Merge pull request #9746 from yang-g/handshake_mgr

Contain the links for the pending handshake managers inside handshake…
diff --git a/src/core/ext/transport/chttp2/server/chttp2_server.c b/src/core/ext/transport/chttp2/server/chttp2_server.c
index ae2c383..0fc180d 100644
--- a/src/core/ext/transport/chttp2/server/chttp2_server.c
+++ b/src/core/ext/transport/chttp2/server/chttp2_server.c
@@ -55,11 +55,6 @@
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/server.h"
 
-typedef struct pending_handshake_manager_node {
-  grpc_handshake_manager *handshake_mgr;
-  struct pending_handshake_manager_node *next;
-} pending_handshake_manager_node;
-
 typedef struct {
   grpc_server *server;
   grpc_tcp_server *tcp_server;
@@ -68,7 +63,7 @@
   bool shutdown;
   grpc_closure tcp_server_shutdown_complete;
   grpc_closure *server_destroy_listener_done;
-  pending_handshake_manager_node *pending_handshake_mgrs;
+  grpc_handshake_manager *pending_handshake_mgrs;
 } server_state;
 
 typedef struct {
@@ -78,44 +73,6 @@
   grpc_handshake_manager *handshake_mgr;
 } server_connection_state;
 
-static void pending_handshake_manager_add_locked(
-    server_state *state, grpc_handshake_manager *handshake_mgr) {
-  pending_handshake_manager_node *node = gpr_malloc(sizeof(*node));
-  node->handshake_mgr = handshake_mgr;
-  node->next = state->pending_handshake_mgrs;
-  state->pending_handshake_mgrs = node;
-}
-
-static void pending_handshake_manager_remove_locked(
-    server_state *state, grpc_handshake_manager *handshake_mgr) {
-  pending_handshake_manager_node **prev_node = &state->pending_handshake_mgrs;
-  for (pending_handshake_manager_node *node = state->pending_handshake_mgrs;
-       node != NULL; node = node->next) {
-    if (node->handshake_mgr == handshake_mgr) {
-      *prev_node = node->next;
-      gpr_free(node);
-      break;
-    }
-    prev_node = &node->next;
-  }
-}
-
-static void pending_handshake_manager_shutdown_locked(grpc_exec_ctx *exec_ctx,
-                                                      server_state *state,
-                                                      grpc_error *why) {
-  pending_handshake_manager_node *prev_node = NULL;
-  for (pending_handshake_manager_node *node = state->pending_handshake_mgrs;
-       node != NULL; node = node->next) {
-    grpc_handshake_manager_shutdown(exec_ctx, node->handshake_mgr,
-                                    GRPC_ERROR_REF(why));
-    gpr_free(prev_node);
-    prev_node = node;
-  }
-  gpr_free(prev_node);
-  state->pending_handshake_mgrs = NULL;
-  GRPC_ERROR_UNREF(why);
-}
-
 static void on_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
                               grpc_error *error) {
   grpc_handshaker_args *args = arg;
@@ -153,8 +110,9 @@
       grpc_channel_args_destroy(exec_ctx, args->args);
     }
   }
-  pending_handshake_manager_remove_locked(connection_state->server_state,
-                                          connection_state->handshake_mgr);
+  grpc_handshake_manager_pending_list_remove(
+      &connection_state->server_state->pending_handshake_mgrs,
+      connection_state->handshake_mgr);
   gpr_mu_unlock(&connection_state->server_state->mu);
   grpc_handshake_manager_destroy(exec_ctx, connection_state->handshake_mgr);
   grpc_tcp_server_unref(exec_ctx, connection_state->server_state->tcp_server);
@@ -174,7 +132,8 @@
     return;
   }
   grpc_handshake_manager *handshake_mgr = grpc_handshake_manager_create();
-  pending_handshake_manager_add_locked(state, handshake_mgr);
+  grpc_handshake_manager_pending_list_add(&state->pending_handshake_mgrs,
+                                          handshake_mgr);
   gpr_mu_unlock(&state->mu);
   grpc_tcp_server_ref(state->tcp_server);
   server_connection_state *connection_state =
@@ -213,8 +172,8 @@
   gpr_mu_lock(&state->mu);
   grpc_closure *destroy_done = state->server_destroy_listener_done;
   GPR_ASSERT(state->shutdown);
-  pending_handshake_manager_shutdown_locked(exec_ctx, state,
-                                            GRPC_ERROR_REF(error));
+  grpc_handshake_manager_pending_list_shutdown_all(
+      exec_ctx, state->pending_handshake_mgrs, GRPC_ERROR_REF(error));
   gpr_mu_unlock(&state->mu);
   // Flush queued work before destroying handshaker factory, since that
   // may do a synchronous unref.
diff --git a/src/core/lib/channel/handshaker.c b/src/core/lib/channel/handshaker.c
index 5bed2d0..82c361c 100644
--- a/src/core/lib/channel/handshaker.c
+++ b/src/core/lib/channel/handshaker.c
@@ -92,6 +92,10 @@
   void* user_data;
   // Handshaker args.
   grpc_handshaker_args args;
+  // Links to the previous and next managers in a list of all pending handshakes
+  // Used at server side only.
+  grpc_handshake_manager* prev;
+  grpc_handshake_manager* next;
 };
 
