rlz/mac: Make sure a crashing process doesn't leave a stale lockfile behind.

rlz/lib/rlz_lib_test.cc

Index: rlz/lib/rlz_lib_test.cc
diff --git a/rlz/lib/rlz_lib_test.cc b/rlz/lib/rlz_lib_test.cc
index 0f8cb4c21c4379114ae43d4c45abb42b3a485366..795935037d216770fd5d23a42b40f6a39e63dce5 100644
--- a/rlz/lib/rlz_lib_test.cc
+++ b/rlz/lib/rlz_lib_test.cc
@@ -795,7 +795,9 @@ class ReadonlyRlzDirectoryTest : public RlzLibTestNoMachineState {
 void ReadonlyRlzDirectoryTest::SetUp() {
   RlzLibTestNoMachineState::SetUp();
   // Make the rlz directory non-writeable.
-  chmod(temp_dir_.path().value().c_str(), 0500);
+  int chmod_result = chmod(temp_dir_.path().value().c_str(), 0500);
+  ASSERT_EQ(0, chmod_result);
+

[Mark Mentovai, 2012/08/15 00:50:54]

Blank line nit.

 }
 
 TEST_F(ReadonlyRlzDirectoryTest, WriteFails) {
@@ -821,4 +823,46 @@ TEST_F(ReadonlyRlzDirectoryTest, SupplementaryBrandingDoesNotCrash) {
   EXPECT_FALSE(rlz_lib::RecordProductEvent(rlz_lib::TOOLBAR_NOTIFIER,
       rlz_lib::IE_DEFAULT_SEARCH, rlz_lib::INSTALL));
 }
+
+// Regression test for http://crbug.com/141108
+TEST_F(RlzLibTest, ConcurrentStoreAccessWithProcessExitsWhileLockHeld) {
+  // See the comment at the top of WriteFails.
+  if (!rlz_lib::SupplementaryBranding::GetBrand().empty())
+    return;
+
+  std::vector<pid_t> pids;
+  for (int i = 0; i < 10; ++i) {
+    pid_t pid = fork();
+    ASSERT_NE(-1, pid);
+    if (pid == 0) {
+      // Child.
+      {
+        // SupplementaryBranding is a RAII object for the rlz lock.
+        rlz_lib::SupplementaryBranding branding("TEST");
+
+        // Simulate a crash while holding the lock in some of the children.
+        if (i > 0 && i % 3 == 0)
+          _exit(1);
+
+        // Note: Since this is in a forked child, a failing expectation won't
+        // make the test fail. It does however cause lots of "check failed"

[Mark Mentovai, 2012/08/15 00:50:54]

You could make the test fail in the parent by signaling a bad condition with a
special exit code, and checking the exit statuses down in your waitpid.

[Nico, 2012/08/15 03:24:12]

Done.

+        // error output.
+        EXPECT_TRUE(rlz_lib::RecordProductEvent(rlz_lib::TOOLBAR_NOTIFIER,
+            rlz_lib::IE_DEFAULT_SEARCH, rlz_lib::INSTALL));
+      }
+      _exit(0);
+    } else {
+      // Parent.
+      pids.push_back(pid);
+    }
+  }
+
+  int status;
+  for (size_t i = 0; i < pids.size(); ++i)
+    waitpid(pids[i], &status, 0);
+
+  // No child should have the lock at this point, not even the crashed ones.
+  EXPECT_TRUE(rlz_lib::RecordProductEvent(rlz_lib::TOOLBAR_NOTIFIER,
+      rlz_lib::IE_DEFAULT_SEARCH, rlz_lib::INSTALL));
+}
 #endif