diff -r 000000000000 -r 6474c204b198 storage/test/test_true_async.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/storage/test/test_true_async.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,355 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
+ * 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 "storage_test_harness.h"
+#include "prthread.h"
+#include "nsIEventTarget.h"
+#include "nsIInterfaceRequestorUtils.h"
+
+#include "sqlite3.h"
+
+#include "mozilla/ReentrantMonitor.h"
+
+using mozilla::ReentrantMonitor;
+using mozilla::ReentrantMonitorAutoEnter;
+
+/**
+ * Verify that mozIStorageAsyncStatement's life-cycle never triggers a mutex on
+ * the caller (generally main) thread.  We do this by decorating the sqlite
+ * mutex logic with our own code that checks what thread it is being invoked on
+ * and sets a flag if it is invoked on the main thread.  We are able to easily
+ * decorate the SQLite mutex logic because SQLite allows us to retrieve the
+ * current function pointers being used and then provide a new set.
+ */
+
+/* ===== Mutex Watching ===== */
+
+sqlite3_mutex_methods orig_mutex_methods;
+sqlite3_mutex_methods wrapped_mutex_methods;
+
+bool mutex_used_on_watched_thread = false;
+PRThread *watched_thread = nullptr;
+/**
+ * Ugly hack to let us figure out what a connection's async thread is.  If we
+ * were MOZILLA_INTERNAL_API and linked as such we could just include
+ * mozStorageConnection.h and just ask Connection directly.  But that turns out
+ * poorly.
+ *
+ * When the thread a mutex is invoked on isn't watched_thread we save it to this
+ * variable.
+ */
+PRThread *last_non_watched_thread = nullptr;
+
+/**
+ * Set a flag if the mutex is used on the thread we are watching, but always
+ * call the real mutex function.
+ */
+extern "C" void wrapped_MutexEnter(sqlite3_mutex *mutex)
+{
+  PRThread *curThread = ::PR_GetCurrentThread();
+  if (curThread == watched_thread)
+    mutex_used_on_watched_thread = true;
+  else
+    last_non_watched_thread = curThread;
+  orig_mutex_methods.xMutexEnter(mutex);
+}
+
+extern "C" int wrapped_MutexTry(sqlite3_mutex *mutex)
+{
+  if (::PR_GetCurrentThread() == watched_thread)
+    mutex_used_on_watched_thread = true;
+  return orig_mutex_methods.xMutexTry(mutex);
+}
+
+
+#define do_check_ok(aInvoc) do_check_true((aInvoc) == SQLITE_OK)
+
+void hook_sqlite_mutex()
+{
+  // We need to initialize and teardown SQLite to get it to set up the
+  // default mutex handlers for us so we can steal them and wrap them.
+  do_check_ok(sqlite3_initialize());
+  do_check_ok(sqlite3_shutdown());
+  do_check_ok(::sqlite3_config(SQLITE_CONFIG_GETMUTEX, &orig_mutex_methods));
+  do_check_ok(::sqlite3_config(SQLITE_CONFIG_GETMUTEX, &wrapped_mutex_methods));
+  wrapped_mutex_methods.xMutexEnter = wrapped_MutexEnter;
+  wrapped_mutex_methods.xMutexTry = wrapped_MutexTry;
+  do_check_ok(::sqlite3_config(SQLITE_CONFIG_MUTEX, &wrapped_mutex_methods));
+}
+
+/**
+ * Call to clear the watch state and to set the watching against this thread.
+ *
+ * Check |mutex_used_on_watched_thread| to see if the mutex has fired since
+ * this method was last called.  Since we're talking about the current thread,
+ * there are no race issues to be concerned about
+ */
+void watch_for_mutex_use_on_this_thread()
+{
+  watched_thread = ::PR_GetCurrentThread();
+  mutex_used_on_watched_thread = false;
+}
+
+
+////////////////////////////////////////////////////////////////////////////////
+//// Thread Wedgers
+
+/**
+ * A runnable that blocks until code on another thread invokes its unwedge
+ * method.  By dispatching this to a thread you can ensure that no subsequent
+ * runnables dispatched to the thread will execute until you invoke unwedge.
+ *
+ * The wedger is self-dispatching, just construct it with its target.
