Merge pull request #8303 from markdroth/service_config

Support service configs in core.

7 files changed, 153 insertions, 40 deletions

diff --git a/src/core/lib/channel/channel_args.c b/src/core/lib/channel/channel_args.c
index 3a56b1ff20..2957d2c818 100644
--- a/src/core/lib/channel/channel_args.c
+++ b/src/core/lib/channel/channel_args.c
@@ -272,6 +272,18 @@ int grpc_channel_args_compare(const grpc_channel_args *a,
   return 0;
 }
 
+const grpc_arg *grpc_channel_args_find(const grpc_channel_args *args,
+                                       const char *name) {
+  if (args != NULL) {
+    for (size_t i = 0; i < args->num_args; ++i) {
+      if (strcmp(args->args[i].key, name) == 0) {
+        return &args->args[i];
+      }
+    }
+  }
+  return NULL;
+}
+
 int grpc_channel_arg_get_integer(grpc_arg *arg, grpc_integer_options options) {
   if (arg->type != GRPC_ARG_INTEGER) {
     gpr_log(GPR_ERROR, "%s ignored: it must be an integer", arg->key);
diff --git a/src/core/lib/channel/channel_args.h b/src/core/lib/channel/channel_args.h
index 586a296d1f..a80340c0fa 100644
--- a/src/core/lib/channel/channel_args.h
+++ b/src/core/lib/channel/channel_args.h
@@ -89,6 +89,10 @@ uint32_t grpc_channel_args_compression_algorithm_get_states(
 int grpc_channel_args_compare(const grpc_channel_args *a,
                               const grpc_channel_args *b);
 
+/** Returns the value of argument \a name from \a args, or NULL if not found. */
+const grpc_arg *grpc_channel_args_find(const grpc_channel_args *args,
+                                       const char *name);
+
 typedef struct grpc_integer_options {
   int default_value;  // Return this if value is outside of expected bounds.
   int min_value;
diff --git a/src/core/lib/channel/channel_stack.c b/src/core/lib/channel/channel_stack.c
index 57d34d9e9a..2c5367901d 100644
--- a/src/core/lib/channel/channel_stack.c
+++ b/src/core/lib/channel/channel_stack.c
@@ -162,7 +162,7 @@ grpc_error *grpc_call_stack_init(
     grpc_exec_ctx *exec_ctx, grpc_channel_stack *channel_stack,
     int initial_refs, grpc_iomgr_cb_func destroy, void *destroy_arg,
     grpc_call_context_element *context, const void *transport_server_data,
-    gpr_timespec deadline, grpc_call_stack *call_stack) {
+    grpc_mdstr *path, gpr_timespec deadline, grpc_call_stack *call_stack) {
   grpc_channel_element *channel_elems = CHANNEL_ELEMS_FROM_STACK(channel_stack);
   grpc_call_element_args args;
   size_t count = channel_stack->count;
@@ -179,10 +179,12 @@ grpc_error *grpc_call_stack_init(
 
   /* init per-filter data */
   grpc_error *first_error = GRPC_ERROR_NONE;
+  args.start_time = gpr_now(GPR_CLOCK_MONOTONIC);
   for (i = 0; i < count; i++) {
     args.call_stack = call_stack;
     args.server_transport_data = transport_server_data;
     args.context = context;
+    args.path = path;
     args.deadline = deadline;
     call_elems[i].filter = channel_elems[i].filter;
     call_elems[i].channel_data = channel_elems[i].channel_data;
diff --git a/src/core/lib/channel/channel_stack.h b/src/core/lib/channel/channel_stack.h
index 1cfe2885d8..27f3be7b29 100644
--- a/src/core/lib/channel/channel_stack.h
+++ b/src/core/lib/channel/channel_stack.h
@@ -74,6 +74,8 @@ typedef struct {
   grpc_call_stack *call_stack;
   const void *server_transport_data;
   grpc_call_context_element *context;
+  grpc_mdstr *path;
+  gpr_timespec start_time;
   gpr_timespec deadline;
 } grpc_call_element_args;
 
