Optionalize deadline checking
diff --git a/src/core/ext/filters/deadline/deadline_filter.c b/src/core/ext/filters/deadline/deadline_filter.c
new file mode 100644
index 0000000..18f7145
--- /dev/null
+++ b/src/core/ext/filters/deadline/deadline_filter.c
@@ -0,0 +1,377 @@
+//
+// Copyright 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/ext/filters/deadline/deadline_filter.h"
+
+#include <stdbool.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/time.h>
+
+#include "src/core/lib/channel/channel_stack_builder.h"
+#include "src/core/lib/iomgr/exec_ctx.h"
+#include "src/core/lib/iomgr/timer.h"
+#include "src/core/lib/slice/slice_internal.h"
+#include "src/core/lib/surface/channel_init.h"
+
+//
+// grpc_deadline_state
+//
+
+// Timer callback.
+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;
+ if (error != GRPC_ERROR_CANCELLED) {
+ grpc_call_element_signal_error(
+ exec_ctx, elem,
+ grpc_error_set_int(
+ GRPC_ERROR_CREATE_FROM_STATIC_STRING("Deadline Exceeded"),
+ GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_DEADLINE_EXCEEDED));
+ }
+ GRPC_CALL_STACK_UNREF(exec_ctx, deadline_state->call_stack, "deadline_timer");
+}
+
+// Starts the deadline timer.
+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;
+ 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(grpc_exec_ctx* exec_ctx,
+ grpc_deadline_state* deadline_state) {
+ 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.
+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.
+ grpc_closure_run(exec_ctx, deadline_state->next_on_complete,
+ GRPC_ERROR_REF(error));
+}
+
+// Inject our own on_complete callback into op.
+static void inject_on_complete_cb(grpc_deadline_state* deadline_state,
+ grpc_transport_stream_op* op) {
+ deadline_state->next_on_complete = op->on_complete;
+ grpc_closure_init(&deadline_state->on_complete, on_complete, deadline_state,
+ grpc_schedule_on_exec_ctx);
+ op->on_complete = &deadline_state->on_complete;
+}
+
+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;
+ deadline_state->call_stack = call_stack;
+}
+
+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);
+}
+
+// Callback and associated state for starting the timer after call stack
+// initialization has been completed.
+struct start_timer_after_init_state {
+ grpc_call_element* elem;
+ gpr_timespec deadline;
+ grpc_closure closure;
+};
+static void start_timer_after_init(grpc_exec_ctx* exec_ctx, void* arg,
+ grpc_error* error) {
+ struct start_timer_after_init_state* state = arg;
+ start_timer_if_needed(exec_ctx, state->elem, state->deadline);
+ gpr_free(state);
+}
+
+void grpc_deadline_state_start(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
+ gpr_timespec deadline) {
+ // Deadline will always be infinite on servers, so the timer will only be
+ // set on clients with a finite deadline.
+ deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
+ if (gpr_time_cmp(deadline, gpr_inf_future(GPR_CLOCK_MONOTONIC)) != 0) {
+ // When the deadline passes, we indicate the failure by sending down
+ // an op with cancel_error set. However, we can't send down any ops
+ // until after the call stack is fully initialized. If we start the
+ // timer here, we have no guarantee that the timer won't pop before
+ // call stack initialization is finished. To avoid that problem, we
+ // create a closure to start the timer, and we schedule that closure
+ // to be run after call stack initialization is done.
+ struct start_timer_after_init_state* state = gpr_malloc(sizeof(*state));
+ state->elem = elem;
+ state->deadline = deadline;
+ grpc_closure_init(&state->closure, start_timer_after_init, state,
+ grpc_schedule_on_exec_ctx);
+ grpc_closure_sched(exec_ctx, &state->closure, GRPC_ERROR_NONE);
+ }
+}
+
+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;
+ 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(
+ grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
+ grpc_transport_stream_op* op) {
+ grpc_deadline_state* deadline_state = elem->call_data;
+ if (op->cancel_error != GRPC_ERROR_NONE) {
+ cancel_timer_if_needed(exec_ctx, deadline_state);
+ } else {
+ // Make sure we know when the call is complete, so that we can cancel
+ // the timer.
+ if (op->recv_trailing_metadata != NULL) {
+ inject_on_complete_cb(deadline_state, op);
+ }
+ }
+}
+
+//
+// filter code
+//
+
+// Constructor for channel_data. Used for both client and server filters.
+static grpc_error* init_channel_elem(grpc_exec_ctx* exec_ctx,
+ grpc_channel_element* elem,
+ grpc_channel_element_args* args) {
+ GPR_ASSERT(!args->is_last);
+ return GRPC_ERROR_NONE;
+}
+
+// Destructor for channel_data. Used for both client and server filters.
+static void destroy_channel_elem(grpc_exec_ctx* exec_ctx,
+ grpc_channel_element* elem) {}
+
+// Call data used for both client and server filter.
+typedef struct base_call_data {
+ grpc_deadline_state deadline_state;
+} base_call_data;
+
+// Additional call data used only for the server filter.
+typedef struct server_call_data {
+ base_call_data base; // Must be first.
+ // The closure for receiving initial metadata.
+ grpc_closure recv_initial_metadata_ready;
+ // Received initial metadata batch.
+ grpc_metadata_batch* recv_initial_metadata;
+ // The original recv_initial_metadata_ready closure, which we chain to
+ // after our own closure is invoked.
