Reorganize ext tree
- filters live under filters
- lb_policy, resolver implementations (being part of client_channel) live under client_channel
diff --git a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c
new file mode 100644
index 0000000..6e04eda
--- /dev/null
+++ b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c
@@ -0,0 +1,474 @@
+/*
+ *
+ * Copyright 2015, 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.
+ *
+ */
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+
+#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
+#include "src/core/ext/filters/client_channel/subchannel.h"
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/iomgr/combiner.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
+#include "src/core/lib/transport/connectivity_state.h"
+
+typedef struct pending_pick {
+ struct pending_pick *next;
+ uint32_t initial_metadata_flags;
+ grpc_connected_subchannel **target;
+ grpc_closure *on_complete;
+} pending_pick;
+
+typedef struct {
+ /** base policy: must be first */
+ grpc_lb_policy base;
+ /** all our subchannels */
+ grpc_subchannel **subchannels;
+ size_t num_subchannels;
+
+ grpc_closure connectivity_changed;
+
+ /** remaining members are protected by the combiner */
+
+ /** the selected channel */
+ grpc_connected_subchannel *selected;
+
+ /** have we started picking? */
+ int started_picking;
+ /** are we shut down? */
+ int shutdown;
+ /** which subchannel are we watching? */
+ size_t checking_subchannel;
+ /** what is the connectivity of that channel? */
+ grpc_connectivity_state checking_connectivity;
+ /** list of picks that are waiting on connectivity */
+ pending_pick *pending_picks;
+
+ /** our connectivity state tracker */
+ grpc_connectivity_state_tracker state_tracker;
+} pick_first_lb_policy;
+
+static void pf_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ size_t i;
+ GPR_ASSERT(p->pending_picks == NULL);
+ for (i = 0; i < p->num_subchannels; i++) {
+ GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[i], "pick_first");
+ }
+ if (p->selected != NULL) {
+ GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, p->selected, "picked_first");
+ }
+ grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker);
+ gpr_free(p->subchannels);
+ gpr_free(p);
+}
+
+static void pf_shutdown_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ pending_pick *pp;
+ p->shutdown = 1;
+ pp = p->pending_picks;
+ p->pending_picks = NULL;
+ grpc_connectivity_state_set(
+ exec_ctx, &p->state_tracker, GRPC_CHANNEL_SHUTDOWN,
+ GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel shutdown"), "shutdown");
+ /* cancel subscription */
+ if (p->selected != NULL) {
+ grpc_connected_subchannel_notify_on_state_change(
+ exec_ctx, p->selected, NULL, NULL, &p->connectivity_changed);
+ } else if (p->num_subchannels > 0) {
+ grpc_subchannel_notify_on_state_change(
+ exec_ctx, p->subchannels[p->checking_subchannel], NULL, NULL,
+ &p->connectivity_changed);
+ }
+ while (pp != NULL) {
+ pending_pick *next = pp->next;
+ *pp->target = NULL;
+ grpc_closure_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE);
+ gpr_free(pp);
+ pp = next;
+ }
+}
+
+static void pf_cancel_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+ grpc_connected_subchannel **target,
+ grpc_error *error) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ pending_pick *pp;
+ pp = p->pending_picks;
+ p->pending_picks = NULL;
+ while (pp != NULL) {
+ pending_pick *next = pp->next;
+ if (pp->target == target) {
+ *target = NULL;
+ grpc_closure_sched(exec_ctx, pp->on_complete,
+ GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+ "Pick Cancelled", &error, 1));
+ gpr_free(pp);
+ } else {
+ pp->next = p->pending_picks;
+ p->pending_picks = pp;
