diff options
Diffstat (limited to 'src/core/lib/client_config/subchannel.c')
| -rw-r--r-- | src/core/lib/client_config/subchannel.c | 697 |
1 files changed, 697 insertions, 0 deletions
diff --git a/src/core/lib/client_config/subchannel.c b/src/core/lib/client_config/subchannel.c new file mode 100644 index 0000000000..5203ad2143 --- /dev/null +++ b/src/core/lib/client_config/subchannel.c @@ -0,0 +1,697 @@ +/* + * + * Copyright 2015-2016, 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/lib/client_config/subchannel.h" + +#include <string.h> + +#include <grpc/support/alloc.h> +#include <grpc/support/avl.h> + +#include "src/core/lib/channel/channel_args.h" +#include "src/core/lib/channel/client_channel.h" +#include "src/core/lib/channel/connected_channel.h" +#include "src/core/lib/client_config/initial_connect_string.h" +#include "src/core/lib/client_config/subchannel_index.h" +#include "src/core/lib/iomgr/timer.h" +#include "src/core/lib/profiling/timers.h" +#include "src/core/lib/support/backoff.h" +#include "src/core/lib/surface/channel.h" +#include "src/core/lib/surface/channel_init.h" +#include "src/core/lib/transport/connectivity_state.h" + +#define INTERNAL_REF_BITS 16 +#define STRONG_REF_MASK (~(gpr_atm)((1 << INTERNAL_REF_BITS) - 1)) + +#define GRPC_SUBCHANNEL_MIN_CONNECT_TIMEOUT_SECONDS 20 +#define GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS 1 +#define GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER 1.6 +#define GRPC_SUBCHANNEL_RECONNECT_MAX_BACKOFF_SECONDS 120 +#define GRPC_SUBCHANNEL_RECONNECT_JITTER 0.2 + +#define GET_CONNECTED_SUBCHANNEL(subchannel, barrier) \ + ((grpc_connected_subchannel *)(gpr_atm_##barrier##_load( \ + &(subchannel)->connected_subchannel))) + +typedef struct { + grpc_closure closure; + grpc_subchannel *subchannel; + grpc_connectivity_state connectivity_state; +} state_watcher; + +typedef struct external_state_watcher { + grpc_subchannel *subchannel; + grpc_pollset_set *pollset_set; + grpc_closure *notify; + grpc_closure closure; + struct external_state_watcher *next; + struct external_state_watcher *prev; +} external_state_watcher; + +struct grpc_subchannel { + grpc_connector *connector; + + /** refcount + - lower INTERNAL_REF_BITS bits are for internal references: + these do not keep the subchannel open. + - upper remaining bits are for public references: these do + keep the subchannel open */ + gpr_atm ref_pair; + + /** non-transport related channel filters */ + const grpc_channel_filter **filters; + size_t num_filters; + /** channel arguments */ + grpc_channel_args *args; + /** address to connect to */ + struct sockaddr *addr; + size_t addr_len; + + grpc_subchannel_key *key; + + /** initial string to send to peer */ + gpr_slice initial_connect_string; + + /** set during connection */ + grpc_connect_out_args connecting_result; + + /** callback for connection finishing */ + grpc_closure connected; + + /** pollset_set tracking who's interested in a connection + being setup */ + grpc_pollset_set *pollset_set; + + /** active connection, or null; of type grpc_connected_subchannel */ + gpr_atm connected_subchannel; + + /** mutex protecting remaining elements */ + gpr_mu mu; + + /** have we seen a disconnection? */ + int disconnected; + /** are we connecting */ + int connecting; + /** connectivity state tracking */ + grpc_connectivity_state_tracker state_tracker; + + external_state_watcher root_external_state_watcher; + + /** next connect attempt time */ + gpr_timespec next_attempt; + /** backoff state */ + gpr_backoff backoff_state; + /** do we have an active alarm? */ + int have_alarm; + /** our alarm */ + grpc_timer alarm; + /** current random value */ + uint32_t random; +}; + +struct grpc_subchannel_call { + grpc_connected_subchannel *connection; +}; + +#define