init support for cgroups.

This adds the "writepid" option that instructs init to write the child's
pid to the given filenames (such as /dev/cpuctl/bg_non_interactive/cgroup.procs
and/or /dev/cpuset/foreground/cgroup.procs).

Bug: http://b/21163745
Change-Id: I121bb22aa208bc99c4fb334eb552fdd5bcc47c1a

1 files changed, 11 insertions, 0 deletions

diff --git a/init/init_parser.cpp b/init/init_parser.cpp
index f975b6c0b..956ed255a 100644
--- a/init/init_parser.cpp
+++ b/init/init_parser.cpp
@@ -206,6 +206,7 @@ static int lookup_keyword(const char *s)
         break;
     case 'w':
         if (!strcmp(s, "rite")) return K_write;
+        if (!strcmp(s, "ritepid")) return K_writepid;
         if (!strcmp(s, "ait")) return K_wait;
         break;
     }
@@ -924,6 +925,16 @@ static void parse_line_service(struct parse_state *state, int nargs, char **args
             svc->seclabel = args[1];
         }
         break;
+    case K_writepid:
+        if (nargs < 2) {
+            parse_error(state, "writepid option requires at least one filename\n");
+            break;
+        }
+        svc->writepid_files_ = new std::vector<std::string>;
+        for (int i = 1; i < nargs; ++i) {
+            svc->writepid_files_->push_back(args[i]);
+        }
+        break;
 
     default:
         parse_error(state, "invalid option '%s'\n", args[0]);