+ }
+ pp = next;
+ }
+ GRPC_ERROR_UNREF(error);
+}
+
+static void pf_cancel_picks_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+ uint32_t initial_metadata_flags_mask,
+ uint32_t initial_metadata_flags_eq,
+ grpc_error *error) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ pending_pick *pp;
+ pp = p->pending_picks;
+ p->pending_picks = NULL;
+ while (pp != NULL) {
+ pending_pick *next = pp->next;
+ if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
+ initial_metadata_flags_eq) {
+ grpc_closure_sched(exec_ctx, pp->on_complete,
+ GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+ "Pick Cancelled", &error, 1));
+ gpr_free(pp);
+ } else {
+ pp->next = p->pending_picks;
+ p->pending_picks = pp;
+ }
+ pp = next;
+ }
+ GRPC_ERROR_UNREF(error);
+}
+
+static void start_picking(grpc_exec_ctx *exec_ctx, pick_first_lb_policy *p) {
+ p->started_picking = 1;
+ p->checking_subchannel = 0;
+ p->checking_connectivity = GRPC_CHANNEL_IDLE;
+ GRPC_LB_POLICY_WEAK_REF(&p->base, "pick_first_connectivity");
+ grpc_subchannel_notify_on_state_change(
+ exec_ctx, p->subchannels[p->checking_subchannel],
+ p->base.interested_parties, &p->checking_connectivity,
+ &p->connectivity_changed);
+}
+
+static void pf_exit_idle_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ if (!p->started_picking) {
+ start_picking(exec_ctx, p);
+ }
+}
+
+static int pf_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+ const grpc_lb_policy_pick_args *pick_args,
+ grpc_connected_subchannel **target, void **user_data,
+ grpc_closure *on_complete) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ pending_pick *pp;
+
+ /* Check atomically for a selected channel */
+ if (p->selected != NULL) {
+ *target = GRPC_CONNECTED_SUBCHANNEL_REF(p->selected, "picked");
+ return 1;
+ }
+
+ /* No subchannel selected yet, so try again */
+ if (!p->started_picking) {
+ start_picking(exec_ctx, p);
+ }
+ pp = gpr_malloc(sizeof(*pp));
+ pp->next = p->pending_picks;
+ pp->target = target;
+ pp->initial_metadata_flags = pick_args->initial_metadata_flags;
+ pp->on_complete = on_complete;
+ p->pending_picks = pp;
+ return 0;
+}
+
+static void destroy_subchannels_locked(grpc_exec_ctx *exec_ctx,
+ pick_first_lb_policy *p) {
+ size_t i;
+ size_t num_subchannels = p->num_subchannels;
+ grpc_subchannel **subchannels;
+
+ subchannels = p->subchannels;
+ p->num_subchannels = 0;
+ p->subchannels = NULL;
+ GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "destroy_subchannels");
+
+ for (i = 0; i < num_subchannels; i++) {
+ GRPC_SUBCHANNEL_UNREF(exec_ctx, subchannels[i], "pick_first");
+ }
+
+ gpr_free(subchannels);
+}
+
+static void pf_connectivity_changed_locked(grpc_exec_ctx *exec_ctx, void *arg,
+ grpc_error *error) {
+ pick_first_lb_policy *p = arg;
+ grpc_subchannel *selected_subchannel;
+ pending_pick *pp;
+
+ GRPC_ERROR_REF(error);
+
+ if (p->shutdown) {
+ GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
+ GRPC_ERROR_UNREF(error);
+ return;
+ } else if (p->selected != NULL) {
+ if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+ /* if the selected channel goes bad, we're done */
+ p->checking_connectivity = GRPC_CHANNEL_SHUTDOWN;
+ }
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ p->checking_connectivity, GRPC_ERROR_REF(error),
+ "selected_changed");
+ if (p->checking_connectivity != GRPC_CHANNEL_SHUTDOWN) {
+ grpc_connected_subchannel_notify_on_state_change(
+ exec_ctx, p->selected, p->base.interested_parties,
+ &p->checking_connectivity, &p->connectivity_changed);
+ } else {
+ GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
+ }
+ } else {
+ loop:
+ switch (p->checking_connectivity) {
+ case GRPC_CHANNEL_INIT:
+ GPR_UNREACHABLE_CODE(return );
+ case GRPC_CHANNEL_READY:
