| /* |
| * |
| * Copyright 2016, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #ifndef GRPC_CORE_LIB_SUPPORT_BACKOFF_H |
| #define GRPC_CORE_LIB_SUPPORT_BACKOFF_H |
| |
| #include <grpc/support/time.h> |
| |
| typedef struct { |
| /// const: multiplier between retry attempts |
| double multiplier; |
| /// const: amount to randomize backoffs |
| double jitter; |
| /// const: minimum time between retries in milliseconds |
| int64_t min_timeout_millis; |
| /// const: maximum time between retries in milliseconds |
| int64_t max_timeout_millis; |
| |
| /// random number generator |
| uint32_t rng_state; |
| |
| /// current retry timeout in milliseconds |
| int64_t current_timeout_millis; |
| } gpr_backoff; |
| |
| /// Initialize backoff machinery - does not need to be destroyed |
| void gpr_backoff_init(gpr_backoff *backoff, double multiplier, double jitter, |
| int64_t min_timeout_millis, int64_t max_timeout_millis); |
| |
| /// Begin retry loop: returns a timespec for the NEXT retry |
| gpr_timespec gpr_backoff_begin(gpr_backoff *backoff, gpr_timespec now); |
| /// Step a retry loop: returns a timespec for the NEXT retry |
| gpr_timespec gpr_backoff_step(gpr_backoff *backoff, gpr_timespec now); |
| /// Reset the backoff, so the next gpr_backoff_step will be a gpr_backoff_begin |
| /// instead |
| void gpr_backoff_reset(gpr_backoff *backoff); |
| |
| #endif /* GRPC_CORE_LIB_SUPPORT_BACKOFF_H */ |