The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 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 com.android.internal.os; |
| 18 | |
| 19 | import android.content.pm.ActivityInfo; |
| 20 | import android.content.res.Resources; |
| 21 | import android.content.res.TypedArray; |
| 22 | import android.content.res.ColorStateList; |
| 23 | import android.graphics.drawable.Drawable; |
| 24 | import android.net.LocalServerSocket; |
| 25 | import android.os.Debug; |
| 26 | import android.os.SystemClock; |
| 27 | import android.os.SystemProperties; |
| 28 | import android.util.Config; |
| 29 | import android.util.EventLog; |
| 30 | import android.util.Log; |
| 31 | |
| 32 | import dalvik.system.VMRuntime; |
| 33 | import dalvik.system.Zygote; |
| 34 | |
| 35 | import java.io.BufferedReader; |
| 36 | import java.io.FileDescriptor; |
| 37 | import java.io.IOException; |
| 38 | import java.io.InputStream; |
| 39 | import java.io.InputStreamReader; |
| 40 | import java.lang.reflect.InvocationTargetException; |
| 41 | import java.lang.reflect.Method; |
| 42 | import java.lang.reflect.Modifier; |
| 43 | import java.util.ArrayList; |
| 44 | |
| 45 | /** |
| 46 | * Startup class for the zygote process. |
| 47 | * |
| 48 | * Pre-initializes some classes, and then waits for commands on a UNIX domain |
| 49 | * socket. Based on these commands, forks of child processes that inherit |
| 50 | * the initial state of the VM. |
| 51 | * |
| 52 | * Please see {@link ZygoteConnection.Arguments} for documentation on the |
| 53 | * client protocol. |
| 54 | * |
| 55 | * @hide |
| 56 | */ |
| 57 | public class ZygoteInit { |
| 58 | |
| 59 | private static final String TAG = "Zygote"; |
| 60 | |
| 61 | private static final String ANDROID_SOCKET_ENV = "ANDROID_SOCKET_zygote"; |
| 62 | |
| 63 | private static final int LOG_BOOT_PROGRESS_PRELOAD_START = 3020; |
| 64 | private static final int LOG_BOOT_PROGRESS_PRELOAD_END = 3030; |
| 65 | |
| 66 | /** when preloading, GC after allocating this many bytes */ |
| 67 | private static final int PRELOAD_GC_THRESHOLD = 50000; |
| 68 | |
| 69 | private static LocalServerSocket sServerSocket; |
| 70 | |
| 71 | /** |
| 72 | * Used to pre-load resources. We hold a global reference on it so it |
| 73 | * never gets destroyed. |
| 74 | */ |
| 75 | private static Resources mResources; |
| 76 | |
| 77 | /** |
| 78 | * The number of times that the main Zygote loop |
| 79 | * should run before calling gc() again. |
| 80 | */ |
| 81 | static final int GC_LOOP_COUNT = 10; |
| 82 | |
| 83 | /** |
| 84 | * If true, zygote forks for each peer. If false, a select loop is used |
| 85 | * inside a single process. The latter is preferred. |
| 86 | */ |
| 87 | private static final boolean ZYGOTE_FORK_MODE = false; |
| 88 | |
| 89 | /** |
| 90 | * The name of a resource file that contains classes to preload. |
| 91 | */ |
| 92 | private static final String PRELOADED_CLASSES = "preloaded-classes"; |
| 93 | |
| 94 | /** Controls whether we should preload resources during zygote init. */ |
| 95 | private static final boolean PRELOAD_RESOURCES = true; |
| 96 | |
| 97 | /** |
| 98 | * Invokes a static "main(argv[]) method on class "className". |
| 99 | * Converts various failing exceptions into RuntimeExceptions, with |
| 100 | * the assumption that they will then cause the VM instance to exit. |
| 101 | * |
| 102 | * @param loader class loader to use |
| 103 | * @param className Fully-qualified class name |
