diff --git a/src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c b/src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c
index 90a302396c3de8e3192d943ff0812815aacaffc5..e1db898e7fd0979f5be295f093dd5842cf6128bf 100644
--- a/src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c
+++ b/src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c
@@ -44,6 +44,7 @@
#include "src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h"
#include "src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h"
#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/iomgr/combiner.h"
#include "src/core/lib/iomgr/resolve_address.h"
#include "src/core/lib/iomgr/timer.h"
#include "src/core/lib/support/backoff.h"
@@ -67,8 +68,14 @@ typedef struct {
/** the event driver to drive the lookups */
grpc_ares_ev_driver *ev_driver;
- /** mutex guarding the rest of the state */
- gpr_mu mu;
+ /** Closures used by the combiner */
+ grpc_closure dns_ares_shutdown_locked;
+ grpc_closure dns_ares_channel_saw_error_locked;
+ grpc_closure dns_ares_on_retry_timer_locked;
+ grpc_closure dns_ares_on_resolved_locked;
+
+ /** Combiner guarding the rest of the state */
+ grpc_combiner *lock;
/** are we currently resolving? */
bool resolving;
/** which version of the result have we published? */
@@ -109,10 +116,10 @@ static const grpc_resolver_vtable dns_ares_resolver_vtable = {
dns_ares_destroy, dns_ares_shutdown, dns_ares_channel_saw_error,
dns_ares_next};
-static void dns_ares_shutdown(grpc_exec_ctx *exec_ctx,
- grpc_resolver *resolver) {
- ares_dns_resolver *r = (ares_dns_resolver *)resolver;
- gpr_mu_lock(&r->mu);
+static void dns_ares_shutdown_locked(grpc_exec_ctx *exec_ctx, void *arg,
+ grpc_error *error) {
+ ares_dns_resolver *r = arg;
+ GPR_ASSERT(error == GRPC_ERROR_NONE);
if (r->have_retry_timer) {
grpc_timer_cancel(exec_ctx, &r->retry_timer);
}
@@ -122,39 +129,60 @@ static void dns_ares_shutdown(grpc_exec_ctx *exec_ctx,
GRPC_ERROR_CREATE("Resolver Shutdown"), NULL);
r->next_completion = NULL;
}
- gpr_mu_unlock(&r->mu);
+ GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "dns-ares-shutdown");
}
-static void dns_ares_channel_saw_error(grpc_exec_ctx *exec_ctx,
- grpc_resolver *resolver) {
+static void dns_ares_shutdown(grpc_exec_ctx *exec_ctx,
+ grpc_resolver *resolver) {
ares_dns_resolver *r = (ares_dns_resolver *)resolver;
- gpr_mu_lock(&r->mu);
+ GRPC_RESOLVER_REF(&r->base, "dns-ares-shutdown");
+ grpc_combiner_execute(exec_ctx, r->lock, &r->dns_ares_shutdown_locked,
+ GRPC_ERROR_NONE, false);
+}
+
+static void dns_ares_channel_saw_error_locked(grpc_exec_ctx *exec_ctx,
+ void *arg, grpc_error *error) {
+ GPR_ASSERT(error == GRPC_ERROR_NONE);
+ ares_dns_resolver *r = arg;
if (!r->resolving) {
gpr_backoff_reset(&r->backoff_state);
dns_ares_start_resolving_locked(exec_ctx, r);
}
- gpr_mu_unlock(&r->mu);
+ GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "ares-channel-saw-error");
}
-static void dns_ares_on_retry_timer(grpc_exec_ctx *exec_ctx, void *arg,
- grpc_error *error) {
+static void dns_ares_channel_saw_error(grpc_exec_ctx *exec_ctx,
+ grpc_resolver *resolver) {
+ ares_dns_resolver *r = (ares_dns_resolver *)resolver;
+ GRPC_RESOLVER_REF(&r->base, "ares-channel-saw-error");
+ grpc_combiner_execute(exec_ctx, r->lock,
+ &r->dns_ares_channel_saw_error_locked, GRPC_ERROR_NONE,
+ false);
+}
+
+static void dns_ares_on_retry_timer_locked(grpc_exec_ctx *exec_ctx, void *arg,
+ grpc_error *error) {
ares_dns_resolver *r = arg;
- gpr_mu_lock(&r->mu);
r->have_retry_timer = false;
if (error == GRPC_ERROR_NONE) {
if (!r->resolving) {
dns_ares_start_resolving_locked(exec_ctx, r);
}
}
- gpr_mu_unlock(&r->mu);
GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "retry-timer");
}
-static void dns_ares_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
- grpc_error *error) {
+static void dns_ares_on_retry_timer(grpc_exec_ctx *exec_ctx, void *arg,
+ grpc_error *error) {
+ ares_dns_resolver *r = arg;
+ grpc_combiner_execute(exec_ctx, r->lock, &r->dns_ares_on_retry_timer_locked,
+ GRPC_ERROR_REF(error), false);
+}
+
+static void dns_ares_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg,
+ grpc_error *error) {
ares_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) {
@@ -171,16 +199,16 @@ static void dns_ares_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
