1 /* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package dalvik.system; 18 19 import java.lang.ref.FinalizerReference; 20 import java.util.HashMap; 21 import java.util.Map; 22 23 /** 24 * Provides an interface to VM-global, Dalvik-specific features. 25 * An application cannot create its own Runtime instance, and must obtain 26 * one from the getRuntime method. 27 * 28 * @hide 29 */ 30 public final class VMRuntime { 31 32 /** 33 * Holds the VMRuntime singleton. 34 */ 35 private static final VMRuntime THE_ONE = new VMRuntime(); 36 37 // Note: Instruction set names are used to construct the names of some 38 // system properties. To be sure that the properties stay valid the 39 // instruction set name should not exceed 7 characters. See installd 40 // and the package manager for the actual propeties. 41 private static final Map<String, String> ABI_TO_INSTRUCTION_SET_MAP 42 = new HashMap<String, String>(); 43 static { 44 ABI_TO_INSTRUCTION_SET_MAP.put("armeabi", "arm"); 45 ABI_TO_INSTRUCTION_SET_MAP.put("armeabi-v7a", "arm"); 46 ABI_TO_INSTRUCTION_SET_MAP.put("mips", "mips"); 47 ABI_TO_INSTRUCTION_SET_MAP.put("mips64", "mips64"); 48 ABI_TO_INSTRUCTION_SET_MAP.put("x86", "x86"); 49 ABI_TO_INSTRUCTION_SET_MAP.put("x86_64", "x86_64"); 50 ABI_TO_INSTRUCTION_SET_MAP.put("arm64-v8a", "arm64"); 51 } 52 53 private int targetSdkVersion; 54 55 /** 56 * Prevents this class from being instantiated. 57 */ 58 private VMRuntime() { 59 } 60 61 /** 62 * Returns the object that represents the VM instance's Dalvik-specific 63 * runtime environment. 64 * 65 * @return the runtime object 66 */ 67 public static VMRuntime getRuntime() { 68 return THE_ONE; 69 } 70 71 /** 72 * Returns a copy of the VM's command-line property settings. 73 * These are in the form "name=value" rather than "-Dname=value". 74 */ 75 public native String[] properties(); 76 77 /** 78 * Returns the VM's boot class path. 79 */ 80 public native String bootClassPath(); 81 82 /** 83 * Returns the VM's class path. 84 */ 85 public native String classPath(); 86 87 /** 88 * Returns the VM's version. 89 */ 90 public native String vmVersion(); 91 92 /** 93 * Returns the name of the shared library providing the VM implementation. 94 */ 95 public native String vmLibrary(); 96 97 /** 98 * Returns the VM's instruction set. 99 */ 100 public native String vmInstructionSet(); 101 102 /** 103 * Returns whether the VM is running in 64-bit mode. 104 */ 105 public native boolean is64Bit(); 106 107 /** 108 * Returns whether the VM is running with JNI checking enabled. 109 */ 110 public native boolean isCheckJniEnabled(); 111 112 /** 113 * Gets the current ideal heap utilization, represented as a number 114 * between zero and one. After a GC happens, the Dalvik heap may 115 * be resized so that (size of live objects) / (size of heap) is 116 * equal to this number. 117 * 118 * @return the current ideal heap utilization 119 */ 120 public native float getTargetHeapUtilization(); 121 122 /** 123 * Sets the current ideal heap utilization, represented as a number 124 * between zero and one. After a GC happens, the Dalvik heap may 125 * be resized so that (size of live objects) / (size of heap) is 126 * equal to this number. 127 * 128 * <p>This is only a hint to the garbage collector and may be ignored. 129 * 130 * @param newTarget the new suggested ideal heap utilization. 131 * This value may be adjusted internally. 132 * @return the previous ideal heap utilization 133 * @throws IllegalArgumentException if newTarget is <= 0.0 or >= 1.0 134 */ 135 public float setTargetHeapUtilization(float newTarget) { 136 if (newTarget <= 0.0f || newTarget >= 1.0f) { 137 throw new IllegalArgumentException(newTarget + 138 " out of range (0,1)"); 139 } 140 /* Synchronize to make sure that only one thread gets 141 * a given "old" value if both update at the same time. 142 * Allows for reliable save-and-restore semantics. 