Add multi_process_lock to chrome/common

chrome/common/multi_process_lock_unittest.cc

Index: chrome/common/multi_process_lock_unittest.cc
diff --git a/chrome/common/multi_process_lock_unittest.cc b/chrome/common/multi_process_lock_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ef275abb7824d9304478cb53fadcfe03ebcb873f
--- /dev/null
+++ b/chrome/common/multi_process_lock_unittest.cc
@@ -0,0 +1,205 @@
+// 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 "base/basictypes.h"
+#include "base/logging.h"
+#include "base/rand_util.h"
+#include "base/scoped_ptr.h"
+#include "base/stringprintf.h"
+#include "base/test/multiprocess_test.h"
+#include "base/time.h"
+#include "chrome/common/multi_process_lock.h"
+#include "testing/multiprocess_func_list.h"
+
+#if defined(OS_WIN)
+#include <windows.h>
+#else  // !defined(OS_WIN)
+#include <stdlib.h>
+#endif  // defined(OS_WIN)
+
+class MultiProcessLockTest : public base::MultiProcessTest {
+ public:
+  static const char kLockEnviromentVarName[];
+
+  // TODO(dmaclach): Move to process_utils.
+  class ScopedEnvironmentVariable {
+   public:
+    ScopedEnvironmentVariable(const std::string &name,
+                              const std::string &value) : name_(name) {
+      setenv(name_, value);
+    }
+    ~ScopedEnvironmentVariable() {
+      setenv(name_, "");
+    }
+   private:
+    std::string name_;
+    DISALLOW_COPY_AND_ASSIGN(ScopedEnvironmentVariable);
+  };
+
+  // TODO(dmaclach): Move setenv and getenv to process_utils.
+  static bool setenv(const std::string &name, const std::string &value);
+  static bool getenv(const std::string &name, std::string *value);
+
+  std::string GenerateLockName();
+  void ExpectLockIsLocked(const std::string &name);
+  void ExpectLockIsUnlocked(const std::string &name);
+};
+
+const char MultiProcessLockTest::kLockEnviromentVarName[]
+    = "MULTI_PROCESS_TEST_LOCK_NAME";
+
+bool MultiProcessLockTest::setenv(const std::string &name,

[Mark Mentovai, 2010/11/16 18:55:15]

Does base/environmenth.h help here?