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_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);
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) {
+ 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 {
@@ -195,33 +223,54 @@ static void dns_ares_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
r->resolved_result = result;
r->resolved_version++;
dns_ares_maybe_finish_next_locked(exec_ctx, r);
- gpr_mu_unlock(&r->mu);
GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "dns-resolving");
}
-static void dns_ares_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
- grpc_channel_args **target_result,
- grpc_closure *on_complete) {
- ares_dns_resolver *r = (ares_dns_resolver *)resolver;
- gpr_mu_lock(&r->mu);
+static void dns_ares_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
+ grpc_error *error) {
+ ares_dns_resolver *r = arg;
+ grpc_combiner_execute(exec_ctx, r->lock, &r->dns_ares_on_resolved_locked,
+ GRPC_ERROR_REF(error), false);
+}
+
+typedef struct dns_ares_next_locked_args {
+ grpc_resolver *resolver;
+ grpc_channel_args **target_result;
+ grpc_closure *on_complete;
+} dns_ares_next_locked_args;
+
+static void dns_ares_next_locked(grpc_exec_ctx *exec_ctx, void *arg,
+ grpc_error *error) {
+ GPR_ASSERT(error == GRPC_ERROR_NONE);
+ dns_ares_next_locked_args *args = arg;
+ ares_dns_resolver *r = (ares_dns_resolver *)args->resolver;
gpr_log(GPR_DEBUG, "dns_ares_next is called.");
GPR_ASSERT(!r->next_completion);
- r->next_completion = on_complete;
- r->target_result = target_result;
+ r->next_completion = args->on_complete;
+ r->target_result = args->target_result;
+ gpr_free(arg);
if (r->resolved_version == 0 && !r->resolving) {
gpr_backoff_reset(&r->backoff_state);
dns_ares_start_resolving_locked(exec_ctx, r);
- // GRPC_RESOLVER_REF(&r->base, "dns-resolving");
- // GPR_ASSERT(!r->resolving);
- // r->resolving = true;
- // r->addresses = NULL;
- // grpc_resolve_address_ares(
- // exec_ctx, r->name_to_resolve, r->default_port, r->ev_driver,
- // grpc_closure_create(dns_ares_on_resolved, r), &r->addresses);
} else {
dns_ares_maybe_finish_next_locked(exec_ctx, r);
}
- gpr_mu_unlock(&r->mu);
+ GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "ares-next");
+}
+
+static void dns_ares_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
+ grpc_channel_args **target_result,
+ grpc_closure *on_complete) {
+ ares_dns_resolver *r = (ares_dns_resolver *)resolver;
+ dns_ares_next_locked_args *args =
+ gpr_malloc(sizeof(dns_ares_next_locked_args));
+ args->target_result = target_result;
+ args->on_complete = on_complete;
+ args->resolver = resolver;
+ GRPC_RESOLVER_REF(resolver, "ares-next");
+ grpc_combiner_execute(exec_ctx, r->lock,
+ grpc_closure_create(dns_ares_next_locked, args),
+ GRPC_ERROR_NONE, false);
}
static void dns_ares_start_resolving_locked(grpc_exec_ctx *exec_ctx,
@@ -252,7 +301,7 @@ static void dns_ares_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
gpr_log(GPR_DEBUG, "dns_ares_destroy");
ares_dns_resolver *r = (ares_dns_resolver *)gr;
grpc_ares_ev_driver_destroy(exec_ctx, r->ev_driver);
- gpr_mu_destroy(&r->mu);
+ grpc_combiner_destroy(exec_ctx, r->lock);
grpc_ares_cleanup();
if (r->resolved_result != NULL) {
grpc_channel_args_destroy(r->resolved_result);
@@ -296,7 +345,7 @@ static grpc_resolver *dns_ares_create(grpc_resolver_args *args,
gpr_free(r);
return NULL;
}
- gpr_mu_init(&r->mu);
+ r->lock = grpc_combiner_create(NULL);
r->name_to_resolve = proxy_name == NULL ? gpr_strdup(path) : proxy_name;
r->default_port = gpr_strdup(default_port);
grpc_arg server_name_arg;
@@ -307,6 +356,13 @@ static grpc_resolver *dns_ares_create(grpc_resolver_args *args,
grpc_channel_args_copy_and_add(args->args, &server_name_arg, 1);
gpr_backoff_init(&r->backoff_state, BACKOFF_MULTIPLIER, BACKOFF_JITTER,
BACKOFF_MIN_SECONDS * 1000, BACKOFF_MAX_SECONDS * 1000);
+ grpc_closure_init(&r->dns_ares_shutdown_locked, dns_ares_shutdown_locked, r);
+ grpc_closure_init(&r->dns_ares_channel_saw_error_locked,
+ dns_ares_channel_saw_error_locked, r);
+ grpc_closure_init(&r->dns_ares_on_retry_timer_locked,
+ dns_ares_on_retry_timer_locked, r);
+ grpc_closure_init(&r->dns_ares_on_resolved_locked,
+ dns_ares_on_resolved_locked, r);
return &r->base;
}