| 104 | * @param argv Argument vector for main() |
| 105 | */ |
| 106 | static void invokeStaticMain(ClassLoader loader, |
| 107 | String className, String[] argv) |
| 108 | throws ZygoteInit.MethodAndArgsCaller { |
| 109 | Class<?> cl; |
| 110 | |
| 111 | try { |
| 112 | cl = loader.loadClass(className); |
| 113 | } catch (ClassNotFoundException ex) { |
| 114 | throw new RuntimeException( |
| 115 | "Missing class when invoking static main " + className, |
| 116 | ex); |
| 117 | } |
| 118 | |
| 119 | Method m; |
| 120 | try { |
| 121 | m = cl.getMethod("main", new Class[] { String[].class }); |
| 122 | } catch (NoSuchMethodException ex) { |
| 123 | throw new RuntimeException( |
| 124 | "Missing static main on " + className, ex); |
| 125 | } catch (SecurityException ex) { |
| 126 | throw new RuntimeException( |
| 127 | "Problem getting static main on " + className, ex); |
| 128 | } |
| 129 | |
| 130 | int modifiers = m.getModifiers(); |
| 131 | if (! (Modifier.isStatic(modifiers) && Modifier.isPublic(modifiers))) { |
| 132 | throw new RuntimeException( |
| 133 | "Main method is not public and static on " + className); |
| 134 | } |
| 135 | |
| 136 | /* |
| 137 | * This throw gets caught in ZygoteInit.main(), which responds |
| 138 | * by invoking the exception's run() method. This arrangement |
| 139 | * clears up all the stack frames that were required in setting |
| 140 | * up the process. |
| 141 | */ |
| 142 | throw new ZygoteInit.MethodAndArgsCaller(m, argv); |
| 143 | } |
| 144 | |
| 145 | /** |
| 146 | * Registers a server socket for zygote command connections |
| 147 | * |
| 148 | * @throws RuntimeException when open fails |
| 149 | */ |
| 150 | private static void registerZygoteSocket() { |
| 151 | if (sServerSocket == null) { |
| 152 | int fileDesc; |
| 153 | try { |
| 154 | String env = System.getenv(ANDROID_SOCKET_ENV); |
| 155 | fileDesc = Integer.parseInt(env); |
| 156 | } catch (RuntimeException ex) { |
| 157 | throw new RuntimeException( |
| 158 | ANDROID_SOCKET_ENV + " unset or invalid", ex); |
| 159 | } |
| 160 | |
| 161 | try { |
| 162 | sServerSocket = new LocalServerSocket( |
| 163 | createFileDescriptor(fileDesc)); |
| 164 | } catch (IOException ex) { |
| 165 | throw new RuntimeException( |
| 166 | "Error binding to local socket '" + fileDesc + "'", ex); |
| 167 | } |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * Waits for and accepts a single command connection. Throws |
| 173 | * RuntimeException on failure. |
| 174 | */ |
| 175 | private static ZygoteConnection acceptCommandPeer() { |
| 176 | try { |
| 177 | return new ZygoteConnection(sServerSocket.accept()); |
| 178 | } catch (IOException ex) { |
| 179 | throw new RuntimeException( |
| 180 | "IOException during accept()", ex); |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | /** |
| 185 | * Close and clean up zygote sockets. Called on shutdown and on the |
| 186 | * child's exit path. |
| 187 | */ |
| 188 | static void closeServerSocket() { |
| 189 | try { |
| 190 | if (sServerSocket != null) { |
| 191 | sServerSocket.close(); |
| 192 | } |
| 193 | } catch (IOException ex) { |
| 194 | Log.e(TAG, "Zygote: error closing sockets", ex); |
| 195 | } |
| 196 | |
| 197 | sServerSocket = null; |
| 198 | } |
| 199 | |
| 200 | private static final int UNPRIVILEGED_UID = 9999; |
| 201 | private static final int UNPRIVILEGED_GID = 9999; |
| 202 | |
| 203 | private static final int ROOT_UID = 0; |
