SFI NaCl: Batch-open resource files

components/nacl/loader/nacl_listener.cc

Index: components/nacl/loader/nacl_listener.cc
diff --git a/components/nacl/loader/nacl_listener.cc b/components/nacl/loader/nacl_listener.cc
index 1a2b894f4f0dbda149eda32f4ae23bbba6d3aea7..fc944ea1bef85dab34ccc1ddb9b965a803d6c88e 100644
--- a/components/nacl/loader/nacl_listener.cc
+++ b/components/nacl/loader/nacl_listener.cc
@@ -275,6 +275,38 @@ bool NaClListener::OnMessageReceived(const IPC::Message& msg) {
   return handled;
 }
 
+bool NaClListener::OnOpenResource(
+    const IPC::Message& msg,
+    const std::string& key,
+    NaClIPCAdapter::OpenResourceReplyCallback cb) {
+  // This callback is executed only on |io_thread_| with NaClIPCAdapter's
+  // |lock_| not being held.
+  DCHECK(!cb.is_null());
+  PrefetchedResourceFilesMap::iterator it;
+
+  // TODO(yusukes): Remove the prefix check.
+  const std::string files_prefix = "files/";
+  if (key.find(files_prefix) == 0)
+    it = prefetched_resource_files_.find(key.substr(files_prefix.length()));
+  else
+    it = prefetched_resource_files_.find(key);
+
+  if (it != prefetched_resource_files_.end()) {
+    // Fast path for prefetched FDs.
+    IPC::PlatformFileForTransit file = it->second.first;
+    base::FilePath path = it->second.second;
+    prefetched_resource_files_.erase(it);
+    // A pre-opened resource descriptor is available. Run the reply callback
+    // and return true.
+    cb.Run(msg, file, path);
+    return true;
+  }
+
+  // Return false to fall back to the slow path. Let the IPC adapter issue an
+  // IPC to the renderer.
+  return false;
+}
+
 void NaClListener::OnStart(const nacl::NaClStartParams& params) {
 #if defined(OS_LINUX) || defined(OS_MACOSX)
   int urandom_fd = dup(base::GetUrandomFD());
@@ -302,6 +334,18 @@ void NaClListener::OnStart(const nacl::NaClStartParams& params) {
   IPC::ChannelHandle ppapi_renderer_handle;
   IPC::ChannelHandle manifest_service_handle;
 
+  for (size_t i = 0; i < params.prefetched_resource_files.size(); ++i) {
+    bool result = prefetched_resource_files_.insert(std::make_pair(
+        params.prefetched_resource_files[i].file_key,
+        std::make_pair(
+            params.prefetched_resource_files[i].file,
+            params.prefetched_resource_files[i].file_path_metadata))).second;
+    if (!result) {
+      DLOG(ERROR) << "Duplicated open_resource key: "
+                  << params.prefetched_resource_files[i].file_key;
+    }
+  }
+
   if (params.enable_ipc_proxy) {
     browser_handle = IPC::Channel::GenerateVerifiedChannelID("nacl");
     ppapi_renderer_handle = IPC::Channel::GenerateVerifiedChannelID("nacl");
@@ -322,6 +366,8 @@ void NaClListener::OnStart(const nacl::NaClStartParams& params) {
                         NACL_CHROME_DESC_BASE + 2);
     manifest_ipc_adapter->set_resolve_file_token_callback(

[Mark Seaborn, 2015/04/16 19:00:31]

Yesterday we discussed doing a small cleanup refactoring so that this setter is
called after ConnectChannel(), to avoid a potential race if messages start
arriving on this channel.  Were you going to do that first?

[Yusuke Sato, 2015/04/16 20:22:02]

Done in https://codereview.chromium.org/1090043002/

         base::Bind(&NaClListener::ResolveFileToken, base::Unretained(this)));
+    manifest_ipc_adapter->set_open_resource_callback(
+        base::Bind(&NaClListener::OnOpenResource, base::Unretained(this)));
   }
 
   trusted_listener_ = new NaClTrustedListener(
@@ -438,8 +484,6 @@ void NaClListener::OnStart(const nacl::NaClStartParams& params) {
     // fails on any imc_sendmsg() call to make debugging easier.
     InjectDisabledMojo(nap);
   }
-  // TODO(yusukes): Support pre-opening resource files.
-  CHECK(params.prefetched_resource_files.empty());
 
   int exit_status;
   if (!NaClChromeMainStart(nap, args, &exit_status))