@@ -225,7 +227,7 @@ grpc_error *grpc_call_stack_init(
     grpc_exec_ctx *exec_ctx, grpc_channel_stack *channel_stack,
     int initial_refs, grpc_iomgr_cb_func destroy, void *destroy_arg,
     grpc_call_context_element *context, const void *transport_server_data,
-    gpr_timespec deadline, grpc_call_stack *call_stack);
+    grpc_mdstr *path, gpr_timespec deadline, grpc_call_stack *call_stack);
 /* Set a pollset or a pollset_set for a call stack: must occur before the first
  * op is started */
 void grpc_call_stack_set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx,
diff --git a/src/core/lib/channel/deadline_filter.c b/src/core/lib/channel/deadline_filter.c
index 079b98a2f8..d2ea5250f6 100644
--- a/src/core/lib/channel/deadline_filter.c
+++ b/src/core/lib/channel/deadline_filter.c
@@ -64,30 +64,49 @@ static void timer_callback(grpc_exec_ctx* exec_ctx, void* arg,
 }
 
 // Starts the deadline timer.
-static void start_timer_if_needed(grpc_exec_ctx* exec_ctx,
-                                  grpc_call_element* elem,
-                                  gpr_timespec deadline) {
+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);
-  if (gpr_time_cmp(deadline, gpr_inf_future(GPR_CLOCK_MONOTONIC)) != 0) {
+  // 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");
-    gpr_mu_lock(&deadline_state->timer_mu);
     deadline_state->timer_pending = true;
     grpc_timer_init(exec_ctx, &deadline_state->timer, deadline, timer_callback,
                     elem, gpr_now(GPR_CLOCK_MONOTONIC));
-    gpr_mu_unlock(&deadline_state->timer_mu);
   }
 }
+static void start_timer_if_needed(grpc_exec_ctx* exec_ctx,
+                                  grpc_call_element* elem,
+                                  gpr_timespec deadline) {
+  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);
+}
 
 // Cancels the deadline timer.
-static void cancel_timer_if_needed(grpc_exec_ctx* exec_ctx,
-                                   grpc_deadline_state* deadline_state) {
-  gpr_mu_lock(&deadline_state->timer_mu);
+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);
 }
 
@@ -108,6 +127,21 @@ static void inject_on_complete_cb(grpc_deadline_state* deadline_state,
   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;
+  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
 // initialization has been completed.
 struct start_timer_after_init_state {
@@ -122,16 +156,11 @@ static void start_timer_after_init(grpc_exec_ctx* exec_ctx, void* arg,
   gpr_free(state);
 }
 
-void grpc_deadline_state_init(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
-                              grpc_call_element_args* args) {
-  grpc_deadline_state* deadline_state = elem->call_data;
-  memset(deadline_state, 0, sizeof(*deadline_state));
-  deadline_state->call_stack = args->call_stack;
-  gpr_mu_init(&deadline_state->timer_mu);
+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.
-  const gpr_timespec deadline =
-      gpr_convert_clock_type(args->deadline, GPR_CLOCK_MONOTONIC);
+  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
@@ -148,11 +177,13 @@ void grpc_deadline_state_init(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
   }
 }
 
-void grpc_deadline_state_destroy(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;
-  cancel_timer_if_needed(exec_ctx, deadline_state);
-  gpr_mu_destroy(&deadline_state->timer_mu);
+  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);
 }
 
 void grpc_deadline_state_client_start_transport_stream_op(
@@ -209,7 +240,8 @@ static grpc_error* init_call_elem(grpc_exec_ctx* exec_ctx,
                                   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);
-  grpc_deadline_state_init(exec_ctx, elem, args);
+  grpc_deadline_state_init(exec_ctx, elem, args->call_stack);
+  grpc_deadline_state_start(exec_ctx, elem, args->deadline);
   return GRPC_ERROR_NONE;
 }
 
diff --git a/src/core/lib/channel/deadline_filter.h b/src/core/lib/channel/deadline_filter.h
index 685df87761..716a852565 100644
--- a/src/core/lib/channel/deadline_filter.h
+++ b/src/core/lib/channel/deadline_filter.h
@@ -54,18 +54,37 @@ typedef struct grpc_deadline_state {
   grpc_closure* next_on_complete;
 } grpc_deadline_state;
 
