next_;
}
next_ = nullptr;
prev_ = nullptr;
pthread_cond_destroy(&wait_cond_);
}
bool ThreadEntry::Wait(int value) {
timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
ts.tv_sec += 5;
bool wait_completed = true;
pthread_mutex_lock(&wait_mutex_);
while (wait_value_ != value) {
int ret = pthread_cond_timedwait(&wait_cond_, &wait_mutex_, &ts);
if (ret != 0) {
BACK_ASYNC_SAFE_LOGW("pthread_cond_timedwait for value %d failed: %s", value, strerror(ret));
wait_completed = false;
break;
}
}
pthread_mutex_unlock(&wait_mutex_);
return wait_completed;
}
void ThreadEntry::Wake() {
pthread_mutex_lock(&wait_mutex_);
wait_value_++;
pthread_mutex_unlock(&wait_mutex_);
pthread_cond_signal(&wait_cond_);
}
void ThreadEntry::CopyUcontextFromSigcontext(void* sigcontext) {
ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(sigcontext);
// The only thing the unwinder cares about is the mcontext data.
memcpy(&ucontext_.uc_mcontext, &ucontext->uc_mcontext, sizeof(ucontext->uc_mcontext));
}