+                                  const std::string &value) {
+#if defined(OS_WIN)
+  return _putenv_s(name.c_str(), value.c_str()) == 0;
+#else  // !defined(OS_WIN)
+  if (value.length()) {
+    return ::setenv(name.c_str(), value.c_str(), true) == 0;
+  } else {
+    return unsetenv(name.c_str());
+  }
+#endif  //defined(OS_WIN)
+}
+
+bool MultiProcessLockTest::getenv(const std::string &name, std::string *value) {
+  bool ret = false;
+#if defined(OS_WIN)
+  size_t requiredSize = 0;
+  errno_t err = getenv_s(&requiredSize, NULL, 0, name.c_str());
+  if (err == 0 && requiredSize > 0) {
+    ret = true;
+    if (value) {
+      scoped_array<char> c_value(new char[requiredSize]);
+      err = getenv_s(&requiredSize, c_value.get(), requiredSize, name.c_str());
+      if (err == 0) {
+        *value = c_value.get();
+      } else {
+        ret = false;
+        *value = "";
+      }
+    }
+  }
+#else  // !defined(OS_WIN)
+  const char *c_value = ::getenv(name.c_str());
+  if (c_value) {
+    ret = true;
+    if (value) {
+      *value = c_value;
+    }
+  }
+#endif  //defined(OS_WIN)
+  return ret;
+}
+
+std::string MultiProcessLockTest::GenerateLockName() {
+  base::Time now = base::Time::NowFromSystemTime();
+  return base::StringPrintf("multi_process_test_lock %lf%lf",
+                            now.ToDoubleT(), base::RandDouble());
+}
+
+void MultiProcessLockTest::ExpectLockIsLocked(const std::string &name) {
+  ScopedEnvironmentVariable var(kLockEnviromentVarName, name);
+  base::ProcessHandle handle = SpawnChild("MultiProcessLockTryFailMain", false);
+  ASSERT_TRUE(handle);
+  int exit_code = 0;
+  EXPECT_TRUE(base::WaitForExitCode(handle, &exit_code));
+  EXPECT_EQ(exit_code, 0);
+}
+
+void MultiProcessLockTest::ExpectLockIsUnlocked(
+    const std::string &name) {
+  ScopedEnvironmentVariable var(kLockEnviromentVarName, name);
+  base::ProcessHandle handle = SpawnChild("MultiProcessLockTrySucceedMain",
+                                          false);
+  ASSERT_TRUE(handle);
+  int exit_code = 0;
+  EXPECT_TRUE(base::WaitForExitCode(handle, &exit_code));
+  EXPECT_EQ(exit_code, 0);
+}
+
+TEST_F(MultiProcessLockTest, BasicCreationTest) {
+  // Test basic creation/destruction with no lock taken
+  std::string name = GenerateLockName();
+  scoped_ptr<MultiProcessLock> scoped(MultiProcessLock::Create(name));
+  ExpectLockIsUnlocked(name);
+  scoped.reset(NULL);
+}
+
+TEST_F(MultiProcessLockTest, LongNameTest) {
+  // Linux has a max path name of 108 characters.
+  // http://lxr.linux.no/linux+v2.6.36/include/linux/un.h
+  // This is enforced on all platforms.
+  LOG(INFO) << "Following error log due to long name is expected";
+  std::string name("This is a name that is longer than one hundred and eight "
+      "characters to make sure that we fail appropriately on linux when we "
+      "have a path that is to long for linux to handle");
+  scoped_ptr<MultiProcessLock> test_lock(MultiProcessLock::Create(name));
+  EXPECT_FALSE(test_lock->TryLock());
+}
+
+TEST_F(MultiProcessLockTest, SimpleLock) {
+  std::string name = GenerateLockName();
+  scoped_ptr<MultiProcessLock> test_lock(MultiProcessLock::Create(name));
+  EXPECT_TRUE(test_lock->TryLock());
+  ExpectLockIsLocked(name);
+  test_lock->Unlock();
+  ExpectLockIsUnlocked(name);
+}
+
+TEST_F(MultiProcessLockTest, RecursiveLock) {
+  std::string name = GenerateLockName();
+  scoped_ptr<MultiProcessLock> test_lock(MultiProcessLock::Create(name));
+  EXPECT_TRUE(test_lock->TryLock());
+  ExpectLockIsLocked(name);
+  LOG(INFO) << "Following error log "
+            << "'MultiProcessLock is already locked' is expected";
+  EXPECT_TRUE(test_lock->TryLock());
+  ExpectLockIsLocked(name);
+  test_lock->Unlock();
+  ExpectLockIsUnlocked(name);
+  LOG(INFO) << "Following error log "
+            << "'Over-unlocked MultiProcessLock' is expected";
+  test_lock->Unlock();
+  ExpectLockIsUnlocked(name);
+  test_lock.reset();
+}
+
+TEST_F(MultiProcessLockTest, LockScope) {
+  // Check to see that lock is released when it goes out of scope.
+  std::string name = GenerateLockName();
+  {
+    scoped_ptr<MultiProcessLock> test_lock(MultiProcessLock::Create(name));
+    EXPECT_TRUE(test_lock->TryLock());
+    ExpectLockIsLocked(name);
+  }
+  ExpectLockIsUnlocked(name);
+}
+
+MULTIPROCESS_TEST_MAIN(MultiProcessLockTryFailMain) {
+  std::string name;
+  EXPECT_TRUE(MultiProcessLockTest::getenv(
+      MultiProcessLockTest::kLockEnviromentVarName, &name));
+#if defined(OS_MACOSX)
+  // OS X sends out a log if a lock fails.
+  // Hopefully this will keep people from panicking about it when they
+  // are perusing thge build logs.

[avi_google.com, 2010/11/16 22:07:30]

drive-by typo: thge

+  LOG(INFO) << "Following error log "
+            << "\"CFMessagePort: bootstrap_register(): failed 1100 (0x44c) "
+            << "'Permission denied'\" is expected";
+#endif  // defined(OS_MACOSX)
+  scoped_ptr<MultiProcessLock> test_lock(
+      MultiProcessLock::Create(name));
+  EXPECT_FALSE(test_lock->TryLock());
+  return 0;
+}
+
+MULTIPROCESS_TEST_MAIN(MultiProcessLockTrySucceedMain) {
+  std::string name;
+  EXPECT_TRUE(MultiProcessLockTest::getenv(
+      MultiProcessLockTest::kLockEnviromentVarName, &name));
+  scoped_ptr<MultiProcessLock> test_lock(
+      MultiProcessLock::Create(name));
+  EXPECT_TRUE(test_lock->TryLock());
+  return 0;
+}