Update NetLog to be thread safe.

chrome/browser/net/chrome_net_log_unittest.cc

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/net/chrome_net_log.h"
+
+#include "base/waitable_event.h"
+#include "base/simple_thread.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+const int kThreads = 10;
+const int kEvents = 100;
+
+class ChromeNetLogTestThread : public base::SimpleThread {
+ public:
+  ChromeNetLogTestThread() : base::SimpleThread("ChromeNetLogTest"),
+                             can_start_loop_(false, false),
+                             log_(NULL) {
+  }
+
+  void Init(ChromeNetLog* log) {
+    log_ = log;
+  }
+
+  virtual void Run() {
+    can_start_loop_.Wait();
+    for (int i = 0; i < kEvents; ++i) {
+      net::NetLog::Source source(net::NetLog::SOURCE_SOCKET, log_->NextID());
+      log_->AddEntry(net::NetLog::TYPE_SOCKET_ALIVE, base::TimeTicks(),
+                     source, net::NetLog::PHASE_BEGIN, NULL);
+    }
+    log_->ClearAllPassivelyCapturedEvents();
+  }
+
+  void ReallyStart() {
+    can_start_loop_.Signal();
+  }
+
+ private:
+  // Only triggered once all threads have been created, to make it much less
+  // likely each thread completes before the next one starts.
+  base::WaitableEvent can_start_loop_;
+
+  ChromeNetLog* log_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChromeNetLogTestThread);
+};
+
+}  // namespace
+
+// Attempts to check thread safety, exercising checks in ChromeNetLog and
+// PassiveLogCollector.
+TEST(ChromeNetLogTest, NetLogThreads) {
+  ChromeNetLog log;
+  ChromeNetLogTestThread threads[kThreads];
+
+  for (int i = 0; i < kThreads; ++i) {
+    threads[i].Init(&log);
+    threads[i].Start();
+  }
+
+  for (int i = 0; i < kThreads; ++i)
+    threads[i].ReallyStart();
+
+  for (int i = 0; i < kThreads; ++i)
+    threads[i].Join();
+
+  ChromeNetLog::EntryList entries;
+  log.GetAllPassivelyCapturedEvents(&entries);
+  EXPECT_EQ(0u, entries.size());
+}