| // Copyright 2022 gRPC authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #ifndef GRPC_SRC_CORE_LIB_DEBUG_EVENT_LOG_H |
| #define GRPC_SRC_CORE_LIB_DEBUG_EVENT_LOG_H |
| |
| #include <grpc/support/port_platform.h> |
| |
| #include <stdint.h> |
| |
| #include <atomic> |
| #include <string> |
| #include <vector> |
| |
| #include "absl/base/thread_annotations.h" |
| #include "absl/strings/string_view.h" |
| #include "absl/types/span.h" |
| |
| #include "src/core/lib/gpr/time_precise.h" |
| #include "src/core/lib/gprpp/per_cpu.h" |
| #include "src/core/lib/gprpp/sync.h" |
| |
| namespace grpc_core { |
| |
| // Debug utility to collect a burst of events and then later log them as a |
| // detailed sequence. |
| // Collects (timestamp, counter-name, delta) and gives back a csv with |
| // timestamps and accumulated values for each counter in separate columns. |
| class EventLog { |
| public: |
| EventLog() = default; |
| ~EventLog(); |
| |
| EventLog(const EventLog&) = delete; |
| EventLog& operator=(const EventLog&) = delete; |
| |
| void BeginCollection(); |
| std::string EndCollectionAndReportCsv( |
| absl::Span<const absl::string_view> columns); |
| |
| static void Append(absl::string_view event, int64_t delta) { |
| EventLog* log = g_instance_.load(std::memory_order_acquire); |
| if (log == nullptr) return; |
| log->AppendInternal(event, delta); |
| } |
| |
| private: |
| struct Entry { |
| gpr_cycle_counter when; |
| absl::string_view event; |
| int64_t delta; |
| }; |
| |
| struct Fragment { |
| Mutex mu; |
| std::vector<Entry> entries ABSL_GUARDED_BY(mu); |
| }; |
| |
| void AppendInternal(absl::string_view event, int64_t delta); |
| std::vector<Entry> EndCollection( |
| absl::Span<const absl::string_view> wanted_events); |
| |
| PerCpu<Fragment> fragments_{PerCpuOptions().SetCpusPerShard(2)}; |
| gpr_cycle_counter collection_begin_; |
| static std::atomic<EventLog*> g_instance_; |
| }; |
| |
| } // namespace grpc_core |
| |
| #endif // GRPC_SRC_CORE_LIB_DEBUG_EVENT_LOG_H |