main-loop: remove dead code

qemu_add_child_watch is not called anywhere since commit 2bdb920ece
("slirp: simplify fork_exec()", 2019-01-14), remove it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

include/qemu/main-loop.h

@@ -234,24 +234,6 @@ void event_notifier_set_handler(EventNotifier *e,
 
 GSource *iohandler_get_g_source(void);
 AioContext *iohandler_get_aio_context(void);
-#ifdef CONFIG_POSIX
-/**
- * qemu_add_child_watch: Register a child process for reaping.
- *
- * Under POSIX systems, a parent process must read the exit status of
- * its child processes using waitpid, or the operating system will not
- * free some of the resources attached to that process.
- *
- * This function directs the QEMU main loop to observe a child process
- * and call waitpid as soon as it exits; the watch is then removed
- * automatically.  It is useful whenever QEMU forks a child process
- * but will find out about its termination by other means such as a
- * "broken pipe".
- *
- * @pid: The pid that QEMU should observe.
- */
-int qemu_add_child_watch(pid_t pid);
-#endif
 
 /**
  * qemu_mutex_iothread_locked: Return lock status of the main loop mutex.

util/main-loop.c

@@ -591,64 +591,3 @@ void event_notifier_set_handler(EventNotifier *e,
     aio_set_event_notifier(iohandler_ctx, e, false,
                            handler, NULL);
 }
-
-/* reaping of zombies.  right now we're not passing the status to
-   anyone, but it would be possible to add a callback.  */
-#ifndef _WIN32
-typedef struct ChildProcessRecord {
-    int pid;
-    QLIST_ENTRY(ChildProcessRecord) next;
-} ChildProcessRecord;
-
-static QLIST_HEAD(, ChildProcessRecord) child_watches =
-    QLIST_HEAD_INITIALIZER(child_watches);
-
-static QEMUBH *sigchld_bh;
-
-static void sigchld_handler(int signal)
-{
-    qemu_bh_schedule(sigchld_bh);
-}
-
-static void sigchld_bh_handler(void *opaque)
-{
-    ChildProcessRecord *rec, *next;
-
-    QLIST_FOREACH_SAFE(rec, &child_watches, next, next) {
-        if (waitpid(rec->pid, NULL, WNOHANG) == rec->pid) {
-            QLIST_REMOVE(rec, next);
-            g_free(rec);
-        }
-    }
-}
-
-static void qemu_init_child_watch(void)
-{
-    struct sigaction act;
-    sigchld_bh = qemu_bh_new(sigchld_bh_handler, NULL);
-
-    memset(&act, 0, sizeof(act));
-    act.sa_handler = sigchld_handler;
-    act.sa_flags = SA_NOCLDSTOP;
-    sigaction(SIGCHLD, &act, NULL);
-}
-
-int qemu_add_child_watch(pid_t pid)
-{
-    ChildProcessRecord *rec;
-
-    if (!sigchld_bh) {
-        qemu_init_child_watch();
-    }
-
-    QLIST_FOREACH(rec, &child_watches, next) {
-        if (rec->pid == pid) {
-            return 1;
-        }
-    }
-    rec = g_malloc0(sizeof(ChildProcessRecord));
-    rec->pid = pid;
-    QLIST_INSERT_HEAD(&child_watches, rec, next);
-    return 0;
-}
-#endif