1 // Copyright 2017 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "components/metrics/single_sample_metrics_factory_impl.h"
6
7 #include <memory>
8
9 #include "base/threading/thread_checker.h"
10 #include "mojo/public/cpp/bindings/pending_remote.h"
11 #include "mojo/public/cpp/bindings/remote.h"
12
13 namespace metrics {
14
15 namespace {
16
17 class SingleSampleMetricImpl : public base::SingleSampleMetric {
18 public:
SingleSampleMetricImpl(mojo::PendingRemote<mojom::SingleSampleMetric> metric)19 SingleSampleMetricImpl(mojo::PendingRemote<mojom::SingleSampleMetric> metric)
20 : metric_(std::move(metric)) {}
21
22 SingleSampleMetricImpl(const SingleSampleMetricImpl&) = delete;
23 SingleSampleMetricImpl& operator=(const SingleSampleMetricImpl&) = delete;
24
~SingleSampleMetricImpl()25 ~SingleSampleMetricImpl() override {
26 DCHECK(thread_checker_.CalledOnValidThread());
27 }
28
SetSample(base::HistogramBase::Sample sample)29 void SetSample(base::HistogramBase::Sample sample) override {
30 DCHECK(thread_checker_.CalledOnValidThread());
31 metric_->SetSample(sample);
32 }
33
34 private:
35 base::ThreadChecker thread_checker_;
36 mojo::Remote<mojom::SingleSampleMetric> metric_;
37 };
38
39 constinit thread_local mojo::Remote<mojom::SingleSampleMetricsProvider>*
40 provider = nullptr;
41
42 } // namespace
43
SingleSampleMetricsFactoryImpl(CreateProviderCB create_provider_cb)44 SingleSampleMetricsFactoryImpl::SingleSampleMetricsFactoryImpl(
45 CreateProviderCB create_provider_cb)
46 : create_provider_cb_(std::move(create_provider_cb)) {}
47
48 SingleSampleMetricsFactoryImpl::~SingleSampleMetricsFactoryImpl() = default;
49
50 std::unique_ptr<base::SingleSampleMetric>
CreateCustomCountsMetric(const std::string & histogram_name,base::HistogramBase::Sample min,base::HistogramBase::Sample max,uint32_t bucket_count)51 SingleSampleMetricsFactoryImpl::CreateCustomCountsMetric(
52 const std::string& histogram_name,
53 base::HistogramBase::Sample min,
54 base::HistogramBase::Sample max,
55 uint32_t bucket_count) {
56 return CreateMetric(histogram_name, min, max, bucket_count,
57 base::HistogramBase::kUmaTargetedHistogramFlag);
58 }
59
DestroyProviderForTesting()60 void SingleSampleMetricsFactoryImpl::DestroyProviderForTesting() {
61 delete provider;
62 provider = nullptr;
63 }
64
65 std::unique_ptr<base::SingleSampleMetric>
CreateMetric(const std::string & histogram_name,base::HistogramBase::Sample min,base::HistogramBase::Sample max,uint32_t bucket_count,int32_t flags)66 SingleSampleMetricsFactoryImpl::CreateMetric(const std::string& histogram_name,
67 base::HistogramBase::Sample min,
68 base::HistogramBase::Sample max,
69 uint32_t bucket_count,
70 int32_t flags) {
71 mojo::PendingRemote<mojom::SingleSampleMetric> metric;
72 GetProvider()->AcquireSingleSampleMetric(
73 histogram_name, min, max, bucket_count, flags,
74 metric.InitWithNewPipeAndPassReceiver());
75 return std::make_unique<SingleSampleMetricImpl>(std::move(metric));
76 }
77
78 mojom::SingleSampleMetricsProvider*
GetProvider()79 SingleSampleMetricsFactoryImpl::GetProvider() {
80 // Check the current TLS slot to see if we have created a provider already for
81 // this thread.
82 if (!provider) {
83 // If not, create a new one which will persist until process shutdown and
84 // put it in the TLS slot for the current thread.
85 provider = new mojo::Remote<mojom::SingleSampleMetricsProvider>();
86
87 // Start the provider connection and return it; it won't be fully connected
88 // until later, but mojo will buffer all calls prior to completion.
89 create_provider_cb_.Run(provider->BindNewPipeAndPassReceiver());
90 }
91 return provider->get();
92 }
93
94 } // namespace metrics
95