Merge pull request #2281 from ctiller/and-he-told-us-of-his-life

Fix iomgr shutdown TSAN races

src/core/iomgr/fd_posix.c

@@ -74,6 +74,7 @@ static void freelist_fd(grpc_fd *fd) {
   gpr_mu_lock(&fd_freelist_mu);
   fd->freelist_next = fd_freelist;
   fd_freelist = fd;
+  grpc_iomgr_unregister_object(&fd->iomgr_object);
   gpr_mu_unlock(&fd_freelist_mu);
 }
 
@@ -139,7 +140,6 @@ static void unref_by(grpc_fd *fd, int n) {
 #endif
   old = gpr_atm_full_fetch_add(&fd->refst, -n);
   if (old == n) {
-    grpc_iomgr_unregister_object(&fd->iomgr_object);
     freelist_fd(fd);
   } else {
     GPR_ASSERT(old > n);

src/core/iomgr/resolve_address_posix.c

@@ -155,9 +155,9 @@ static void do_request(void *rp) {
   grpc_resolve_cb cb = r->cb;
   gpr_free(r->name);
   gpr_free(r->default_port);
+  cb(arg, resolved);
   grpc_iomgr_unregister_object(&r->iomgr_object);
   gpr_free(r);
-  cb(arg, resolved);
 }
 
 void grpc_resolved_addresses_destroy(grpc_resolved_addresses *addrs) {