| /* |
| * |
| * Copyright 2016 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_CORE_LIB_BACKOFF_BACKOFF_H |
| #define GRPC_CORE_LIB_BACKOFF_BACKOFF_H |
| |
| #include "src/core/lib/iomgr/exec_ctx.h" |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| typedef struct { |
| /// const: how long to wait after the first failure before retrying |
| grpc_millis initial_backoff; |
| |
| /// const: factor with which to multiply backoff after a failed retry |
| double multiplier; |
| |
| /// const: amount to randomize backoffs |
| double jitter; |
| |
| /// const: minimum time between retries |
| grpc_millis min_connect_timeout; |
| |
| /// const: maximum time between retries |
| grpc_millis max_backoff; |
| |
| /// current delay before retries |
| grpc_millis current_backoff; |
| |
| /// random number generator |
| uint32_t rng_state; |
| } grpc_backoff; |
| |
| typedef struct { |
| /// Deadline to be used for the current attempt. |
| grpc_millis current_deadline; |
| |
| /// Deadline to be used for the next attempt, following the backoff strategy. |
| grpc_millis next_attempt_start_time; |
| } grpc_backoff_result; |
| |
| /// Initialize backoff machinery - does not need to be destroyed |
| void grpc_backoff_init(grpc_backoff* backoff, grpc_millis initial_backoff, |
| double multiplier, double jitter, |
| grpc_millis min_connect_timeout, |
| grpc_millis max_backoff); |
| |
| /// Begin retry loop: returns the deadlines to be used for the current attempt |
| /// and the subsequent retry, if any. |
| grpc_backoff_result grpc_backoff_begin(grpc_exec_ctx* exec_ctx, |
| grpc_backoff* backoff); |
| |
| /// Step a retry loop: returns the deadlines to be used for the current attempt |
| /// and the subsequent retry, if any. |
| grpc_backoff_result grpc_backoff_step(grpc_exec_ctx* exec_ctx, |
| grpc_backoff* backoff); |
| |
| /// Reset the backoff, so the next grpc_backoff_step will be a |
| /// grpc_backoff_begin. |
| void grpc_backoff_reset(grpc_backoff* backoff); |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* GRPC_CORE_LIB_BACKOFF_BACKOFF_H */ |