core: allow PIDs to be watched by two units at the same time

[elogind.git] / src / core / unit.c

diff --git a/src/core/unit.c b/src/core/unit.c
index 6427f9137af3085944ddbcec69fc499d22b4e8af..b0bb0260bcbec7f3f5a9ff1f80bee4a3e4d058c4 100644 (file)
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -50,6 +50,7 @@
 #include "bus-errors.h"
 #include "dbus.h"
 #include "execute.h"
+#include "virt.h"
 
 const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX] = {
         [UNIT_SERVICE] = &service_vtable,
@@ -481,6 +482,8 @@ void unit_free(Unit *u) {
 
         set_free_free(u->names);
 
+        unit_unwatch_all_pids(u);
+
         condition_free_list(u->conditions);
 
         unit_ref_unset(&u->slice);
@@ -1696,20 +1699,142 @@ void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, bool reload_su
 }
 
 int unit_watch_pid(Unit *u, pid_t pid) {
+        int q, r;
+
         assert(u);
         assert(pid >= 1);
 
-        /* Watch a specific PID. We only support one unit watching
-         * each PID for now. */
+        /* Watch a specific PID. We only support one or two units
+         * watching each PID for now, not more. */
+
+        r = hashmap_ensure_allocated(&u->manager->watch_pids1, trivial_hash_func, trivial_compare_func);
+        if (r < 0)
+                return r;
 
-        return hashmap_put(u->manager->watch_pids, LONG_TO_PTR(pid), u);
+        r = set_ensure_allocated(&u->pids, trivial_hash_func, trivial_compare_func);
+        if (r < 0)
+                return r;
+
+        r = hashmap_put(u->manager->watch_pids1, LONG_TO_PTR(pid), u);
+        if (r == -EEXIST) {
+                r = hashmap_ensure_allocated(&u->manager->watch_pids2, trivial_hash_func, trivial_compare_func);
+                if (r < 0)
+                        return r;
+
+                r = hashmap_put(u->manager->watch_pids2, LONG_TO_PTR(pid), u);
+        }
+
+        q = set_put(u->pids, LONG_TO_PTR(pid));
+        if (q < 0)
+                return q;
+
+        return r;
 }
 
 void unit_unwatch_pid(Unit *u, pid_t pid) {
         assert(u);
         assert(pid >= 1);
 
-        hashmap_remove_value(u->manager->watch_pids, LONG_TO_PTR(pid), u);
+        hashmap_remove_value(u->manager->watch_pids1, LONG_TO_PTR(pid), u);
+        hashmap_remove_value(u->manager->watch_pids2, LONG_TO_PTR(pid), u);
+        set_remove(u->pids, LONG_TO_PTR(pid));
+}
+
+static int watch_pids_in_path(Unit *u, const char *path) {
+        _cleanup_closedir_ DIR *d = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        int ret = 0, r;
+
+        assert(u);
+        assert(path);
+
+        /* Adds all PIDs from a specific cgroup path to the set of PIDs we watch. */
+
+        r = cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, path, &f);
+        if (r >= 0) {
+                pid_t pid;
+
+                while ((r = cg_read_pid(f, &pid)) > 0) {
+                        r = unit_watch_pid(u, pid);
+                        if (r < 0 && ret >= 0)
+                                ret = r;
+                }
+                if (r < 0 && ret >= 0)
+                        ret = r;
+
+        } else if (ret >= 0)
+                ret = r;
+
+        r = cg_enumerate_subgroups(SYSTEMD_CGROUP_CONTROLLER, path, &d);
+        if (r >= 0) {
+                char *fn;
+
+                while ((r = cg_read_subgroup(d, &fn)) > 0) {
+                        _cleanup_free_ char *p = NULL;
+
+                        p = strjoin(path, "/", fn, NULL);
+                        free(fn);
+
+                        if (!p)
+                                return -ENOMEM;
+
+                        r = watch_pids_in_path(u, p);
+                        if (r < 0 && ret >= 0)
+                                ret = r;
+                }
+                if (r < 0 && ret >= 0)
+                        ret = r;
+
+        } else if (ret >= 0)
+                ret = r;
+
+        return ret;
+}
+
+
+int unit_watch_all_pids(Unit *u) {
+        assert(u);
+
+        if (!u->cgroup_path)
+                return -ENOENT;
+
+        /* Adds all PIDs from our cgroup to the set of PIDs we watch */
+
+        return watch_pids_in_path(u, u->cgroup_path);
+}
+
+void unit_unwatch_all_pids(Unit *u) {
+        Iterator i;
+        void *e;
+
+        assert(u);
+
+        SET_FOREACH(e, u->pids, i) {
+                hashmap_remove_value(u->manager->watch_pids1, e, u);
+                hashmap_remove_value(u->manager->watch_pids2, e, u);
+        }
+
+        set_free(u->pids);
+        u->pids = NULL;
+}
+
+void unit_tidy_watch_pids(Unit *u, pid_t except1, pid_t except2) {
+        Iterator i;
+        void *e;
+
+        assert(u);
+
+        /* Cleans dead PIDs from our list */
+
+        SET_FOREACH(e, u->pids, i) {
+                pid_t pid = PTR_TO_LONG(e);
+
+                if (pid == except1 || pid == except2)
+                        continue;
+
+                if (kill(pid, 0) < 0 && errno == ESRCH)
+                        set_remove(u->pids, e);
+        }
 }
 
 bool unit_job_is_applicable(Unit *u, JobType j) {
@@ -2921,7 +3046,7 @@ int unit_kill_context(
                 pid_t control_pid,
                 bool main_pid_alien) {
 
-        int sig, wait_for_exit = 0, r;
+        int sig, wait_for_exit = false, r;
 
         assert(u);
         assert(c);
@@ -2940,9 +3065,10 @@ int unit_kill_context(
 
                         log_warning_unit(u->id, "Failed to kill main process " PID_FMT " (%s): %s", main_pid, strna(comm), strerror(-r));
                 } else {
-                        wait_for_exit = !main_pid_alien;
+                        if (!main_pid_alien)
+                                wait_for_exit = true;
 
-                        if (c->send_sighup)
+                        if (c->send_sighup && !sigkill)
                                 kill(main_pid, SIGHUP);
                 }
         }
@@ -2958,7 +3084,7 @@ int unit_kill_context(
                 } else {
                         wait_for_exit = true;
 
-                        if (c->send_sighup)
+                        if (c->send_sighup && !sigkill)
                                 kill(control_pid, SIGHUP);
                 }
         }
@@ -2976,16 +3102,17 @@ int unit_kill_context(
                         if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
                                 log_warning_unit(u->id, "Failed to kill control group: %s", strerror(-r));
                 } else if (r > 0) {
+
                         wait_for_exit = true;
 
-                        if (c->send_sighup) {
+                        if (c->send_sighup && !sigkill) {
                                 set_free(pid_set);
 
                                 pid_set = unit_pid_set(main_pid, control_pid);
                                 if (!pid_set)
                                         return -ENOMEM;
 
-                                cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, SIGHUP, true, true, false, pid_set);
+                                cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, SIGHUP, false, true, false, pid_set);
                         }
                 }
         }