Refactor the code.
The object hierarchy was confusing and convoluted. This removes
a lot of unnecessary code, and consolidates the BacktraceCurrent
and BacktraceThread code into BacktraceCurrent.
Change-Id: I01c8407d493712a48169df49dd3ff46db4a7c3ae
diff --git a/libbacktrace/ThreadEntry.cpp b/libbacktrace/ThreadEntry.cpp
new file mode 100644
index 0000000..e8b60c8
--- /dev/null
+++ b/libbacktrace/ThreadEntry.cpp
@@ -0,0 +1,127 @@
+/*
+ * 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 "BacktraceLog.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) {
+ pthread_mutex_unlock(&entry->mutex_);
+
+ 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_);
+}
+
+void ThreadEntry::Wait(int value) {
+ timespec ts;
+ clock_gettime(CLOCK_MONOTONIC, &ts);
+ ts.tv_sec += 10;
+
+ pthread_mutex_lock(&wait_mutex_);
+ while (wait_value_ != value) {
+ int ret = pthread_cond_timedwait(&wait_cond_, &wait_mutex_, &ts);
+ if (ret != 0) {
+ BACK_LOGW("pthread_cond_timedwait failed: %s", strerror(ret));
+ break;
+ }
+ }
+ pthread_mutex_unlock(&wait_mutex_);
+}
+
+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));
+}