libxl: events: Deregister, don't just modify, sigchld pipe fd

We want to have no fd events registered when we are idle.  This
implies that we must be able to deregister our interest in the sigchld
self-pipe fd, not just modify to request no events.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Tested-by: Ian Campbell <ian.campbell@citrix.com>
Release-Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/tools/libxl/libxl_fork.c b/tools/libxl/libxl_fork.c
index fa150959adcfa6618342ba1eb0085cbba5f75d0a..144208aef23d4ae2e1c17ac0742b32e035468a54 100644 (file)
--- a/tools/libxl/libxl_fork.c
+++ b/tools/libxl/libxl_fork.c
@@ -372,15 +372,8 @@ static void sigchld_user_remove(libxl_ctx *ctx) /* idempotent */
 
 void libxl__sigchld_notneeded(libxl__gc *gc) /* non-reentrant, idempotent */
 {
-    int rc;
-
     sigchld_user_remove(CTX);
-
-    if (libxl__ev_fd_isregistered(&CTX->sigchld_selfpipe_efd)) {
-        rc = libxl__ev_fd_modify(gc, &CTX->sigchld_selfpipe_efd, 0);
-        if (rc)
-            libxl__ev_fd_deregister(gc, &CTX->sigchld_selfpipe_efd);
-    }
+    libxl__ev_fd_deregister(gc, &CTX->sigchld_selfpipe_efd);
 }
 
 int libxl__sigchld_needed(libxl__gc *gc) /* non-reentrant, idempotent */