1 /*
2 * Copyright (C) 2019 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 #include "src/traced/service/lazy_producer.h"
18
19 #include "perfetto/base/build_config.h"
20
21 #include "perfetto/tracing/core/data_source_config.h"
22 #include "perfetto/tracing/core/data_source_descriptor.h"
23
24 #if PERFETTO_BUILDFLAG(PERFETTO_OS_ANDROID)
25 #include <sys/system_properties.h>
26 #endif
27
28 namespace perfetto {
29
LazyProducer(base::TaskRunner * task_runner,uint32_t delay_ms,std::string data_source_name,std::string property_name)30 LazyProducer::LazyProducer(base::TaskRunner* task_runner,
31 uint32_t delay_ms,
32 std::string data_source_name,
33 std::string property_name)
34 : task_runner_(task_runner),
35 delay_ms_(delay_ms),
36 data_source_name_(data_source_name),
37 property_name_(property_name),
38 weak_factory_(this) {}
39
ConnectInProcess(TracingService * svc)40 void LazyProducer::ConnectInProcess(TracingService* svc) {
41 endpoint_ = svc->ConnectProducer(this, geteuid(), "lazy_producer",
42 /*shm_hint_kb*/ 16, /*in_process*/ true);
43 }
44
OnConnect()45 void LazyProducer::OnConnect() {
46 DataSourceDescriptor dsd;
47 dsd.set_name(data_source_name_);
48 endpoint_->RegisterDataSource(dsd);
49 }
50
SetupDataSource(DataSourceInstanceID,const DataSourceConfig &)51 void LazyProducer::SetupDataSource(DataSourceInstanceID,
52 const DataSourceConfig&) {
53 SetAndroidProperty(property_name_, "1");
54 active_sessions_++;
55 generation_++;
56 }
57
StopDataSource(DataSourceInstanceID)58 void LazyProducer::StopDataSource(DataSourceInstanceID) {
59 if (--active_sessions_)
60 return;
61
62 uint64_t cur_generation = generation_;
63 auto weak_this = weak_factory_.GetWeakPtr();
64 task_runner_->PostDelayedTask(
65 [weak_this, cur_generation] {
66 if (!weak_this)
67 return;
68 if (weak_this->generation_ == cur_generation)
69 weak_this->SetAndroidProperty(weak_this->property_name_, "0");
70 },
71 delay_ms_);
72 }
73
SetAndroidProperty(const std::string & name,const std::string & value)74 bool LazyProducer::SetAndroidProperty(const std::string& name,
75 const std::string& value) {
76 #if PERFETTO_BUILDFLAG(PERFETTO_OS_ANDROID)
77 return __system_property_set(name.c_str(), value.c_str()) == 0;
78 #else
79 // Allow this to be mocked out for tests on other platforms.
80 base::ignore_result(name);
81 base::ignore_result(value);
82 return true;
83 #endif
84 }
85
~LazyProducer()86 LazyProducer::~LazyProducer() {
87 if (active_sessions_)
88 SetAndroidProperty(property_name_, "0");
89 }
90
91 } // namespace perfetto
92