| 204 | private static final int ROOT_GID = 0; |
| 205 | |
| 206 | /** |
| 207 | * Sets effective user ID. |
| 208 | */ |
| 209 | private static void setEffectiveUser(int uid) { |
| 210 | int errno = setreuid(ROOT_UID, uid); |
| 211 | if (errno != 0) { |
| 212 | Log.e(TAG, "setreuid() failed. errno: " + errno); |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | /** |
| 217 | * Sets effective group ID. |
| 218 | */ |
| 219 | private static void setEffectiveGroup(int gid) { |
| 220 | int errno = setregid(ROOT_GID, gid); |
| 221 | if (errno != 0) { |
| 222 | Log.e(TAG, "setregid() failed. errno: " + errno); |
| 223 | } |
| 224 | } |
| 225 | |
| 226 | /** |
| 227 | * Performs Zygote process initialization. Loads and initializes |
| 228 | * commonly used classes. |
| 229 | * |
| 230 | * Most classes only cause a few hundred bytes to be allocated, but |
| 231 | * a few will allocate a dozen Kbytes (in one case, 500+K). |
| 232 | */ |
| 233 | private static void preloadClasses() { |
| 234 | final VMRuntime runtime = VMRuntime.getRuntime(); |
| 235 | |
| 236 | InputStream is = ZygoteInit.class.getClassLoader().getResourceAsStream( |
| 237 | PRELOADED_CLASSES); |
| 238 | if (is == null) { |
| 239 | Log.e(TAG, "Couldn't find " + PRELOADED_CLASSES + "."); |
| 240 | } else { |
| 241 | Log.i(TAG, "Preloading classes..."); |
| 242 | long startTime = SystemClock.uptimeMillis(); |
| 243 | |
| 244 | // Drop root perms while running static initializers. |
| 245 | setEffectiveGroup(UNPRIVILEGED_GID); |
| 246 | setEffectiveUser(UNPRIVILEGED_UID); |
| 247 | |
| 248 | // Alter the target heap utilization. With explicit GCs this |
| 249 | // is not likely to have any effect. |
| 250 | float defaultUtilization = runtime.getTargetHeapUtilization(); |
| 251 | runtime.setTargetHeapUtilization(0.8f); |
| 252 | |
| 253 | // Start with a clean slate. |
| 254 | runtime.gcSoftReferences(); |
| 255 | runtime.runFinalizationSync(); |
| 256 | Debug.startAllocCounting(); |
| 257 | |
| 258 | try { |
| 259 | BufferedReader br |
| 260 | = new BufferedReader(new InputStreamReader(is), 256); |
| 261 | |
| 262 | int count = 0; |
| 263 | String line; |
| 264 | String missingClasses = null; |
| 265 | while ((line = br.readLine()) != null) { |
| 266 | // Skip comments and blank lines. |
| 267 | line = line.trim(); |
| 268 | if (line.startsWith("#") || line.equals("")) { |
| 269 | continue; |
| 270 | } |
| 271 | |
| 272 | try { |
| 273 | if (Config.LOGV) { |
| 274 | Log.v(TAG, "Preloading " + line + "..."); |
| 275 | } |
| 276 | Class.forName(line); |
| 277 | if (Debug.getGlobalAllocSize() > PRELOAD_GC_THRESHOLD) { |
| 278 | if (Config.LOGV) { |
| 279 | Log.v(TAG, |
| 280 | " GC at " + Debug.getGlobalAllocSize()); |
| 281 | } |
| 282 | runtime.gcSoftReferences(); |
| 283 | runtime.runFinalizationSync(); |
| 284 | Debug.resetGlobalAllocSize(); |
| 285 | } |
| 286 | count++; |
| 287 | } catch (ClassNotFoundException e) { |
| 288 | Log.e(TAG, "Class not found for preloading: " + line); |
| 289 | if (missingClasses == null) { |
| 290 | missingClasses = line; |
| 291 | } else { |
| 292 | missingClasses += " " + line; |
| 293 | } |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | if (missingClasses != null && |
| 298 | "1".equals(SystemProperties.get("persist.service.adb.enable"))) { |
| 299 | throw new IllegalStateException( |
| 300 | "Missing class(es) for preloading, update preloaded-classes [" |