143 */ 144 synchronized (this) { 145 float oldTarget = getTargetHeapUtilization(); 146 nativeSetTargetHeapUtilization(newTarget); 147 return oldTarget; 148 } 149 } 150 151 /** 152 * Sets the target SDK version. Should only be called before the 153 * app starts to run, because it may change the VM's behavior in 154 * dangerous ways. Use 0 to mean "current" (since callers won't 155 * necessarily know the actual current SDK version, and the 156 * allocated version numbers start at 1), and 10000 to mean 157 * CUR_DEVELOPMENT. 158 */ 159 public synchronized void setTargetSdkVersion(int targetSdkVersion) { 160 this.targetSdkVersion = targetSdkVersion; 161 setTargetSdkVersionNative(this.targetSdkVersion); 162 } 163 164 /** 165 * Gets the target SDK version. See {@link #setTargetSdkVersion} for 166 * special values. 167 */ 168 public synchronized int getTargetSdkVersion() { 169 return targetSdkVersion; 170 } 171 172 private native void setTargetSdkVersionNative(int targetSdkVersion); 173 174 /** 175 * This method exists for binary compatibility. It was part of a 176 * heap sizing API which was removed in Android 3.0 (Honeycomb). 177 */ 178 @Deprecated 179 public long getMinimumHeapSize() { 180 return 0; 181 } 182 183 /** 184 * This method exists for binary compatibility. It was part of a 185 * heap sizing API which was removed in Android 3.0 (Honeycomb). 186 */ 187 @Deprecated 188 public long setMinimumHeapSize(long size) { 189 return 0; 190 } 191 192 /** 193 * This method exists for binary compatibility. It used to 194 * perform a garbage collection that cleared SoftReferences. 195 */ 196 @Deprecated 197 public void gcSoftReferences() {} 198 199 /** 200 * This method exists for binary compatibility. It is equivalent 201 * to {@link System#runFinalization}. 202 */ 203 @Deprecated 204 public void runFinalizationSync() { 205 System.runFinalization(); 206 } 207 208 /** 209 * Implements setTargetHeapUtilization(). 210 * 211 * @param newTarget the new suggested ideal heap utilization. 212 * This value may be adjusted internally. 213 */ 214 private native void nativeSetTargetHeapUtilization(float newTarget); 215 216 /** 217 * This method exists for binary compatibility. It was part of 218 * the external allocation API which was removed in Android 3.0 (Honeycomb). 219 */ 220 @Deprecated 221 public boolean trackExternalAllocation(long size) { 222 return true; 223 } 224 225 /** 226 * This method exists for binary compatibility. It was part of 227 * the external allocation API which was removed in Android 3.0 (Honeycomb). 228 */ 229 @Deprecated 230 public void trackExternalFree(long size) {} 231 232 /** 233 * This method exists for binary compatibility. It was part of 234 * the external allocation API which was removed in Android 3.0 (Honeycomb). 235 */ 236 @Deprecated 237 public long getExternalBytesAllocated() { 238 return 0; 239 } 240 241 /** 242 * Tells the VM to enable the JIT compiler. If the VM does not have a JIT 243 * implementation, calling this method should have no effect. 244 */ 245 public native void startJitCompilation(); 246 247 /** 248 * Tells the VM to disable the JIT compiler. If the VM does not have a JIT 249 * implementation, calling this method should have no effect. 250 */ 251 public native void disableJitCompilation(); 252 253 /** 254 * Returns an array allocated in an area of the Java heap where it will never be moved. 255 * This is used to implement native allocations on the Java heap, such as DirectByteBuffers 256 * and Bitmaps. 257 */ 258 public native Object newNonMovableArray(Class<?> componentType, int length); 259 260 /** 261 * Returns an array of at least minLength, but potentially larger. The increased size comes from 262 * avoiding any padding after the array. The amount of padding varies depending on the 263 * componentType and the memory allocator implementation. 264 */ 265 public native Object newUnpaddedArray(Class<?> componentType, int minLength); 266 267 /** 268 * Returns the address of array[0]. This differs from using JNI in that JNI might lie and 269 * give you the address of a copy of the array when in forcecopy mode. 270 */ 271 public native long addressOf(Object array); 272 273 /** 274 * Removes any growth limits, allowing the application to allocate 275 * up to the maximum heap size. 276 */ 277 public native void clearGrowthLimit(); 278 279 /** 280 * Make the current growth limit the new non growth limit capacity by releasing pages which 281 * are after the growth limit but before the non growth limit capacity. 