Correctly init code cache path for RS

Bug: 27439261

Script Group needs to know the code cache path before it can call bcc to
merge kernels. However, before this change, the code cache path has been
initialized by the ScriptC class.

In the case where a script group (or even the entire app) does not contain any
regular script but only intrinsics, the code cache would remain uninitialized.

Fixed this by initializing the code cache path in the RenderScript class
the first time when the accessor method is called.

Change-Id: I87f9e62e0f3b479f94e43daa3e9695a5b38710db
(cherry picked from commit 689f637700)

rs/java/android/renderscript/RenderScript.java

@@ -1386,6 +1386,27 @@ public class RenderScript {
         return mApplicationContext;
     }
 
+    /**
+     * Name of the file that holds the object cache.
+     */
+    private static String mCachePath;
+
+    /**
+     * Gets the path to the code cache.
+     */
+    static synchronized String getCachePath() {
+        if (mCachePath == null) {
+            final String CACHE_PATH = "com.android.renderscript.cache";
+            if (RenderScriptCacheDir.mCacheDir == null) {
+                throw new RSRuntimeException("RenderScript code cache directory uninitialized.");
+            }
+            File f = new File(RenderScriptCacheDir.mCacheDir, CACHE_PATH);
+            mCachePath = f.getAbsolutePath();
+            f.mkdirs();
+        }
+        return mCachePath;
+    }
+
     /**
      * Create a RenderScript context.
      *
@@ -1415,11 +1436,7 @@ public class RenderScript {
         }
 
         // set up cache directory for entire context
-        final String CACHE_PATH = "com.android.renderscript.cache";
-        File f = new File(RenderScriptCacheDir.mCacheDir, CACHE_PATH);
-        String mCachePath = f.getAbsolutePath();
-        f.mkdirs();
-        rs.nContextSetCacheDir(mCachePath);
+        rs.nContextSetCacheDir(RenderScript.getCachePath());
 
         rs.mMessageThread = new MessageThread(rs);
         rs.mMessageThread.start();

rs/java/android/renderscript/ScriptC.java

@@ -84,13 +84,6 @@ public class ScriptC extends Script {
         setID(id);
     }
 
-    /**
-     * Name of the file that holds the object cache.
-     */
-    private static final String CACHE_PATH = "com.android.renderscript.cache";
-
-    static String mCachePath;
-
     private static synchronized long internalCreate(RenderScript rs, Resources resources, int resourceID) {
         byte[] pgm;
         int pgmLength;
@@ -122,26 +115,12 @@ public class ScriptC extends Script {
 
         String resName = resources.getResourceEntryName(resourceID);
 
-        // Create the RS cache path if we haven't done so already.
-        if (mCachePath == null) {
-            File f = new File(RenderScriptCacheDir.mCacheDir, CACHE_PATH);
-            mCachePath = f.getAbsolutePath();
-            f.mkdirs();
-        }
         //        Log.v(TAG, "Create script for resource = " + resName);
-        return rs.nScriptCCreate(resName, mCachePath, pgm, pgmLength);
+        return rs.nScriptCCreate(resName, RenderScript.getCachePath(), pgm, pgmLength);
     }
 
     private static synchronized long internalStringCreate(RenderScript rs, String resName, byte[] bitcode) {
-        // Create the RS cache path if we haven't done so already.
-        if (mCachePath == null) {
-            File f = new File(RenderScriptCacheDir.mCacheDir, CACHE_PATH);
-            mCachePath = f.getAbsolutePath();
-            f.mkdirs();
-        }
         //        Log.v(TAG, "Create script for resource = " + resName);
-        return rs.nScriptCCreate(resName, mCachePath, bitcode, bitcode.length);
+        return rs.nScriptCCreate(resName, RenderScript.getCachePath(), bitcode, bitcode.length);
     }
-
-
 }

rs/java/android/renderscript/ScriptGroup.java

@@ -396,7 +396,7 @@ public final class ScriptGroup extends BaseObj {
         for (int i = 0; i < closureIDs.length; i++) {
             closureIDs[i] = closures.get(i).getID(rs);
         }
-        long id = rs.nScriptGroup2Create(name, ScriptC.mCachePath, closureIDs);
+        long id = rs.nScriptGroup2Create(name, RenderScript.getCachePath(), closureIDs);
         setID(id);
     }