+ grpc_closure* next_recv_initial_metadata_ready;
+} 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,
+ 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;
+}
+
+// Destructor for call_data. Used for both client and server filters.
+static void destroy_call_elem(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
+ const grpc_call_final_info* final_info,
+ grpc_closure* ignored) {
+ grpc_deadline_state_destroy(exec_ctx, elem);
+}
+
+// Method for starting a call op for client filter.
+static void client_start_transport_stream_op(grpc_exec_ctx* exec_ctx,
+ grpc_call_element* elem,
+ grpc_transport_stream_op* op) {
+ grpc_deadline_state_client_start_transport_stream_op(exec_ctx, elem, op);
+ // Chain to next filter.
+ grpc_call_next_op(exec_ctx, elem, op);
+}
+
+// Callback for receiving initial metadata on the server.
+static void recv_initial_metadata_ready(grpc_exec_ctx* exec_ctx, void* arg,
+ grpc_error* error) {
+ grpc_call_element* elem = arg;
+ server_call_data* calld = elem->call_data;
+ // Get deadline from metadata and start the timer if needed.
+ start_timer_if_needed(exec_ctx, elem, calld->recv_initial_metadata->deadline);
+ // Invoke the next callback.
+ calld->next_recv_initial_metadata_ready->cb(
+ exec_ctx, calld->next_recv_initial_metadata_ready->cb_arg, error);
+}
+
+// Method for starting a call op for server filter.
+static void server_start_transport_stream_op(grpc_exec_ctx* exec_ctx,
+ grpc_call_element* elem,
+ grpc_transport_stream_op* op) {
+ server_call_data* calld = elem->call_data;
+ if (op->cancel_error != GRPC_ERROR_NONE) {
+ cancel_timer_if_needed(exec_ctx, &calld->base.deadline_state);
+ } else {
+ // If we're receiving initial metadata, we need to get the deadline
+ // from the recv_initial_metadata_ready callback. So we inject our
+ // own callback into that hook.
+ if (op->recv_initial_metadata_ready != NULL) {
+ calld->next_recv_initial_metadata_ready = op->recv_initial_metadata_ready;
+ calld->recv_initial_metadata = op->recv_initial_metadata;
+ grpc_closure_init(&calld->recv_initial_metadata_ready,
+ recv_initial_metadata_ready, elem,
+ grpc_schedule_on_exec_ctx);
+ op->recv_initial_metadata_ready = &calld->recv_initial_metadata_ready;
+ }
+ // Make sure we know when the call is complete, so that we can cancel
+ // the timer.
+ // Note that we trigger this on recv_trailing_metadata, even though
+ // the client never sends trailing metadata, because this is the
+ // hook that tells us when the call is complete on the server side.
+ if (op->recv_trailing_metadata != NULL) {
+ inject_on_complete_cb(&calld->base.deadline_state, op);
+ }
+ }
+ // Chain to next filter.
+ grpc_call_next_op(exec_ctx, elem, op);
+}
+
+const grpc_channel_filter grpc_client_deadline_filter = {
+ client_start_transport_stream_op,
+ grpc_channel_next_op,
+ sizeof(base_call_data),
+ init_call_elem,
+ grpc_call_stack_ignore_set_pollset_or_pollset_set,
+ destroy_call_elem,
+ 0, // sizeof(channel_data)
+ init_channel_elem,
+ destroy_channel_elem,
+ grpc_call_next_get_peer,
+ grpc_channel_next_get_info,
+ "deadline",
+};
+
+const grpc_channel_filter grpc_server_deadline_filter = {
+ server_start_transport_stream_op,
+ grpc_channel_next_op,
+ sizeof(server_call_data),
+ init_call_elem,
+ grpc_call_stack_ignore_set_pollset_or_pollset_set,
+ destroy_call_elem,
+ 0, // sizeof(channel_data)
+ init_channel_elem,
+ destroy_channel_elem,
+ grpc_call_next_get_peer,
+ grpc_channel_next_get_info,
+ "deadline",
+};
+
+bool grpc_deadline_checking_enabled(const grpc_channel_args* channel_args) {
+ bool enable = !grpc_channel_args_want_minimal_stack(channel_args);
+ const grpc_arg* a =
+ grpc_channel_args_find(channel_args, GRPC_ARG_ENABLE_DEADLINE_CHECKS);
+ if (a != NULL && a->type == GRPC_ARG_INTEGER && a->value.integer != 0) {
+ enable = true;
+ }
+ return enable;
+}
+
+static bool maybe_add_deadline_filter(grpc_exec_ctx* exec_ctx,
+ grpc_channel_stack_builder* builder,
+ void* arg) {
+ return grpc_deadline_checking_enabled(
+ grpc_channel_stack_builder_get_channel_arguments(builder))
+ ? grpc_channel_stack_builder_prepend_filter(builder, arg, NULL,
+ NULL)
+ : true;
+}
+
+void grpc_deadline_filter_init(void) {
+ grpc_channel_init_register_stage(
+ GRPC_CLIENT_DIRECT_CHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+ maybe_add_deadline_filter, (void*)&grpc_client_deadline_filter);
+ grpc_channel_init_register_stage(
+ GRPC_SERVER_CHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+ maybe_add_deadline_filter, (void*)&grpc_server_deadline_filter);
+}
+
+void grpc_deadline_filter_shutdown(void) {}