282 */ 283 public native void clampGrowthLimit(); 284 285 /** 286 * Returns true if either a Java debugger or native debugger is active. 287 */ 288 public native boolean isDebuggerActive(); 289 290 /** 291 * Registers a native allocation so that the heap knows about it and performs GC as required. 292 * If the number of native allocated bytes exceeds the native allocation watermark, the 293 * function requests a concurrent GC. If the native bytes allocated exceeds a second higher 294 * watermark, it is determined that the application is registering native allocations at an 295 * unusually high rate and a GC is performed inside of the function to prevent memory usage 296 * from excessively increasing. 297 */ 298 public native void registerNativeAllocation(int bytes); 299 300 /** 301 * Registers a native free by reducing the number of native bytes accounted for. 302 */ 303 public native void registerNativeFree(int bytes); 304 305 /** 306 * Wait for objects to be finalized. 307 * 308 * If finalization takes longer than timeout, then the function returns before all objects are 309 * finalized. 310 * 311 * @param timeout 312 * timeout in nanoseconds of the maximum time to wait until all pending finalizers 313 * are run. If timeout is 0, then there is no timeout. Note that the timeout does 314 * not stop the finalization process, it merely stops the wait. 315 * 316 * @see #Runtime.runFinalization() 317 * @see #wait(long,int) 318 */ 319 public static void runFinalization(long timeout) { 320 try { 321 FinalizerReference.finalizeAllEnqueued(timeout); 322 } catch (InterruptedException e) { 323 // Interrupt the current thread without actually throwing the InterruptionException 324 // for the caller. 325 Thread.currentThread().interrupt(); 326 } 327 } 328 329 public native void requestConcurrentGC(); 330 public native void concurrentGC(); 331 public native void requestHeapTrim(); 332 public native void trimHeap(); 333 public native void startHeapTaskProcessor(); 334 public native void stopHeapTaskProcessor(); 335 public native void runHeapTasks(); 336 337 /** 338 * Let the heap know of the new process state. This can change allocation and garbage collection 339 * behavior regarding trimming and compaction. 340 */ 341 public native void updateProcessState(int state); 342 343 /** 344 * Fill in dex caches with classes, fields, and methods that are 345 * already loaded. Typically used after Zygote preloading. 346 */ 347 public native void preloadDexCaches(); 348 349 /** 350 * Register application info 351 */ 352 public static native void registerAppInfo(String appDir, String processName, String pkgname); 353 354 /** 355 * Returns the runtime instruction set corresponding to a given ABI. Multiple 356 * compatible ABIs might map to the same instruction set. For example 357 * {@code armeabi-v7a} and {@code armeabi} might map to the instruction set {@code arm}. 358 * 359 * This influences the compilation of the applications classes. 360 */ 361 public static String getInstructionSet(String abi) { 362 final String instructionSet = ABI_TO_INSTRUCTION_SET_MAP.get(abi); 363 if (instructionSet == null) { 364 throw new IllegalArgumentException("Unsupported ABI: " + abi); 365 } 366 367 return instructionSet; 368 } 369 370 public static boolean is64BitInstructionSet(String instructionSet) { 371 return "arm64".equals(instructionSet) || 372 "x86_64".equals(instructionSet) || 373 "mips64".equals(instructionSet); 374 } 375 376 public static boolean is64BitAbi(String abi) { 377 return is64BitInstructionSet(getInstructionSet(abi)); 378 } 379 380 /** 381 * Return false if the boot class path for the given instruction 382 * set mapped from disk storage, versus being interpretted from 383 * dirty pages in memory. 384 */ 385 public static native boolean isBootClassPathOnDisk(String instructionSet); 386 387 /** 388 * Returns the instruction set of the current runtime. 389 */ 390 public static native String getCurrentInstructionSet(); 391 392 } 393