| 301 | + missingClasses + "]"); |
| 302 | } |
| 303 | |
| 304 | Log.i(TAG, "...preloaded " + count + " classes in " |
| 305 | + (SystemClock.uptimeMillis()-startTime) + "ms."); |
| 306 | } catch (IOException e) { |
| 307 | Log.e(TAG, "Error reading " + PRELOADED_CLASSES + ".", e); |
| 308 | } finally { |
| 309 | // Restore default. |
| 310 | runtime.setTargetHeapUtilization(defaultUtilization); |
| 311 | |
| 312 | Debug.stopAllocCounting(); |
| 313 | |
| 314 | // Bring back root. We'll need it later. |
| 315 | setEffectiveUser(ROOT_UID); |
| 316 | setEffectiveGroup(ROOT_GID); |
| 317 | } |
| 318 | } |
| 319 | } |
| 320 | |
| 321 | /** |
| 322 | * Load in commonly used resources, so they can be shared across |
| 323 | * processes. |
| 324 | * |
| 325 | * These tend to be a few Kbytes, but are frequently in the 20-40K |
| 326 | * range, and occasionally even larger. |
| 327 | */ |
| 328 | private static void preloadResources() { |
| 329 | final VMRuntime runtime = VMRuntime.getRuntime(); |
| 330 | |
| 331 | Debug.startAllocCounting(); |
| 332 | try { |
| 333 | runtime.gcSoftReferences(); |
| 334 | runtime.runFinalizationSync(); |
| 335 | mResources = Resources.getSystem(); |
| 336 | mResources.startPreloading(); |
| 337 | if (PRELOAD_RESOURCES) { |
| 338 | Log.i(TAG, "Preloading resources..."); |
| 339 | |
| 340 | long startTime = SystemClock.uptimeMillis(); |
| 341 | TypedArray ar = mResources.obtainTypedArray( |
| 342 | com.android.internal.R.array.preloaded_drawables); |
| 343 | int N = preloadDrawables(runtime, ar); |
| 344 | Log.i(TAG, "...preloaded " + N + " resources in " |
| 345 | + (SystemClock.uptimeMillis()-startTime) + "ms."); |
| 346 | |
| 347 | startTime = SystemClock.uptimeMillis(); |
| 348 | ar = mResources.obtainTypedArray( |
| 349 | com.android.internal.R.array.preloaded_color_state_lists); |
| 350 | N = preloadColorStateLists(runtime, ar); |
| 351 | Log.i(TAG, "...preloaded " + N + " resources in " |
| 352 | + (SystemClock.uptimeMillis()-startTime) + "ms."); |
| 353 | } |
| 354 | mResources.finishPreloading(); |
| 355 | } catch (RuntimeException e) { |
| 356 | Log.w(TAG, "Failure preloading resources", e); |
| 357 | } finally { |
| 358 | Debug.stopAllocCounting(); |
| 359 | } |
| 360 | } |
| 361 | |
| 362 | private static int preloadColorStateLists(VMRuntime runtime, TypedArray ar) { |
| 363 | int N = ar.length(); |
| 364 | for (int i=0; i<N; i++) { |
| 365 | if (Debug.getGlobalAllocSize() > PRELOAD_GC_THRESHOLD) { |
| 366 | if (Config.LOGV) { |
| 367 | Log.v(TAG, " GC at " + Debug.getGlobalAllocSize()); |
| 368 | } |
| 369 | runtime.gcSoftReferences(); |
| 370 | runtime.runFinalizationSync(); |
| 371 | Debug.resetGlobalAllocSize(); |
| 372 | } |
| 373 | int id = ar.getResourceId(i, 0); |
| 374 | if (Config.LOGV) { |
| 375 | Log.v(TAG, "Preloading resource #" + Integer.toHexString(id)); |
| 376 | } |
| 377 | if (id != 0) { |
| 378 | mResources.getColorStateList(id); |
| 379 | } |
| 380 | } |
| 381 | return N; |
| 382 | } |
| 383 | |
| 384 | |
| 385 | private static int preloadDrawables(VMRuntime runtime, TypedArray ar) { |
| 386 | int N = ar.length(); |
| 387 | for (int i=0; i<N; i++) { |
| 388 | if (Debug.getGlobalAllocSize() > PRELOAD_GC_THRESHOLD) { |
| 389 | if (Config.LOGV) { |
| 390 | Log.v(TAG, " GC at " + Debug.getGlobalAllocSize()); |
| 391 | } |
| 392 | runtime.gcSoftReferences(); |
| 393 | runtime.runFinalizationSync(); |
| 394 | Debug.resetGlobalAllocSize(); |
