Merge "cutils: add thread_defs header"

include/system/thread_defs.h

@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_THREAD_DEFS_H
+#define ANDROID_THREAD_DEFS_H
+
+#include <sys/cdefs.h>
+#include "graphics.h"
+
+__BEGIN_DECLS
+
+enum {
+    /*
+     * ***********************************************
+     * ** Keep in sync with android.os.Process.java **
+     * ***********************************************
+     * 
+     * This maps directly to the "nice" priorities we use in Android.
+     * A thread priority should be chosen inverse-proportionally to
+     * the amount of work the thread is expected to do. The more work
+     * a thread will do, the less favorable priority it should get so that 
+     * it doesn't starve the system. Threads not behaving properly might
+     * be "punished" by the kernel.
+     * Use the levels below when appropriate. Intermediate values are
+     * acceptable, preferably use the {MORE|LESS}_FAVORABLE constants below.
+     */
+    ANDROID_PRIORITY_LOWEST         =  19,
+
+    /* use for background tasks */
+    ANDROID_PRIORITY_BACKGROUND     =  10,
+    
+    /* most threads run at normal priority */
+    ANDROID_PRIORITY_NORMAL         =   0,
+    
+    /* threads currently running a UI that the user is interacting with */
+    ANDROID_PRIORITY_FOREGROUND     =  -2,
+
+    /* the main UI thread has a slightly more favorable priority */
+    ANDROID_PRIORITY_DISPLAY        =  -4,
+    
+    /* ui service treads might want to run at a urgent display (uncommon) */
+    ANDROID_PRIORITY_URGENT_DISPLAY =  HAL_PRIORITY_URGENT_DISPLAY,
+    
+    /* all normal audio threads */
+    ANDROID_PRIORITY_AUDIO          = -16,
+    
+    /* service audio threads (uncommon) */
+    ANDROID_PRIORITY_URGENT_AUDIO   = -19,
+
+    /* should never be used in practice. regular process might not 
+     * be allowed to use this level */
+    ANDROID_PRIORITY_HIGHEST        = -20,
+
+    ANDROID_PRIORITY_DEFAULT        = ANDROID_PRIORITY_NORMAL,
+    ANDROID_PRIORITY_MORE_FAVORABLE = -1,
+    ANDROID_PRIORITY_LESS_FAVORABLE = +1,
+};
+
+__END_DECLS
+
+#endif /* ANDROID_THREAD_DEFS_H */