1 // Copyright 2022 gRPC authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "src/core/util/event_log.h"
16
17 #include <grpc/support/port_platform.h>
18
19 #include <algorithm>
20 #include <atomic>
21
22 #include "absl/log/check.h"
23 #include "absl/strings/str_cat.h"
24 #include "absl/strings/str_join.h"
25
26 namespace grpc_core {
27
28 std::atomic<EventLog*> EventLog::g_instance_{nullptr};
29
~EventLog()30 EventLog::~EventLog() {
31 CHECK(g_instance_.load(std::memory_order_acquire) != this);
32 }
33
BeginCollection()34 void EventLog::BeginCollection() {
35 for (auto& fragment : fragments_) {
36 MutexLock lock(&fragment.mu);
37 fragment.entries.clear();
38 }
39 collection_begin_ = gpr_get_cycle_counter();
40 g_instance_.store(this, std::memory_order_release);
41 Append("logging", 1);
42 }
43
EndCollection(absl::Span<const absl::string_view> wanted_events)44 std::vector<EventLog::Entry> EventLog::EndCollection(
45 absl::Span<const absl::string_view> wanted_events) {
46 Append("logging", -1);
47 g_instance_.store(nullptr, std::memory_order_release);
48 std::vector<Entry> result;
49 for (auto& fragment : fragments_) {
50 MutexLock lock(&fragment.mu);
51 for (const auto& entry : fragment.entries) {
52 if (std::find(wanted_events.begin(), wanted_events.end(), entry.event) !=
53 wanted_events.end()) {
54 result.push_back(entry);
55 }
56 }
57 fragment.entries.clear();
58 }
59 std::stable_sort(
60 result.begin(), result.end(),
61 [](const Entry& a, const Entry& b) { return a.when < b.when; });
62 return result;
63 }
64
AppendInternal(absl::string_view event,int64_t delta)65 void EventLog::AppendInternal(absl::string_view event, int64_t delta) {
66 auto& fragment = fragments_.this_cpu();
67 MutexLock lock(&fragment.mu);
68 fragment.entries.push_back({gpr_get_cycle_counter(), event, delta});
69 }
70
EndCollectionAndReportCsv(absl::Span<const absl::string_view> columns)71 std::string EventLog::EndCollectionAndReportCsv(
72 absl::Span<const absl::string_view> columns) {
73 auto events = EndCollection(columns);
74 std::vector<int64_t> values(columns.size(), 0);
75 std::string result =
76 absl::StrCat("timestamp,", absl::StrJoin(columns, ","), "\n");
77 for (const auto& entry : events) {
78 auto idx = std::find(columns.begin(), columns.end(), entry.event) -
79 columns.begin();
80 values[idx] += entry.delta;
81 absl::StrAppend(&result, entry.when - collection_begin_, ",",
82 absl::StrJoin(values, ","), "\n");
83 }
84 return result;
85 }
86
87 } // namespace grpc_core
88