util: generalize code that checks whether PIDs are alive or unwaited for

2 files changed, 20 insertions, 2 deletions

diff --git a/src/shared/util.c b/src/shared/util.c
index 4f3145b2bc..72b1e2f3c8 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -6045,7 +6045,9 @@ int namespace_enter(int pidns_fd, int mntns_fd, int root_fd) {
         return 0;
 }
 
-bool pid_valid(pid_t pid) {
+bool pid_is_unwaited(pid_t pid) {
+        /* Checks whether a PID is still valid at all, including a zombie */
+
         if (pid <= 0)
                 return false;
 
@@ -6055,6 +6057,21 @@ bool pid_valid(pid_t pid) {
         return errno != ESRCH;
 }
 
+bool pid_is_alive(pid_t pid) {
+        int r;
+
+        /* Checks whether a PID is still valid and not a zombie */
+
+        if (pid <= 0)
+                return false;
+
+        r = get_process_state(pid);
+        if (r == -ENOENT || r == 'Z')
+                return false;
+
+        return true;
+}
+
 int getpeercred(int fd, struct ucred *ucred) {
         socklen_t n = sizeof(struct ucred);
         struct ucred u;
diff --git a/src/shared/util.h b/src/shared/util.h
index 7c88dad631..a41348e32e 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -858,7 +858,8 @@ int container_get_leader(const char *machine, pid_t *pid);
 int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *root_fd);
 int namespace_enter(int pidns_fd, int mntns_fd, int root_fd);
 
-bool pid_valid(pid_t pid);
+bool pid_is_alive(pid_t pid);
+bool pid_is_unwaited(pid_t pid);
 
 int getpeercred(int fd, struct ucred *ucred);
 int getpeersec(int fd, char **ret);