Fix a TSAN reported error

We now pass down pointers to closures instead of (callback, arg) pair
elements separately. This allows us to store one word atomically, fixing
a race condition.

All call sites have been updated to the new API. No new allocations are
incurred. grpc_fd_state is deleted to avoid any temptation to ever add
anything there again.

1 files changed, 5 insertions, 2 deletions

diff --git a/src/core/iomgr/tcp_server_posix.c b/src/core/iomgr/tcp_server_posix.c
index b7a0625949..90b7eb451d 100644
--- a/src/core/iomgr/tcp_server_posix.c
+++ b/src/core/iomgr/tcp_server_posix.c
@@ -82,6 +82,7 @@ typedef struct {
     struct sockaddr_un un;
   } addr;
   int addr_len;
+  grpc_iomgr_closure read_closure;
 } server_port;
 
 static void unlink_if_unix_domain_socket(const struct sockaddr_un *un) {
@@ -244,7 +245,7 @@ static void on_read(void *arg, int success) {
         case EINTR:
           continue;
         case EAGAIN:
-          grpc_fd_notify_on_read(sp->emfd, on_read, sp);
+          grpc_fd_notify_on_read(sp->emfd, &sp->read_closure);
           return;
         default:
           gpr_log(GPR_ERROR, "Failed accept4: %s", strerror(errno));
@@ -393,7 +394,9 @@ void grpc_tcp_server_start(grpc_tcp_server *s, grpc_pollset **pollsets,
     for (j = 0; j < pollset_count; j++) {
       grpc_pollset_add_fd(pollsets[j], s->ports[i].emfd);
     }
-    grpc_fd_notify_on_read(s->ports[i].emfd, on_read, &s->ports[i]);
+    s->ports[i].read_closure.cb = on_read;
+    s->ports[i].read_closure.cb_arg = &s->ports[i];
+    grpc_fd_notify_on_read(s->ports[i].emfd, &s->ports[i].read_closure);
     s->active_ports++;
   }
   gpr_mu_unlock(&s->mu);