Add conditional class starting

This adds the ability to prevent a class from starting
if a certain persistent property has been set to
disallow it.

A class will only load if there is not a property named
persist.init.dont_start_class.[class name] set to 1.

Test: Set a property called persist.dont_start_class.[class]
      to 1. Verify that the given class does not start
Change-Id: I51c70ad635762ed77855d0509e630adb0aec0eb1

1 files changed, 6 insertions, 0 deletions

diff --git a/init/builtins.cpp b/init/builtins.cpp
index 7fd4e2737..52828c00d 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -100,6 +100,9 @@ static void ForEachServiceInClass(const std::string& classname, F function) {
 }
 
 static Result<Success> do_class_start(const BuiltinArguments& args) {
+    // Do not start a class if it has a property persist.dont_start_class.CLASS set to 1.
+    if (android::base::GetBoolProperty("persist.init.dont_start_class." + args[1], false))
+        return Success();
     // Starting a class does not start services which are explicitly disabled.
     // They must  be started individually.
     for (const auto& service : ServiceList::GetInstance()) {
@@ -124,6 +127,9 @@ static Result<Success> do_class_reset(const BuiltinArguments& args) {
 }
 
 static Result<Success> do_class_restart(const BuiltinArguments& args) {
+    // Do not restart a class if it has a property persist.dont_start_class.CLASS set to 1.
+    if (android::base::GetBoolProperty("persist.init.dont_start_class." + args[1], false))
+        return Success();
     ForEachServiceInClass(args[1], &Service::Restart);
     return Success();
 }