1 files changed, 74 insertions, 0 deletions
diff --git a/toolkit/profile/gtest/TestProfileLockRetry.cpp b/toolkit/profile/gtest/TestProfileLockRetry.cpp
new file mode 100644
index 0000000000..8301103493
--- /dev/null
+++ b/toolkit/profile/gtest/TestProfileLockRetry.cpp
@@ -0,0 +1,74 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "gtest/gtest.h"
+
+#include <sys/eventfd.h>
+#include <sched.h>
+
+#include "nsComponentManagerUtils.h"
+#include "nsCOMPtr.h"
+#include "nsIFile.h"
+#include "nsProfileLock.h"
+#include "nsString.h"
+
+TEST(ProfileLock, RetryLock)
+{
+  char templ[] = "/tmp/profilelocktest.XXXXXX";
+  char* tmpdir = mkdtemp(templ);
+  ASSERT_NE(tmpdir, nullptr);
+
+  nsProfileLock myLock;
+  nsProfileLock myLock2;
+  nsresult rv;
+  nsCOMPtr<nsIFile> dir(do_CreateInstance(NS_LOCAL_FILE_CONTRACTID, &rv));
+  ASSERT_EQ(NS_SUCCEEDED(rv), true);
+
+  rv = dir->InitWithNativePath(nsCString(tmpdir));
+  ASSERT_EQ(NS_SUCCEEDED(rv), true);
+
+  int eventfd_fd = eventfd(0, 0);
+  ASSERT_GE(eventfd_fd, 0);
+
+  // fcntl advisory locks are per process, so it's hard
+  // to avoid using fork here.
+  pid_t childpid = fork();
+
+  if (childpid) {
+    // parent
+
+    // blocking read causing us to lose the race
+    eventfd_t value;
+    EXPECT_EQ(0, eventfd_read(eventfd_fd, &value));
+
+    rv = myLock2.Lock(dir, nullptr);
+    EXPECT_EQ(NS_ERROR_FILE_ACCESS_DENIED, rv);
+
+    // kill the child
+    EXPECT_EQ(0, kill(childpid, SIGTERM));
+
+    // reap zombie (required to collect the lock)
+    int status;
+    EXPECT_EQ(childpid, waitpid(childpid, &status, 0));
+
+    rv = myLock2.Lock(dir, nullptr);
+    EXPECT_EQ(NS_SUCCEEDED(rv), true);
+  } else {
+    // child
+    rv = myLock.Lock(dir, nullptr);
+    ASSERT_EQ(NS_SUCCEEDED(rv), true);
+
+    // unblock parent
+    EXPECT_EQ(0, eventfd_write(eventfd_fd, 1));
+
+    // parent will kill us
+    for (;;) sleep(1);
+  }
+
+  close(eventfd_fd);
+
+  myLock.Cleanup();
+  myLock2.Cleanup();
+}