diff options
Diffstat (limited to 'src/core/lib/channel/deadline_filter.c')
-rw-r--r-- | src/core/lib/channel/deadline_filter.c | 107 |
1 files changed, 54 insertions, 53 deletions
diff --git a/src/core/lib/channel/deadline_filter.c b/src/core/lib/channel/deadline_filter.c index bc9a2effc2..5a12d62f1d 100644 --- a/src/core/lib/channel/deadline_filter.c +++ b/src/core/lib/channel/deadline_filter.c @@ -52,9 +52,6 @@ static void timer_callback(grpc_exec_ctx* exec_ctx, void* arg, grpc_error* error) { grpc_call_element* elem = arg; grpc_deadline_state* deadline_state = elem->call_data; - gpr_mu_lock(&deadline_state->timer_mu); - deadline_state->timer_pending = false; - gpr_mu_unlock(&deadline_state->timer_mu); if (error != GRPC_ERROR_CANCELLED) { grpc_call_element_signal_error( exec_ctx, elem, @@ -66,53 +63,64 @@ static void timer_callback(grpc_exec_ctx* exec_ctx, void* arg, } // Starts the deadline timer. -static void start_timer_if_needed_locked(grpc_exec_ctx* exec_ctx, - grpc_call_element* elem, - gpr_timespec deadline) { - grpc_deadline_state* deadline_state = elem->call_data; - deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC); - // Note: We do not start the timer if there is already a timer - // pending. This should be okay, because this is only called from two - // functions exported by this module: grpc_deadline_state_start(), which - // starts the initial timer, and grpc_deadline_state_reset(), which - // cancels any pre-existing timer before starting a new one. In - // particular, we want to ensure that if grpc_deadline_state_start() - // winds up trying to start the timer after grpc_deadline_state_reset() - // has already done so, we ignore the value from the former. - if (!deadline_state->timer_pending && - gpr_time_cmp(deadline, gpr_inf_future(GPR_CLOCK_MONOTONIC)) != 0) { - // Take a reference to the call stack, to be owned by the timer. - GRPC_CALL_STACK_REF(deadline_state->call_stack, "deadline_timer"); - deadline_state->timer_pending = true; - grpc_closure_init(&deadline_state->timer_callback, timer_callback, elem, - grpc_schedule_on_exec_ctx); - grpc_timer_init(exec_ctx, &deadline_state->timer, deadline, - &deadline_state->timer_callback, - gpr_now(GPR_CLOCK_MONOTONIC)); - } -} static void start_timer_if_needed(grpc_exec_ctx* exec_ctx, grpc_call_element* elem, gpr_timespec deadline) { + deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC); + if (gpr_time_cmp(deadline, gpr_inf_future(GPR_CLOCK_MONOTONIC)) == 0) { + return; + } grpc_deadline_state* deadline_state = elem->call_data; - gpr_mu_lock(&deadline_state->timer_mu); - start_timer_if_needed_locked(exec_ctx, elem, deadline); - gpr_mu_unlock(&deadline_state->timer_mu); + grpc_deadline_timer_state cur_state; + grpc_closure* closure = NULL; +retry: + cur_state = + (grpc_deadline_timer_state)gpr_atm_acq_load(&deadline_state->timer_state); + switch (cur_state) { + case GRPC_DEADLINE_STATE_PENDING: + // Note: We do not start the timer if there is already a timer + return; + case GRPC_DEADLINE_STATE_FINISHED: + if (gpr_atm_rel_cas(&deadline_state->timer_state, + GRPC_DEADLINE_STATE_FINISHED, + GRPC_DEADLINE_STATE_PENDING)) { + // If we've already created and destroyed a timer, we always create a + // new closure: we have no other guarantee that the inlined closure is + // not in use (it may hold a pending call to timer_callback) + closure = grpc_closure_create(timer_callback, elem, + grpc_schedule_on_exec_ctx); + } else { + goto retry; + } + break; + case GRPC_DEADLINE_STATE_INITIAL: + if (gpr_atm_rel_cas(&deadline_state->timer_state, + GRPC_DEADLINE_STATE_INITIAL, + GRPC_DEADLINE_STATE_PENDING)) { + closure = + grpc_closure_init(&deadline_state->timer_callback, timer_callback, + elem, grpc_schedule_on_exec_ctx); + } else { + goto retry; + } + break; + } + GPR_ASSERT(closure); + GRPC_CALL_STACK_REF(deadline_state->call_stack, "deadline_timer"); + grpc_timer_init(exec_ctx, &deadline_state->timer, deadline, closure, + gpr_now(GPR_CLOCK_MONOTONIC)); } // Cancels the deadline timer. -static void cancel_timer_if_needed_locked(grpc_exec_ctx* exec_ctx, - grpc_deadline_state* deadline_state) { - if (deadline_state->timer_pending) { - grpc_timer_cancel(exec_ctx, &deadline_state->timer); - deadline_state->timer_pending = false; - } -} static void cancel_timer_if_needed(grpc_exec_ctx* exec_ctx, grpc_deadline_state* deadline_state) { - gpr_mu_lock(&deadline_state->timer_mu); - cancel_timer_if_needed_locked(exec_ctx, deadline_state); - gpr_mu_unlock(&deadline_state->timer_mu); + if (gpr_atm_rel_cas(&deadline_state->timer_state, GRPC_DEADLINE_STATE_PENDING, + GRPC_DEADLINE_STATE_FINISHED)) { + grpc_timer_cancel(exec_ctx, &deadline_state->timer); + } else { + // timer was either in STATE_INITAL (nothing to cancel) + // OR in STATE_FINISHED (again nothing to cancel) + } } // Callback run when the call is complete. @@ -120,8 +128,8 @@ static void on_complete(grpc_exec_ctx* exec_ctx, void* arg, grpc_error* error) { grpc_deadline_state* deadline_state = arg; cancel_timer_if_needed(exec_ctx, deadline_state); // Invoke the next callback. - deadline_state->next_on_complete->cb( - exec_ctx, deadline_state->next_on_complete->cb_arg, error); + grpc_closure_run(exec_ctx, deadline_state->next_on_complete, + GRPC_ERROR_REF(error)); } // Inject our own on_complete callback into op. @@ -136,16 +144,13 @@ static void inject_on_complete_cb(grpc_deadline_state* deadline_state, void grpc_deadline_state_init(grpc_exec_ctx* exec_ctx, grpc_call_element* elem, grpc_call_stack* call_stack) { grpc_deadline_state* deadline_state = elem->call_data; - memset(deadline_state, 0, sizeof(*deadline_state)); deadline_state->call_stack = call_stack; - gpr_mu_init(&deadline_state->timer_mu); } void grpc_deadline_state_destroy(grpc_exec_ctx* exec_ctx, grpc_call_element* elem) { grpc_deadline_state* deadline_state = elem->call_data; cancel_timer_if_needed(exec_ctx, deadline_state); - gpr_mu_destroy(&deadline_state->timer_mu); } // Callback and associated state for starting the timer after call stack @@ -187,10 +192,8 @@ void grpc_deadline_state_start(grpc_exec_ctx* exec_ctx, grpc_call_element* elem, void grpc_deadline_state_reset(grpc_exec_ctx* exec_ctx, grpc_call_element* elem, gpr_timespec new_deadline) { grpc_deadline_state* deadline_state = elem->call_data; - gpr_mu_lock(&deadline_state->timer_mu); - cancel_timer_if_needed_locked(exec_ctx, deadline_state); - start_timer_if_needed_locked(exec_ctx, elem, new_deadline); - gpr_mu_unlock(&deadline_state->timer_mu); + cancel_timer_if_needed(exec_ctx, deadline_state); + start_timer_if_needed(exec_ctx, elem, new_deadline); } void grpc_deadline_state_client_start_transport_stream_op( @@ -244,9 +247,7 @@ typedef struct server_call_data { // Constructor for call_data. Used for both client and server filters. static grpc_error* init_call_elem(grpc_exec_ctx* exec_ctx, grpc_call_element* elem, - grpc_call_element_args* args) { - // Note: size of call data is different between client and server. - memset(elem->call_data, 0, elem->filter->sizeof_call_data); + const grpc_call_element_args* args) { grpc_deadline_state_init(exec_ctx, elem, args->call_stack); grpc_deadline_state_start(exec_ctx, elem, args->deadline); return GRPC_ERROR_NONE; |