static int pf_pick(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 */ grpc_connected_subchannel *selected = GET_SELECTED(p); if (selected != NULL) { *target = selected; return 1; } /* No subchannel selected yet, so acquire lock and then attempt again */ gpr_mu_lock(&p->mu); selected = GET_SELECTED(p); if (selected) { gpr_mu_unlock(&p->mu); *target = selected; return 1; } else { 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; gpr_mu_unlock(&p->mu); return 0; } }
static void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { pick_first_lb_policy *p = (pick_first_lb_policy *)pol; pending_pick *pp; grpc_connected_subchannel *selected; gpr_mu_lock(&p->mu); selected = GET_SELECTED(p); 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("Channel shutdown"), "shutdown"); /* cancel subscription */ if (selected != NULL) { grpc_connected_subchannel_notify_on_state_change( exec_ctx, 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); } gpr_mu_unlock(&p->mu); while (pp != NULL) { pending_pick *next = pp->next; *pp->target = NULL; grpc_exec_ctx_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE, NULL); gpr_free(pp); pp = next; } }
void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { pick_first_lb_policy *p = (pick_first_lb_policy *)pol; pending_pick *pp; grpc_connected_subchannel *selected; gpr_mu_lock(&p->mu); selected = GET_SELECTED(p); p->shutdown = 1; pp = p->pending_picks; p->pending_picks = NULL; grpc_connectivity_state_set(exec_ctx, &p->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "shutdown"); /* cancel subscription */ if (selected != NULL) { grpc_connected_subchannel_notify_on_state_change( exec_ctx, selected, NULL, NULL, &p->connectivity_changed); } else { grpc_subchannel_notify_on_state_change( exec_ctx, p->subchannels[p->checking_subchannel], NULL, NULL, &p->connectivity_changed); } gpr_mu_unlock(&p->mu); while (pp != NULL) { pending_pick *next = pp->next; *pp->target = NULL; grpc_pollset_set_del_pollset(exec_ctx, &p->base.interested_parties, pp->pollset); grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, 1); gpr_free(pp); pp = next; } }
void pf_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_closure *closure) { pick_first_lb_policy *p = (pick_first_lb_policy *)pol; grpc_connected_subchannel *selected = GET_SELECTED(p); if (selected) { grpc_connected_subchannel_ping(exec_ctx, selected, closure); } else { grpc_exec_ctx_enqueue(exec_ctx, closure, 0); } }
static void pf_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_closure *closure) { pick_first_lb_policy *p = (pick_first_lb_policy *)pol; grpc_connected_subchannel *selected = GET_SELECTED(p); if (selected) { grpc_connected_subchannel_ping(exec_ctx, selected, closure); } else { grpc_exec_ctx_sched(exec_ctx, closure, GRPC_ERROR_CREATE("Not connected"), NULL); } }
static int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset, grpc_metadata_batch *initial_metadata, uint32_t initial_metadata_flags, grpc_connected_subchannel **target, grpc_closure *on_complete) { pick_first_lb_policy *p = (pick_first_lb_policy *)pol; pending_pick *pp; /* Check atomically for a selected channel */ grpc_connected_subchannel *selected = GET_SELECTED(p); if (selected != NULL) { *target = selected; return 1; } /* No subchannel selected yet, so acquire lock and then attempt again */ gpr_mu_lock(&p->mu); selected = GET_SELECTED(p); if (selected) { gpr_mu_unlock(&p->mu); *target = selected; return 1; } else { if (!p->started_picking) { start_picking(exec_ctx, p); } grpc_pollset_set_add_pollset(exec_ctx, p->base.interested_parties, pollset); pp = gpr_malloc(sizeof(*pp)); pp->next = p->pending_picks; pp->pollset = pollset; pp->target = target; pp->initial_metadata_flags = initial_metadata_flags; pp->on_complete = on_complete; p->pending_picks = pp; gpr_mu_unlock(&p->mu); return 0; } }
static void pf_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { pick_first_lb_policy *p = (pick_first_lb_policy *)pol; grpc_connected_subchannel *selected = GET_SELECTED(p); 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 (selected != NULL) { GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, selected, "picked_first"); } grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker); gpr_free(p->subchannels); gpr_mu_destroy(&p->mu); gpr_free(p); }
