am c0a7e690: Add Parcel::readExceptionCode() and Parcel::writeNoException()

Merge commit 'c0a7e690bfd32dd897ceccd04dd0fa6bf6e9cee6' into gingerbread-plus-aosp

* commit 'c0a7e690bfd32dd897ceccd04dd0fa6bf6e9cee6':
  Add Parcel::readExceptionCode() and Parcel::writeNoException()

core/jni/ActivityManager.cpp

@@ -39,7 +39,7 @@ int openContentProviderFile(const String16& uri)
         data.writeString16(uri);
         status_t ret = am->transact(OPEN_CONTENT_URI_TRANSACTION, data, &reply);
         if (ret == NO_ERROR) {
-            int32_t exceptionCode = reply.readInt32();
+            int32_t exceptionCode = reply.readExceptionCode();
             if (!exceptionCode) {
                 // Success is indicated here by a nonzero int followed by the fd;
                 // failure by a zero int with no data following.

include/binder/Parcel.h

@@ -103,6 +103,11 @@ public:
     
     status_t            writeObject(const flat_binder_object& val, bool nullMetaData);
 
+    // Like Parcel.java's writeNoException().  Just writes a zero int32.
+    // Currently the native implementation doesn't do any of the StrictMode
+    // stack gathering and serialization that the Java implementation does.
+    status_t            writeNoException();
+
     void                remove(size_t start, size_t amt);
     
     status_t            read(void* outData, size_t len) const;
@@ -125,7 +130,14 @@ public:
     sp<IBinder>         readStrongBinder() const;
     wp<IBinder>         readWeakBinder() const;
     status_t            read(Flattenable& val) const;
-    
+
+    // Like Parcel.java's readExceptionCode().  Reads the first int32
+    // off of a Parcel's header, returning 0 or the negative error
+    // code on exceptions, but also deals with skipping over rich
+    // response headers.  Callers should use this to read & parse the
+    // response headers rather than doing it by hand.
+    int32_t             readExceptionCode() const;
+
     // Retrieve native_handle from the parcel. This returns a copy of the
     // parcel's native_handle (the caller takes ownership). The caller
     // must free the native_handle with native_handle_close() and 

libs/binder/IPermissionController.cpp

@@ -36,7 +36,7 @@ public:
         : BpInterface<IPermissionController>(impl)
     {
     }
-        
+
     virtual bool checkPermission(const String16& permission, int32_t pid, int32_t uid)
     {
         Parcel data, reply;
@@ -46,7 +46,7 @@ public:
         data.writeInt32(uid);
         remote()->transact(CHECK_PERMISSION_TRANSACTION, data, &reply);
         // fail on exception
-        if (reply.readInt32() != 0) return 0;
+        if (reply.readExceptionCode() != 0) return 0;
         return reply.readInt32() != 0;
     }
 };
@@ -66,8 +66,7 @@ status_t BnPermissionController::onTransact(
             int32_t pid = data.readInt32();
             int32_t uid = data.readInt32();
             bool res = checkPermission(permission, pid, uid);
-            // write exception
-            reply->writeInt32(0);
+            reply->writeNoException();
             reply->writeInt32(res ? 1 : 0);
             return NO_ERROR;
         } break;
@@ -77,4 +76,3 @@ status_t BnPermissionController::onTransact(
 }
 
 }; // namespace android
-

libs/binder/IServiceManager.cpp

@@ -158,7 +158,7 @@ public:
         data.writeString16(name);
         data.writeStrongBinder(service);
         status_t err = remote()->transact(ADD_SERVICE_TRANSACTION, data, &reply);
-        return err == NO_ERROR ? reply.readInt32() : err;
+        return err == NO_ERROR ? reply.readExceptionCode() : err;
     }
 
     virtual Vector<String16> listServices()

libs/binder/Parcel.cpp

@@ -754,6 +754,11 @@ restart_write:
     goto restart_write;
 }
 
+status_t Parcel::writeNoException()
+{
+    return writeInt32(0);
+}
+
 void Parcel::remove(size_t start, size_t amt)
 {
     LOG_ALWAYS_FATAL("Parcel::remove() not yet implemented!");
@@ -942,6 +947,12 @@ wp<IBinder> Parcel::readWeakBinder() const
     return val;
 }
 
+int32_t Parcel::readExceptionCode() const
+{
+  int32_t exception_code = readAligned<int32_t>();
+  // TODO: skip over the response header here, once that's in.
+  return exception_code;
+}
 
 native_handle* Parcel::readNativeHandle() const
 {