[PATCH 10/12] libxl: fork: Break out sigchld_installhandler_core

[Ian Jackson <ian.jackson@eu.citrix.com>]

Pure code motion.  This is going to make the final substantive patch
easier to read.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: Jim Fehlig <jfehlig@suse.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
---
 tools/libxl/libxl_fork.c |   38 ++++++++++++++++++++++----------------
 1 file changed, 22 insertions(+), 16 deletions(-)

diff --git a/tools/libxl/libxl_fork.c b/tools/libxl/libxl_fork.c
index a15af8e..ce8e8eb 100644
--- a/tools/libxl/libxl_fork.c
+++ b/tools/libxl/libxl_fork.c
@@ -194,6 +194,27 @@ static void sigchld_removehandler_core(void)
     sigchld_owner = 0;
 }
 
+static void sigchld_installhandler_core(libxl__gc *gc)
+{
+    struct sigaction ours;
+    int r;
+
+    assert(!sigchld_owner);
+    sigchld_owner = CTX;
+
+    memset(&ours,0,sizeof(ours));
+    ours.sa_handler = sigchld_handler;
+    sigemptyset(&ours.sa_mask);
+    ours.sa_flags = SA_NOCLDSTOP | SA_RESTART;
+    r = sigaction(SIGCHLD, &ours, &sigchld_saved_action);
+    assert(!r);
+
+    assert(((void)"application must negotiate with libxl about SIGCHLD",
+            !(sigchld_saved_action.sa_flags & SA_SIGINFO) &&
+            (sigchld_saved_action.sa_handler == SIG_DFL ||
+             sigchld_saved_action.sa_handler == SIG_IGN)));
+}
+
 void libxl__sigchld_notneeded(libxl__gc *gc) /* non-reentrant, idempotent */
 {
     int rc;
@@ -236,22 +257,7 @@ int libxl__sigchld_needed(libxl__gc *gc) /* non-reentrant, idempotent */
 
     atfork_lock();
     if (sigchld_owner != CTX) {
-        struct sigaction ours;
-
-        assert(!sigchld_owner);
-        sigchld_owner = CTX;
-
-        memset(&ours,0,sizeof(ours));
-        ours.sa_handler = sigchld_handler;
-        sigemptyset(&ours.sa_mask);
-        ours.sa_flags = SA_NOCLDSTOP | SA_RESTART;
-        r = sigaction(SIGCHLD, &ours, &sigchld_saved_action);
-        assert(!r);
-
-        assert(((void)"application must negotiate with libxl about SIGCHLD",
-                !(sigchld_saved_action.sa_flags & SA_SIGINFO) &&
-                (sigchld_saved_action.sa_handler == SIG_DFL ||
-                 sigchld_saved_action.sa_handler == SIG_IGN)));
+        sigchld_installhandler_core(gc);
     }
     atfork_unlock();
 
-- 
1.7.10.4