diff options
Diffstat (limited to 'src/core/ext/client_config/client_channel.c')
| -rw-r--r-- | src/core/ext/client_config/client_channel.c | 548 |
1 files changed, 548 insertions, 0 deletions
diff --git a/src/core/ext/client_config/client_channel.c b/src/core/ext/client_config/client_channel.c new file mode 100644 index 0000000000..93d54fdcfe --- /dev/null +++ b/src/core/ext/client_config/client_channel.c @@ -0,0 +1,548 @@ +/* + * + * 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 "src/core/ext/client_config/client_channel.h" + +#include <stdio.h> +#include <string.h> + +#include <grpc/support/alloc.h> +#include <grpc/support/log.h> +#include <grpc/support/sync.h> +#include <grpc/support/useful.h> + +#include "src/core/ext/client_config/subchannel_call_holder.h" +#include "src/core/lib/channel/channel_args.h" +#include "src/core/lib/channel/connected_channel.h" +#include "src/core/lib/iomgr/iomgr.h" +#include "src/core/lib/profiling/timers.h" +#include "src/core/lib/support/string.h" +#include "src/core/lib/surface/channel.h" +#include "src/core/lib/transport/connectivity_state.h" + +/* Client channel implementation */ + +typedef grpc_subchannel_call_holder call_data; + +typedef struct client_channel_channel_data { + /** resolver for this channel */ + grpc_resolver *resolver; + /** have we started resolving this channel */ + int started_resolving; + + /** mutex protecting client configuration, including all + variables below in this data structure */ + gpr_mu mu_config; + /** currently active load balancer - guarded by mu_config */ + grpc_lb_policy *lb_policy; + /** incoming configuration - set by resolver.next + guarded by mu_config */ + grpc_client_config *incoming_configuration; + /** a list of closures that are all waiting for config to come in */ + grpc_closure_list waiting_for_config_closures; + /** resolver callback */ + grpc_closure on_config_changed; + /** connectivity state being tracked */ + grpc_connectivity_state_tracker state_tracker; + /** when an lb_policy arrives, should we try to exit idle */ + int exit_idle_when_lb_policy_arrives; + /** owning stack */ + grpc_channel_stack *owning_stack; + /** interested parties (owned) */ + grpc_pollset_set *interested_parties; +} channel_data; + +/** We create one watcher for each new lb_policy that is returned from a + resolver, + to watch for state changes from the lb_policy. When a state change is seen, + we + update the channel, and create a new watcher */ +typedef struct { + channel_data *chand; + grpc_closure on_changed; + grpc_connectivity_state state; + grpc_lb_policy *lb_policy; +} lb_policy_connectivity_watcher; + +typedef struct { + grpc_closure closure; + grpc_call_element *elem; +} waiting_call; + +static char *cc_get_peer(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) { + return grpc_subchannel_call_holder_get_peer(exec_ctx, elem->call_data); +} + +static void cc_start_transport_stream_op(grpc_exec_ctx *exec_ctx, + grpc_call_element *elem, + grpc_transport_stream_op *op) { + GRPC_CALL_LOG_OP(GPR_INFO, elem, op); + grpc_subchannel_call_holder_perform_op(exec_ctx, elem->call_data, op); +} + +static void watch_lb_policy(grpc_exec_ctx *exec_ctx, channel_data *chand, + grpc_lb_policy *lb_policy, + grpc_connectivity_state current_state); + +static void set_channel_connectivity_state_locked(grpc_exec_ctx *exec_ctx, + channel_data *chand, + grpc_connectivity_state state, + const char *reason) { + if ((state == GRPC_CHANNEL_TRANSIENT_FAILURE || + state == GRPC_CHANNEL_FATAL_FAILURE) && + chand->lb_policy != NULL) { + /* cancel fail-fast picks */ + grpc_lb_policy_cancel_picks( + exec_ctx, chand->lb_policy, + /* mask= */ GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY, + /* check= */ 0); + } + grpc_connectivity_state_set(exec_ctx, &chand->state_tracker, state, reason); +} + +static void on_lb_policy_state_changed_locked( + grpc_exec_ctx *exec_ctx, lb_policy_connectivity_watcher *w) { + grpc_connectivity_state publish_state = w->state; + /* check if the notification is for a stale policy */ + if (w->lb_policy != w->chand->lb_policy) return; + + if (publish_state == GRPC_CHANNEL_FATAL_FAILURE && + w->chand->resolver != NULL) { + publish_state = GRPC_CHANNEL_TRANSIENT_FAILURE; + grpc_resolver_channel_saw_error(exec_ctx, w->chand->resolver); + GRPC_LB_POLICY_UNREF(exec_ctx, w->chand->lb_policy, "channel"); + w->chand->lb_policy = NULL; + } + set_channel_connectivity_state_locked(exec_ctx, w->chand, publish_state, + "lb_changed"); + if (w->state != GRPC_CHANNEL_FATAL_FAILURE) { + watch_lb_policy(exec_ctx, w->chand, w->lb_policy, w->state); + } +} + +static void on_lb_policy_state_changed(grpc_exec_ctx *exec_ctx, void *arg, + bool iomgr_success) { + lb_policy_connectivity_watcher *w = arg; + + gpr_mu_lock(&w->chand->mu_config); + on_lb_policy_state_changed_locked(exec_ctx, w); + gpr_mu_unlock(&w->chand->mu_config); + + GRPC_CHANNEL_STACK_UNREF(exec_ctx, w->chand->owning_stack, "watch_lb_policy"); + gpr_free(w); +} + +static void watch_lb_policy(grpc_exec_ctx *exec_ctx, channel_data *chand, + grpc_lb_policy *lb_policy, + grpc_connectivity_state current_state) { + lb_policy_connectivity_watcher *w = gpr_malloc(sizeof(*w)); + GRPC_CHANNEL_STACK_REF(chand->owning_stack, "watch_lb_policy"); + + w->chand = chand; + grpc_closure_init(&w->on_changed, on_lb_policy_state_changed, w); + w->state = current_state; + w->lb_policy = lb_policy; + grpc_lb_policy_notify_on_state_change(exec_ctx, lb_policy, &w->state, + &w->on_changed); +} + +static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg, + bool iomgr_success) { + channel_data *chand = arg; + grpc_lb_policy *lb_policy = NULL; + grpc_lb_policy *old_lb_policy; + grpc_connectivity_state state = GRPC_CHANNEL_TRANSIENT_FAILURE; + int exit_idle = 0; + + if (chand->incoming_configuration != NULL) { + lb_policy = grpc_client_config_get_lb_policy(chand->incoming_configuration); + if (lb_policy != NULL) { + GRPC_LB_POLICY_REF(lb_policy, "channel"); + GRPC_LB_POLICY_REF(lb_policy, "config_change"); + state = grpc_lb_policy_check_connectivity(exec_ctx, lb_policy); + } + + grpc_client_config_unref(exec_ctx, chand->incoming_configuration); + } + + chand->incoming_configuration = NULL; + + if (lb_policy != NULL) { + grpc_pollset_set_add_pollset_set(exec_ctx, lb_policy->interested_parties, + chand->interested_parties); + } + + gpr_mu_lock(&chand->mu_config); + old_lb_policy = chand->lb_policy; + chand->lb_policy = lb_policy; + if (lb_policy != NULL || chand->resolver == NULL /* disconnected */) { + grpc_exec_ctx_enqueue_list(exec_ctx, &chand->waiting_for_config_closures, + NULL); + } + if (lb_policy != NULL && chand->exit_idle_when_lb_policy_arrives) { + GRPC_LB_POLICY_REF(lb_policy, "exit_idle"); + exit_idle = 1; + chand->exit_idle_when_lb_policy_arrives = 0; + } + + if (iomgr_success && chand->resolver) { + set_channel_connectivity_state_locked(exec_ctx, chand, state, + "new_lb+resolver"); + if (lb_policy != NULL) { + watch_lb_policy(exec_ctx, chand, lb_policy, state); + } + GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver"); + grpc_resolver_next(exec_ctx, chand->resolver, + &chand->incoming_configuration, + &chand->on_config_changed); + gpr_mu_unlock(&chand->mu_config); + } else { + if (chand->resolver != NULL) { + grpc_resolver_shutdown(exec_ctx, chand->resolver); + GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel"); + chand->resolver = NULL; + } + set_channel_connectivity_state_locked( + exec_ctx, chand, GRPC_CHANNEL_FATAL_FAILURE, "resolver_gone"); + gpr_mu_unlock(&chand->mu_config); + } + + if (exit_idle) { + grpc_lb_policy_exit_idle(exec_ctx, lb_policy); + GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "exit_idle"); + } + + if (old_lb_policy != NULL) { + grpc_pollset_set_del_pollset_set( + exec_ctx, old_lb_policy->interested_parties, chand->interested_parties); + GRPC_LB_POLICY_UNREF(exec_ctx, old_lb_policy, "channel"); + } + + if (lb_policy != NULL) { + GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "config_change"); + } + + GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->owning_stack, "resolver"); +} + +static void cc_start_transport_op(grpc_exec_ctx *exec_ctx, + grpc_channel_element *elem, + grpc_transport_op *op) { + channel_data *chand = elem->channel_data; + + grpc_exec_ctx_enqueue(exec_ctx, op->on_consumed, true, NULL); + + GPR_ASSERT(op->set_accept_stream == false); + if (op->bind_pollset != NULL) { + grpc_pollset_set_add_pollset(exec_ctx, chand->interested_parties, + op->bind_pollset); + } + + gpr_mu_lock(&chand->mu_config); + if (op->on_connectivity_state_change != NULL) { + grpc_connectivity_state_notify_on_state_change( + exec_ctx, &chand->state_tracker, op->connectivity_state, + op->on_connectivity_state_change); + op->on_connectivity_state_change = NULL; + op->connectivity_state = NULL; + } + + if (op->send_ping != NULL) { + if (chand->lb_policy == NULL) { + grpc_exec_ctx_enqueue(exec_ctx, op->send_ping, false, NULL); + } else { + grpc_lb_policy_ping_one(exec_ctx, chand->lb_policy, op->send_ping); + op->bind_pollset = NULL; + } + op->send_ping = NULL; + } + + if (op->disconnect && chand->resolver != NULL) { + set_channel_connectivity_state_locked( + exec_ctx, chand, GRPC_CHANNEL_FATAL_FAILURE, "disconnect"); + grpc_resolver_shutdown(exec_ctx, chand->resolver); + GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel"); + chand->resolver = NULL; + if (chand->lb_policy != NULL) { + grpc_pollset_set_del_pollset_set(exec_ctx, + chand->lb_policy->interested_parties, + chand->interested_parties); + GRPC_LB_POLICY_UNREF(exec_ctx, chand->lb_policy, "channel"); + chand->lb_policy = NULL; + } + } + gpr_mu_unlock(&chand->mu_config); +} + +typedef struct { + grpc_metadata_batch *initial_metadata; + uint32_t initial_metadata_flags; + grpc_connected_subchannel **connected_subchannel; + grpc_closure *on_ready; + grpc_call_element *elem; + grpc_closure closure; +} continue_picking_args; + +static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *arg, + grpc_metadata_batch *initial_metadata, + uint32_t initial_metadata_flags, + grpc_connected_subchannel **connected_subchannel, + grpc_closure *on_ready); + +static void continue_picking(grpc_exec_ctx *exec_ctx, void *arg, bool success) { + continue_picking_args *cpa = arg; + if (!success) { + grpc_exec_ctx_enqueue(exec_ctx, cpa->on_ready, false, NULL); + } else if (cpa->connected_subchannel == NULL) { + /* cancelled, do nothing */ + } else if (cc_pick_subchannel(exec_ctx, cpa->elem, cpa->initial_metadata, + cpa->initial_metadata_flags, + cpa->connected_subchannel, cpa->on_ready)) { + grpc_exec_ctx_enqueue(exec_ctx, cpa->on_ready, true, NULL); + } + gpr_free(cpa); +} + +static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp, + grpc_metadata_batch *initial_metadata, + uint32_t initial_metadata_flags, + grpc_connected_subchannel **connected_subchannel, + grpc_closure *on_ready) { + grpc_call_element *elem = elemp; + channel_data *chand = elem->channel_data; + call_data *calld = elem->call_data; + continue_picking_args *cpa; + grpc_closure *closure; + + GPR_ASSERT(connected_subchannel); + + gpr_mu_lock(&chand->mu_config); + if (initial_metadata == NULL) { + if (chand->lb_policy != NULL) { + grpc_lb_policy_cancel_pick(exec_ctx, chand->lb_policy, + connected_subchannel); + } + for (closure = chand->waiting_for_config_closures.head; closure != NULL; + closure = grpc_closure_next(closure)) { + cpa = closure->cb_arg; + if (cpa->connected_subchannel == connected_subchannel) { + cpa->connected_subchannel = NULL; + grpc_exec_ctx_enqueue(exec_ctx, cpa->on_ready, false, NULL); + } + } + gpr_mu_unlock(&chand->mu_config); + return 1; + } + if (chand->lb_policy != NULL) { + grpc_lb_policy *lb_policy = chand->lb_policy; + int r; + GRPC_LB_POLICY_REF(lb_policy, "cc_pick_subchannel"); + gpr_mu_unlock(&chand->mu_config); + r = grpc_lb_policy_pick(exec_ctx, lb_policy, calld->pollset, + initial_metadata, initial_metadata_flags, + connected_subchannel, on_ready); + GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "cc_pick_subchannel"); + return r; + } + if (chand->resolver != NULL && !chand->started_resolving) { + chand->started_resolving = 1; + GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver"); + grpc_resolver_next(exec_ctx, chand->resolver, + &chand->incoming_configuration, + &chand->on_config_changed); + } + cpa = gpr_malloc(sizeof(*cpa)); + cpa->initial_metadata = initial_metadata; + cpa->initial_metadata_flags = initial_metadata_flags; + cpa->connected_subchannel = connected_subchannel; + cpa->on_ready = on_ready; + cpa->elem = elem; + grpc_closure_init(&cpa->closure, continue_picking, cpa); + grpc_closure_list_add(&chand->waiting_for_config_closures, &cpa->closure, 1); + gpr_mu_unlock(&chand->mu_config); + return 0; +} + +/* Constructor for call_data */ +static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem, + grpc_call_element_args *args) { + grpc_subchannel_call_holder_init(elem->call_data, cc_pick_subchannel, elem, + args->call_stack); +} + +/* Destructor for call_data */ +static void destroy_call_elem(grpc_exec_ctx *exec_ctx, + grpc_call_element *elem) { + grpc_subchannel_call_holder_destroy(exec_ctx, elem->call_data); +} + +/* Constructor for channel_data */ +static void init_channel_elem(grpc_exec_ctx *exec_ctx, + grpc_channel_element *elem, + grpc_channel_element_args *args) { + channel_data *chand = elem->channel_data; + + memset(chand, 0, sizeof(*chand)); + + GPR_ASSERT(args->is_last); + GPR_ASSERT(elem->filter == &grpc_client_channel_filter); + + gpr_mu_init(&chand->mu_config); + grpc_closure_init(&chand->on_config_changed, cc_on_config_changed, chand); + chand->owning_stack = args->channel_stack; + + grpc_connectivity_state_init(&chand->state_tracker, GRPC_CHANNEL_IDLE, + "client_channel"); + chand->interested_parties = grpc_pollset_set_create(); +} + +/* Destructor for channel_data */ +static void destroy_channel_elem(grpc_exec_ctx *exec_ctx, + grpc_channel_element *elem) { + channel_data *chand = elem->channel_data; + + if (chand->resolver != NULL) { + grpc_resolver_shutdown(exec_ctx, chand->resolver); + GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel"); + } + if (chand->lb_policy != NULL) { + grpc_pollset_set_del_pollset_set(exec_ctx, + chand->lb_policy->interested_parties, + chand->interested_parties); + GRPC_LB_POLICY_UNREF(exec_ctx, chand->lb_policy, "channel"); + } + grpc_connectivity_state_destroy(exec_ctx, &chand->state_tracker); + grpc_pollset_set_destroy(chand->interested_parties); + gpr_mu_destroy(&chand->mu_config); +} + +static