| /* |
| * Copyright (C) 2007 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. |
| */ |
| |
| package dalvik.system; |
| |
| /** |
| * Provides an interface to VM-global, Dalvik-specific features. |
| * An application cannot create its own Runtime instance, and must obtain |
| * one from the getRuntime method. |
| * |
| * @hide |
| */ |
| public final class VMRuntime { |
| |
| /** |
| * Holds the VMRuntime singleton. |
| */ |
| private static final VMRuntime THE_ONE = new VMRuntime(); |
| |
| /** |
| * Prevents this class from being instantiated. |
| */ |
| private VMRuntime() { |
| } |
| |
| /** |
| * Returns the object that represents the VM instance's Dalvik-specific |
| * runtime environment. |
| * |
| * @return the runtime object |
| */ |
| public static VMRuntime getRuntime() { |
| return THE_ONE; |
| } |
| |
| /** |
| * Returns a copy of the VM's command-line property settings. |
| * These are in the form "name=value" rather than "-Dname=value". |
| */ |
| public native String[] properties(); |
| |
| /** |
| * Returns the VM's boot class path. |
| */ |
| public native String bootClassPath(); |
| |
| /** |
| * Returns the VM's class path. |
| */ |
| public native String classPath(); |
| |
| /** |
| * Returns the VM's version. |
| */ |
| public native String vmVersion(); |
| |
| /** |
| * Returns the name of the shared library providing the VM implementation. |
| */ |
| public native String vmLibrary(); |
| |
| /** |
| * Gets the current ideal heap utilization, represented as a number |
| * between zero and one. After a GC happens, the Dalvik heap may |
| * be resized so that (size of live objects) / (size of heap) is |
| * equal to this number. |
| * |
| * @return the current ideal heap utilization |
| */ |
| public native float getTargetHeapUtilization(); |
| |
| /** |
| * Sets the current ideal heap utilization, represented as a number |
| * between zero and one. After a GC happens, the Dalvik heap may |
| * be resized so that (size of live objects) / (size of heap) is |
| * equal to this number. |
| * |
| * <p>This is only a hint to the garbage collector and may be ignored. |
| * |
| * @param newTarget the new suggested ideal heap utilization. |
| * This value may be adjusted internally. |
| * @return the previous ideal heap utilization |
| * @throws IllegalArgumentException if newTarget is <= 0.0 or >= 1.0 |
| */ |
| public float setTargetHeapUtilization(float newTarget) { |
| if (newTarget <= 0.0f || newTarget >= 1.0f) { |
| throw new IllegalArgumentException(newTarget + |
| " out of range (0,1)"); |
| } |
| /* Synchronize to make sure that only one thread gets |
| * a given "old" value if both update at the same time. |
| * Allows for reliable save-and-restore semantics. |
| */ |
| synchronized (this) { |
| float oldTarget = getTargetHeapUtilization(); |
| nativeSetTargetHeapUtilization(newTarget); |
| return oldTarget; |
| } |
| } |
| |
| /** |
| * Sets the target SDK version. Should only be called before the |
| * app starts to run, because it may change the VM's behavior in |
| * dangerous ways. Use 0 to mean "current" (since callers won't |
| * necessarily know the actual current SDK version, and the |
| * allocated version numbers start at 1). |
| */ |
| public native void setTargetSdkVersion(int targetSdkVersion); |
| |
| /** |
| * This method exists for binary compatibility. It was part of a |
| * heap sizing API which was removed in Android 3.0 (Honeycomb). |
| */ |
| @Deprecated |
| public long getMinimumHeapSize() { |
| return 0; |
| } |
| |
| /** |
| * This method exists for binary compatibility. It was part of a |
| * heap sizing API which was removed in Android 3.0 (Honeycomb). |
| */ |
| @Deprecated |
| public long setMinimumHeapSize(long size) { |
| return 0; |
| } |
| |
| /** |
| * This method exists for binary compatibility. It used to |
| * perform a garbage collection that cleared SoftReferences. |
| */ |
| @Deprecated |
| public void gcSoftReferences() {} |
| |
| /** |
| * This method exists for binary compatibility. It is equivalent |
| * to {@link System#runFinalization}. |
| */ |
| @Deprecated |
| public void runFinalizationSync() { |
| System.runFinalization(); |
| } |
| |
| /** |
| * Implements setTargetHeapUtilization(). |
| * |
| * @param newTarget the new suggested ideal heap utilization. |
| * This value may be adjusted internally. |
| */ |
| private native void nativeSetTargetHeapUtilization(float newTarget); |
| |
| /** |
| * This method exists for binary compatibility. It was part of |
| * the external allocation API which was removed in Android 3.0 (Honeycomb). |
| */ |
| @Deprecated |
| public boolean trackExternalAllocation(long size) { |
| return true; |
| } |
| |
| /** |
| * This method exists for binary compatibility. It was part of |
| * the external allocation API which was removed in Android 3.0 (Honeycomb). |
| */ |
| @Deprecated |
| public void trackExternalFree(long size) {} |
| |
| /** |
| * This method exists for binary compatibility. It was part of |
| * the external allocation API which was removed in Android 3.0 (Honeycomb). |
| */ |
| @Deprecated |
| public long getExternalBytesAllocated() { |
| return 0; |
| } |
| |
| /** |
| * Tells the VM to enable the JIT compiler. If the VM does not have a JIT |
| * implementation, calling this method should have no effect. |
| */ |
| public native void startJitCompilation(); |
| |
| /** |
| * Tells the VM to disable the JIT compiler. If the VM does not have a JIT |
| * implementation, calling this method should have no effect. |
| */ |
| public native void disableJitCompilation(); |
| |
| /** |
| * Returns an array allocated in an area of the Java heap where it will never be moved. |
| * This is used to implement native allocations on the Java heap, such as DirectByteBuffers |
| * and Bitmaps. |
| */ |
| public native Object newNonMovableArray(Class<?> componentType, int length); |
| |
| /** |
| * Returns the address of array[0]. This differs from using JNI in that JNI might lie and |
| * give you the address of a copy of the array when in forcecopy mode. |
| */ |
| public native long addressOf(Object array); |
| |
| /** |
| * Removes any growth limits, allowing the application to allocate |
| * up to the maximum heap size. |
| */ |
| public native void clearGrowthLimit(); |
| |
| /** |
| * Returns true if either a Java debugger or native debugger is active. |
| */ |
| public native boolean isDebuggerActive(); |
| |
| /** |
| * Registers a native allocation so that the heap knows about it and performs GC as required. |
| * If the number of native allocated bytes exceeds the native allocation watermark, the |
| * function requests a concurrent GC. If the native bytes allocated exceeds a second higher |
| * watermark, it is determined that the application is registering native allocations at an |
| * unusually high rate and a GC is performed inside of the function to prevent memory usage |
| * from excessively increasing. |
| */ |
| public native void registerNativeAllocation(int bytes); |
| |
| /** |
| * Registers a native free by reducing the number of native bytes accounted for. |
| */ |
| public native void registerNativeFree(int bytes); |
| |
| public native void trimHeap(); |
| public native void concurrentGC(); |
| |
| /** |
| * Fill in dex caches with classes, fields, and methods that are |
| * already loaded. Typically used after Zygote preloading. |
| */ |
| public native void preloadDexCaches(); |
| } |