-// To be used in a filter's init_call_elem(), destroy_call_elem(), and
-// start_transport_stream_op() methods to enforce call deadlines.
 //
-// REQUIRES: The first field in elem->call_data is a grpc_deadline_state.
+// NOTE: All of these functions require that the first field in
+// elem->call_data is a grpc_deadline_state.
 //
-// For grpc_deadline_state_client_start_transport_stream_op(), it is the
-// caller's responsibility to chain to the next filter if necessary
-// after the function returns.
+
 void grpc_deadline_state_init(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
-                              grpc_call_element_args* args);
+                              grpc_call_stack* call_stack);
 void grpc_deadline_state_destroy(grpc_exec_ctx* exec_ctx,
                                  grpc_call_element* elem);
+
+// Starts the timer with the specified deadline.
+// Should be called from the filter's init_call_elem() method.
+void grpc_deadline_state_start(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
+                               gpr_timespec deadline);
+
+// Cancels the existing timer and starts a new one with new_deadline.
+//
+// Note: It is generally safe to call this with an earlier deadline
+// value than the current one, but not the reverse.  No checks are done
+// to ensure that the timer callback is not invoked while it is in the
+// process of being reset, which means that attempting to increase the
+// deadline may result in the timer being called twice.
+void grpc_deadline_state_reset(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
+                               gpr_timespec new_deadline);
+
+// To be called from the client-side filter's start_transport_stream_op()
+// method.  Ensures that the deadline timer is cancelled when the call
+// is completed.
+//
+// Note: It is the caller's responsibility to chain to the next filter if
+// necessary after this function returns.
 void grpc_deadline_state_client_start_transport_stream_op(
     grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
     grpc_transport_stream_op* op);
diff --git a/src/core/lib/channel/message_size_filter.c b/src/core/lib/channel/message_size_filter.c
index f067a3a51c..1382f19945 100644
--- a/src/core/lib/channel/message_size_filter.c
+++ b/src/core/lib/channel/message_size_filter.c
@@ -38,6 +38,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/ext/client_config/method_config.h"
 #include "src/core/lib/channel/channel_args.h"
 
 #define DEFAULT_MAX_SEND_MESSAGE_LENGTH -1  // Unlimited.
@@ -45,6 +46,8 @@
 #define DEFAULT_MAX_RECV_MESSAGE_LENGTH (4 * 1024 * 1024)
 
 typedef struct call_data {
+  int max_send_size;
+  int max_recv_size;
   // Receive closures are chained: we inject this closure as the
   // recv_message_ready up-call on transport_stream_op, and remember to
   // call our next_recv_message_ready member after handling it.
@@ -58,6 +61,8 @@ typedef struct call_data {
 typedef struct channel_data {
   int max_send_size;
   int max_recv_size;
+  // Method config table.
+  grpc_method_config_table* method_config_table;
 } channel_data;
 
