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 #include "third_party/abseil-cpp/absl/base/attributes.h"
13
14 namespace metrics {
15
16 namespace {
17
18 class SingleSampleMetricImpl : public base::SingleSampleMetric {
19 public:
SingleSampleMetricImpl(mojo::PendingRemote<mojom::SingleSampleMetric> metric)20 SingleSampleMetricImpl(mojo::PendingRemote<mojom::SingleSampleMetric> metric)
21 : metric_(std::move(metric)) {}
22
23 SingleSampleMetricImpl(const SingleSampleMetricImpl&) = delete;
24 SingleSampleMetricImpl& operator=(const SingleSampleMetricImpl&) = delete;
25
~SingleSampleMetricImpl()26 ~SingleSampleMetricImpl() override {
27 DCHECK(thread_checker_.CalledOnValidThread());
28 }
29
SetSample(base::HistogramBase::Sample sample)30 void SetSample(base::HistogramBase::Sample sample) override {
31 DCHECK(thread_checker_.CalledOnValidThread());
32 metric_->SetSample(sample);
33 }
34
35 private:
36 base::ThreadChecker thread_checker_;
37 mojo::Remote<mojom::SingleSampleMetric> metric_;
38 };
39
40 ABSL_CONST_INIT thread_local mojo::Remote<mojom::SingleSampleMetricsProvider>*
41 provider = nullptr;
42
43 } // namespace
44
SingleSampleMetricsFactoryImpl(CreateProviderCB create_provider_cb)45 SingleSampleMetricsFactoryImpl::SingleSampleMetricsFactoryImpl(
46 CreateProviderCB create_provider_cb)
47 : create_provider_cb_(std::move(create_provider_cb)) {}
48
~SingleSampleMetricsFactoryImpl()49 SingleSampleMetricsFactoryImpl::~SingleSampleMetricsFactoryImpl() {}
50
51 std::unique_ptr<base::SingleSampleMetric>
CreateCustomCountsMetric(const std::string & histogram_name,base::HistogramBase::Sample min,base::HistogramBase::Sample max,uint32_t bucket_count)52 SingleSampleMetricsFactoryImpl::CreateCustomCountsMetric(
53 const std::string& histogram_name,
54 base::HistogramBase::Sample min,
55 base::HistogramBase::Sample max,
56 uint32_t bucket_count) {
57 return CreateMetric(histogram_name, min, max, bucket_count,
58 base::HistogramBase::kUmaTargetedHistogramFlag);
59 }
60
DestroyProviderForTesting()61 void SingleSampleMetricsFactoryImpl::DestroyProviderForTesting() {
62 delete provider;
63 provider = nullptr;
64 }
65
66 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)67 SingleSampleMetricsFactoryImpl::CreateMetric(const std::string& histogram_name,
68 base::HistogramBase::Sample min,
69 base::HistogramBase::Sample max,
70 uint32_t bucket_count,
71 int32_t flags) {
72 mojo::PendingRemote<mojom::SingleSampleMetric> metric;
73 GetProvider()->AcquireSingleSampleMetric(
74 histogram_name, min, max, bucket_count, flags,
75 metric.InitWithNewPipeAndPassReceiver());
76 return std::make_unique<SingleSampleMetricImpl>(std::move(metric));
77 }
78
79 mojom::SingleSampleMetricsProvider*
GetProvider()80 SingleSampleMetricsFactoryImpl::GetProvider() {
81 // Check the current TLS slot to see if we have created a provider already for
82 // this thread.
83 if (!provider) {
84 // If not, create a new one which will persist until process shutdown and
85 // put it in the TLS slot for the current thread.
86 provider = new mojo::Remote<mojom::SingleSampleMetricsProvider>();
87
88 // Start the provider connection and return it; it won't be fully connected
89 // until later, but mojo will buffer all calls prior to completion.
90 create_provider_cb_.Run(provider->BindNewPipeAndPassReceiver());
91 }
92 return provider->get();
93 }
94
95 } // namespace metrics
96