Process.java revision e9d376b801b7890b1ef5006ed55de4208e64bb63
1/* 2 * Copyright (C) 2006 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 17package android.os; 18 19import android.net.LocalSocketAddress; 20import android.net.LocalSocket; 21import android.util.Log; 22import dalvik.system.Zygote; 23 24import java.io.BufferedWriter; 25import java.io.DataInputStream; 26import java.io.IOException; 27import java.io.OutputStreamWriter; 28import java.util.ArrayList; 29 30/*package*/ class ZygoteStartFailedEx extends Exception { 31 /** 32 * Something prevented the zygote process startup from happening normally 33 */ 34 35 ZygoteStartFailedEx() {}; 36 ZygoteStartFailedEx(String s) {super(s);} 37 ZygoteStartFailedEx(Throwable cause) {super(cause);} 38} 39 40/** 41 * Tools for managing OS processes. 42 */ 43public class Process { 44 private static final String LOG_TAG = "Process"; 45 46 private static final String ZYGOTE_SOCKET = "zygote"; 47 48 /** 49 * Name of a process for running the platform's media services. 50 * {@hide} 51 */ 52 public static final String ANDROID_SHARED_MEDIA = "com.android.process.media"; 53 54 /** 55 * Name of the process that Google content providers can share. 56 * {@hide} 57 */ 58 public static final String GOOGLE_SHARED_APP_CONTENT = "com.google.process.content"; 59 60 /** 61 * Defines the UID/GID under which system code runs. 62 */ 63 public static final int SYSTEM_UID = 1000; 64 65 /** 66 * Defines the UID/GID under which the telephony code runs. 67 */ 68 public static final int PHONE_UID = 1001; 69 70 /** 71 * Defines the start of a range of UIDs (and GIDs), going from this 72 * number to {@link #LAST_APPLICATION_UID} that are reserved for assigning 73 * to applications. 74 */ 75 public static final int FIRST_APPLICATION_UID = 10000; 76 /** 77 * Last of application-specific UIDs starting at 78 * {@link #FIRST_APPLICATION_UID}. 79 */ 80 public static final int LAST_APPLICATION_UID = 99999; 81 82 /** 83 * Defines a secondary group id for access to the bluetooth hardware. 84 */ 85 public static final int BLUETOOTH_GID = 2000; 86 87 /** 88 * Standard priority of application threads. 89 * Use with {@link #setThreadPriority(int)} and 90 * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal 91 * {@link java.lang.Thread} class. 92 */ 93 public static final int THREAD_PRIORITY_DEFAULT = 0; 94 95 /* 96 * *************************************** 97 * ** Keep in sync with utils/threads.h ** 98 * *************************************** 99 */ 100 101 /** 102 * Lowest available thread priority. Only for those who really, really 103 * don't want to run if anything else is happening. 104 * Use with {@link #setThreadPriority(int)} and 105 * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal 106 * {@link java.lang.Thread} class. 107 */ 108 public static final int THREAD_PRIORITY_LOWEST = 19; 109 110 /** 111 * Standard priority background threads. This gives your thread a slightly 112 * lower than normal priority, so that it will have less chance of impacting 113 * the responsiveness of the user interface. 114 * Use with {@link #setThreadPriority(int)} and 115 * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal 116 * {@link java.lang.Thread} class. 117 */ 118 public static final int THREAD_PRIORITY_BACKGROUND = 10; 119 120 /** 121 * Standard priority of threads that are currently running a user interface 122 * that the user is interacting with. Applications can not normally 123 * change to this priority; the system will automatically adjust your 124 * application threads as the user moves through the UI. 125 * Use with {@link #setThreadPriority(int)} and 126 * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal 127 * {@link java.lang.Thread} class. 128 */ 129 public static final int THREAD_PRIORITY_FOREGROUND = -2; 130 131 /** 132 * Standard priority of system display threads, involved in updating 133 * the user interface. Applications can not 134 * normally change to this priority. 135 * Use with {@link #setThreadPriority(int)} and 136 * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal 137 * {@link java.lang.Thread} class. 138 */ 139 public static final int THREAD_PRIORITY_DISPLAY = -4; 140 141 /** 142 * Standard priority of the most important display threads, for compositing 143 * the screen and retrieving input events. Applications can not normally 144 * change to this priority. 145 * Use with {@link #setThreadPriority(int)} and 146 * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal 147 * {@link java.lang.Thread} class. 148 */ 149 public static final int THREAD_PRIORITY_URGENT_DISPLAY = -8; 150 151 /** 152 * Standard priority of audio threads. Applications can not normally 153 * change to this priority. 154 * Use with {@link #setThreadPriority(int)} and 155 * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal 156 * {@link java.lang.Thread} class. 