text: /*
   * Knobs.h
   *
   * This source file is part of the FoundationDB open source project
   *
   * Copyright 2013-2018 Apple Inc. and the FoundationDB project 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 FLOW_KNOBS_H
  #define FLOW_KNOBS_H
  #pragma once
  
  #include "flow/Platform.h"
  
  #include <map>
  #include <set>
  #include <string>
  #include <stdint.h>
  
  class Knobs {
  public:
  	bool setKnob( std::string const& name, std::string const& value ); // Returns true if the knob name is known, false if it is unknown
  	void trace();
  
  protected:
  	void initKnob( double& knob, double value, std::string const& name );
  	void initKnob( int64_t& knob, int64_t value, std::string const& name );
  	void initKnob( int& knob, int value, std::string const& name );
  	void initKnob( std::string& knob, const std::string& value, const std::string& name );
  	void initKnob( bool& knob, bool value, std::string const& name );
  
  	std::map<std::string, double*> double_knobs;
  	std::map<std::string, int64_t*> int64_knobs;
  	std::map<std::string, int*> int_knobs;
  	std::map<std::string, std::string*> string_knobs;
  	std::map<std::string, bool*> bool_knobs;
  	std::set<std::string> explicitlySetKnobs;
  };
  
  class FlowKnobs : public Knobs {
  public:
  	int AUTOMATIC_TRACE_DUMP;
  	double PREVENT_FAST_SPIN_DELAY;
  	double CACHE_REFRESH_INTERVAL_WHEN_ALL_ALTERNATIVES_FAILED;
  
  	double DELAY_JITTER_OFFSET;
  	double DELAY_JITTER_RANGE;
  	double BUSY_WAIT_THRESHOLD;
  	double CLIENT_REQUEST_INTERVAL;
  	double SERVER_REQUEST_INTERVAL;
  
  	int DISABLE_ASSERTS;
  	double QUEUE_MODEL_SMOOTHING_AMOUNT;
  
  	int RANDOMSEED_RETRY_LIMIT;
  	double FAST_ALLOC_LOGGING_BYTES;
  	double HUGE_ARENA_LOGGING_BYTES;
  	double HUGE_ARENA_LOGGING_INTERVAL;
  
  	bool WRITE_TRACING_ENABLED;
  
  	//run loop profiling
  	double RUN_LOOP_PROFILING_INTERVAL;
  	double SLOWTASK_PROFILING_LOG_INTERVAL;
  	double SLOWTASK_PROFILING_MAX_LOG_INTERVAL;
  	double SLOWTASK_PROFILING_LOG_BACKOFF;
  	double SATURATION_PROFILING_LOG_INTERVAL;
  	double SATURATION_PROFILING_MAX_LOG_INTERVAL;
  	double SATURATION_PROFILING_LOG_BACKOFF;
  
  	//connectionMonitor
  	double CONNECTION_MONITOR_LOOP_TIME;
  	double CONNECTION_MONITOR_TIMEOUT;
  	double CONNECTION_MONITOR_IDLE_TIMEOUT;
  	double CONNECTION_MONITOR_INCOMING_IDLE_MULTIPLIER;
  	double CONNECTION_MONITOR_UNREFERENCED_CLOSE_DELAY;
  
  	//FlowTransport
  	double CONNECTION_REJECTED_MESSAGE_DELAY;
  	double CONNECTION_ID_TIMEOUT;
  	double CONNECTION_CLEANUP_DELAY;
  	double INITIAL_RECONNECTION_TIME;
  	double MAX_RECONNECTION_TIME;
  	double RECONNECTION_TIME_GROWTH_RATE;
  	double RECONNECTION_RESET_TIME;
  	double ALWAYS_ACCEPT_DELAY;
  	int ACCEPT_BATCH_SIZE;
  	double INCOMPATIBLE_PEER_DELAY_BEFORE_LOGGING;
  	double PING_LOGGING_INTERVAL;
  	int PING_SAMPLE_AMOUNT;
  	int NETWORK_CONNECT_SAMPLE_AMOUNT;
  
