JNI memory stats

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -65,7 +65,6 @@ import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.CancellationSignal;
-import android.os.Debug;
 import android.os.OperationCanceledException;
 import android.os.Parcel;
 import android.os.Parcelable;
@@ -7118,10 +7117,16 @@ public class FragmentMessages extends FragmentBase
         if (!getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.STARTED))
             return;
 
-        Runtime rt = Runtime.getRuntime();
-        long hused = rt.totalMemory() - rt.freeMemory();
-        long hmax = rt.maxMemory();
-        long nheap = Debug.getNativeHeapAllocatedSize();
+        long[] stats = Log.jni_safe_runtime_stats();
+        if (stats == null) {
+            tvDebug.setText("OOM");
+            return;
+        }
+
+        long hused = stats[0] - stats[1];
+        long hmax = stats[2];
+        int processors = (int) stats[3];
+        long nheap = stats[4];
         int perc = Math.round(hused * 100f / hmax);
 
         int utilization = 0;
@@ -7131,13 +7136,12 @@ public class FragmentMessages extends FragmentBase
             int cpuDelta = (int) (cpu - lastCpu);
             int timeDelta = (int) (time - lastTime);
             if (timeDelta != 0)
-                utilization = 100 * cpuDelta / timeDelta / rt.availableProcessors();
+                utilization = 100 * cpuDelta / timeDelta / processors;
         }
         lastCpu = cpu;
         lastTime = time;
 
-
-        tvDebug.setText(utilization + "%\n" + perc + "% " + (nheap / (1024 * 1024)) + "M"); // TODO CASA
+        tvDebug.setText(utilization + "%\n" + perc + "% " + (nheap / (1024 * 1024)) + "M");
     }
 
     private boolean handleThreadActions(

app/src/main/java/eu/faircode/email/Log.java

@@ -245,6 +245,8 @@ public class Log {
 
     public static native Process jni_safe_runtime_exec(Runtime runtime, String[] cmd);
 
+    public static native long[] jni_safe_runtime_stats();
+
     public static void setLevel(Context context) {
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
         boolean debug = prefs.getBoolean("debug", false);

app/src/main/jni/fairemail.cc

@@ -74,6 +74,43 @@ Java_eu_faircode_email_Log_jni_1safe_1runtime_1exec(JNIEnv *env, jclass clazz,
     return env->CallObjectMethod(runtime, mid, cmd);
 }
 
+extern "C"
+JNIEXPORT jlongArray JNICALL
+Java_eu_faircode_email_Log_jni_1safe_1runtime_1stats(JNIEnv *env, jclass clazz) {
+    jclass clsRuntime = env->FindClass("java/lang/Runtime");
+    jmethodID mid = env->GetStaticMethodID(clsRuntime, "getRuntime", "()Ljava/lang/Runtime;");
+    jobject jruntime = env->CallStaticObjectMethod(clsRuntime, mid);
+
+    jmethodID midTotalMemory = env->GetMethodID(clsRuntime, "totalMemory", "()J");
+    jlong totalMemory = env->CallLongMethod(jruntime, midTotalMemory);
+
+    jmethodID midFreeMemory = env->GetMethodID(clsRuntime, "freeMemory", "()J");
+    jlong freeMemory = env->CallLongMethod(jruntime, midFreeMemory);
+
+    jmethodID midMaxMemory = env->GetMethodID(clsRuntime, "maxMemory", "()J");
+    jlong maxMemory = env->CallLongMethod(jruntime, midMaxMemory);
+
+    jmethodID midAvailableProcessors = env->GetMethodID(clsRuntime, "availableProcessors", "()I");
+    jlong availableProcessors = env->CallIntMethod(jruntime, midAvailableProcessors);
+
+    jclass clsDebug = env->FindClass("android/os/Debug");
+    jmethodID midGetNativeHeapAllocatedSize = env->GetStaticMethodID(clsDebug, "getNativeHeapAllocatedSize", "()J");
+    jlong getNativeHeapAllocatedSize = env->CallStaticLongMethod(clsDebug, midGetNativeHeapAllocatedSize);
+
+    jlongArray result = env->NewLongArray(5);
+    if (result == NULL)
+        return NULL; /* out of memory error thrown */
+
+    env->SetLongArrayRegion(result, 0, 1, &totalMemory);
+    env->SetLongArrayRegion(result, 1, 1, &freeMemory);
+    env->SetLongArrayRegion(result, 2, 1, &maxMemory);
+    env->SetLongArrayRegion(result, 3, 1, &availableProcessors);
+    env->SetLongArrayRegion(result, 4, 1, &getNativeHeapAllocatedSize);
+
+    return result;
+}
+
+
 extern "C"
 JNIEXPORT jobject JNICALL
 Java_eu_faircode_email_CharsetHelper_jni_1detect_1charset(