SUBCHANNEL_CALL_TO_CALL_STACK(call) ((grpc_call_stack *)((call) + 1)) +#define CHANNEL_STACK_FROM_CONNECTION(con) ((grpc_channel_stack *)(con)) +#define CALLSTACK_TO_SUBCHANNEL_CALL(callstack) \ + (((grpc_subchannel_call *)(callstack)) - 1) + +static void subchannel_connected(grpc_exec_ctx *exec_ctx, void *subchannel, + bool iomgr_success); + +#ifdef GRPC_STREAM_REFCOUNT_DEBUG +#define REF_REASON reason +#define REF_LOG(name, p) \ + gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "%s: %p ref %d -> %d %s", \ + (name), (p), (p)->refs.count, (p)->refs.count + 1, reason) +#define UNREF_LOG(name, p) \ + gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "%s: %p unref %d -> %d %s", \ + (name), (p), (p)->refs.count, (p)->refs.count - 1, reason) +#define REF_MUTATE_EXTRA_ARGS \ + GRPC_SUBCHANNEL_REF_EXTRA_ARGS, const char *purpose +#define REF_MUTATE_PURPOSE(x) , file, line, reason, x +#else +#define REF_REASON "" +#define REF_LOG(name, p) \ + do { \ + } while (0) +#define UNREF_LOG(name, p) \ + do { \ + } while (0) +#define REF_MUTATE_EXTRA_ARGS +#define REF_MUTATE_PURPOSE(x) +#endif + +/* + * connection implementation + */ + +static void connection_destroy(grpc_exec_ctx *exec_ctx, void *arg, + bool success) { + grpc_connected_subchannel *c = arg; + grpc_channel_stack_destroy(exec_ctx, CHANNEL_STACK_FROM_CONNECTION(c)); + gpr_free(c); +} + +void grpc_connected_subchannel_ref( + grpc_connected_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) { + GRPC_CHANNEL_STACK_REF(CHANNEL_STACK_FROM_CONNECTION(c), REF_REASON); +} + +void grpc_connected_subchannel_unref(grpc_exec_ctx *exec_ctx, + grpc_connected_subchannel *c + GRPC_SUBCHANNEL_REF_EXTRA_ARGS) { + GRPC_CHANNEL_STACK_UNREF(exec_ctx, CHANNEL_STACK_FROM_CONNECTION(c), + REF_REASON); +} + +/* + * grpc_subchannel implementation + */ + +static void subchannel_destroy(grpc_exec_ctx *exec_ctx, void *arg, + bool success) { + grpc_subchannel *c = arg; + gpr_free((void *)c->filters); + grpc_channel_args_destroy(c->args); + gpr_free(c->addr); + gpr_slice_unref(c->initial_connect_string); + grpc_connectivity_state_destroy(exec_ctx, &c->state_tracker); + grpc_connector_unref(exec_ctx, c->connector); + grpc_pollset_set_destroy(c->pollset_set); + grpc_subchannel_key_destroy(exec_ctx, c->key); + gpr_free(c); +} + +static gpr_atm ref_mutate(grpc_subchannel *c, gpr_atm delta, + int barrier REF_MUTATE_EXTRA_ARGS) { + gpr_atm old_val = barrier ? gpr_atm_full_fetch_add(&c->ref_pair, delta) + : gpr_atm_no_barrier_fetch_add(&c->ref_pair, delta); +#ifdef GRPC_STREAM_REFCOUNT_DEBUG + gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, + "SUBCHANNEL: %p % 12s 0x%08x -> 0x%08x [%s]", c, purpose, old_val, + old_val + delta, reason); +#endif + return old_val; +} + +grpc_subchannel *grpc_subchannel_ref( + grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) { + gpr_atm old_refs; + old_refs = ref_mutate(c, (1 << INTERNAL_REF_BITS), + 0 REF_MUTATE_PURPOSE("STRONG_REF")); + GPR_ASSERT((old_refs & STRONG_REF_MASK) != 0); + return c; +} + +grpc_subchannel *grpc_subchannel_weak_ref( + grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) { + gpr_atm old_refs; + old_refs = ref_mutate(c, 1, 0 REF_MUTATE_PURPOSE("WEAK_REF")); + GPR_ASSERT(old_refs != 0); + return c; +} + +grpc_subchannel *grpc_subchannel_ref_from_weak_ref( + grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) { + if (!c) return NULL; + for (;;) { + gpr_atm old_refs = gpr_atm_acq_load(&c->ref_pair); + if (old_refs >= (1 << INTERNAL_REF_BITS)) { + gpr_atm new_refs = old_refs + (1 << INTERNAL_REF_BITS); + if (gpr_atm_rel_cas(&c->ref_pair, old_refs, new_refs)) { + return c; + } + } else { + return NULL; + } + } +} + +static void disconnect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) { + grpc_connected_subchannel *con; + grpc_subchannel_index_unregister(exec_ctx, c->key, c); + gpr_mu_lock(&c->mu); + GPR_ASSERT(!c->disconnected); + c->disconnected = 1; + grpc_connector_shutdown(exec_ctx, c->connector); + con = GET_CONNECTED_SUBCHANNEL(c, no_barrier); + if (con != NULL) { + GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, con, "connection"); + gpr_atm_no_barrier_store(&c->connected_subchannel, 0xdeadbeef); + } + gpr_mu_unlock(&c->mu); +} + +void grpc_subchannel_unref(grpc_exec_ctx *exec_ctx, + grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) { + gpr_atm old_refs; + old_refs = ref_mutate(c, (gpr_atm)1 - (gpr_atm)(1 << INTERNAL_REF_BITS), + 1 REF_MUTATE_PURPOSE("STRONG_UNREF")); + if ((old_refs & STRONG_REF_MASK) == (1 << INTERNAL_REF_BITS)) { + disconnect(exec_ctx, c); + } + GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "strong-unref"); +} + +void grpc_subchannel_weak_unref(grpc_exec_ctx *exec_ctx, + grpc_subchannel *c + GRPC_SUBCHANNEL_REF_EXTRA_ARGS) { + gpr_atm old_refs; + old_refs = ref_mutate(c, -(gpr_atm)1, 1 REF_MUTATE_PURPOSE("WEAK_UNREF")); + if (old_refs == 1) { + grpc_exec_ctx_enqueue(exec_ctx, grpc_closure_create(subchannel_destroy, c), + true, NULL); + } +} + +static uint32_t random_seed() { + return (uint32_t)(gpr_time_to_millis(gpr_now(GPR_CLOCK_MONOTONIC))); +} + +grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx, + grpc_connector *connector, + grpc_subchannel_args *args) { + grpc_subchannel_key *key = grpc_subchannel_key_create(connector, args); + grpc_subchannel *c = grpc_subchannel_index_find(exec_ctx, key); + if (c) { + grpc_subchannel_key_destroy(exec_ctx, key); + return c; + } + + c = gpr_malloc(sizeof(*c)); + memset(c, 0, sizeof(*c)); + c->key = key; + gpr_atm_no_barrier_store(&c->ref_pair, 1 << INTERNAL_REF_BITS); + c->connector = connector; + grpc_connector_ref(c->connector); + c->num_filters = args->filter_count; + if (c->num_filters > 0) { + c->filters = gpr_malloc(sizeof(grpc_channel_filter *) * c->num_filters); + memcpy((void *)c->filters, args->filters, + sizeof(grpc_channel_filter *) * c->num_filters); + } else { + c->filters = NULL; + } + c->addr = gpr_malloc(args->addr_len); + memcpy(c->addr, args->addr, args->addr_len); + c->pollset_set = grpc_pollset_set_create(); + c->addr_len = args->addr_len; + grpc_set_initial_connect_string(&c->addr, &c->addr_len, + &c->initial_connect_string); + c->args = grpc_channel_args_copy(args->args); + c->random = random_seed(); + c->root_external_state_watcher.next = c->root_external_state_watcher.prev = + &c->root_external_state_watcher; + grpc_closure_init(&c->connected, subchannel_connected, c); + grpc_connectivity_state_init(&c->state_tracker, GRPC_CHANNEL_IDLE, + "subchannel"); + gpr_backoff_init(&c->backoff_state, + GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER, + GRPC_SUBCHANNEL_RECONNECT_JITTER, + GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS * 1000, + GRPC_SUBCHANNEL_RECONNECT_MAX_BACKOFF_SECONDS * 1000); + if (c->args) { + for (size_t i = 0; i < c->args->num_args; i++) { + if (0 == strcmp(c->args->args[i].key, + "grpc.testing.fixed_reconnect_backoff")) { + GPR_ASSERT(c->args->args[i].type == GRPC_ARG_INTEGER); + gpr_backoff_init(&c->backoff_state, 1.0, 0.0, + c->args->args[i].value.integer, + c->args->args[i].value.integer); + } + if (0 == + strcmp(c->args->args[i].key, GRPC_ARG_MAX_RECONNECT_BACKOFF_MS)) { + if (c->args->args[i].type == GRPC_ARG_INTEGER) { + if (c->args->args[i].value.integer >= 0) { + gpr_backoff_init( + &c->backoff_state, GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER, + GRPC_SUBCHANNEL_RECONNECT_JITTER, + GPR_MIN(c->args->args[i].value.integer, + GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS * 1000), + c->args->args[i].value.integer); + } else { + gpr_log(GPR_ERROR, GRPC_ARG_MAX_RECONNECT_BACKOFF_MS + " : must be non-negative"); + } + } else { + gpr_log(GPR_ERROR, + GRPC_ARG_MAX_RECONNECT_BACKOFF_MS " : must be an integer"); + } + } + } + } + gpr_mu_init(&c->mu); + + return grpc_subchannel_index_register(exec_ctx, key, c); +} + +static void continue_connect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) { + grpc_connect_in_args args; + + args.interested_parties = c->pollset_set; + args.addr = c->addr; + args.addr_len = c->addr_len; + args.deadline = c->next_attempt; + args.channel_args = c->args; + args.initial_connect_string = c->initial_connect_string; + + grpc_connectivity_state_set(exec_ctx, &c->state_tracker, + GRPC_CHANNEL_CONNECTING, "state_change"); + grpc_connector_connect(exec_ctx, c->connector, &args, &c->connecting_result, + &c->connected); +} + +static void start_connect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) { + c->next_attempt = + gpr_backoff_begin(&c->backoff_state, gpr_now(GPR_CLOCK_MONOTONIC)); + continue_connect(exec_ctx, c); +} + +grpc_connectivity_state grpc_subchannel_check_connectivity(grpc_subchannel *c) { + grpc_connectivity_state state; + gpr_mu_lock(&c->mu); + state = grpc_connectivity_state_check(&c->state_tracker); + gpr_mu_unlock(&c->mu); + return state; +} + +static void on_external_state_watcher_done(grpc_exec_ctx *exec_ctx, void *arg, + bool success) { + external_state_watcher *w = arg; + grpc_closure *follow_up = w->notify; + if (w->pollset_set != NULL) { + grpc_pollset_set_del_pollset_set(exec_ctx, w->subchannel->pollset_set, + w->pollset_set); + } + gpr_mu_lock(&w->subchannel->mu); + w->next->prev = w->prev; + w->prev->next = w->next; + gpr_mu_unlock(&w->subchannel->mu); + GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, w->subchannel, "external_state_watcher"); + gpr_free(w); + follow_up->cb(exec_ctx, follow_up->cb_arg, success); +} + +void grpc_subchannel_notify_on_state_change( + grpc_exec_ctx *exec_ctx, grpc_subchannel *c, + grpc_pollset_set *interested_parties, grpc_connectivity_state *state, + grpc_closure *notify) { + external_state_watcher *w; + + if (state == NULL) { + gpr_mu_lock(&c->mu); + for (w = c->root_external_state_watcher.next; + w != &c->root_external_state_watcher; w = w->next) { + if (w->notify == notify) { + grpc_connectivity_state_notify_on_state_change( + exec_ctx, &c->state_tracker, NULL, &w->closure); + } + } + gpr_mu_unlock(&c->mu); + } else { + w = gpr_malloc(sizeof(*w)); + w->subchannel = c; + w->pollset_set = interested_parties; + w->notify = notify; + grpc_closure_init(&w->closure, on_external_state_watcher_done, w); + if (interested_parties != NULL) { + grpc_pollset_set_add_pollset_set(exec_ctx, c->pollset_set, + interested_parties); + } + GRPC_SUBCHANNEL_WEAK_REF(c, "external_state_watcher"); + gpr_mu_lock(&c->mu); + w->next = &c->root_external_state_watcher; + w->prev = w->next->prev; + w->next->prev = w->prev->next = w; + if (grpc_connectivity_state_notify_on_state_change( + exec_ctx, &c->state_tracker, state, &w->closure)) { + c->connecting = 1; + /* released by connection */ + GRPC_SUBCHANNEL_WEAK_REF(c, "connecting"); + start_connect(exec_ctx, c); + } + gpr_mu_unlock(&c->mu); + } +} + +void grpc_connected_subchannel_process_transport_op( + grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *con, + grpc_transport_op *op) { + grpc_channel_stack *channel_stack = CHANNEL_STACK_FROM_CONNECTION(con); + grpc_channel_element *top_elem = grpc_channel_stack_element(channel_stack, 0); + top_elem->filter->start_transport_op(exec_ctx, top_elem, op); +} + +static void subchannel_on_child_state_changed(grpc_exec_ctx *exec_ctx, void *p, + bool iomgr_success) { + state_watcher *sw = p; + grpc_subchannel *c = sw->subchannel; + gpr_mu *mu = &c->mu; + + gpr_mu_lock(mu); + + /* if