| 395 | } |
| 396 | int id = ar.getResourceId(i, 0); |
| 397 | if (Config.LOGV) { |
| 398 | Log.v(TAG, "Preloading resource #" + Integer.toHexString(id)); |
| 399 | } |
| 400 | if (id != 0) { |
| 401 | Drawable dr = mResources.getDrawable(id); |
| 402 | if ((dr.getChangingConfigurations()&~ActivityInfo.CONFIG_FONT_SCALE) != 0) { |
| 403 | Log.w(TAG, "Preloaded drawable resource #0x" |
| 404 | + Integer.toHexString(id) |
| 405 | + " (" + ar.getString(i) + ") that varies with configuration!!"); |
| 406 | } |
| 407 | } |
| 408 | } |
| 409 | return N; |
| 410 | } |
| 411 | |
| 412 | /** |
| 413 | * Runs several special GCs to try to clean up a few generations of |
| 414 | * softly- and final-reachable objects, along with any other garbage. |
| 415 | * This is only useful just before a fork(). |
| 416 | */ |
| 417 | /*package*/ static void gc() { |
| 418 | final VMRuntime runtime = VMRuntime.getRuntime(); |
| 419 | |
| 420 | /* runFinalizationSync() lets finalizers be called in Zygote, |
| 421 | * which doesn't have a HeapWorker thread. |
| 422 | */ |
| 423 | runtime.gcSoftReferences(); |
| 424 | runtime.runFinalizationSync(); |
| 425 | runtime.gcSoftReferences(); |
| 426 | runtime.runFinalizationSync(); |
| 427 | runtime.gcSoftReferences(); |
| 428 | runtime.runFinalizationSync(); |
| 429 | } |
| 430 | |
| 431 | /** |
| 432 | * Finish remaining work for the newly forked system server process. |
| 433 | */ |
| 434 | private static void handleSystemServerProcess( |
| 435 | ZygoteConnection.Arguments parsedArgs) |
| 436 | throws ZygoteInit.MethodAndArgsCaller { |
| 437 | /* |
| 438 | * First, set the capabilities if necessary |
| 439 | */ |
| 440 | |
| 441 | if (parsedArgs.uid != 0) { |
| 442 | try { |
| 443 | setCapabilities(parsedArgs.permittedCapabilities, |
| 444 | parsedArgs.effectiveCapabilities); |
| 445 | } catch (IOException ex) { |
| 446 | Log.e(TAG, "Error setting capabilities", ex); |
| 447 | } |
| 448 | } |
| 449 | |
| 450 | closeServerSocket(); |
| 451 | |
| 452 | /* |
| 453 | * Pass the remaining arguments to SystemServer. |
| 454 | * "--nice-name=system_server com.android.server.SystemServer" |
| 455 | */ |
| 456 | RuntimeInit.zygoteInit(parsedArgs.remainingArgs); |
| 457 | /* should never reach here */ |
| 458 | } |
| 459 | |
| 460 | /** |
| 461 | * Prepare the arguments and fork for the system server process. |
| 462 | */ |
| 463 | private static boolean startSystemServer() |
| 464 | throws MethodAndArgsCaller, RuntimeException { |
| 465 | /* Hardcoded command line to start the system server */ |
| 466 | String args[] = { |
| 467 | "--setuid=1000", |
| 468 | "--setgid=1000", |
| 469 | "--setgroups=1001,1002,1003,1004,1005,1006,1007,1008,1009,1010,3001,3002,3003", |
| 470 | "--capabilities=121715744,121715744", |
| 471 | "--runtime-init", |
| 472 | "--nice-name=system_server", |
| 473 | "com.android.server.SystemServer", |
| 474 | }; |
| 475 | ZygoteConnection.Arguments parsedArgs = null; |
| 476 | |
| 477 | int pid; |
| 478 | |
| 479 | try { |
| 480 | parsedArgs = new ZygoteConnection.Arguments(args); |
| 481 | |
| 482 | /* |
| 483 | * Enable debugging of the system process if *either* the command line flags |
| 484 | * indicate it should be debuggable or the ro.debuggable system property |
| 485 | * is set to "1" |
| 486 | */ |
| 487 | int debugFlags = parsedArgs.debugFlags; |
| 488 | if ("1".equals(SystemProperties.get("ro.debuggable"))) |