+ */
+class ThreadWedger : public nsRunnable
+{
+public:
+  ThreadWedger(nsIEventTarget *aTarget)
+  : mReentrantMonitor("thread wedger")
+  , unwedged(false)
+  {
+    aTarget->Dispatch(this, aTarget->NS_DISPATCH_NORMAL);
+  }
+
+  NS_IMETHOD Run()
+  {
+    ReentrantMonitorAutoEnter automon(mReentrantMonitor);
+
+    if (!unwedged)
+      automon.Wait();
+
+    return NS_OK;
+  }
+
+  void unwedge()
+  {
+    ReentrantMonitorAutoEnter automon(mReentrantMonitor);
+    unwedged = true;
+    automon.Notify();
+  }
+
+private:
+  ReentrantMonitor mReentrantMonitor;
+  bool unwedged;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+//// Async Helpers
+
+/**
+ * A horrible hack to figure out what the connection's async thread is.  By
+ * creating a statement and async dispatching we can tell from the mutex who
+ * is the async thread, PRThread style.  Then we map that to an nsIThread.
+ */
+already_AddRefed<nsIThread>
+get_conn_async_thread(mozIStorageConnection *db)
+{
+  // Make sure we are tracking the current thread as the watched thread
+  watch_for_mutex_use_on_this_thread();
+
+  // - statement with nothing to bind
+  nsCOMPtr<mozIStorageAsyncStatement> stmt;
+  db->CreateAsyncStatement(
+    NS_LITERAL_CSTRING("SELECT 1"),
+    getter_AddRefs(stmt));
+  blocking_async_execute(stmt);
+  stmt->Finalize();
+
+  nsCOMPtr<nsIThreadManager> threadMan =
+    do_GetService("@mozilla.org/thread-manager;1");
+  nsCOMPtr<nsIThread> asyncThread;
+  threadMan->GetThreadFromPRThread(last_non_watched_thread,
+                                   getter_AddRefs(asyncThread));
+
+  // Additionally, check that the thread we get as the background thread is the
+  // same one as the one we report from getInterface.
+  nsCOMPtr<nsIEventTarget> target = do_GetInterface(db);
+  nsCOMPtr<nsIThread> allegedAsyncThread = do_QueryInterface(target);
+  PRThread *allegedPRThread;
+  (void)allegedAsyncThread->GetPRThread(&allegedPRThread);
+  do_check_eq(allegedPRThread, last_non_watched_thread);
+  return asyncThread.forget();
+}
+
+
+////////////////////////////////////////////////////////////////////////////////
+//// Tests
+
+void
+test_TrueAsyncStatement()
+{
+  // (only the first test needs to call this)
+  hook_sqlite_mutex();
+
+  nsCOMPtr<mozIStorageConnection> db(getMemoryDatabase());
+
+  // Start watching for forbidden mutex usage.
+  watch_for_mutex_use_on_this_thread();
+
+  // - statement with nothing to bind
+  nsCOMPtr<mozIStorageAsyncStatement> stmt;
+  db->CreateAsyncStatement(
+    NS_LITERAL_CSTRING("CREATE TABLE test (id INTEGER PRIMARY KEY)"),
+    getter_AddRefs(stmt)
+  );
+  blocking_async_execute(stmt);
+  stmt->Finalize();
+  do_check_false(mutex_used_on_watched_thread);
+
+  // - statement with something to bind ordinally
+  db->CreateAsyncStatement(
+    NS_LITERAL_CSTRING("INSERT INTO test (id) VALUES (?)"),
+    getter_AddRefs(stmt)
+  );
+  stmt->BindInt32ByIndex(0, 1);
+  blocking_async_execute(stmt);
+  stmt->Finalize();
+  do_check_false(mutex_used_on_watched_thread);
+  
+  // - statement with something to bind by name
+  db->CreateAsyncStatement(
+    NS_LITERAL_CSTRING("INSERT INTO test (id) VALUES (:id)"),
+    getter_AddRefs(stmt)
+  );
+  nsCOMPtr<mozIStorageBindingParamsArray> paramsArray;
+  stmt->NewBindingParamsArray(getter_AddRefs(paramsArray));
+  nsCOMPtr<mozIStorageBindingParams> params;
+  paramsArray->NewBindingParams(getter_AddRefs(params));
+  params->BindInt32ByName(NS_LITERAL_CSTRING("id"), 2);
+  paramsArray->AddParams(params);
+  params = nullptr;
+  stmt->BindParameters(paramsArray);
+  paramsArray = nullptr;
+  blocking_async_execute(stmt);
+  stmt->Finalize();
+  do_check_false(mutex_used_on_watched_thread);
+
+  // - now, make sure creating a sync statement does trigger our guard.
+  // (If this doesn't happen, our test is bunk and it's important to know that.)
+  nsCOMPtr<mozIStorageStatement> syncStmt;
+  db->CreateStatement(NS_LITERAL_CSTRING("SELECT * FROM test"),
+                      getter_AddRefs(syncStmt));
+  syncStmt->Finalize();
+  do_check_true(mutex_used_on_watched_thread);
+
+  blocking_async_close(db);
+}
+
+/**
+ * Test that cancellation before a statement is run successfully stops the
+ * statement from executing.
