Make InstawebHandler cleanup its driver by default.

pagespeed/apache/instaweb_handler.cc

@@ -99,6 +99,7 @@ InstawebHandler::InstawebHandler(request_rec* request)
       server_context_(InstawebContext::ServerContextFromServerRec(
           request->server)),
       rewrite_driver_(NULL),
+      driver_owned_(true),
       num_response_attributes_(0),
       fetch_(NULL) {
   apache_request_context_ = server_context_->NewApacheRequestContext(request);
@@ -125,6 +126,10 @@ InstawebHandler::~InstawebHandler() {
     WaitForFetch();
     delete fetch_;
   }
+  if (driver_owned_ && rewrite_driver_ != nullptr) {
+    rewrite_driver_->Cleanup();
+    rewrite_driver_ = nullptr;
+  }
 }
 
 void InstawebHandler::WaitForFetch() {
@@ -134,6 +139,11 @@ void InstawebHandler::WaitForFetch() {
   fetch_->Wait();
 }
 
+void InstawebHandler::DisownDriver() {
+  DCHECK(rewrite_driver_ != nullptr);
+  driver_owned_ = false;
+}
+
 // Makes a driver from the request_context and options.  Note that
 // this can only be called once, as it potentially mutates the options
 // as it transfers ownership of custom_options.
@@ -390,6 +400,7 @@ void InstawebHandler::RemoveStrippedResponseHeadersFromApacheRequest() {
 // Handle url as .pagespeed. rewritten resource.
 void InstawebHandler::HandleAsPagespeedResource() {
   RewriteDriver* driver = MakeDriver();
+  DisownDriver();
   GoogleString output;  // TODO(jmarantz): Quit buffering resource output.
   StringWriter writer(&output);
 
@@ -444,6 +455,7 @@ bool InstawebHandler::HandleAsInPlace() {
   MakeFetch(false /* not buffered */, "ipro");
   fetch_->set_handle_error(false);
 
+  DisownDriver();
   driver->FetchInPlaceResource(stripped_gurl_, false /* proxy_mode */, fetch_);
   WaitForFetch();
   if (fetch_->status_ok()) {
@@ -509,6 +521,7 @@ bool InstawebHandler::HandleAsProxy() {
     RewriteDriver* driver = MakeDriver();
     MakeFetch(mapped_url, true /* buffered */, "proxy");
     fetch_->set_is_proxy(true);
+    DisownDriver();
     server_context_->proxy_fetch_factory()->StartNewProxyFetch(
         mapped_url, fetch_, driver, NULL, NULL);
     WaitForFetch();

pagespeed/apache/instaweb_handler.h

@@ -82,9 +82,14 @@ class InstawebHandler {
 
   // Makes a driver from the request_context and options.  Note that
   // this can only be called once, as it potentially mutates the options
-  // as it transfers ownership of custom_options.
+  // as it transfers ownership of custom_options. The driver is owned by
+  // the InstawebHandler and will be cleaned up at destruction, unless you
+  // call DisownDriver().
   RewriteDriver* MakeDriver();
 
+  // Prevent "this" from cleaning up rewrite_driver_ at destruction.
+  void DisownDriver();
+
   // Allocates a Fetch object associated with the current request and
   // the specified URL.  Include in debug_info anything that's cheap to create
   // and would be informative if something went wrong with the fetch.
@@ -261,6 +266,7 @@ class InstawebHandler {
   // the same.  Only the ownership changes.
   const ApacheConfig* options_;
   RewriteDriver* rewrite_driver_;
+  bool driver_owned_;
   int num_response_attributes_;
   RewriteQuery rewrite_query_;
   ApacheFetch* fetch_;