| 489 | debugFlags |= Zygote.DEBUG_ENABLE_DEBUGGER; |
| 490 | |
| 491 | /* Request to fork the system server process */ |
| 492 | pid = Zygote.forkSystemServer( |
| 493 | parsedArgs.uid, parsedArgs.gid, |
| 494 | parsedArgs.gids, debugFlags, null); |
| 495 | } catch (IllegalArgumentException ex) { |
| 496 | throw new RuntimeException(ex); |
| 497 | } |
| 498 | |
| 499 | /* For child process */ |
| 500 | if (pid == 0) { |
| 501 | handleSystemServerProcess(parsedArgs); |
| 502 | } |
| 503 | |
| 504 | return true; |
| 505 | } |
| 506 | |
| 507 | public static void main(String argv[]) { |
| 508 | try { |
| 509 | registerZygoteSocket(); |
| 510 | EventLog.writeEvent(LOG_BOOT_PROGRESS_PRELOAD_START, |
| 511 | SystemClock.uptimeMillis()); |
| 512 | preloadClasses(); |
| 513 | preloadResources(); |
| 514 | EventLog.writeEvent(LOG_BOOT_PROGRESS_PRELOAD_END, |
| 515 | SystemClock.uptimeMillis()); |
| 516 | |
| 517 | // Do an initial gc to clean up after startup |
| 518 | gc(); |
| 519 | |
| 520 | // If requested, start system server directly from Zygote |
| 521 | if (argv.length != 2) { |
| 522 | throw new RuntimeException( |
| 523 | "ZygoteInit.main expects two arguments"); |
| 524 | } |
| 525 | |
| 526 | if (argv[1].equals("true")) { |
| 527 | startSystemServer(); |
| 528 | } |
| 529 | |
| 530 | Log.i(TAG, "Accepting command socket connections"); |
| 531 | |
| 532 | if (ZYGOTE_FORK_MODE) { |
| 533 | runForkMode(); |
| 534 | } else { |
| 535 | runSelectLoopMode(); |
| 536 | } |
| 537 | |
| 538 | closeServerSocket(); |
| 539 | } catch (MethodAndArgsCaller caller) { |
| 540 | caller.run(); |
| 541 | } catch (RuntimeException ex) { |
| 542 | Log.e(TAG, "Zygote died with exception", ex); |
| 543 | closeServerSocket(); |
| 544 | throw ex; |
| 545 | } |
| 546 | } |
| 547 | |
| 548 | /** |
| 549 | * Runs the zygote in accept-and-fork mode. In this mode, each peer |
| 550 | * gets its own zygote spawner process. This code is retained for |
| 551 | * reference only. |
| 552 | * |
| 553 | * @throws MethodAndArgsCaller in a child process when a main() should |
| 554 | * be executed. |
| 555 | */ |
| 556 | private static void runForkMode() throws MethodAndArgsCaller { |
| 557 | while (true) { |
| 558 | ZygoteConnection peer = acceptCommandPeer(); |
| 559 | |
| 560 | int pid; |
| 561 | |
| 562 | pid = Zygote.fork(); |
| 563 | |
| 564 | if (pid == 0) { |
| 565 | // The child process should handle the peer requests |
| 566 | |
| 567 | // The child does not accept any more connections |
| 568 | try { |
| 569 | sServerSocket.close(); |
| 570 | } catch (IOException ex) { |
| 571 | Log.e(TAG, "Zygote Child: error closing sockets", ex); |
| 572 | } finally { |
| 573 | sServerSocket = null; |
| 574 | } |
| 575 | |
| 576 | peer.run(); |
| 577 | break; |
| 578 | } else if (pid > 0) { |
| 579 | peer.closeSocket(); |
| 580 | } else { |
| 581 | throw new RuntimeException("Error invoking fork()"); |
| 582 | } |
| 583 | } |
| 584 | } |
| 585 | |
| 586 | /** |
| 587 | * Runs the zygote process's select loop. Accepts new connections as |
| 588 | * they happen, and reads commands from connections one spawn-request's |
| 589 | * worth at a time. |
| 590 | * |
| 591 | * @throws MethodAndArgsCaller in a child process when a main() should |
| 592 | * be executed. |
| 593 | */ |
| 594 | private static void runSelectLoopMode() throws MethodAndArgsCaller { |
| 595 | ArrayList<FileDescriptor> fds = new ArrayList(); |
| 596 | ArrayList<ZygoteConnection> peers = new ArrayList(); |