we failed just leave this closure */ + if (iomgr_success) { + if (sw->connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) { + /* any errors on a subchannel ==> we're done, create a new one */ + sw->connectivity_state = GRPC_CHANNEL_FATAL_FAILURE; + } + grpc_connectivity_state_set(exec_ctx, &c->state_tracker, + sw->connectivity_state, "reflect_child"); + if (sw->connectivity_state != GRPC_CHANNEL_FATAL_FAILURE) { + grpc_connected_subchannel_notify_on_state_change( + exec_ctx, GET_CONNECTED_SUBCHANNEL(c, no_barrier), NULL, + &sw->connectivity_state, &sw->closure); + GRPC_SUBCHANNEL_WEAK_REF(c, "state_watcher"); + sw = NULL; + } + } + + gpr_mu_unlock(mu); + GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "state_watcher"); + gpr_free(sw); +} + +static void connected_subchannel_state_op(grpc_exec_ctx *exec_ctx, + grpc_connected_subchannel *con, + grpc_pollset_set *interested_parties, + grpc_connectivity_state *state, + grpc_closure *closure) { + grpc_transport_op op; + grpc_channel_element *elem; + memset(&op, 0, sizeof(op)); + op.connectivity_state = state; + op.on_connectivity_state_change = closure; + op.bind_pollset_set = interested_parties; + elem = grpc_channel_stack_element(CHANNEL_STACK_FROM_CONNECTION(con), 0); + elem->filter->start_transport_op(exec_ctx, elem, &op); +} + +void grpc_connected_subchannel_notify_on_state_change( + grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *con, + grpc_pollset_set *interested_parties, grpc_connectivity_state *state, + grpc_closure *closure) { + connected_subchannel_state_op(exec_ctx, con, interested_parties, state, + closure); +} + +void grpc_connected_subchannel_ping(grpc_exec_ctx *exec_ctx, + grpc_connected_subchannel *con, + grpc_closure *closure) { + grpc_transport_op op; + grpc_channel_element *elem; + memset(&op, 0, sizeof(op)); + op.send_ping = closure; + elem = grpc_channel_stack_element(CHANNEL_STACK_FROM_CONNECTION(con), 0); + elem->filter->start_transport_op(exec_ctx, elem, &op); +} + +static void publish_transport_locked(grpc_exec_ctx *exec_ctx, + grpc_subchannel *c) { + grpc_connected_subchannel *con; + grpc_channel_stack *stk; + state_watcher *sw_subchannel; + + /* construct channel stack */ + con = grpc_channel_init_create_stack( + exec_ctx, GRPC_CLIENT_SUBCHANNEL, 0, c->connecting_result.channel_args, 1, + connection_destroy, NULL, c->connecting_result.transport); + stk = CHANNEL_STACK_FROM_CONNECTION(con); + memset(&c->connecting_result, 0, sizeof(c->connecting_result)); + + /* initialize state watcher */ + sw_subchannel = gpr_malloc(sizeof(*sw_subchannel)); + sw_subchannel->subchannel = c; + sw_subchannel->connectivity_state = GRPC_CHANNEL_READY; + grpc_closure_init(&sw_subchannel->closure, subchannel_on_child_state_changed, + sw_subchannel); + + if (c->disconnected) { + gpr_free(sw_subchannel); + grpc_channel_stack_destroy(exec_ctx, stk); + gpr_free(con); + GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting"); + return; + } + + /* publish */ + /* TODO(ctiller): this full barrier seems to clear up a TSAN failure. + I'd have expected the rel_cas below to be enough, but + seemingly it's not. + Re-evaluate if we really need this. */ + gpr_atm_full_barrier(); + GPR_ASSERT(gpr_atm_rel_cas(&c->connected_subchannel, 0, (gpr_atm)con)); + c->connecting = 0; + + /* setup subchannel watching connected subchannel for changes; subchannel ref + for connecting is donated + to the state watcher */ + GRPC_SUBCHANNEL_WEAK_REF(c, "state_watcher"); + GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting"); + grpc_connected_subchannel_notify_on_state_change( + exec_ctx, con, c->pollset_set, &sw_subchannel->connectivity_state, + &sw_subchannel->closure); + + /* signal completion */ + grpc_connectivity_state_set(exec_ctx, &c->state_tracker, GRPC_CHANNEL_READY, + "connected"); +} + +static void on_alarm(grpc_exec_ctx *exec_ctx, void *arg, bool iomgr_success) { + grpc_subchannel *c = arg; + gpr_mu_lock(&c->mu); + c->have_alarm = 0; + if (c->disconnected) { + iomgr_success = 0; + } + if (iomgr_success) { + c->next_attempt = + gpr_backoff_step(&c->backoff_state, gpr_now(GPR_CLOCK_MONOTONIC)); + continue_connect(exec_ctx, c); + gpr_mu_unlock(&c->mu); + } else { + gpr_mu_unlock(&c->mu); + GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting"); + } +} + +static void subchannel_connected(grpc_exec_ctx *exec_ctx, void *arg, + bool iomgr_success) { + grpc_subchannel *c = arg; + + GRPC_SUBCHANNEL_WEAK_REF(c, "connected"); + gpr_mu_lock(&c->mu); + if (c->connecting_result.transport != NULL) { + publish_transport_locked(exec_ctx, c); + } else if (c->disconnected) { + GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting"); + } else { + gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC); + GPR_ASSERT(!c->have_alarm); + c->have_alarm = 1; + grpc_connectivity_state_set(exec_ctx, &c->state_tracker, + GRPC_CHANNEL_TRANSIENT_FAILURE, + "connect_failed"); + grpc_timer_init(exec_ctx, &c->alarm, c->next_attempt, on_alarm, c, now); + } + gpr_mu_unlock(&c->mu); + GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting"); +} + +/* + * grpc_subchannel_call implementation + */ + +static void subchannel_call_destroy(grpc_exec_ctx *exec_ctx, void *call, + bool success) { + grpc_subchannel_call *c = call; + GPR_TIMER_BEGIN("grpc_subchannel_call_unref.destroy", 0); + grpc_call_stack_destroy(exec_ctx, SUBCHANNEL_CALL_TO_CALL_STACK(c)); + GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, c->connection, "subchannel_call"); + gpr_free(c); + GPR_TIMER_END("grpc_subchannel_call_unref.destroy", 0); +} + +void grpc_subchannel_call_ref( + grpc_subchannel_call *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) { + GRPC_CALL_STACK_REF(SUBCHANNEL_CALL_TO_CALL_STACK(c), REF_REASON); +} + +void grpc_subchannel_call_unref(grpc_exec_ctx *exec_ctx, + grpc_subchannel_call *c + GRPC_SUBCHANNEL_REF_EXTRA_ARGS) { + GRPC_CALL_STACK_UNREF(exec_ctx, SUBCHANNEL_CALL_TO_CALL_STACK(c), REF_REASON); +} + +char *grpc_subchannel_call_get_peer(grpc_exec_ctx *exec_ctx, + grpc_subchannel_call *call) { + grpc_call_stack *call_stack = SUBCHANNEL_CALL_TO_CALL_STACK(call); + grpc_call_element *top_elem = grpc_call_stack_element(call_stack, 0); + return top_elem->filter->get_peer(exec_ctx, top_elem); +} + +void grpc_subchannel_call_process_op(grpc_exec_ctx *exec_ctx, + grpc_subchannel_call *call, + grpc_transport_stream_op *op) { + grpc_call_stack *call_stack = SUBCHANNEL_CALL_TO_CALL_STACK(call); + grpc_call_element *top_elem = grpc_call_stack_element(call_stack, 0); + top_elem->filter->start_transport_stream_op(exec_ctx, top_elem, op); +} + +grpc_connected_subchannel *grpc_subchannel_get_connected_subchannel( + grpc_subchannel *c) { + return GET_CONNECTED_SUBCHANNEL(c, acq); +} + +grpc_subchannel_call *grpc_connected_subchannel_create_call( + grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *con, + grpc_pollset *pollset) { + grpc_channel_stack *chanstk = CHANNEL_STACK_FROM_CONNECTION(con); + grpc_subchannel_call *call = + gpr_malloc(sizeof(grpc_subchannel_call) + chanstk->call_stack_size); + grpc_call_stack *callstk = SUBCHANNEL_CALL_TO_CALL_STACK(call); + call->connection = con; + GRPC_CONNECTED_SUBCHANNEL_REF(con, "subchannel_call"); + grpc_call_stack_init(exec_ctx, chanstk, 1, subchannel_call_destroy, call, + NULL, NULL, callstk); + grpc_call_stack_set_pollset(exec_ctx, callstk, pollset); + return call; +} + +grpc_call_stack *grpc_subchannel_call_get_call_stack( + grpc_subchannel_call *subchannel_call) { + return SUBCHANNEL_CALL_TO_CALL_STACK(subchannel_call); +} |