Pepper: Stop using SRPC for irt_open_resource().

ppapi/nacl_irt/manifest_service.cc

Index: ppapi/nacl_irt/manifest_service.cc
diff --git a/ppapi/nacl_irt/manifest_service.cc b/ppapi/nacl_irt/manifest_service.cc
index d84b3f35f717f5f98a9b4016724733dad80edbfa..e7953e4fdfc24001206f384871c6a51f2babc63c 100644
--- a/ppapi/nacl_irt/manifest_service.cc
+++ b/ppapi/nacl_irt/manifest_service.cc
@@ -80,18 +80,41 @@ void ManifestService::StartupInitializationComplete() {
 }
 
 bool ManifestService::OpenResource(const char* file, int* fd) {
+  // We currently restrict to only allow one concurrent open_resource() call
+  // per plugin. This could be fixed by doing a token lookup with
+  // NaClProcessMsg_ResolveFileTokenAsyncReply instead of using a
+  // global inside components/nacl/loader/nacl_listener.cc
+  base::AutoLock lock(open_resource_lock_);
+
   // OpenResource will return INVALID SerializedHandle, if it is not supported.
   // Specifically, PNaCl doesn't support open resource.
   ppapi::proxy::SerializedHandle ipc_fd;
+
+  // File tokens are ignored here, but needed when the message is processed
+  // inside NaClIPCAdapter.
+  uint64_t file_token_lo;
+  uint64_t file_token_hi;
   if (!filter_->Send(new PpapiHostMsg_OpenResource(
-          std::string(kFilePrefix) + file, &ipc_fd)) ||
-      !ipc_fd.is_file()) {
+          std::string(kFilePrefix) + file,
+          &ipc_fd,
+          &file_token_lo,
+          &file_token_hi))) {
     LOG(ERROR) << "ManifestService::OpenResource failed:" << file;
     *fd = -1;
     return false;
   }
 
-  *fd = ipc_fd.descriptor().fd;
+  // TODO(teravest): Check that file_token_lo and file_token_hi are 0. That
+  // currently works on Linux, but not on Windows...

[Mark Seaborn, 2014/08/28 21:33:49]

Why doesn't it work on Windows?

[teravest, 2014/09/04 22:13:30]

I'm going to debug this. I wanted to get some feedback on this change and make
sure this was the right approach before I took the time to figure this out.

+
+  // Copy the file if we received a valid file descriptor. Otherwise, if we got
+  // a reply, the file doesn't exist, so provide an fd of -1.
+  // See ppapi/nacl_irt/manifest_service.cc for how this function's result is

[Mark Seaborn, 2014/08/28 21:33:49]

That is this file, in the function immediately below. :-)

[teravest, 2014/09/04 22:13:30]

Thanks, I've worded this a bit better now.

+  // interpreted.
+  if (ipc_fd.is_file())
+    *fd = ipc_fd.descriptor().fd;
+  else
+    *fd = -1;
   return true;
 }
 
@@ -105,7 +128,6 @@ int IrtOpenResource(const char* file, int* fd) {
       !manifest_service->OpenResource(file, fd)) {
     return NACL_ABI_EIO;
   }
-
   return (*fd == -1) ? NACL_ABI_ENOENT : 0;
 }