chromium/third_party/perfetto/include/perfetto/ext/tracing/core/producer.h

/*
 * 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_EXT_TRACING_CORE_PRODUCER_H_
#define INCLUDE_PERFETTO_EXT_TRACING_CORE_PRODUCER_H_

#include "perfetto/base/export.h"
#include "perfetto/ext/tracing/core/basic_types.h"
#include "perfetto/tracing/core/flush_flags.h"
#include "perfetto/tracing/core/forward_decls.h"

namespace perfetto {

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_COMPONENT Producer { … };

}  // namespace perfetto

#endif  // INCLUDE_PERFETTO_EXT_TRACING_CORE_PRODUCER_H_