Merge remote-tracking branch 'upstream/master' into filter_call_init_failure

4 files changed, 157 insertions, 119 deletions

diff --git a/src/core/ext/load_reporting/load_reporting.c b/src/core/ext/load_reporting/load_reporting.c
index 9e4d32676f..df1ea0ec9a 100644
--- a/src/core/ext/load_reporting/load_reporting.c
+++ b/src/core/ext/load_reporting/load_reporting.c
@@ -42,42 +42,12 @@
 #include "src/core/lib/channel/channel_stack_builder.h"
 #include "src/core/lib/surface/channel_init.h"
 
-struct grpc_load_reporting_config {
-  grpc_load_reporting_fn fn;
-  void *user_data;
-};
-
-grpc_load_reporting_config *grpc_load_reporting_config_create(
-    grpc_load_reporting_fn fn, void *user_data) {
-  GPR_ASSERT(fn != NULL);
-  grpc_load_reporting_config *lrc =
-      gpr_malloc(sizeof(grpc_load_reporting_config));
-  lrc->fn = fn;
-  lrc->user_data = user_data;
-  return lrc;
-}
-
-grpc_load_reporting_config *grpc_load_reporting_config_copy(
-    grpc_load_reporting_config *src) {
-  return grpc_load_reporting_config_create(src->fn, src->user_data);
-}
-
-void grpc_load_reporting_config_destroy(grpc_load_reporting_config *lrc) {
-  gpr_free(lrc);
-}
-
-void grpc_load_reporting_config_call(
-    grpc_load_reporting_config *lrc,
-    const grpc_load_reporting_call_data *call_data) {
-  lrc->fn(call_data, lrc->user_data);
-}
-
 static bool is_load_reporting_enabled(const grpc_channel_args *a) {
   if (a == NULL) return false;
   for (size_t i = 0; i < a->num_args; i++) {
     if (0 == strcmp(a->args[i].key, GRPC_ARG_ENABLE_LOAD_REPORTING)) {
-      return a->args[i].type == GRPC_ARG_POINTER &&
-             a->args[i].value.pointer.p != NULL;
+      return a->args[i].type == GRPC_ARG_INTEGER &&
+             a->args[i].value.integer != 0;
     }
   }
   return false;
@@ -94,37 +64,17 @@ static bool maybe_add_load_reporting_filter(grpc_channel_stack_builder *builder,
   return true;
 }
 
-static void lrd_arg_destroy(void *p) { grpc_load_reporting_config_destroy(p); }
-
-static void *lrd_arg_copy(void *p) {
-  return grpc_load_reporting_config_copy(p);
-}
-
-static int lrd_arg_cmp(void *a, void *b) {
-  grpc_load_reporting_config *lhs = a;
-  grpc_load_reporting_config *rhs = b;
-  return !(lhs->fn == rhs->fn && lhs->user_data == rhs->user_data);
-}
-
-static const grpc_arg_pointer_vtable lrd_ptr_vtable = {
-    lrd_arg_copy, lrd_arg_destroy, lrd_arg_cmp};
-
-grpc_arg grpc_load_reporting_config_create_arg(
-    grpc_load_reporting_config *lrc) {
+grpc_arg grpc_load_reporting_enable_arg() {
   grpc_arg arg;
-  arg.type = GRPC_ARG_POINTER;
+  arg.type = GRPC_ARG_INTEGER;
   arg.key = GRPC_ARG_ENABLE_LOAD_REPORTING;
-  arg.value.pointer.p = lrc;
-  arg.value.pointer.vtable = &lrd_ptr_vtable;
+  arg.value.integer = 1;
   return arg;
 }
 
 /* Plugin registration */
 
 void grpc_load_reporting_plugin_init(void) {
-  grpc_channel_init_register_stage(GRPC_CLIENT_CHANNEL, INT_MAX,
-                                   maybe_add_load_reporting_filter,
-                                   (void *)&grpc_load_reporting_filter);
   grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX,
                                    maybe_add_load_reporting_filter,
                                    (void *)&grpc_load_reporting_filter);
diff --git a/src/core/ext/load_reporting/load_reporting.h b/src/core/ext/load_reporting/load_reporting.h
index 316cd89bd7..e37817d8c2 100644
--- a/src/core/ext/load_reporting/load_reporting.h
+++ b/src/core/ext/load_reporting/load_reporting.h
@@ -34,42 +34,47 @@
 #ifndef GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_H
 #define GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_H
 