static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) { pick_first_lb_policy *p = arg; grpc_subchannel *selected_subchannel; pending_pick *pp; grpc_connected_subchannel *selected; GRPC_ERROR_REF(error); gpr_mu_lock(&p->mu); selected = GET_SELECTED(p); if (p->shutdown) { gpr_mu_unlock(&p->mu); GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pick_first_connectivity"); GRPC_ERROR_UNREF(error); return; } else if (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, 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_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]; selected = grpc_subchannel_get_connected_subchannel(selected_subchannel); GPR_ASSERT(selected != NULL); GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked_first"); /* drop the pick list: we are connected now */ GRPC_LB_POLICY_WEAK_REF(&p->base, "destroy_subchannels"); gpr_atm_rel_store(&p->selected, (gpr_atm)selected); grpc_exec_ctx_sched(exec_ctx, grpc_closure_create(destroy_subchannels, p), GRPC_ERROR_NONE, NULL); /* update any calls that were waiting for a pick */ while ((pp = p->pending_picks)) { p->pending_picks = pp->next; *pp->target = selected; grpc_exec_ctx_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE, NULL); gpr_free(pp); } grpc_connected_subchannel_notify_on_state_change( exec_ctx, 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("Pick first exhausted channels", &error, 1), "no_more_channels"); while ((pp = p->pending_picks)) { p->pending_picks = pp->next; *pp->target = NULL; grpc_exec_ctx_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE, NULL); 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; } } } gpr_mu_unlock(&p->mu); GRPC_ERROR_UNREF(error); }
static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg, int iomgr_success) { pick_first_lb_policy *p = arg; grpc_subchannel *selected_subchannel; pending_pick *pp; grpc_connected_subchannel *selected; gpr_mu_lock(&p->mu); selected = GET_SELECTED(p); if (p->shutdown) { gpr_mu_unlock(&p->mu); GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pick_first_connectivity"); return; } else if (selected != NULL) { if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) { /* if the selected channel goes bad, we're done */ p->checking_connectivity = GRPC_CHANNEL_FATAL_FAILURE; } grpc_connectivity_state_set(exec_ctx, &p->state_tracker, p->checking_connectivity, "selected_changed"); if (p->checking_connectivity != GRPC_CHANNEL_FATAL_FAILURE) { grpc_connected_subchannel_notify_on_state_change( exec_ctx, 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_READY: grpc_connectivity_state_set(exec_ctx, &p->state_tracker, GRPC_CHANNEL_READY, "connecting_ready"); selected_subchannel = p->subchannels[p->checking_subchannel]; selected = grpc_subchannel_get_connected_subchannel(selected_subchannel); GPR_ASSERT(selected != NULL); gpr_atm_no_barrier_store(&p->selected, (gpr_atm)selected); GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked_first"); /* drop the pick list: we are connected now */ GRPC_LB_POLICY_WEAK_REF(&p->base, "destroy_subchannels"); grpc_exec_ctx_enqueue(exec_ctx, grpc_closure_create(destroy_subchannels, p), 1); /* update any calls that were waiting for a pick */ while ((pp = p->pending_picks)) { p->pending_picks = pp->next; *pp->target = selected; grpc_pollset_set_del_pollset(exec_ctx, &p->base.interested_parties, pp->pollset); grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, 1); gpr_free(pp); } grpc_connected_subchannel_notify_on_state_change( exec_ctx, selected, &p->base.interested_parties, &p->checking_connectivity, &p->connectivity_changed); break; case GRPC_CHANNEL_TRANSIENT_FAILURE: grpc_connectivity_state_set(exec_ctx, &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, "connecting_transient_failure"); p->checking_subchannel = (p->checking_subchannel + 1) % p->num_subchannels; p->checking_connectivity = grpc_subchannel_check_connectivity( p->subchannels[p->checking_subchannel]); 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, "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_FATAL_FAILURE: 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_FATAL_FAILURE, "no_more_channels"); while ((pp = p->pending_picks)) { p->pending_picks = pp->next; *pp->target = NULL; grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, 1); 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, "subchannel_failed"); p->checking_subchannel %= p->num_subchannels; p->checking_connectivity = grpc_subchannel_check_connectivity( p->subchannels[p->checking_subchannel]); goto loop; } } } gpr_mu_unlock(&p->mu); }