 grpc_handshake_manager* grpc_handshake_manager_create() {
@@ -102,6 +106,39 @@
   return mgr;
 }
 
+void grpc_handshake_manager_pending_list_add(grpc_handshake_manager** head,
+                                             grpc_handshake_manager* mgr) {
+  GPR_ASSERT(mgr->prev == NULL);
+  GPR_ASSERT(mgr->next == NULL);
+  mgr->next = *head;
+  if (*head) {
+    (*head)->prev = mgr;
+  }
+  *head = mgr;
+}
+
+void grpc_handshake_manager_pending_list_remove(grpc_handshake_manager** head,
+                                                grpc_handshake_manager* mgr) {
+  if (mgr->next != NULL) {
+    mgr->next->prev = mgr->prev;
+  }
+  if (mgr->prev != NULL) {
+    mgr->prev->next = mgr->next;
+  } else {
+    GPR_ASSERT(*head == mgr);
+    *head = mgr->next;
+  }
+}
+
+void grpc_handshake_manager_pending_list_shutdown_all(
+    grpc_exec_ctx* exec_ctx, grpc_handshake_manager* head, grpc_error* why) {
+  while (head != NULL) {
+    grpc_handshake_manager_shutdown(exec_ctx, head, GRPC_ERROR_REF(why));
+    head = head->next;
+  }
+  GRPC_ERROR_UNREF(why);
+}
+
 static bool is_power_of_2(size_t n) { return (n & (n - 1)) == 0; }
 
 void grpc_handshake_manager_add(grpc_handshake_manager* mgr,
diff --git a/src/core/lib/channel/handshaker.h b/src/core/lib/channel/handshaker.h
index a8e3692..5f97c3f 100644
--- a/src/core/lib/channel/handshaker.h
+++ b/src/core/lib/channel/handshaker.h
@@ -163,4 +163,20 @@
     gpr_timespec deadline, grpc_tcp_server_acceptor* acceptor,
     grpc_iomgr_cb_func on_handshake_done, void* user_data);
 
+/// Add \a mgr to the server side list of all pending handshake managers, the
+/// list starts with \a *head.
+// Not thread-safe. Caller needs to synchronize.
+void grpc_handshake_manager_pending_list_add(grpc_handshake_manager** head,
+                                             grpc_handshake_manager* mgr);
+
+/// Remove \a mgr from the server side list of all pending handshake managers.
+// Not thread-safe. Caller needs to synchronize.
+void grpc_handshake_manager_pending_list_remove(grpc_handshake_manager** head,
+                                                grpc_handshake_manager* mgr);
+
+/// Shutdown all pending handshake managers on the server side.
+// Not thread-safe. Caller needs to synchronize.
+void grpc_handshake_manager_pending_list_shutdown_all(
+    grpc_exec_ctx* exec_ctx, grpc_handshake_manager* head, grpc_error* why);
+
 #endif /* GRPC_CORE_LIB_CHANNEL_HANDSHAKER_H */