| 597 | FileDescriptor[] fdArray = new FileDescriptor[4]; |
| 598 | |
| 599 | fds.add(sServerSocket.getFileDescriptor()); |
| 600 | peers.add(null); |
| 601 | |
| 602 | int loopCount = GC_LOOP_COUNT; |
| 603 | while (true) { |
| 604 | int index; |
| 605 | |
| 606 | /* |
| 607 | * Call gc() before we block in select(). |
| 608 | * It's work that has to be done anyway, and it's better |
| 609 | * to avoid making every child do it. It will also |
| 610 | * madvise() any free memory as a side-effect. |
| 611 | * |
| 612 | * Don't call it every time, because walking the entire |
| 613 | * heap is a lot of overhead to free a few hundred bytes. |
| 614 | */ |
| 615 | if (loopCount <= 0) { |
| 616 | gc(); |
| 617 | loopCount = GC_LOOP_COUNT; |
| 618 | } else { |
| 619 | loopCount--; |
| 620 | } |
| 621 | |
| 622 | |
| 623 | try { |
| 624 | fdArray = fds.toArray(fdArray); |
| 625 | index = selectReadable(fdArray); |
| 626 | } catch (IOException ex) { |
| 627 | throw new RuntimeException("Error in select()", ex); |
| 628 | } |
| 629 | |
| 630 | if (index < 0) { |
| 631 | throw new RuntimeException("Error in select()"); |
| 632 | } else if (index == 0) { |
| 633 | ZygoteConnection newPeer = acceptCommandPeer(); |
| 634 | peers.add(newPeer); |
| 635 | fds.add(newPeer.getFileDesciptor()); |
| 636 | } else { |
| 637 | boolean done; |
| 638 | done = peers.get(index).runOnce(); |
| 639 | |
| 640 | if (done) { |
| 641 | peers.remove(index); |
| 642 | fds.remove(index); |
| 643 | } |
| 644 | } |
| 645 | } |
| 646 | } |
| 647 | |
| 648 | /** |
| 649 | * The Linux syscall "setreuid()" |
| 650 | * @param ruid real uid |
| 651 | * @param euid effective uid |
| 652 | * @return 0 on success, non-zero errno on fail |
| 653 | */ |
| 654 | static native int setreuid(int ruid, int euid); |
| 655 | |
| 656 | /** |
| 657 | * The Linux syscall "setregid()" |
| 658 | * @param rgid real gid |
| 659 | * @param egid effective gid |
| 660 | * @return 0 on success, non-zero errno on fail |
| 661 | */ |
| 662 | static native int setregid(int rgid, int egid); |
| 663 | |
| 664 | /** |
| 665 | * Invokes the linux syscall "setpgid" |
| 666 | * |
| 667 | * @param pid pid to change |
| 668 | * @param pgid new process group of pid |
| 669 | * @return 0 on success or non-zero errno on fail |
| 670 | */ |
| 671 | static native int setpgid(int pid, int pgid); |
| 672 | |
| 673 | /** |
| 674 | * Invokes the linux syscall "getpgid" |
| 675 | * |
| 676 | * @param pid pid to query |
| 677 | * @return pgid of pid in question |
| 678 | * @throws IOException on error |
| 679 | */ |
| 680 | static native int getpgid(int pid) throws IOException; |
| 681 | |
| 682 | /** |
| 683 | * Invokes the syscall dup2() to copy the specified descriptors into |
| 684 | * stdin, stdout, and stderr. The existing stdio descriptors will be |
| 685 | * closed and errors during close will be ignored. The specified |
| 686 | * descriptors will also remain open at their original descriptor numbers, |
| 687 | * so the caller may want to close the original descriptors. |
| 688 | * |
| 689 | * @param in new stdin |
| 690 | * @param out new stdout |
| 691 | * @param err new stderr |
| 692 | * @throws IOException |
| 693 | */ |
| 694 | static native void reopenStdio(FileDescriptor in, |
| 695 | FileDescriptor out, FileDescriptor err) throws IOException; |
| 696 | |
| 697 | /** |
| 698 | * Calls close() on a file descriptor |
| 699 | * |
