1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
/*
* 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));
}
|
