static void test_constant_backoff(void) {
gpr_backoff backoff;
gpr_backoff_init(&backoff, 1.0, 0.0, 1000, 1000);
gpr_timespec now = gpr_time_0(GPR_TIMESPAN);
gpr_timespec next = gpr_backoff_begin(&backoff, now);
GPR_ASSERT(gpr_time_to_millis(gpr_time_sub(next, now)) == 1000);
for (int i = 0; i < 10000; i++) {
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_to_millis(gpr_time_sub(next, now)) == 1000);
now = next;
}
}
static void dns_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
grpc_error *error) {
dns_resolver *r = arg;
grpc_channel_args *result = NULL;
gpr_mu_lock(&r->mu);
GPR_ASSERT(r->resolving);
r->resolving = false;
if (r->addresses != NULL) {
grpc_lb_addresses *addresses = grpc_lb_addresses_create(
r->addresses->naddrs, NULL /* user_data_vtable */);
for (size_t i = 0; i < r->addresses->naddrs; ++i) {
grpc_lb_addresses_set_address(
addresses, i, &r->addresses->addrs[i].addr,
r->addresses->addrs[i].len, false /* is_balancer */,
NULL /* balancer_name */, NULL /* user_data */);
}
grpc_arg new_arg = grpc_lb_addresses_create_channel_arg(addresses);
result = grpc_channel_args_copy_and_add(r->channel_args, &new_arg, 1);
grpc_resolved_addresses_destroy(r->addresses);
grpc_lb_addresses_destroy(addresses);
} else {
gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);
gpr_timespec timeout = gpr_time_sub(next_try, now);
const char *msg = grpc_error_string(error);
gpr_log(GPR_DEBUG, "dns resolution failed: %s", msg);
grpc_error_free_string(msg);
GPR_ASSERT(!r->have_retry_timer);
r->have_retry_timer = true;
GRPC_RESOLVER_REF(&r->base, "retry-timer");
if (gpr_time_cmp(timeout, gpr_time_0(timeout.clock_type)) > 0) {
gpr_log(GPR_DEBUG, "retrying in %" PRId64 ".%09d seconds", timeout.tv_sec,
timeout.tv_nsec);
} else {
gpr_log(GPR_DEBUG, "retrying immediately");
}
grpc_timer_init(exec_ctx, &r->retry_timer, next_try, dns_on_retry_timer, r,
now);
}
if (r->resolved_result != NULL) {
grpc_channel_args_destroy(r->resolved_result);
}
r->resolved_result = result;
r->resolved_version++;
dns_maybe_finish_next_locked(exec_ctx, r);
gpr_mu_unlock(&r->mu);
GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "dns-resolving");
}
static void test_no_jitter_backoff(void) {
gpr_backoff backoff;
gpr_backoff_init(&backoff, 2.0, 0.0, 1, 513);
gpr_timespec now = gpr_time_0(GPR_TIMESPAN);
gpr_timespec next = gpr_backoff_begin(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(1, GPR_TIMESPAN), next) == 0);
now = next;
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(3, GPR_TIMESPAN), next) == 0);
now = next;
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(7, GPR_TIMESPAN), next) == 0);
now = next;
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(15, GPR_TIMESPAN), next) == 0);
now = next;
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(31, GPR_TIMESPAN), next) == 0);
now = next;
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(63, GPR_TIMESPAN), next) == 0);
now = next;
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(127, GPR_TIMESPAN), next) == 0);
now = next;
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(255, GPR_TIMESPAN), next) == 0);
now = next;
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(511, GPR_TIMESPAN), next) == 0);
now = next;
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(1023, GPR_TIMESPAN), next) == 0);
now = next;
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(1536, GPR_TIMESPAN), next) == 0);
now = next;
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(2049, GPR_TIMESPAN), next) == 0);
now = next;
next = gpr_backoff_step(&backoff, now);
GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(2562, GPR_TIMESPAN), next) == 0);
}
