motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-12-11 16:00:50 -07:00
Code Issues Projects Releases Packages Wiki Activity Actions

add a service to reap zombies, use it in SLIRP

Browse source 
SLIRP -smb support wants to fork a process and forget about reaping it.
To please it, add a generic service to register a process id and let
QEMU reap it.  In the future it could be enhanced to pass a status,
but this would be unused.

With this in place, the SIGCHLD signal handler would not stomp on pclose
anymore.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Paolo Bonzini 2011-03-09 18:21:10 +01:00 • committed by Anthony Liguori
parent 0298141998
commit 4d54ec7898
4 changed files with 69 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

64
iohandler.c
View file

@ -27,6 +27,10 @@
#include "qemu-char.h"
#include "qemu-queue.h"
#ifndef _WIN32
#include <sys/wait.h>
#endif
typedef struct IOHandlerRecord {
int fd;
IOCanReadHandler *fd_read_poll;
@ -127,3 +131,63 @@ void qemu_iohandler_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds, int re
}
}
}
/* 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);
qemu_free(rec);
}
}
}
static void qemu_init_child_watch(void)
{
struct sigaction act;
sigchld_bh = qemu_bh_new(sigchld_bh_handler, NULL);
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 = qemu_mallocz(sizeof(ChildProcessRecord));
rec->pid = pid;
QLIST_INSERT_HEAD(&child_watches, rec, next);
return 0;
}
#endif