Initial version of stressapptest

From http://stressapptest.googlecode.com/files/stressapptest-1.0.4_autoconf.tar.gz
with the addition of MODULE_LICENSE_APACHE2 and NOTICE.

Change-Id: I1f3e80fce2c500766bcc7a67d7d42e485ddf57b4
diff --git a/src/logger.cc b/src/logger.cc
new file mode 100644
index 0000000..e4ecb03
--- /dev/null
+++ b/src/logger.cc
@@ -0,0 +1,152 @@
+// Copyright 2009 Google Inc. All Rights Reserved.
+
+// 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 "logger.h"
+
+#include <pthread.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "sattypes.h"
+
+
+Logger *Logger::GlobalLogger() {
+  static Logger logger;
+  return &logger;
+}
+
+void Logger::VLogF(int priority, const char *format, va_list args) {
+  if (priority > verbosity_) {
+    return;
+  }
+  char buffer[4096];
+  int length = vsnprintf(buffer, sizeof buffer, format, args);
+  if (static_cast<size_t>(length) >= sizeof buffer) {
+    length = sizeof buffer;
+    buffer[sizeof buffer - 1] = '\n';
+  }
+  QueueLogLine(new string(buffer, length));
+}
+
+void Logger::StartThread() {
+  LOGGER_ASSERT(!thread_running_);
+  thread_running_ = true;
+  LOGGER_ASSERT(0 == pthread_create(&thread_, NULL, &StartRoutine, this));
+}
+
+void Logger::StopThread() {
+  LOGGER_ASSERT(thread_running_);
+  thread_running_ = false;
+  LOGGER_ASSERT(0 == pthread_mutex_lock(&queued_lines_mutex_));
+  bool need_cond_signal = queued_lines_.empty();
+  queued_lines_.push_back(NULL);
+  LOGGER_ASSERT(0 == pthread_mutex_unlock(&queued_lines_mutex_));
+  if (need_cond_signal) {
+    LOGGER_ASSERT(0 == pthread_cond_signal(&queued_lines_cond_));
+  }
+  LOGGER_ASSERT(0 == pthread_join(thread_, NULL));
+}
+
+Logger::Logger() : verbosity_(20), log_fd_(-1), thread_running_(false) {
+  LOGGER_ASSERT(0 == pthread_mutex_init(&queued_lines_mutex_, NULL));
+  LOGGER_ASSERT(0 == pthread_cond_init(&queued_lines_cond_, NULL));
+  LOGGER_ASSERT(0 == pthread_cond_init(&full_queue_cond_, NULL));
+}
+
+Logger::~Logger() {
+  LOGGER_ASSERT(0 == pthread_mutex_destroy(&queued_lines_mutex_));
+  LOGGER_ASSERT(0 == pthread_cond_destroy(&queued_lines_cond_));
+  LOGGER_ASSERT(0 == pthread_cond_destroy(&full_queue_cond_));
+}
+
+void Logger::QueueLogLine(string *line) {
+  LOGGER_ASSERT(line != NULL);
+  LOGGER_ASSERT(0 == pthread_mutex_lock(&queued_lines_mutex_));
+  if (thread_running_) {
+    if (queued_lines_.size() >= kMaxQueueSize) {
+      LOGGER_ASSERT(0 == pthread_cond_wait(&full_queue_cond_,
+                                           &queued_lines_mutex_));
+    }
+    if (queued_lines_.empty()) {
+      LOGGER_ASSERT(0 == pthread_cond_signal(&queued_lines_cond_));
+    }
+    queued_lines_.push_back(line);
+  } else {
+    WriteAndDeleteLogLine(line);
+  }
+  LOGGER_ASSERT(0 == pthread_mutex_unlock(&queued_lines_mutex_));
+}
+
+namespace {
+void WriteToFile(const string& line, int fd) {
+  LOGGER_ASSERT(write(fd, line.data(), line.size()) ==
+                static_cast<ssize_t>(line.size()));
+}
+}
+
+void Logger::WriteAndDeleteLogLine(string *line) {
+  LOGGER_ASSERT(line != NULL);
+  if (log_fd_ >= 0) {
+    WriteToFile(*line, log_fd_);
+  }
+  WriteToFile(*line, 1);
+  delete line;
+}
+
+void *Logger::StartRoutine(void *ptr) {
+  Logger *self = static_cast<Logger*>(ptr);
+  self->ThreadMain();
+  return NULL;
+}
+
+void Logger::ThreadMain() {
+  vector<string*> local_queue;
+  LOGGER_ASSERT(0 == pthread_mutex_lock(&queued_lines_mutex_));
+
+  for (;;) {
+    if (queued_lines_.empty()) {
+      LOGGER_ASSERT(0 == pthread_cond_wait(&queued_lines_cond_,
+                                           &queued_lines_mutex_));
+      continue;
+    }
+
+    // We move the log lines into a local queue so we can release the lock
+    // while writing them to disk, preventing other threads from blocking on
+    // our writes.
+    local_queue.swap(queued_lines_);
+    if (local_queue.size() >= kMaxQueueSize) {
+      LOGGER_ASSERT(0 == pthread_cond_broadcast(&full_queue_cond_));
+    }
+
+    // Unlock while we process our local queue.
+    LOGGER_ASSERT(0 == pthread_mutex_unlock(&queued_lines_mutex_));
+    for (vector<string*>::const_iterator it = local_queue.begin();
+         it != local_queue.end(); ++it) {
+      if (*it == NULL) {
+        // NULL is guaranteed to be at the end.
+        return;
+      }
+      WriteAndDeleteLogLine(*it);
+    }
+    local_queue.clear();
+    // We must hold the lock at the start of each iteration of this for loop.
+    LOGGER_ASSERT(0 == pthread_mutex_lock(&queued_lines_mutex_));
+  }
+}