| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef INCLUDE_PERFETTO_TRACING_CORE_PRODUCER_H_ |
| #define INCLUDE_PERFETTO_TRACING_CORE_PRODUCER_H_ |
| |
| #include "perfetto/base/export.h" |
| #include "perfetto/tracing/core/basic_types.h" |
| |
| namespace perfetto { |
| |
| class DataSourceConfig; |
| class SharedMemory; |
| |
| // A Producer is an entity that connects to the write-only port of the Service |
| // and exposes the ability to produce performance data on-demand. The lifecycle |
| // of a Producer is as follows: |
| // 1. The producer connects to the service and advertises its data sources |
| // (e.g., the ability to get kernel ftraces, to list process stats). |
| // 2. The service acknowledges the connection and sends over the SharedMemory |
| // region that will be used to exchange data (together with the signalling |
| // API TracingService::ProducerEndpoint::OnPageAcquired()/OnPageReleased()). |
| // 3. At some point later on, the Service asks the Producer to turn on some of |
| // the previously registered data sources, together with some configuration |
| // parameters. This happens via the StartDataSource() callback. |
| // 4. In response to that the Producer will spawn an instance of the given data |
| // source and inject its data into the shared memory buffer (obtained during |
| // OnConnect). |
| // This interface is subclassed by: |
| // 1. The actual producer code in the clients e.g., the ftrace reader process. |
| // 2. The transport layer when interposing RPC between service and producers. |
| class PERFETTO_EXPORT Producer { |
| public: |
| virtual ~Producer(); |
| |
| // Called by Service (or more typically by the transport layer, on behalf of |
| // the remote Service), once the Producer <> Service connection has been |
| // established. |
| virtual void OnConnect() = 0; |
| |
| // Called by the Service or by the transport layer if the connection with the |
| // service drops, either voluntarily (e.g., by destroying the ProducerEndpoint |
| // obtained through Service::ConnectProducer()) or involuntarily (e.g., if the |
| // Service process crashes). |
| // The Producer is expected to tear down all its data sources if this happens. |
| // Once this call returns it is possible to safely destroy the Producer |
| // instance. |
| virtual void OnDisconnect() = 0; |
| |
| // Called by the Service to turn on one of the data source previously |
| // registered through TracingService::ProducerEndpoint::RegisterDataSource(). |
| // Args: |
| // - DataSourceInstanceID is an identifier chosen by the Service that should |
| // be assigned to the newly created data source instance. It is used to |
| // match the StopDataSource() request below. |
| // - DataSourceConfig is the configuration for the new data source (e.g., |
| // tells which trace categories to enable). |
| virtual void StartDataSource(DataSourceInstanceID, |
| const DataSourceConfig&) = 0; |
| |
| // Called by the Service to shut down an existing data source instance. |
| virtual void StopDataSource(DataSourceInstanceID) = 0; |
| |
| // Called by the Service after OnConnect but before the first DataSource is |
| // created. Can be used for any setup required before tracing begins. |
| virtual void OnTracingSetup() = 0; |
| |
| // Called by the service to request the Producer to commit the data of the |
| // given data sources and return their chunks into the shared memory buffer. |
| // The Producer is expected to invoke NotifyFlushComplete(FlushRequestID) on |
| // the Service after the data has been committed. The producer has to either |
| // reply to the flush requests in order, or can just reply to the latest one |
| // Upon seeing a NotifyFlushComplete(N), the service will assume that all |
| // flushes < N have also been committed. |
| virtual void Flush(FlushRequestID, |
| const DataSourceInstanceID* data_source_ids, |
| size_t num_data_sources) = 0; |
| }; |
| |
| } // namespace perfetto |
| |
| #endif // INCLUDE_PERFETTO_TRACING_CORE_PRODUCER_H_ |