Isolate tests by running AtExit callbacks between them.

base/test/test_suite.h

 // Copyright (c) 2009 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.
 
 #ifndef BASE_TEST_SUITE_H_
 #define BASE_TEST_SUITE_H_
 
 // Defines a basic test suite framework for running gtest based tests.  You can
 // instantiate this class in your main function and call its Run method to run
 // any gtest based tests that are linked into your executable.
 
 #include "base/at_exit.h"
 #include "base/base_paths.h"
 #include "base/debug_on_start.h"
 #include "base/i18n/icu_util.h"
 #include "base/multiprocess_test.h"
+#include "base/nss_init.h"
 #include "base/process_util.h"
 #include "base/scoped_nsautorelease_pool.h"
+#include "base/scoped_ptr.h"
 #include "base/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/multiprocess_func_list.h"
 
 #if defined(OS_LINUX)
 #include <gtk/gtk.h>
 #endif
 
 // Match function used by the GetTestCount method.
 typedef bool (*TestMatch)(const testing::TestInfo&);
 
+// By setting up a shadow AtExitManager, this test event listener ensures that
+// no state is carried between tests (like singletons, lazy instances, etc).
+// Of course it won't help if the code under test corrupts memory.
+class TestIsolationEnforcer : public testing::EmptyTestEventListener {
+ public:
+  virtual void OnTestStart(const testing::TestInfo& test_info) {
+    ASSERT_FALSE(exit_manager_.get());
+    exit_manager_.reset(new base::ShadowingAtExitManager());
+  }
+
+  virtual void OnTestEnd(const testing::TestInfo& test_info) {
+    ASSERT_TRUE(exit_manager_.get());
+    exit_manager_.reset();
+  }
+
+ private:
+  scoped_ptr<base::ShadowingAtExitManager> exit_manager_;
+};
+
 class TestSuite {
  public:
   TestSuite(int argc, char** argv) {
     base::EnableTerminationOnHeapCorruption();
     CommandLine::Init(argc, argv);
     testing::InitGoogleTest(&argc, argv);
 #if defined(OS_LINUX)
     g_thread_init(NULL);
     gtk_init_check(&argc, &argv);
 #endif
@@ skipping 30 matching lines @@
       for (int j = 0; j < test_case.total_test_count(); ++j) {
         if (test_match(*test_case.GetTestInfo(j))) {
           count++;
         }
       }
     }
 
     return count;
   }
 
+  // TODO(phajdan.jr): Enforce isolation for all tests once it's stable.
+  void EnforceTestIsolation() {
+    testing::TestEventListeners& listeners =
+        testing::UnitTest::GetInstance()->listeners();
+    listeners.Append(new TestIsolationEnforcer);
+  }
+
   // Don't add additional code to this method.  Instead add it to
   // Initialize().  See bug 6436.
   int Run() {
     base::ScopedNSAutoreleasePool scoped_pool;
 
     Initialize();
     std::wstring client_func =
         CommandLine::ForCurrentProcess()->GetSwitchValue(kRunClientProcess);
     // Check to see if we are being run as a client process.
     if (!client_func.empty()) {
@@ skipping 75 matching lines @@
       SuppressErrorDialogs();
 #if !defined(PURIFY)
       // When the code in this file moved around, bug 6436 resurfaced.
       // As a hack workaround, just #ifdef out this code for Purify builds.
       logging::SetLogAssertHandler(UnitTestAssertHandler);
 #endif  // !defined(PURIFY)
     }
 #endif  // defined(OS_WIN)
 
     icu_util::Initialize();
+
+#if defined(OS_LINUX)
+    // Trying to repeatedly initialize and cleanup NSS and NSPR may result in
+    // a deadlock. Such repeated initialization will happen when using test
+    // isolation. Prevent problems by initializing NSS here, so that the cleanup
+    // will be done only on process exit.
+    base::EnsureNSSInit();
+#endif  // defined(OS_LINUX)
   }
 
   virtual void Shutdown() {
   }
 
   // Make sure that we setup an AtExitManager so Singleton objects will be
   // destroyed.
   base::AtExitManager at_exit_manager_;
 };
 
 #endif  // BASE_TEST_SUITE_H_