  	int TLS_CERT_REFRESH_DELAY_SECONDS;
  	double TLS_SERVER_CONNECTION_THROTTLE_TIMEOUT;
  	double TLS_CLIENT_CONNECTION_THROTTLE_TIMEOUT;
  	int TLS_SERVER_CONNECTION_THROTTLE_ATTEMPTS;
  	int TLS_CLIENT_CONNECTION_THROTTLE_ATTEMPTS;
  	int TLS_CLIENT_HANDSHAKE_THREADS;
  	int TLS_SERVER_HANDSHAKE_THREADS;
  	int TLS_HANDSHAKE_THREAD_STACKSIZE;
  	int TLS_MALLOC_ARENA_MAX;
  	int TLS_HANDSHAKE_LIMIT;
  
  	int NETWORK_TEST_CLIENT_COUNT;
  	int NETWORK_TEST_REPLY_SIZE;
  	int NETWORK_TEST_REQUEST_COUNT;
  	int NETWORK_TEST_REQUEST_SIZE;
  	bool NETWORK_TEST_SCRIPT_MODE;
  
  	//AsyncFileCached
  	int64_t PAGE_CACHE_4K;
  	int64_t PAGE_CACHE_64K;
  	int64_t SIM_PAGE_CACHE_4K;
  	int64_t SIM_PAGE_CACHE_64K;
  	int64_t BUGGIFY_SIM_PAGE_CACHE_4K;
  	int64_t BUGGIFY_SIM_PAGE_CACHE_64K;
  	std::string CACHE_EVICTION_POLICY; // for now, "random", "lru", are supported
  	int MAX_EVICT_ATTEMPTS;
  	double PAGE_CACHE_TRUNCATE_LOOKUP_FRACTION;
  	double TOO_MANY_CONNECTIONS_CLOSED_RESET_DELAY;
  	int TOO_MANY_CONNECTIONS_CLOSED_TIMEOUT;
  	int PEER_UNAVAILABLE_FOR_LONG_TIME_TIMEOUT;
  
  	//AsyncFileEIO
  	int EIO_MAX_PARALLELISM;
  	int EIO_USE_ODIRECT;
  
  	//AsyncFileKAIO
  	int MAX_OUTSTANDING;
  	int MIN_SUBMIT;
  
  	int PAGE_WRITE_CHECKSUM_HISTORY;
  	int DISABLE_POSIX_KERNEL_AIO;
  
  	//AsyncFileNonDurable
  	double MAX_PRIOR_MODIFICATION_DELAY;
  
  	//GenericActors
  	double BUGGIFY_FLOW_LOCK_RELEASE_DELAY;
  	int LOW_PRIORITY_DELAY_COUNT;
  
  	//IAsyncFile
  	int64_t INCREMENTAL_DELETE_TRUNCATE_AMOUNT;
  	double INCREMENTAL_DELETE_INTERVAL;
  
  	//Net2
  	double MIN_COALESCE_DELAY;
  	double MAX_COALESCE_DELAY;
  	double SLOW_LOOP_CUTOFF;
  	double SLOW_LOOP_SAMPLING_RATE;
  	int64_t TSC_YIELD_TIME;
  	int64_t REACTOR_FLAGS;
  	double MIN_LOGGED_PRIORITY_BUSY_FRACTION;
  	int CERT_FILE_MAX_SIZE;
  
  	//Network
  	int64_t PACKET_LIMIT;
  	int64_t PACKET_WARNING;  // 2MB packet warning quietly allows for 1MB system messages
  	double TIME_OFFSET_LOGGING_INTERVAL;
  	int MAX_PACKET_SEND_BYTES;
  	int MIN_PACKET_BUFFER_BYTES;
  	int MIN_PACKET_BUFFER_FREE_BYTES;
  	int FLOW_TCP_NODELAY;
  	int FLOW_TCP_QUICKACK;
  
  	//Sim2
  	//FIMXE: more parameters could be factored out
  	double MIN_OPEN_TIME;
  	double MAX_OPEN_TIME;
  	int64_t SIM_DISK_IOPS;
  	int64_t SIM_DISK_BANDWIDTH;
  	double MIN_NETWORK_LATENCY;
  	double FAST_NETWORK_LATENCY;
  	double SLOW_NETWORK_LATENCY;
  	double MAX_CLOGGING_LATENCY;
  	double MAX_BUGGIFIED_DELAY;
  	int SIM_CONNECT_ERROR_MODE;
  