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ GRPC_CHANNEL_READY, GRPC_ERROR_NONE,
+ "connecting_ready");
+ selected_subchannel = p->subchannels[p->checking_subchannel];
+ p->selected = GRPC_CONNECTED_SUBCHANNEL_REF(
+ grpc_subchannel_get_connected_subchannel(selected_subchannel),
+ "picked_first");
+ /* drop the pick list: we are connected now */
+ GRPC_LB_POLICY_WEAK_REF(&p->base, "destroy_subchannels");
+ destroy_subchannels_locked(exec_ctx, p);
+ /* update any calls that were waiting for a pick */
+ while ((pp = p->pending_picks)) {
+ p->pending_picks = pp->next;
+ *pp->target = GRPC_CONNECTED_SUBCHANNEL_REF(p->selected, "picked");
+ grpc_closure_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE);
+ gpr_free(pp);
+ }
+ grpc_connected_subchannel_notify_on_state_change(
+ exec_ctx, p->selected, p->base.interested_parties,
+ &p->checking_connectivity, &p->connectivity_changed);
+ break;
+ case GRPC_CHANNEL_TRANSIENT_FAILURE:
+ p->checking_subchannel =
+ (p->checking_subchannel + 1) % p->num_subchannels;
+ if (p->checking_subchannel == 0) {
+ /* only trigger transient failure when we've tried all alternatives */
+ grpc_connectivity_state_set(
+ exec_ctx, &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE,
+ GRPC_ERROR_REF(error), "connecting_transient_failure");
+ }
+ GRPC_ERROR_UNREF(error);
+ p->checking_connectivity = grpc_subchannel_check_connectivity(
+ p->subchannels[p->checking_subchannel], &error);
+ if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+ grpc_subchannel_notify_on_state_change(
+ exec_ctx, p->subchannels[p->checking_subchannel],
+ p->base.interested_parties, &p->checking_connectivity,
+ &p->connectivity_changed);
+ } else {
+ goto loop;
+ }
+ break;
+ case GRPC_CHANNEL_CONNECTING:
+ case GRPC_CHANNEL_IDLE:
+ grpc_connectivity_state_set(
+ exec_ctx, &p->state_tracker, GRPC_CHANNEL_CONNECTING,
+ GRPC_ERROR_REF(error), "connecting_changed");
+ grpc_subchannel_notify_on_state_change(
+ exec_ctx, p->subchannels[p->checking_subchannel],
+ p->base.interested_parties, &p->checking_connectivity,
+ &p->connectivity_changed);
+ break;
+ case GRPC_CHANNEL_SHUTDOWN:
+ p->num_subchannels--;
+ GPR_SWAP(grpc_subchannel *, p->subchannels[p->checking_subchannel],
+ p->subchannels[p->num_subchannels]);
+ GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[p->num_subchannels],
+ "pick_first");
+ if (p->num_subchannels == 0) {
+ grpc_connectivity_state_set(
+ exec_ctx, &p->state_tracker, GRPC_CHANNEL_SHUTDOWN,
+ GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+ "Pick first exhausted channels", &error, 1),
+ "no_more_channels");
+ while ((pp = p->pending_picks)) {
+ p->pending_picks = pp->next;
+ *pp->target = NULL;
+ grpc_closure_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE);
+ gpr_free(pp);
+ }
+ GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base,
+ "pick_first_connectivity");
+ } else {
+ grpc_connectivity_state_set(
+ exec_ctx, &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE,
+ GRPC_ERROR_REF(error), "subchannel_failed");
+ p->checking_subchannel %= p->num_subchannels;
+ GRPC_ERROR_UNREF(error);
+ p->checking_connectivity = grpc_subchannel_check_connectivity(
+ p->subchannels[p->checking_subchannel], &error);
+ goto loop;
+ }
+ }
+ }
+
+ GRPC_ERROR_UNREF(error);
+}
+
+static grpc_connectivity_state pf_check_connectivity_locked(
+ grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_error **error) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ return grpc_connectivity_state_get(&p->state_tracker, error);
+}
+
+static void pf_notify_on_state_change_locked(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy *pol,
+ grpc_connectivity_state *current,
