DroidFish: Implemented chmod using JNI. More efficient than starting a process.

DroidFish/jni/nativeutil.cpp

@@ -19,6 +19,7 @@
 #include <jni.h>
 #include <unistd.h>
 #include <stdlib.h>
+#include <sys/stat.h>
 
 /*
  * Class:     org_petero_droidfish_engine_EngineUtil
@@ -30,3 +31,19 @@ extern "C" JNIEXPORT jint JNICALL Java_org_petero_droidfish_engine_EngineUtil_ge
 {
 	return sysconf(_SC_NPROCESSORS_ONLN);
 }
+
+/*
+ * Class:     org_petero_droidfish_engine_EngineUtil
+ * Method:    chmod
+ * Signature: (Ljava/lang/String;)Z
+ */
+extern "C" JNIEXPORT jboolean JNICALL Java_org_petero_droidfish_engine_EngineUtil_chmod
+  (JNIEnv *env, jclass, jstring jExePath)
+{
+    const char* exePath = (*env).GetStringUTFChars(jExePath, NULL);
+    if (!exePath)
+        return false;
+    bool ret = chmod(exePath, 0744) == 0;
+    (*env).ReleaseStringUTFChars(jExePath, exePath);
+    return ret;
+}

DroidFish/src/org/petero/droidfish/engine/EngineUtil.java

@@ -43,4 +43,7 @@ public class EngineUtil {
             abi = "armeabi"; // Unknown ABI, assume original ARM
         return "stockfish-" + abi;
     }
+
+    /** Executes chmod 744 exePath. */
+    final static native boolean chmod(String exePath);
 }

DroidFish/src/org/petero/droidfish/engine/ExternalEngine.java

@@ -240,12 +240,7 @@ public class ExternalEngine extends UCIEngineBase {
     }
 
     private final void chmod(String exePath) throws IOException {
-        Process proc = Runtime.getRuntime().exec(new String[]{"chmod", "744", exePath});
+        if (!EngineUtil.chmod(exePath))
-        try {
-            proc.waitFor();
-        } catch (InterruptedException e) {
-            proc.destroy();
             throw new IOException("chmod failed");
-        }
     }
 }