Add resize test

src/core/lib/iomgr/buffer_pool.c

@@ -138,6 +138,10 @@ static void bpstep_sched(grpc_exec_ctx *exec_ctx,
 
 /* returns true if all allocations are completed */
 static bool bpalloc(grpc_exec_ctx *exec_ctx, grpc_buffer_pool *buffer_pool) {
+  if (buffer_pool->free_pool <= 0) {
+    return false;
+  }
+
   grpc_buffer_user *buffer_user;
   while ((buffer_user =
               bulist_pop(buffer_pool, GRPC_BULIST_AWAITING_ALLOCATION))) {
@@ -242,6 +246,25 @@ static void bu_post_destructive_reclaimer(grpc_exec_ctx *exec_ctx, void *bu,
   bulist_add_tail(buffer_user, GRPC_BULIST_RECLAIMER_DESTRUCTIVE);
 }
 
+typedef struct {
+  int64_t size;
+  grpc_buffer_pool *buffer_pool;
+  grpc_closure closure;
+} bp_resize_args;
+
+static void bp_resize(grpc_exec_ctx *exec_ctx, void *args, grpc_error *error) {
+  bp_resize_args *a = args;
+  int64_t delta = a->size - a->buffer_pool->size;
+  a->buffer_pool->size += delta;
+  a->buffer_pool->free_pool += delta;
+  if (delta < 0 && a->buffer_pool->free_pool < 0) {
+    bpstep_sched(exec_ctx, a->buffer_pool);
+  } else if (delta > 0 &&
+             !bulist_empty(a->buffer_pool, GRPC_BULIST_AWAITING_ALLOCATION)) {
+    bpstep_sched(exec_ctx, a->buffer_pool);
+  }
+}
+
 /*******************************************************************************
  * grpc_buffer_pool api
  */
@@ -279,6 +302,17 @@ void grpc_buffer_pool_ref(grpc_buffer_pool *buffer_pool) {
   grpc_buffer_pool_internal_ref(buffer_pool);
 }
 
+void grpc_buffer_pool_resize(grpc_buffer_pool *buffer_pool, size_t size) {
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  bp_resize_args *a = gpr_malloc(sizeof(*a));
+  a->buffer_pool = grpc_buffer_pool_internal_ref(buffer_pool);
+  a->size = (int64_t)size;
+  grpc_closure_init(&a->closure, bp_resize, a);
+  grpc_combiner_execute(&exec_ctx, buffer_pool->combiner, &a->closure,
+                        GRPC_ERROR_NONE);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
 /*******************************************************************************
  * grpc_buffer_user api
  */

test/core/iomgr/buffer_pool_test.c

@@ -42,10 +42,18 @@ static void test_no_op(void) {
   grpc_buffer_pool_unref(grpc_buffer_pool_create());
 }
 
+static void test_resize_then_destroy(void) {
+  gpr_log(GPR_DEBUG, "** test_resize_then_destroy **");
+  grpc_buffer_pool *p = grpc_buffer_pool_create();
+  grpc_buffer_pool_resize(p, 1024 * 1024);
+  grpc_buffer_pool_unref(p);
+}
+
 int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
   grpc_init();
   test_no_op();
+  test_resize_then_destroy();
   grpc_shutdown();
   return 0;
 }