Lock the stack and use the same working thread to set/get attributes

examples/common/pigweed/rpc_services/Attributes.h

@@ -28,19 +28,30 @@
 #include <lib/core/TLVTags.h>
 #include <lib/core/TLVTypes.h>
 #include <platform/PlatformManager.h>
+#include <future>
 
 namespace chip {
 namespace rpc {
 
+struct WriteArgs {
+    std::promise<EmberAfStatus> *promise;
+    const chip_rpc_AttributeWrite *request;
+    const void *data;
+};
+
+struct ReadArgs {
+    std::promise<CHIP_ERROR> *promise;
+    const app::ConcreteAttributePath *path;
+    app::AttributeReportIBs::Builder *attributeReports;
+};
+
 // Implementation class for chip.rpc.Attributes.
 class Attributes : public pw_rpc::nanopb::Attributes::Service<Attributes>
 {
 public:
     ::pw::Status Write(const chip_rpc_AttributeWrite & request, pw_protobuf_Empty & response)
     {
         const void * data;
-        DeviceLayer::StackLock lock;
-
         switch (request.data.which_data)
         {
         case chip_rpc_AttributeData_data_bool_tag:
@@ -70,9 +81,28 @@ class Attributes : public pw_rpc::nanopb::Attributes::Service<Attributes>
         default:
             return pw::Status::InvalidArgument();
         }
-        RETURN_STATUS_IF_NOT_OK(
-            emberAfWriteAttribute(request.metadata.endpoint, request.metadata.cluster, request.metadata.attribute_id,
-                                  const_cast<uint8_t *>(static_cast<const uint8_t *>(data)), request.metadata.type));
+
+        std::promise<EmberAfStatus> writeStatusPromise;
+        WriteArgs writeArgs = {
+            .promise = &writeStatusPromise,
+            .request = &request,
+            .data = data,
+        };
+        chip::DeviceLayer::PlatformMgr().ScheduleWork([](intptr_t ctx) {
+            DeviceLayer::StackLock lock;
+
+            WriteArgs *args = reinterpret_cast<WriteArgs*>(ctx);
+            args->promise->set_value(
+                 emberAfWriteAttribute(
+                     args->request->metadata.endpoint,
+                     args->request->metadata.cluster,
+                     args->request->metadata.attribute_id,
+                     const_cast<uint8_t *>(static_cast<const uint8_t *>(args->data)),
+                     args->request->metadata.type));
+        }, reinterpret_cast<intptr_t>(&writeArgs));
+
+        RETURN_STATUS_IF_NOT_OK(writeStatusPromise.get_future().get());
+
         return pw::OkStatus();
     }
 
@@ -190,7 +220,6 @@ class Attributes : public pw_rpc::nanopb::Attributes::Service<Attributes>
 
     ::pw::Status ReadAttributeIntoTlvBuffer(const app::ConcreteAttributePath & path, MutableByteSpan & tlvBuffer)
     {
-        Access::SubjectDescriptor subjectDescriptor{ .authMode = chip::Access::AuthMode::kPase };
         app::AttributeReportIBs::Builder attributeReports;
         TLV::TLVWriter writer;
         TLV::TLVType outer;
@@ -199,7 +228,21 @@ class Attributes : public pw_rpc::nanopb::Attributes::Service<Attributes>
         writer.Init(tlvBuffer);
         PW_TRY(ChipErrorToPwStatus(writer.StartContainer(TLV::AnonymousTag(), TLV::kTLVType_Structure, outer)));
         PW_TRY(ChipErrorToPwStatus(attributeReports.Init(&writer, kReportContextTag)));
-        PW_TRY(ChipErrorToPwStatus(app::ReadSingleClusterData(subjectDescriptor, false, path, attributeReports, nullptr)));
+
+        std::promise<CHIP_ERROR> readStatusPromise;
+        ReadArgs readArgs = {
+            .promise = &readStatusPromise,
+            .path = &path,
+            .attributeReports = &attributeReports,
+        };
+        chip::DeviceLayer::PlatformMgr().ScheduleWork([](intptr_t ctx) {
+            Access::SubjectDescriptor subjectDescriptor{ .authMode = chip::Access::AuthMode::kPase };
+            ReadArgs *args = reinterpret_cast<ReadArgs*>(ctx);
+            args->promise->set_value(app::ReadSingleClusterData(subjectDescriptor, false, *(args->path), *(args->attributeReports), nullptr));
+        }, reinterpret_cast<intptr_t>(&readArgs));
+
+        PW_TRY(ChipErrorToPwStatus(readStatusPromise.get_future().get()));
+
         attributeReports.EndOfContainer();
         PW_TRY(ChipErrorToPwStatus(writer.EndContainer(outer)));
         PW_TRY(ChipErrorToPwStatus(writer.Finalize()));