-#include "src/core/lib/iomgr/closure.h"
-#include "src/core/lib/surface/call.h"
+#include <grpc/impl/codegen/grpc_types.h>
+#include "src/core/lib/channel/channel_stack.h"
 
-typedef struct grpc_load_reporting_config grpc_load_reporting_config;
+/** Metadata key for initial metadata coming from clients */
+/* TODO(dgq): change to the final value TBD */
+#define GRPC_LOAD_REPORTING_INITIAL_MD_KEY "load-reporting-initial"
 
-/** Call information to be passed to the provided load reporting function upon
- * completion of the call */
-typedef struct grpc_load_reporting_call_data {
-  const grpc_call_stats *stats;   /**< Stats for the call */
-  const char *trailing_md_string; /**< LR trailing metadata info */
-} grpc_load_reporting_call_data;
+/** Metadata key for trailing metadata from servers */
+/* TODO(dgq): change to the final value TBD */
+#define GRPC_LOAD_REPORTING_TRAILING_MD_KEY "load-reporting-trailing"
 
-/** Custom function to be called by the load reporting filter. */
-typedef void (*grpc_load_reporting_fn)(
-    const grpc_load_reporting_call_data *call_data, void *user_data);
+/** Identifiers for the invocation point of the users LR callback */
+typedef enum grpc_load_reporting_source {
+  GRPC_LR_POINT_UNKNOWN = 0,
+  GRPC_LR_POINT_CHANNEL_CREATION,
+  GRPC_LR_POINT_CHANNEL_DESTRUCTION,
+  GRPC_LR_POINT_CALL_CREATION,
+  GRPC_LR_POINT_CALL_DESTRUCTION
+} grpc_load_reporting_source;
 
-/** Register \a fn as the function to be invoked by the load reporting filter.
- * \a fn will be invoked at the beginning and at the end of the call.
- *
- * For the first invocation, \a fn's first argument
- * (grpc_load_reporting_call_data*) will be NULL. \a user_data is always passed
- * as-is. */
-grpc_load_reporting_config *grpc_load_reporting_config_create(
-    grpc_load_reporting_fn fn, void *user_data);
+/** Call information to be passed to the provided LR callback. */
+typedef struct grpc_load_reporting_call_data {
+  const grpc_load_reporting_source source; /**< point of last data update. */
+
+  /** Unique identifier for the channel associated with the data */
+  intptr_t channel_id;
 
-grpc_load_reporting_config *grpc_load_reporting_config_copy(
-    grpc_load_reporting_config *src);
+  /** Unique identifier for the call associated with the data. If the call
+   * hasn't been created yet, it'll have a value of zero. */
+  intptr_t call_id;
 
-void grpc_load_reporting_config_destroy(grpc_load_reporting_config *lrc);
+  /** Only valid when \a source is \a GRPC_LR_POINT_CALL_DESTRUCTION, that is,
+   * once the call has completed */
+  const grpc_call_final_info *final_info;
 
-/** Invoke the function registered by \a grpc_load_reporting_init. */
-void grpc_load_reporting_config_call(
-    grpc_load_reporting_config *lrc,
-    const grpc_load_reporting_call_data *call_data);
+  const char *initial_md_string;  /**< value string for LR's initial md key */
+  const char *trailing_md_string; /**< value string for LR's trailing md key */
+  const char *method_name;        /**< Corresponds to :path header */
+} grpc_load_reporting_call_data;
 
 /** Return a \a grpc_arg enabling load reporting */
-grpc_arg grpc_load_reporting_config_create_arg(grpc_load_reporting_config *lrc);
+grpc_arg grpc_load_reporting_enable_arg();
 
 #endif /* GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_H */
diff --git a/src/core/ext/load_reporting/load_reporting_filter.c b/src/core/ext/load_reporting/load_reporting_filter.c
index b584e31c5d..394f0cb832 100644
--- a/src/core/ext/load_reporting/load_reporting_filter.c
+++ b/src/core/ext/load_reporting/load_reporting_filter.c
@@ -31,6 +31,7 @@
  *
  */
 
+#include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/sync.h>
@@ -42,17 +43,67 @@
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/transport/static_metadata.h"
 