+ grpc_closure *notify) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ grpc_connectivity_state_notify_on_state_change(exec_ctx, &p->state_tracker,
+ current, notify);
+}
+
+static void pf_ping_one_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+ grpc_closure *closure) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ if (p->selected) {
+ grpc_connected_subchannel_ping(exec_ctx, p->selected, closure);
+ } else {
+ grpc_closure_sched(exec_ctx, closure,
+ GRPC_ERROR_CREATE_FROM_STATIC_STRING("Not connected"));
+ }
+}
+
+static const grpc_lb_policy_vtable pick_first_lb_policy_vtable = {
+ pf_destroy,
+ pf_shutdown_locked,
+ pf_pick_locked,
+ pf_cancel_pick_locked,
+ pf_cancel_picks_locked,
+ pf_ping_one_locked,
+ pf_exit_idle_locked,
+ pf_check_connectivity_locked,
+ pf_notify_on_state_change_locked};
+
+static void pick_first_factory_ref(grpc_lb_policy_factory *factory) {}
+
+static void pick_first_factory_unref(grpc_lb_policy_factory *factory) {}
+
+static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy_factory *factory,
+ grpc_lb_policy_args *args) {
+ GPR_ASSERT(args->client_channel_factory != NULL);
+
+ /* Find the number of backend addresses. We ignore balancer
+ * addresses, since we don't know how to handle them. */
+ const grpc_arg *arg =
+ grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
+ GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
+ grpc_lb_addresses *addresses = arg->value.pointer.p;
+ size_t num_addrs = 0;
+ for (size_t i = 0; i < addresses->num_addresses; i++) {
+ if (!addresses->addresses[i].is_balancer) ++num_addrs;
+ }
+ if (num_addrs == 0) return NULL;
+
+ pick_first_lb_policy *p = gpr_zalloc(sizeof(*p));
+
+ p->subchannels = gpr_zalloc(sizeof(grpc_subchannel *) * num_addrs);
+ grpc_subchannel_args sc_args;
+ size_t subchannel_idx = 0;
+ for (size_t i = 0; i < addresses->num_addresses; i++) {
+ /* Skip balancer addresses, since we only know how to handle backends. */
+ if (addresses->addresses[i].is_balancer) continue;
+
+ if (addresses->addresses[i].user_data != NULL) {
+ gpr_log(GPR_ERROR,
+ "This LB policy doesn't support user data. It will be ignored");
+ }
+
+ static const char *keys_to_remove[] = {GRPC_ARG_SUBCHANNEL_ADDRESS};
+ memset(&sc_args, 0, sizeof(grpc_subchannel_args));
+ grpc_arg addr_arg =
+ grpc_create_subchannel_address_arg(&addresses->addresses[i].address);
+ grpc_channel_args *new_args = grpc_channel_args_copy_and_add_and_remove(
+ args->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &addr_arg,
+ 1);
+ gpr_free(addr_arg.value.string);
+ sc_args.args = new_args;
+ grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
+ exec_ctx, args->client_channel_factory, &sc_args);
+ grpc_channel_args_destroy(exec_ctx, new_args);
+
+ if (subchannel != NULL) {
+ p->subchannels[subchannel_idx++] = subchannel;
+ }
+ }
+ if (subchannel_idx == 0) {
+ gpr_free(p->subchannels);
+ gpr_free(p);
+ return NULL;
+ }
+ p->num_subchannels = subchannel_idx;
+
+ grpc_lb_policy_init(&p->base, &pick_first_lb_policy_vtable, args->combiner);
+ grpc_closure_init(&p->connectivity_changed, pf_connectivity_changed_locked, p,
+ grpc_combiner_scheduler(args->combiner, false));
+ return &p->base;
+}
+
+static const grpc_lb_policy_factory_vtable pick_first_factory_vtable = {
+ pick_first_factory_ref, pick_first_factory_unref, create_pick_first,
+ "pick_first"};
+
+static grpc_lb_policy_factory pick_first_lb_policy_factory = {
+ &pick_first_factory_vtable};
+
+static grpc_lb_policy_factory *pick_first_lb_factory_create() {
+ return &pick_first_lb_policy_factory;
+}
+
+/* Plugin registration */
+
+void grpc_lb_policy_pick_first_init() {
+ grpc_register_lb_policy(pick_first_lb_factory_create());
+}
+
+void grpc_lb_policy_pick_first_shutdown() {}