diff options
author | 2016-12-02 22:33:37 -0800 | |
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committer | 2016-12-02 22:33:37 -0800 | |
commit | ad158893deb4a149f1b90018bc3ae91e04fbd788 (patch) | |
tree | 51a700110b5ae1f37aaec4103f3f2e2675fefe5a /src/core/lib/support | |
parent | 80c7e9200e7e5da5b69b32b71aae7088ee8f6c96 (diff) | |
parent | f4936517723ce63dcb1deca6c2c07dfab6fa1497 (diff) |
Merge pull request #8854 from dgquintas/backoff
Updated backoff to spec.
Diffstat (limited to 'src/core/lib/support')
-rw-r--r-- | src/core/lib/support/backoff.c | 37 | ||||
-rw-r--r-- | src/core/lib/support/backoff.h | 7 |
2 files changed, 29 insertions, 15 deletions
diff --git a/src/core/lib/support/backoff.c b/src/core/lib/support/backoff.c index e89ef47220..0612472712 100644 --- a/src/core/lib/support/backoff.c +++ b/src/core/lib/support/backoff.c @@ -35,8 +35,10 @@ #include <grpc/support/useful.h> -void gpr_backoff_init(gpr_backoff *backoff, double multiplier, double jitter, +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) { + backoff->initial_connect_timeout = initial_connect_timeout; backoff->multiplier = multiplier; backoff->jitter = jitter; backoff->min_timeout_millis = min_timeout_millis; @@ -45,9 +47,10 @@ void gpr_backoff_init(gpr_backoff *backoff, double multiplier, double jitter, } gpr_timespec gpr_backoff_begin(gpr_backoff *backoff, gpr_timespec now) { - backoff->current_timeout_millis = backoff->min_timeout_millis; - return gpr_time_add( - now, gpr_time_from_millis(backoff->current_timeout_millis, GPR_TIMESPAN)); + backoff->current_timeout_millis = backoff->initial_connect_timeout; + const int64_t first_timeout = + GPR_MAX(backoff->current_timeout_millis, backoff->min_timeout_millis); + return gpr_time_add(now, gpr_time_from_millis(first_timeout, GPR_TIMESPAN)); } /* Generate a random number between 0 and 1. */ @@ -57,20 +60,28 @@ static double generate_uniform_random_number(uint32_t *rng_state) { } gpr_timespec gpr_backoff_step(gpr_backoff *backoff, gpr_timespec now) { - double new_timeout_millis = + const double new_timeout_millis = backoff->multiplier * (double)backoff->current_timeout_millis; - double jitter_range = backoff->jitter * new_timeout_millis; - double jitter = + backoff->current_timeout_millis = + GPR_MIN((int64_t)new_timeout_millis, backoff->max_timeout_millis); + + const double jitter_range_width = backoff->jitter * new_timeout_millis; + const double jitter = (2 * generate_uniform_random_number(&backoff->rng_state) - 1) * - jitter_range; + jitter_range_width; + backoff->current_timeout_millis = - GPR_CLAMP((int64_t)(new_timeout_millis + jitter), - backoff->min_timeout_millis, backoff->max_timeout_millis); - return gpr_time_add( + (int64_t)((double)(backoff->current_timeout_millis) + jitter); + + const gpr_timespec current_deadline = gpr_time_add( now, gpr_time_from_millis(backoff->current_timeout_millis, GPR_TIMESPAN)); + + const gpr_timespec min_deadline = gpr_time_add( + now, gpr_time_from_millis(backoff->min_timeout_millis, GPR_TIMESPAN)); + + return gpr_time_max(current_deadline, min_deadline); } void gpr_backoff_reset(gpr_backoff *backoff) { - // forces step() to return a timeout of min_timeout_millis - backoff->current_timeout_millis = 0; + backoff->current_timeout_millis = backoff->initial_connect_timeout; } diff --git a/src/core/lib/support/backoff.h b/src/core/lib/support/backoff.h index 6d40c15546..5e9b740824 100644 --- a/src/core/lib/support/backoff.h +++ b/src/core/lib/support/backoff.h @@ -37,7 +37,9 @@ #include <grpc/support/time.h> typedef struct { - /// const: multiplier between retry attempts + /// 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; @@ -54,7 +56,8 @@ typedef struct { } gpr_backoff; /// Initialize backoff machinery - does not need to be destroyed -void gpr_backoff_init(gpr_backoff *backoff, double multiplier, double jitter, +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 |