void cc_set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem, + grpc_pollset *pollset) { + call_data *calld = elem->call_data; + calld->pollset = pollset; +} + +const grpc_channel_filter grpc_client_channel_filter = { + cc_start_transport_stream_op, + cc_start_transport_op, + sizeof(call_data), + init_call_elem, + cc_set_pollset, + destroy_call_elem, + sizeof(channel_data), + init_channel_elem, + destroy_channel_elem, + cc_get_peer, + "client-channel", +}; + +void grpc_client_channel_set_resolver(grpc_exec_ctx *exec_ctx, + grpc_channel_stack *channel_stack, + grpc_resolver *resolver) { + /* post construction initialization: set the transport setup pointer */ + grpc_channel_element *elem = grpc_channel_stack_last_element(channel_stack); + channel_data *chand = elem->channel_data; + gpr_mu_lock(&chand->mu_config); + GPR_ASSERT(!chand->resolver); + chand->resolver = resolver; + GRPC_RESOLVER_REF(resolver, "channel"); + if (!grpc_closure_list_empty(chand->waiting_for_config_closures) || + chand->exit_idle_when_lb_policy_arrives) { + chand->started_resolving = 1; + GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver"); + grpc_resolver_next(exec_ctx, resolver, &chand->incoming_configuration, + &chand->on_config_changed); + } + gpr_mu_unlock(&chand->mu_config); +} + +grpc_connectivity_state grpc_client_channel_check_connectivity_state( + grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, int try_to_connect) { + channel_data *chand = elem->channel_data; + grpc_connectivity_state out; + gpr_mu_lock(&chand->mu_config); + out = grpc_connectivity_state_check(&chand->state_tracker); + if (out == GRPC_CHANNEL_IDLE && try_to_connect) { + if (chand->lb_policy != NULL) { + grpc_lb_policy_exit_idle(exec_ctx, chand->lb_policy); + } else { + chand->exit_idle_when_lb_policy_arrives = 1; + if (!chand->started_resolving && chand->resolver != NULL) { + GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver"); + chand->started_resolving = 1; + grpc_resolver_next(exec_ctx, chand->resolver, + &chand->incoming_configuration, + &chand->on_config_changed); + } + } + } + gpr_mu_unlock(&chand->mu_config); + return out; +} + +typedef struct { + channel_data *chand; + grpc_pollset *pollset; + grpc_closure *on_complete; + grpc_closure my_closure; +} external_connectivity_watcher; + +static void on_external_watch_complete(grpc_exec_ctx *exec_ctx, void *arg, + bool iomgr_success) { + external_connectivity_watcher *w = arg; + grpc_closure *follow_up = w->on_complete; + grpc_pollset_set_del_pollset(exec_ctx, w->chand->interested_parties, + w->pollset); + GRPC_CHANNEL_STACK_UNREF(exec_ctx, w->chand->owning_stack, + "external_connectivity_watcher"); + gpr_free(w); + follow_up->cb(exec_ctx, follow_up->cb_arg, iomgr_success); +} + +void grpc_client_channel_watch_connectivity_state( + grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, grpc_pollset *pollset, + grpc_connectivity_state *state, grpc_closure *on_complete) { + channel_data *chand = elem->channel_data; + external_connectivity_watcher *w = gpr_malloc(sizeof(*w)); + w->chand = chand; + w->pollset = pollset; + w->on_complete = on_complete; + grpc_pollset_set_add_pollset(exec_ctx, chand->interested_parties, pollset); + grpc_closure_init(&w->my_closure, on_external_watch_complete, w); + GRPC_CHANNEL_STACK_REF(w->chand->owning_stack, + "external_connectivity_watcher"); + gpr_mu_lock(&chand->mu_config); + grpc_connectivity_state_notify_on_state_change( + exec_ctx, &chand->state_tracker, state, &w->my_closure); + gpr_mu_unlock(&chand->mu_config); +} |