3 files changed, 59 insertions, 4 deletions
diff --git a/src/core/lib/channel/handshaker.c b/src/core/lib/channel/handshaker.c
index 5bed2d041d..82c361c7ef 100644
--- a/src/core/lib/channel/handshaker.c
+++ b/src/core/lib/channel/handshaker.c
@@ -92,6 +92,10 @@ struct grpc_handshake_manager {
   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 @@ grpc_handshake_manager* grpc_handshake_manager_create() {
   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 a8e3692add..5f97c3fc73 100644
--- a/src/core/lib/channel/handshaker.h
+++ b/src/core/lib/channel/handshaker.h
@@ -163,4 +163,20 @@ void grpc_handshake_manager_do_handshake(
     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 */
diff --git a/src/core/lib/support/sync_posix.c b/src/core/lib/support/sync_posix.c
index de0f0484b5..16e7d6e12a 100644
--- a/src/core/lib/support/sync_posix.c
+++ b/src/core/lib/support/sync_posix.c
@@ -42,8 +42,10 @@
 #include <time.h>
 #include "src/core/lib/profiling/timers.h"
 
-#ifdef GPR_MU_COUNTERS
-gpr_atm grpc_mu_locks = 0;
+#ifdef GPR_LOW_LEVEL_COUNTERS
+gpr_atm gpr_mu_locks = 0;
+gpr_atm gpr_counter_atm_cas = 0;
+gpr_atm gpr_counter_atm_add = 0;
 #endif
 
 void gpr_mu_init(gpr_mu* mu) { GPR_ASSERT(pthread_mutex_init(mu, NULL) == 0); }
@@ -51,8 +53,8 @@ void gpr_mu_init(gpr_mu* mu) { GPR_ASSERT(pthread_mutex_init(mu, NULL) == 0); }
 void gpr_mu_destroy(gpr_mu* mu) { GPR_ASSERT(pthread_mutex_destroy(mu) == 0); }
 
 void gpr_mu_lock(gpr_mu* mu) {
-#ifdef GPR_MU_COUNTERS
-  gpr_atm_no_barrier_fetch_add(&grpc_mu_locks, 1);
+#ifdef GPR_LOW_LEVEL_COUNTERS
+  GPR_ATM_INC_COUNTER(gpr_mu_locks);
 #endif
   GPR_TIMER_BEGIN("gpr_mu_lock", 0);
   GPR_ASSERT(pthread_mutex_lock(mu) == 0);