-typedef struct call_data { const char *trailing_md_string; } call_data;
+typedef struct call_data {
+  intptr_t id; /**< an id unique to the call */
+  char *trailing_md_string;
+  char *initial_md_string;
+  const char *service_method;
+
+  /* stores the recv_initial_metadata op's ready closure, which we wrap with our
+   * own (on_initial_md_ready) in order to capture the incoming initial metadata
+   * */
+  grpc_closure *ops_recv_initial_metadata_ready;
+
+  /* to get notified of the availability of the incoming initial metadata. */
+  grpc_closure on_initial_md_ready;
+  grpc_metadata_batch *recv_initial_metadata;
+} call_data;
+
 typedef struct channel_data {
-  gpr_mu mu;
-  grpc_load_reporting_config *lrc;
+  intptr_t id; /**< an id unique to the channel */
 } channel_data;
 
-static void invoke_lr_fn_locked(grpc_load_reporting_config *lrc,
-                                grpc_load_reporting_call_data *lr_call_data) {
-  GPR_TIMER_BEGIN("load_reporting_config_fn", 0);
-  grpc_load_reporting_config_call(lrc, lr_call_data);
-  GPR_TIMER_END("load_reporting_config_fn", 0);
+typedef struct {
+  grpc_call_element *elem;
+  grpc_exec_ctx *exec_ctx;
+} recv_md_filter_args;
+
+static grpc_mdelem *recv_md_filter(void *user_data, grpc_mdelem *md) {
+  recv_md_filter_args *a = user_data;
+  grpc_call_element *elem = a->elem;
+  call_data *calld = elem->call_data;
+
+  if (md->key == GRPC_MDSTR_PATH) {
+    calld->service_method = grpc_mdstr_as_c_string(md->value);
+  } else if (md->key == GRPC_MDSTR_LOAD_REPORTING_INITIAL) {
+    calld->initial_md_string = gpr_strdup(grpc_mdstr_as_c_string(md->value));
+    return NULL;
+  }
+
+  return md;
+}
+
+static void on_initial_md_ready(grpc_exec_ctx *exec_ctx, void *user_data,
+                                grpc_error *err) {
+  grpc_call_element *elem = user_data;
+  call_data *calld = elem->call_data;
+
+  if (err == GRPC_ERROR_NONE) {
+    recv_md_filter_args a;
+    a.elem = elem;
+    a.exec_ctx = exec_ctx;
+    grpc_metadata_batch_filter(calld->recv_initial_metadata, recv_md_filter,
+                               &a);
+    if (calld->service_method == NULL) {
+      err =
+          grpc_error_add_child(err, GRPC_ERROR_CREATE("Missing :path header"));
+    }
+  } else {
+    GRPC_ERROR_REF(err);
+  }
+  calld->ops_recv_initial_metadata_ready->cb(
+      exec_ctx, calld->ops_recv_initial_metadata_ready->cb_arg, err);
+  GRPC_ERROR_UNREF(err);
 }
 
 /* Constructor for call_data */
@@ -61,21 +112,43 @@ static grpc_error *init_call_elem(grpc_exec_ctx *exec_ctx,
                                   grpc_call_element_args *args) {
   call_data *calld = elem->call_data;
   memset(calld, 0, sizeof(call_data));
+
+  calld->id = (intptr_t)args->call_stack;
+  grpc_closure_init(&calld->on_initial_md_ready, on_initial_md_ready, elem);
+
+  /* TODO(dgq): do something with the data
+  channel_data *chand = elem->channel_data;
+  grpc_load_reporting_call_data lr_call_data = {GRPC_LR_POINT_CALL_CREATION,
+                                                (intptr_t)chand->id,
+                                                (intptr_t)calld->id,
+                                                NULL,
+                                                NULL,
+                                                NULL,
+                                                NULL};
+  */
+
   return GRPC_ERROR_NONE;
 }
 
 /* Destructor for call_data */
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                              const grpc_call_stats *stats, void *ignored) {
-  channel_data *chand = elem->channel_data;
+                              const grpc_call_final_info *final_info,
+                              void *ignored) {
   call_data *calld = elem->call_data;
 
