CdmAdapter: Allow parallel SendPlatformChallenge() calls.

media/cdm/ppapi/cdm_adapter.cc

Index: media/cdm/ppapi/cdm_adapter.cc
diff --git a/media/cdm/ppapi/cdm_adapter.cc b/media/cdm/ppapi/cdm_adapter.cc
index 8388f449880cf28d0d41486e821d63101546cee4..0843602e279a3e4ae8fa75ee11313efbbb5b928c 100644
--- a/media/cdm/ppapi/cdm_adapter.cc
+++ b/media/cdm/ppapi/cdm_adapter.cc
@@ -255,7 +255,6 @@ CdmAdapter::CdmAdapter(PP_Instance instance, pp::Module* module)
 #if defined(OS_CHROMEOS)
       output_protection_(this),
       platform_verification_(this),
-      challenge_in_progress_(false),
       output_link_mask_(0),
       output_protection_mask_(0),
       query_output_protection_in_progress_(false),
@@ -1005,34 +1004,33 @@ void CdmAdapter::SendPlatformChallenge(
     const char* service_id, uint32_t service_id_length,
     const char* challenge, uint32_t challenge_length) {
 #if defined(OS_CHROMEOS)
-  PP_DCHECK(!challenge_in_progress_);
-
-  // Ensure member variables set by the callback are in a clean state.
-  signed_data_output_ = pp::Var();
-  signed_data_signature_output_ = pp::Var();
-  platform_key_certificate_output_ = pp::Var();
-
   pp::VarArrayBuffer challenge_var(challenge_length);
   uint8_t* var_data = static_cast<uint8_t*>(challenge_var.Map());
   memcpy(var_data, challenge, challenge_length);
 
   std::string service_id_str(service_id, service_id_length);
+
+  linked_ptr<PepperPlatformChallengeResponse> response(
+      new PepperPlatformChallengeResponse());
+
   int32_t result = platform_verification_.ChallengePlatform(
-      pp::Var(service_id_str), challenge_var, &signed_data_output_,
-      &signed_data_signature_output_, &platform_key_certificate_output_,
-      callback_factory_.NewCallback(&CdmAdapter::SendPlatformChallengeDone));
+      pp::Var(service_id_str),
+      challenge_var,
+      &response->signed_data,
+      &response->signed_data_signature,
+      &response->platform_key_certificate,
+      callback_factory_.NewCallback(&CdmAdapter::SendPlatformChallengeDone,
+                                    response));
   challenge_var.Unmap();
-  if (result == PP_OK_COMPLETIONPENDING) {
-    challenge_in_progress_ = true;
+  if (result == PP_OK_COMPLETIONPENDING)
     return;
-  }
 
   // Fall through on error and issue an empty OnPlatformChallengeResponse().
   PP_DCHECK(result != PP_OK);
 #endif
 
-  cdm::PlatformChallengeResponse response = {};
-  cdm_->OnPlatformChallengeResponse(response);
+  cdm::PlatformChallengeResponse platform_challenge_response = {};

[xhwang, 2014/07/16 00:13:18]

rename because we have a different "response" on l.1013.

+  cdm_->OnPlatformChallengeResponse(platform_challenge_response);
 }
 
 void CdmAdapter::EnableOutputProtection(uint32_t desired_protection_mask) {
@@ -1150,29 +1148,29 @@ void CdmAdapter::ReportOutputProtectionQueryResult() {
   // queries and success results.
 }
 
-void CdmAdapter::SendPlatformChallengeDone(int32_t result) {
-  challenge_in_progress_ = false;
-
+void CdmAdapter::SendPlatformChallengeDone(
+    int32_t result,
+    const linked_ptr<PepperPlatformChallengeResponse>& response) {
   if (result != PP_OK) {
     CDM_DLOG() << __FUNCTION__ << ": Platform challenge failed!";
-    cdm::PlatformChallengeResponse response = {};
-    cdm_->OnPlatformChallengeResponse(response);
+    cdm::PlatformChallengeResponse platform_challenge_response = {};
+    cdm_->OnPlatformChallengeResponse(platform_challenge_response);
     return;
   }
 
-  pp::VarArrayBuffer signed_data_var(signed_data_output_);
-  pp::VarArrayBuffer signed_data_signature_var(signed_data_signature_output_);
+  pp::VarArrayBuffer signed_data_var(response->signed_data);
+  pp::VarArrayBuffer signed_data_signature_var(response->signed_data_signature);
   std::string platform_key_certificate_string =
-      platform_key_certificate_output_.AsString();
+      response->platform_key_certificate.AsString();
 
-  cdm::PlatformChallengeResponse response = {
+  cdm::PlatformChallengeResponse platform_challenge_response = {
       static_cast<uint8_t*>(signed_data_var.Map()),
       signed_data_var.ByteLength(),
       static_cast<uint8_t*>(signed_data_signature_var.Map()),
       signed_data_signature_var.ByteLength(),
       reinterpret_cast<const uint8_t*>(platform_key_certificate_string.data()),
       static_cast<uint32_t>(platform_key_certificate_string.length())};
-  cdm_->OnPlatformChallengeResponse(response);
+  cdm_->OnPlatformChallengeResponse(platform_challenge_response);

[dmichael (off chromium), 2014/07/16 15:21:32]

One thing I just noticed...  OnPlatformChallengeResponse here has to make use of
those buffers immediately, because they will be deleted when this function
(SendPlatformChallengeDone) goes out of scope. That seems correct & appropriate
from an API standpoint, but I wanted to point it out, because it looks like a
behavior change from prior to this CL, so I want to make sure it works with your
CDM code.

[xhwang, 2014/07/16 16:14:31]

Thanks for pointing this out. In all CDM interface calls, the pointer is only
guaranteed to be valid in the scope of that call. CDM has to use it immediately
or copy it for future use. So this should be fine.

 
   signed_data_var.Unmap();
   signed_data_signature_var.Unmap();