diff options
Diffstat (limited to 'src/core/ext/lb_policy/pick_first/pick_first.c')
-rw-r--r-- | src/core/ext/lb_policy/pick_first/pick_first.c | 181 |
1 files changed, 69 insertions, 112 deletions
diff --git a/src/core/ext/lb_policy/pick_first/pick_first.c b/src/core/ext/lb_policy/pick_first/pick_first.c index 9f2aa461be..501cb6d94d 100644 --- a/src/core/ext/lb_policy/pick_first/pick_first.c +++ b/src/core/ext/lb_policy/pick_first/pick_first.c @@ -38,6 +38,7 @@ #include "src/core/ext/client_channel/lb_policy_registry.h" #include "src/core/ext/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" @@ -57,11 +58,11 @@ typedef struct { grpc_closure connectivity_changed; - /** the selected channel (a grpc_connected_subchannel) */ - gpr_atm selected; + /** remaining members are protected by the combiner */ + + /** the selected channel */ + grpc_connected_subchannel *selected; - /** mutex protecting remaining members */ - gpr_mu mu; /** have we started picking? */ int started_picking; /** are we shut down? */ @@ -77,32 +78,24 @@ typedef struct { grpc_connectivity_state_tracker state_tracker; } pick_first_lb_policy; -#define GET_SELECTED(p) \ - ((grpc_connected_subchannel *)gpr_atm_acq_load(&(p)->selected)) - 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"); + 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_mu_destroy(&p->mu); gpr_free(p); } -static void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { +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; - grpc_connected_subchannel *selected; - gpr_mu_lock(&p->mu); - selected = GET_SELECTED(p); p->shutdown = 1; pp = p->pending_picks; p->pending_picks = NULL; @@ -110,15 +103,14 @@ static void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { exec_ctx, &p->state_tracker, GRPC_CHANNEL_SHUTDOWN, GRPC_ERROR_CREATE("Channel shutdown"), "shutdown"); /* cancel subscription */ - if (selected != NULL) { + if (p->selected != NULL) { grpc_connected_subchannel_notify_on_state_change( - exec_ctx, selected, NULL, NULL, &p->connectivity_changed); + 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); } - gpr_mu_unlock(&p->mu); while (pp != NULL) { pending_pick *next = pp->next; *pp->target = NULL; @@ -128,12 +120,11 @@ static void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { } } -static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, - grpc_connected_subchannel **target, - grpc_error *error) { +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; - gpr_mu_lock(&p->mu); pp = p->pending_picks; p->pending_picks = NULL; while (pp != NULL) { @@ -150,17 +141,15 @@ static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, } pp = next; } - gpr_mu_unlock(&p->mu); GRPC_ERROR_UNREF(error); } -static void pf_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, - uint32_t initial_metadata_flags_mask, - uint32_t initial_metadata_flags_eq, - grpc_error *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; - gpr_mu_lock(&p->mu); pp = p->pending_picks; p->pending_picks = NULL; while (pp != NULL) { @@ -177,7 +166,6 @@ static void pf_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, } pp = next; } - gpr_mu_unlock(&p->mu); GRPC_ERROR_UNREF(error); } @@ -192,63 +180,48 @@ static void start_picking(grpc_exec_ctx *exec_ctx, pick_first_lb_policy *p) { &p->connectivity_changed); } -static void pf_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { +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; - gpr_mu_lock(&p->mu); if (!p->started_picking) { start_picking(exec_ctx, p); } - gpr_mu_unlock(&p->mu); } -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) { +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 */ - grpc_connected_subchannel *selected = GET_SELECTED(p); - if (selected != NULL) { - *target = GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked"); + if (p->selected != NULL) { + *target = GRPC_CONNECTED_SUBCHANNEL_REF(p->selected, "picked"); 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 = GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked"); - 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; + /* 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(grpc_exec_ctx *exec_ctx, void *arg, - grpc_error *error) { - pick_first_lb_policy *p = arg; +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; - gpr_mu_lock(&p->mu); subchannels = p->subchannels; p->num_subchannels = 0; p->subchannels = NULL; - gpr_mu_unlock(&p->mu); GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "destroy_subchannels"); for (i = 0; i < num_subchannels; i++) { @@ -258,25 +231,19 @@ static void destroy_subchannels(grpc_exec_ctx *exec_ctx, void *arg, gpr_free(subchannels); } -static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg, - grpc_error *error) { +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_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) { + } 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; @@ -286,7 +253,7 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg, "selected_changed"); if (p->checking_connectivity != GRPC_CHANNEL_SHUTDOWN) { grpc_connected_subchannel_notify_on_state_change( - exec_ctx, selected, p->base.interested_parties, + 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"); @@ -301,26 +268,21 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg, 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"); + 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"); - gpr_atm_rel_store(&p->selected, (gpr_atm)selected); - grpc_closure_sched(exec_ctx, - grpc_closure_create(destroy_subchannels, p, - grpc_schedule_on_exec_ctx), - GRPC_ERROR_NONE); + 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(selected, "picked"); + *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, selected, p->base.interested_parties, + exec_ctx, p->selected, p->base.interested_parties, &p->checking_connectivity, &p->connectivity_changed); break; case GRPC_CHANNEL_TRANSIENT_FAILURE: @@ -387,48 +349,44 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg, } } - gpr_mu_unlock(&p->mu); - GRPC_ERROR_UNREF(error); } -static grpc_connectivity_state pf_check_connectivity(grpc_exec_ctx *exec_ctx, - grpc_lb_policy *pol, - grpc_error **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; - grpc_connectivity_state st; - gpr_mu_lock(&p->mu); - st = grpc_connectivity_state_check(&p->state_tracker, error); - gpr_mu_unlock(&p->mu); - return st; + return grpc_connectivity_state_get(&p->state_tracker, error); } -static void pf_notify_on_state_change(grpc_exec_ctx *exec_ctx, - grpc_lb_policy *pol, - grpc_connectivity_state *current, - grpc_closure *notify) { +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; - gpr_mu_lock(&p->mu); grpc_connectivity_state_notify_on_state_change(exec_ctx, &p->state_tracker, current, notify); - gpr_mu_unlock(&p->mu); } -static void pf_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, - grpc_closure *closure) { +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; - grpc_connected_subchannel *selected = GET_SELECTED(p); - if (selected) { - grpc_connected_subchannel_ping(exec_ctx, selected, closure); + if (p->selected) { + grpc_connected_subchannel_ping(exec_ctx, p->selected, closure); } else { grpc_closure_sched(exec_ctx, closure, GRPC_ERROR_CREATE("Not connected")); } } static const grpc_lb_policy_vtable pick_first_lb_policy_vtable = { - pf_destroy, pf_shutdown, pf_pick, - pf_cancel_pick, pf_cancel_picks, pf_ping_one, - pf_exit_idle, pf_check_connectivity, pf_notify_on_state_change}; + 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) {} @@ -489,10 +447,9 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx, } p->num_subchannels = subchannel_idx; - grpc_lb_policy_init(&p->base, &pick_first_lb_policy_vtable); - grpc_closure_init(&p->connectivity_changed, pf_connectivity_changed, p, - grpc_schedule_on_exec_ctx); - gpr_mu_init(&p->mu); + 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; } |