| 700 | * @param fd descriptor to close |
| 701 | * @throws IOException |
| 702 | */ |
| 703 | static native void closeDescriptor(FileDescriptor fd) |
| 704 | throws IOException; |
| 705 | |
| 706 | /** |
| 707 | * Toggles the close-on-exec flag for the specified file descriptor. |
| 708 | * |
| 709 | * @param fd non-null; file descriptor |
| 710 | * @param flag desired close-on-exec flag state |
| 711 | * @throws IOException |
| 712 | */ |
| 713 | static native void setCloseOnExec(FileDescriptor fd, boolean flag) |
| 714 | throws IOException; |
| 715 | |
| 716 | /** |
| 717 | * Retrieves the permitted capability set from another process. |
| 718 | * |
| 719 | * @param pid >=0 process ID or 0 for this process |
| 720 | * @throws IOException on error |
| 721 | */ |
| 722 | static native long capgetPermitted(int pid) |
| 723 | throws IOException; |
| 724 | |
| 725 | /** |
| 726 | * Sets the permitted and effective capability sets of this process. |
| 727 | * |
| 728 | * @param permittedCapabilities permitted set |
| 729 | * @param effectiveCapabilities effective set |
| 730 | * @throws IOException on error |
| 731 | */ |
| 732 | static native void setCapabilities( |
| 733 | long permittedCapabilities, |
| 734 | long effectiveCapabilities) throws IOException; |
| 735 | |
| 736 | /** |
| 737 | * Invokes select() on the provider array of file descriptors (selecting |
| 738 | * for readability only). Array elements of null are ignored. |
| 739 | * |
| 740 | * @param fds non-null; array of readable file descriptors |
| 741 | * @return index of descriptor that is now readable or -1 for empty array. |
| 742 | * @throws IOException if an error occurs |
| 743 | */ |
| 744 | static native int selectReadable(FileDescriptor[] fds) throws IOException; |
| 745 | |
| 746 | /** |
| 747 | * Creates a file descriptor from an int fd. |
| 748 | * |
| 749 | * @param fd integer OS file descriptor |
| 750 | * @return non-null; FileDescriptor instance |
| 751 | * @throws IOException if fd is invalid |
| 752 | */ |
| 753 | static native FileDescriptor createFileDescriptor(int fd) |
| 754 | throws IOException; |
| 755 | |
| 756 | /** |
| 757 | * Class not instantiable. |
| 758 | */ |
| 759 | private ZygoteInit() { |
| 760 | } |
| 761 | |
| 762 | /** |
| 763 | * Helper exception class which holds a method and arguments and |
| 764 | * can call them. This is used as part of a trampoline to get rid of |
| 765 | * the initial process setup stack frames. |
| 766 | */ |
| 767 | public static class MethodAndArgsCaller extends Exception |
| 768 | implements Runnable { |
| 769 | /** method to call */ |
| 770 | private final Method mMethod; |
| 771 | |
| 772 | /** argument array */ |
| 773 | private final String[] mArgs; |
| 774 | |
| 775 | public MethodAndArgsCaller(Method method, String[] args) { |
| 776 | mMethod = method; |
| 777 | mArgs = args; |
| 778 | } |
| 779 | |
| 780 | public void run() { |
| 781 | try { |
| 782 | mMethod.invoke(null, new Object[] { mArgs }); |
| 783 | } catch (IllegalAccessException ex) { |
| 784 | throw new RuntimeException(ex); |
| 785 | } catch (InvocationTargetException ex) { |
| 786 | Throwable cause = ex.getCause(); |
| 787 | if (cause instanceof RuntimeException) { |
| 788 | throw (RuntimeException) cause; |
| 789 | } else if (cause instanceof Error) { |
| 790 | throw (Error) cause; |
| 791 | } |
| 792 | throw new RuntimeException(ex); |
| 793 | } |
| 794 | } |
| 795 | } |
| 796 | } |