1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
/*
*
* 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
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (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: how long to wait after the first failure before retrying
int64_t initial_connect_timeout;
/// 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 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, int64_t initial_connect_timeout,
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 */
|
