1 files changed, 108 insertions, 0 deletions
diff --git a/src/core/lib/surface/channel_init.cc b/src/core/lib/surface/channel_init.cc
new file mode 100644
index 0000000000..33f444b89e
--- /dev/null
+++ b/src/core/lib/surface/channel_init.cc
@@ -0,0 +1,108 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include "src/core/lib/surface/channel_init.h"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/useful.h>
+
+typedef struct stage_slot {
+  grpc_channel_init_stage fn;
+  void *arg;
+  int priority;
+  size_t insertion_order;
+} stage_slot;
+
+typedef struct stage_slots {
+  stage_slot *slots;
+  size_t num_slots;
+  size_t cap_slots;
+} stage_slots;
+
+static stage_slots g_slots[GRPC_NUM_CHANNEL_STACK_TYPES];
+static bool g_finalized;
+
+void grpc_channel_init_init(void) {
+  for (int i = 0; i < GRPC_NUM_CHANNEL_STACK_TYPES; i++) {
+    g_slots[i].slots = NULL;
+    g_slots[i].num_slots = 0;
+    g_slots[i].cap_slots = 0;
+  }
+  g_finalized = false;
+}
+
+void grpc_channel_init_register_stage(grpc_channel_stack_type type,
+                                      int priority,
+                                      grpc_channel_init_stage stage,
+                                      void *stage_arg) {
+  GPR_ASSERT(!g_finalized);
+  if (g_slots[type].cap_slots == g_slots[type].num_slots) {
+    g_slots[type].cap_slots = GPR_MAX(8, 3 * g_slots[type].cap_slots / 2);
+    g_slots[type].slots = (stage_slot *)gpr_realloc(
+        g_slots[type].slots,
+        g_slots[type].cap_slots * sizeof(*g_slots[type].slots));
+  }
+  stage_slot *s = &g_slots[type].slots[g_slots[type].num_slots++];
+  s->insertion_order = g_slots[type].num_slots;
+  s->priority = priority;
+  s->fn = stage;
+  s->arg = stage_arg;
+}
+
+static int compare_slots(const void *a, const void *b) {
+  const stage_slot *sa = (const stage_slot *)a;
+  const stage_slot *sb = (const stage_slot *)b;
+
+  int c = GPR_ICMP(sa->priority, sb->priority);
+  if (c != 0) return c;
+  return GPR_ICMP(sa->insertion_order, sb->insertion_order);
+}
+
+void grpc_channel_init_finalize(void) {
+  GPR_ASSERT(!g_finalized);
+  for (int i = 0; i < GRPC_NUM_CHANNEL_STACK_TYPES; i++) {
+    qsort(g_slots[i].slots, g_slots[i].num_slots, sizeof(*g_slots[i].slots),
+          compare_slots);
+  }
+  g_finalized = true;
+}
+
+void grpc_channel_init_shutdown(void) {
+  for (int i = 0; i < GRPC_NUM_CHANNEL_STACK_TYPES; i++) {
+    gpr_free(g_slots[i].slots);
+    g_slots[i].slots = (stage_slot *)(void *)(uintptr_t)0xdeadbeef;
+  }
+}
+
+bool grpc_channel_init_create_stack(grpc_exec_ctx *exec_ctx,
+                                    grpc_channel_stack_builder *builder,
+                                    grpc_channel_stack_type type) {
+  GPR_ASSERT(g_finalized);
+
+  grpc_channel_stack_builder_set_name(builder,
+                                      grpc_channel_stack_type_string(type));
+
+  for (size_t i = 0; i < g_slots[type].num_slots; i++) {
+    const stage_slot *slot = &g_slots[type].slots[i];
+    if (!slot->fn(exec_ctx, builder, slot->arg)) {
+      return false;
+    }
+  }
+
+  return true;
+}