  	//Tracefiles
  	int ZERO_LENGTH_FILE_PAD;
  	double TRACE_FLUSH_INTERVAL;
  	double TRACE_RETRY_OPEN_INTERVAL;
  	int MIN_TRACE_SEVERITY;
  	int MAX_TRACE_SUPPRESSIONS;
  	bool TRACE_DATETIME_ENABLED;
  	int TRACE_SYNC_ENABLED;
  	int TRACE_EVENT_METRIC_UNITS_PER_SAMPLE;
  	int TRACE_EVENT_THROTTLER_SAMPLE_EXPIRY;
  	int TRACE_EVENT_THROTTLER_MSG_LIMIT;
  	int MAX_TRACE_FIELD_LENGTH;
  	int MAX_TRACE_EVENT_LENGTH;
  	bool ALLOCATION_TRACING_ENABLED;
  
  	//TDMetrics
  	int64_t MAX_METRIC_SIZE;
  	int64_t MAX_METRIC_LEVEL;
  	double METRIC_LEVEL_DIVISOR;
  	int METRIC_LIMIT_START_QUEUE_SIZE;
  	int METRIC_LIMIT_RESPONSE_FACTOR;
  	int MAX_METRICS;
  
  	//Load Balancing
  	int LOAD_BALANCE_ZONE_ID_LOCALITY_ENABLED;
  	int LOAD_BALANCE_DC_ID_LOCALITY_ENABLED;
  	double LOAD_BALANCE_MAX_BACKOFF;
  	double LOAD_BALANCE_START_BACKOFF;
  	double LOAD_BALANCE_BACKOFF_RATE;
  	int64_t MAX_LAGGING_REQUESTS_OUTSTANDING;
  	double INSTANT_SECOND_REQUEST_MULTIPLIER;
  	double BASE_SECOND_REQUEST_TIME;
  	double SECOND_REQUEST_MULTIPLIER_GROWTH;
  	double SECOND_REQUEST_MULTIPLIER_DECAY;
  	double SECOND_REQUEST_BUDGET_GROWTH;
  	double SECOND_REQUEST_MAX_BUDGET;
  	double ALTERNATIVES_FAILURE_RESET_TIME;
  	double ALTERNATIVES_FAILURE_MIN_DELAY;
  	double ALTERNATIVES_FAILURE_DELAY_RATIO;
  	double ALTERNATIVES_FAILURE_MAX_DELAY;
  	double ALTERNATIVES_FAILURE_SLOW_DELAY_RATIO;
  	double ALTERNATIVES_FAILURE_SLOW_MAX_DELAY;
  	double ALTERNATIVES_FAILURE_SKIP_DELAY;
  	double FUTURE_VERSION_INITIAL_BACKOFF;
  	double FUTURE_VERSION_MAX_BACKOFF;
  	double FUTURE_VERSION_BACKOFF_GROWTH;
  	int LOAD_BALANCE_MAX_BAD_OPTIONS;
  	bool LOAD_BALANCE_PENALTY_IS_BAD;
  	double BASIC_LOAD_BALANCE_UPDATE_RATE;
  	double BASIC_LOAD_BALANCE_MAX_CHANGE;
  	double BASIC_LOAD_BALANCE_MAX_PROB;
  	int BASIC_LOAD_BALANCE_BUCKETS;
  	int BASIC_LOAD_BALANCE_COMPUTE_PRECISION;
  	double BASIC_LOAD_BALANCE_MIN_REQUESTS;
  	double BASIC_LOAD_BALANCE_MIN_CPU;
  
  	// Health Monitor
  	int FAILURE_DETECTION_DELAY;
  	bool HEALTH_MONITOR_MARK_FAILED_UNSTABLE_CONNECTIONS;
  	int HEALTH_MONITOR_CLIENT_REQUEST_INTERVAL_SECS;
  	int HEALTH_MONITOR_CONNECTION_MAX_CLOSED;
  
  	FlowKnobs();
  	void initialize(bool randomize = false, bool isSimulated = false);
  };
  
  extern FlowKnobs const* FLOW_KNOBS;
  
  #endif
  