2 files changed, 16 insertions, 1 deletions
diff --git a/src/core/lib/support/mpscq.c b/src/core/lib/support/mpscq.c
index 5b9323275a..1015cc6776 100644
--- a/src/core/lib/support/mpscq.c
+++ b/src/core/lib/support/mpscq.c
@@ -54,21 +54,31 @@ void gpr_mpscq_push(gpr_mpscq *q, gpr_mpscq_node *n) {
 }
 
 gpr_mpscq_node *gpr_mpscq_pop(gpr_mpscq *q) {
+  bool empty;
+  return gpr_mpscq_pop_and_check_end(q, &empty);
+}
+
+gpr_mpscq_node *gpr_mpscq_pop_and_check_end(gpr_mpscq *q, bool *empty) {
   gpr_mpscq_node *tail = q->tail;
   gpr_mpscq_node *next = (gpr_mpscq_node *)gpr_atm_acq_load(&tail->next);
   if (tail == &q->stub) {
     // indicates the list is actually (ephemerally) empty
-    if (next == NULL) return NULL;
+    if (next == NULL) {
+      *empty = true;
+      return NULL;
+    }
     q->tail = next;
     tail = next;
     next = (gpr_mpscq_node *)gpr_atm_acq_load(&tail->next);
   }
   if (next != NULL) {
+    *empty = false;
     q->tail = next;
     return tail;
   }
   gpr_mpscq_node *head = (gpr_mpscq_node *)gpr_atm_acq_load(&q->head);
   if (tail != head) {
+    *empty = false;
     // indicates a retry is in order: we're still adding
     return NULL;
   }
@@ -79,5 +89,6 @@ gpr_mpscq_node *gpr_mpscq_pop(gpr_mpscq *q) {
     return tail;
   }
   // indicates a retry is in order: we're still adding
+  *empty = false;
   return NULL;
 }
diff --git a/src/core/lib/support/mpscq.h b/src/core/lib/support/mpscq.h
index 977a117952..24c89f90c9 100644
--- a/src/core/lib/support/mpscq.h
+++ b/src/core/lib/support/mpscq.h
@@ -35,6 +35,7 @@
 #define GRPC_CORE_LIB_SUPPORT_MPSCQ_H
 
 #include <grpc/support/atm.h>
+#include <stdbool.h>
 #include <stddef.h>
 
 // Multiple-producer single-consumer lock free queue, based upon the
@@ -62,4 +63,7 @@ void gpr_mpscq_push(gpr_mpscq *q, gpr_mpscq_node *n);
 // the queue is empty!!)
 gpr_mpscq_node *gpr_mpscq_pop(gpr_mpscq *q);
 
+// Pop a node; sets *empty to true if the queue is empty, or false if it is not
+gpr_mpscq_node *gpr_mpscq_pop_and_check_end(gpr_mpscq *q, bool *empty);
+
 #endif /* GRPC_CORE_LIB_SUPPORT_MPSCQ_H */