-  grpc_load_reporting_call_data lr_call_data = {stats,
-                                                calld->trailing_md_string};
-
-  gpr_mu_lock(&chand->mu);
-  invoke_lr_fn_locked(chand->lrc, &lr_call_data);
-  gpr_mu_unlock(&chand->mu);
+  /* TODO(dgq): do something with the data
+  channel_data *chand = elem->channel_data;
+  grpc_load_reporting_call_data lr_call_data = {GRPC_LR_POINT_CALL_DESTRUCTION,
+                                                (intptr_t)chand->id,
+                                                (intptr_t)calld->id,
+                                                final_info,
+                                                calld->initial_md_string,
+                                                calld->trailing_md_string,
+                                                calld->service_method};
+  */
+
+  gpr_free(calld->initial_md_string);
+  gpr_free(calld->trailing_md_string);
 }
 
 /* Constructor for channel_data */
@@ -87,37 +160,40 @@ static void init_channel_elem(grpc_exec_ctx *exec_ctx,
   channel_data *chand = elem->channel_data;
   memset(chand, 0, sizeof(channel_data));
 
-  gpr_mu_init(&chand->mu);
-  for (size_t i = 0; i < args->channel_args->num_args; i++) {
-    if (0 == strcmp(args->channel_args->args[i].key,
-                    GRPC_ARG_ENABLE_LOAD_REPORTING)) {
-      grpc_load_reporting_config *arg_lrc =
-          args->channel_args->args[i].value.pointer.p;
-      chand->lrc = grpc_load_reporting_config_copy(arg_lrc);
-      GPR_ASSERT(chand->lrc != NULL);
-      break;
-    }
-  }
-  GPR_ASSERT(chand->lrc != NULL); /* arg actually found */
-
-  gpr_mu_lock(&chand->mu);
-  invoke_lr_fn_locked(chand->lrc, NULL);
-  gpr_mu_unlock(&chand->mu);
+  chand->id = (intptr_t)args->channel_stack;
+
+  /* TODO(dgq): do something with the data
+  grpc_load_reporting_call_data lr_call_data = {GRPC_LR_POINT_CHANNEL_CREATION,
+                                                (intptr_t)chand,
+                                                0,
+                                                NULL,
+                                                NULL,
+                                                NULL,
+                                                NULL};
+                                                */
 }
 
 /* Destructor for channel data */
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
                                  grpc_channel_element *elem) {
+  /* TODO(dgq): do something with the data
   channel_data *chand = elem->channel_data;
-  gpr_mu_destroy(&chand->mu);
-  grpc_load_reporting_config_destroy(chand->lrc);
+  grpc_load_reporting_call_data lr_call_data = {
+      GRPC_LR_POINT_CHANNEL_DESTRUCTION,
+      (intptr_t)chand->id,
+      0,
+      NULL,
+      NULL,
+      NULL,
+      NULL};
+  */
 }
 
 static grpc_mdelem *lr_trailing_md_filter(void *user_data, grpc_mdelem *md) {
   grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
 
-  if (md->key == GRPC_MDSTR_LOAD_REPORTING) {
+  if (md->key == GRPC_MDSTR_LOAD_REPORTING_TRAILING) {
     calld->trailing_md_string = gpr_strdup(grpc_mdstr_as_c_string(md->value));
     return NULL;
   }
@@ -129,8 +205,14 @@ static void lr_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
                                          grpc_call_element *elem,
                                          grpc_transport_stream_op *op) {
   GPR_TIMER_BEGIN("lr_start_transport_stream_op", 0);
+  call_data *calld = elem->call_data;
 
-  if (op->send_trailing_metadata) {
+  if (op->recv_initial_metadata) {
+    calld->recv_initial_metadata = op->recv_initial_metadata;
+    /* substitute our callback for the higher callback */
+    calld->ops_recv_initial_metadata_ready = op->recv_initial_metadata_ready;
+    op->recv_initial_metadata_ready = &calld->on_initial_md_ready;
+  } else if (op->send_trailing_metadata) {
     grpc_metadata_batch_filter(op->send_trailing_metadata,
                                lr_trailing_md_filter, elem);
   }
diff --git a/src/core/ext/load_reporting/load_reporting_filter.h b/src/core/ext/load_reporting/load_reporting_filter.h
index f69cd6fdc6..160ed32af9 100644
--- a/src/core/ext/load_reporting/load_reporting_filter.h
+++ b/src/core/ext/load_reporting/load_reporting_filter.h
@@ -34,6 +34,7 @@
 #ifndef GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_FILTER_H
 #define GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_FILTER_H
 
+#include "src/core/ext/load_reporting/load_reporting.h"
 #include "src/core/lib/channel/channel_stack.h"
 
 extern const grpc_channel_filter grpc_load_reporting_filter;