Bug 619623 - Wait for the WAL checkpoint in case that helps avoiding the intermittent failure in test_IHistory.cpp

r=test-only-experiment-not-worth-it a=nonlibxul

toolkit/components/places/tests/cpp/places_test_harness.h

@@ -16,6 +16,9 @@
 #include "mozilla/IHistory.h"
 #include "mozIStorageConnection.h"
 #include "mozIStorageStatement.h"
+#include "mozIStorageAsyncStatement.h"
+#include "mozIStorageStatementCallback.h"
+#include "mozIStoragePendingStatement.h"
 #include "nsPIPlacesDatabase.h"
 #include "nsIObserver.h"
 #include "prinrval.h"
@@ -142,6 +145,62 @@ NS_IMPL_ISUPPORTS1(
   nsIObserver
 )
 
+/**
+ * Spins current thread until an async statement is executed.
+ */
+class AsyncStatementSpinner MOZ_FINAL : public mozIStorageStatementCallback
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_MOZISTORAGESTATEMENTCALLBACK
+
+  AsyncStatementSpinner();
+  void SpinUntilCompleted();
+  uint16_t completionReason;
+
+protected:
+  volatile bool mCompleted;
+};
+
+NS_IMPL_ISUPPORTS1(AsyncStatementSpinner,
+                   mozIStorageStatementCallback)
+
+AsyncStatementSpinner::AsyncStatementSpinner()
+: completionReason(0)
+, mCompleted(false)
+{
+}
+
+NS_IMETHODIMP
+AsyncStatementSpinner::HandleResult(mozIStorageResultSet *aResultSet)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+AsyncStatementSpinner::HandleError(mozIStorageError *aError)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+AsyncStatementSpinner::HandleCompletion(uint16_t aReason)
+{
+  completionReason = aReason;
+  mCompleted = true;
+  return NS_OK;
+}
+
+void AsyncStatementSpinner::SpinUntilCompleted()
+{
+  nsCOMPtr<nsIThread> thread(::do_GetCurrentThread());
+  nsresult rv = NS_OK;
+  bool processed = true;
+  while (!mCompleted && NS_SUCCEEDED(rv)) {
+    rv = thread->ProcessNextEvent(true, &processed);
+  }
+}
+
 /**
  * Adds a URI to the database.
  *

toolkit/components/places/tests/cpp/test_IHistory.cpp

@@ -114,6 +114,26 @@ test_set_places_enabled()
   run_next_test();
 }
 
+
+void
+test_wait_checkpoint()
+{
+  // This "fake" test is here to wait for the initial WAL checkpoint we force
+  // after creating the database schema, since that may happen at any time,
+  // and cause concurrent readers to access an older checkpoint.
+  nsCOMPtr<mozIStorageConnection> db = do_get_db();
+  nsCOMPtr<mozIStorageAsyncStatement> stmt;
+  db->CreateAsyncStatement(NS_LITERAL_CSTRING("SELECT 1"),
+                           getter_AddRefs(stmt));
+  nsRefPtr<AsyncStatementSpinner> spinner = new AsyncStatementSpinner();
+  nsCOMPtr<mozIStoragePendingStatement> pending;
+  (void)stmt->ExecuteAsync(spinner, getter_AddRefs(pending));
+  spinner->SpinUntilCompleted();
+
+  // Run the next test.
+  run_next_test();
+}
+
 // These variables are shared between part 1 and part 2 of the test.  Part 2
 // sets the nsCOMPtr's to nullptr, freeing the reference.
 namespace test_unvisited_does_not_notify {
@@ -591,6 +611,7 @@ test_two_null_links_same_uri()
  */
 Test gTests[] = {
   TEST(test_set_places_enabled), // Must come first!
+  TEST(test_wait_checkpoint), // Must come second!
   TEST(test_unvisited_does_not_notify_part1), // Order Important!
   TEST(test_visited_notifies),
   TEST(test_unvisited_does_not_notify_part2), // Order Important!