+ */
+void
+test_AsyncCancellation()
+{
+  nsCOMPtr<mozIStorageConnection> db(getMemoryDatabase());
+
+  // -- wedge the thread
+  nsCOMPtr<nsIThread> target(get_conn_async_thread(db));
+  do_check_true(target);
+  nsRefPtr<ThreadWedger> wedger (new ThreadWedger(target));
+
+  // -- create statements and cancel them
+  // - async
+  nsCOMPtr<mozIStorageAsyncStatement> asyncStmt;
+  db->CreateAsyncStatement(
+    NS_LITERAL_CSTRING("CREATE TABLE asyncTable (id INTEGER PRIMARY KEY)"),
+    getter_AddRefs(asyncStmt)
+  );
+
+  nsRefPtr<AsyncStatementSpinner> asyncSpin(new AsyncStatementSpinner());
+  nsCOMPtr<mozIStoragePendingStatement> asyncPend;
+  (void)asyncStmt->ExecuteAsync(asyncSpin, getter_AddRefs(asyncPend));
+  do_check_true(asyncPend);
+  asyncPend->Cancel();
+
+  // - sync
+  nsCOMPtr<mozIStorageStatement> syncStmt;
+  db->CreateStatement(
+    NS_LITERAL_CSTRING("CREATE TABLE syncTable (id INTEGER PRIMARY KEY)"),
+    getter_AddRefs(syncStmt)
+  );
+
+  nsRefPtr<AsyncStatementSpinner> syncSpin(new AsyncStatementSpinner());
+  nsCOMPtr<mozIStoragePendingStatement> syncPend;
+  (void)syncStmt->ExecuteAsync(syncSpin, getter_AddRefs(syncPend));
+  do_check_true(syncPend);
+  syncPend->Cancel();
+
+  // -- unwedge the async thread
+  wedger->unwedge();
+
+  // -- verify that both statements report they were canceled
+  asyncSpin->SpinUntilCompleted();
+  do_check_true(asyncSpin->completionReason ==
+                mozIStorageStatementCallback::REASON_CANCELED);
+
+  syncSpin->SpinUntilCompleted();
+  do_check_true(syncSpin->completionReason ==
+                mozIStorageStatementCallback::REASON_CANCELED);
+
+  // -- verify that neither statement constructed their tables
+  nsresult rv;
+  bool exists;
+  rv = db->TableExists(NS_LITERAL_CSTRING("asyncTable"), &exists);
+  do_check_true(rv == NS_OK);
+  do_check_false(exists);
+  rv = db->TableExists(NS_LITERAL_CSTRING("syncTable"), &exists);
+  do_check_true(rv == NS_OK);
+  do_check_false(exists);
+
+  // -- cleanup
+  asyncStmt->Finalize();
+  syncStmt->Finalize();
+  blocking_async_close(db);
+}
+
+/**
+ * Test that the destructor for an asynchronous statement which has a
+ *  sqlite3_stmt will dispatch that statement to the async thread for
+ *  finalization rather than trying to finalize it on the main thread
+ *  (and thereby running afoul of our mutex use detector).
+ */
+void test_AsyncDestructorFinalizesOnAsyncThread()
+{
+  // test_TrueAsyncStatement called hook_sqlite_mutex() for us
+
+  nsCOMPtr<mozIStorageConnection> db(getMemoryDatabase());
+  watch_for_mutex_use_on_this_thread();
+
+  // -- create an async statement
+  nsCOMPtr<mozIStorageAsyncStatement> stmt;
+  db->CreateAsyncStatement(
+    NS_LITERAL_CSTRING("CREATE TABLE test (id INTEGER PRIMARY KEY)"),
+    getter_AddRefs(stmt)
+  );
+
+  // -- execute it so it gets a sqlite3_stmt that needs to be finalized
+  blocking_async_execute(stmt);
+  do_check_false(mutex_used_on_watched_thread);
+
+  // -- forget our reference
+  stmt = nullptr;
+
+  // -- verify the mutex was not touched
+  do_check_false(mutex_used_on_watched_thread);
+
+  // -- make sure the statement actually gets finalized / cleanup
+  // the close will assert if we failed to finalize!
+  blocking_async_close(db);
+}
+
+void (*gTests[])(void) = {
+  // this test must be first because it hooks the mutex mechanics
+  test_TrueAsyncStatement,
+  test_AsyncCancellation,
+  test_AsyncDestructorFinalizesOnAsyncThread
+};
+
+const char *file = __FILE__;
+#define TEST_NAME "true async statement"
+#define TEST_FILE file
+#include "storage_test_harness_tail.h"