1 files changed, 49 insertions, 13 deletions

diff --git a/libs/binder/Binder.cpp b/libs/binder/Binder.cpp
index f6cc3afc97..96ee29556c 100644
--- a/libs/binder/Binder.cpp
+++ b/libs/binder/Binder.cpp
@@ -86,6 +86,10 @@ status_t IBinder::shellCommand(const sp<IBinder>& target, int in, int out, int e
 class BBinder::Extras
 {
 public:
+    // unlocked objects
+    bool mRequestingSid = false;
+
+    // for below objects
     Mutex mLock;
     BpBinder::ObjectManager mObjects;
 };
@@ -163,19 +167,8 @@ void BBinder::attachObject(
     const void* objectID, void* object, void* cleanupCookie,
     object_cleanup_func func)
 {
-    Extras* e = mExtras.load(std::memory_order_acquire);
-
-    if (!e) {
-        e = new Extras;
-        Extras* expected = nullptr;
-        if (!mExtras.compare_exchange_strong(expected, e,
-                                             std::memory_order_release,
-                                             std::memory_order_acquire)) {
-            delete e;
-            e = expected;  // Filled in by CAS
-        }
-        if (e == nullptr) return; // out of memory
-    }
+    Extras* e = getOrCreateExtras();
+    if (!e) return; // out of memory
 
     AutoMutex _l(e->mLock);
     e->mObjects.attach(objectID, object, cleanupCookie, func);
@@ -204,6 +197,30 @@ BBinder* BBinder::localBinder()
     return this;
 }
 
+bool BBinder::isRequestingSid()
+{
+    Extras* e = mExtras.load(std::memory_order_acquire);
+
+    return e && e->mRequestingSid;
+}
+
+void BBinder::setRequestingSid(bool requestingSid)
+{
+    Extras* e = mExtras.load(std::memory_order_acquire);
+
+    if (!e) {
+        // default is false. Most things don't need sids, so avoiding allocations when possible.
+        if (!requestingSid) {
+            return;
+        }
+
+        e = getOrCreateExtras();
+        if (!e) return; // out of memory
+    }
+
+    e->mRequestingSid = true;
+}
+
 BBinder::~BBinder()
 {
     Extras* e = mExtras.load(std::memory_order_relaxed);
@@ -267,6 +284,25 @@ status_t BBinder::onTransact(
     }
 }
 
+BBinder::Extras* BBinder::getOrCreateExtras()
+{
+    Extras* e = mExtras.load(std::memory_order_acquire);
+
+    if (!e) {
+        e = new Extras;
+        Extras* expected = nullptr;
+        if (!mExtras.compare_exchange_strong(expected, e,
+                                             std::memory_order_release,
+                                             std::memory_order_acquire)) {
+            delete e;
+            e = expected;  // Filled in by CAS
+        }
+        if (e == nullptr) return nullptr; // out of memory
+    }
+
+    return e;
+}
+
 // ---------------------------------------------------------------------------
 
 enum {