1/*
2 * Copyright (C) 2018 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef INCLUDE_PERFETTO_TRACING_CORE_SHARED_MEMORY_ARBITER_H_
18#define INCLUDE_PERFETTO_TRACING_CORE_SHARED_MEMORY_ARBITER_H_
19
20#include <stddef.h>
21
22#include <functional>
23#include <memory>
24#include <vector>
25
26#include "perfetto/base/export.h"
27#include "perfetto/tracing/core/basic_types.h"
28#include "perfetto/tracing/core/service.h"
29
30namespace perfetto {
31
32namespace base {
33class TaskRunner;
34}
35
36class CommitDataRequest;
37class SharedMemory;
38class TraceWriter;
39
40// Used by the Producer-side of the transport layer to vend TraceWriters
41// from the SharedMemory it receives from the Service-side.
42class PERFETTO_EXPORT SharedMemoryArbiter {
43 public:
44  virtual ~SharedMemoryArbiter();
45
46  // Creates a new TraceWriter and assigns it a new WriterID. The WriterID is
47  // written in each chunk header owned by a given TraceWriter and is used by
48  // the Service to reconstruct TracePackets written by the same TraceWriter.
49  // Returns null impl of TraceWriter if all WriterID slots are exhausted.
50  virtual std::unique_ptr<TraceWriter> CreateTraceWriter(
51      BufferID target_buffer) = 0;
52
53  // Notifies the service that all data for the given FlushRequestID has been
54  // committed in the shared memory buffer.
55  virtual void NotifyFlushComplete(FlushRequestID) = 0;
56
57  // Implemented in src/core/shared_memory_arbiter_impl.cc .
58  static std::unique_ptr<SharedMemoryArbiter> CreateInstance(
59      SharedMemory*,
60      size_t page_size,
61      Service::ProducerEndpoint*,
62      base::TaskRunner*);
63};
64
65}  // namespace perfetto
66
67#endif  // INCLUDE_PERFETTO_TRACING_CORE_SHARED_MEMORY_ARBITER_H_
68