 // Callback invoked when we receive a message.  Here we check the max
@@ -66,13 +71,12 @@ static void recv_message_ready(grpc_exec_ctx* exec_ctx, void* user_data,
                                grpc_error* error) {
   grpc_call_element* elem = user_data;
   call_data* calld = elem->call_data;
-  channel_data* chand = elem->channel_data;
-  if (*calld->recv_message != NULL && chand->max_recv_size >= 0 &&
-      (*calld->recv_message)->length > (size_t)chand->max_recv_size) {
+  if (*calld->recv_message != NULL && calld->max_recv_size >= 0 &&
+      (*calld->recv_message)->length > (size_t)calld->max_recv_size) {
     char* message_string;
     gpr_asprintf(&message_string,
                  "Received message larger than max (%u vs. %d)",
-                 (*calld->recv_message)->length, chand->max_recv_size);
+                 (*calld->recv_message)->length, calld->max_recv_size);
     grpc_error* new_error = grpc_error_set_int(
         GRPC_ERROR_CREATE(message_string), GRPC_ERROR_INT_GRPC_STATUS,
         GRPC_STATUS_INVALID_ARGUMENT);
@@ -93,13 +97,12 @@ static void start_transport_stream_op(grpc_exec_ctx* exec_ctx,
                                       grpc_call_element* elem,
                                       grpc_transport_stream_op* op) {
   call_data* calld = elem->call_data;
-  channel_data* chand = elem->channel_data;
   // Check max send message size.
-  if (op->send_message != NULL && chand->max_send_size >= 0 &&
-      op->send_message->length > (size_t)chand->max_send_size) {
+  if (op->send_message != NULL && calld->max_send_size >= 0 &&
+      op->send_message->length > (size_t)calld->max_send_size) {
     char* message_string;
     gpr_asprintf(&message_string, "Sent message larger than max (%u vs. %d)",
-                 op->send_message->length, chand->max_send_size);
+                 op->send_message->length, calld->max_send_size);
     gpr_slice message = gpr_slice_from_copied_string(message_string);
     gpr_free(message_string);
     grpc_call_element_send_close_with_message(
@@ -119,9 +122,37 @@ static void start_transport_stream_op(grpc_exec_ctx* exec_ctx,
 static grpc_error* init_call_elem(grpc_exec_ctx* exec_ctx,
                                   grpc_call_element* elem,
                                   grpc_call_element_args* args) {
+  channel_data* chand = elem->channel_data;
   call_data* calld = elem->call_data;
   calld->next_recv_message_ready = NULL;
   grpc_closure_init(&calld->recv_message_ready, recv_message_ready, elem);
+  // Get max sizes from channel data, then merge in per-method config values.
+  // Note: Per-method config is only available on the client, so we
+  // apply the max request size to the send limit and the max response
+  // size to the receive limit.
+  calld->max_send_size = chand->max_send_size;
+  calld->max_recv_size = chand->max_recv_size;
+  if (chand->method_config_table != NULL) {
+    grpc_method_config* method_config =
+        grpc_method_config_table_get_method_config(chand->method_config_table,
+                                                   args->path);
+    if (method_config != NULL) {
+      const int32_t* max_request_message_bytes =
+          grpc_method_config_get_max_request_message_bytes(method_config);
+      if (max_request_message_bytes != NULL &&
+          (*max_request_message_bytes < calld->max_send_size ||
+           calld->max_send_size < 0)) {
+        calld->max_send_size = *max_request_message_bytes;
+      }
+      const int32_t* max_response_message_bytes =
+          grpc_method_config_get_max_response_message_bytes(method_config);
+      if (max_response_message_bytes != NULL &&
+          (*max_response_message_bytes < calld->max_recv_size ||
+           calld->max_recv_size < 0)) {
+        calld->max_recv_size = *max_response_message_bytes;
+      }
+    }
+  }
   return GRPC_ERROR_NONE;
 }
 
@@ -155,11 +186,22 @@ static void init_channel_elem(grpc_exec_ctx* exec_ctx,
           grpc_channel_arg_get_integer(&args->channel_args->args[i], options);
     }
   }
+  // Get method config table from channel args.
+  const grpc_arg* channel_arg =
+      grpc_channel_args_find(args->channel_args, GRPC_ARG_SERVICE_CONFIG);
+  if (channel_arg != NULL) {
+    GPR_ASSERT(channel_arg->type == GRPC_ARG_POINTER);
+    chand->method_config_table = grpc_method_config_table_ref(
+        (grpc_method_config_table*)channel_arg->value.pointer.p);
+  }
 }
 
 // Destructor for channel_data.
 static void destroy_channel_elem(grpc_exec_ctx* exec_ctx,
-                                 grpc_channel_element* elem) {}
+                                 grpc_channel_element* elem) {
+  channel_data* chand = elem->channel_data;
+  grpc_method_config_table_unref(chand->method_config_table);
+}
 
 const grpc_channel_filter grpc_message_size_filter = {
     start_transport_stream_op,