157 */ 158 public static final int THREAD_PRIORITY_AUDIO = -16; 159 160 /** 161 * Standard priority of the most important audio threads. 162 * Applications can not normally change to this priority. 163 * Use with {@link #setThreadPriority(int)} and 164 * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal 165 * {@link java.lang.Thread} class. 166 */ 167 public static final int THREAD_PRIORITY_URGENT_AUDIO = -19; 168 169 /** 170 * Minimum increment to make a priority more favorable. 171 */ 172 public static final int THREAD_PRIORITY_MORE_FAVORABLE = -1; 173 174 /** 175 * Minimum increment to make a priority less favorable. 176 */ 177 public static final int THREAD_PRIORITY_LESS_FAVORABLE = +1; 178 179 /** 180 * Default thread group - gets a 'normal' share of the CPU 181 * @hide 182 */ 183 public static final int THREAD_GROUP_DEFAULT = 0; 184 185 /** 186 * Background non-interactive thread group - All threads in 187 * this group are scheduled with a reduced share of the CPU. 188 * @hide 189 */ 190 public static final int THREAD_GROUP_BG_NONINTERACTIVE = 1; 191 192 /** 193 * Foreground 'boost' thread group - All threads in 194 * this group are scheduled with an increased share of the CPU 195 * @hide 196 **/ 197 public static final int THREAD_GROUP_FG_BOOST = 2; 198 199 public static final int SIGNAL_QUIT = 3; 200 public static final int SIGNAL_KILL = 9; 201 public static final int SIGNAL_USR1 = 10; 202 203 // State for communicating with zygote process 204 205 static LocalSocket sZygoteSocket; 206 static DataInputStream sZygoteInputStream; 207 static BufferedWriter sZygoteWriter; 208 209 /** true if previous zygote open failed */ 210 static boolean sPreviousZygoteOpenFailed; 211 212 /** 213 * Start a new process. 214 * 215 * <p>If processes are enabled, a new process is created and the 216 * static main() function of a <var>processClass</var> is executed there. 217 * The process will continue running after this function returns. 218 * 219 * <p>If processes are not enabled, a new thread in the caller's 220 * process is created and main() of <var>processClass</var> called there. 221 * 222 * <p>The niceName parameter, if not an empty string, is a custom name to 223 * give to the process instead of using processClass. This allows you to 224 * make easily identifyable processes even if you are using the same base 225 * <var>processClass</var> to start them. 226 * 227 * @param processClass The class to use as the process's main entry 228 * point. 229 * @param niceName A more readable name to use for the process. 230 * @param uid The user-id under which the process will run. 231 * @param gid The group-id under which the process will run. 232 * @param gids Additional group-ids associated with the process. 233 * @param enableDebugger True if debugging should be enabled for this process. 234 * @param zygoteArgs Additional arguments to supply to the zygote process. 235 * 236 * @return int If > 0 the pid of the new process; if 0 the process is 237 * being emulated by a thread 238 * @throws RuntimeException on fatal start failure 239 * 240 * {@hide} 241 */ 242 public static final int start(final String processClass, 243 final String niceName, 244 int uid, int gid, int[] gids, 245 int debugFlags, 246 String[] zygoteArgs) 247 { 248 if (supportsProcesses()) { 249 try { 250 return startViaZygote(processClass, niceName, uid, gid, gids, 251 debugFlags, zygoteArgs); 252 } catch (ZygoteStartFailedEx ex) { 253 Log.e(LOG_TAG, 254 "Starting VM process through Zygote failed"); 255 throw new RuntimeException( 256 "Starting VM process through Zygote failed", ex); 257 } 258 } else { 259 // Running in single-process mode 260 261 Runnable runnable = new Runnable() { 262 public void run() { 263 Process.invokeStaticMain(processClass); 264 } 265 }; 266 267 // Thread constructors must not be called with null names (see spec). 268 if (niceName != null) { 269 new Thread(runnable, niceName).start(); 270 } else { 271 new Thread(runnable).start(); 272 } 273 274 return 0; 275 } 276 } 277 278 /** 279 * Start a new process. Don't supply a custom nice name. 280 * {@hide} 281 */ 282 public static final int start(String processClass, int uid, int gid, 283 int[] gids, int debugFlags, String[] zygoteArgs) { 284 return start(processClass, "", uid, gid, gids, 285 debugFlags, zygoteArgs); 286 } 287 288 private static void invokeStaticMain(String className) { 289 Class cl; 290 Object args[] = new Object[1]; 291 292 args[0] = new String[0]; //this is argv 293 294 try { 295 cl = Class.forName(className); 296 cl.getMethod("main", new Class[] { String[].class }) 297 .invoke(null, args); 298 } catch (Exception ex) { 299 // can be: ClassNotFoundException, 300 // NoSuchMethodException, SecurityException, 301 // IllegalAccessException, IllegalArgumentException 302 // InvocationTargetException 303 // or uncaught exception from main() 304 305 Log.e(LOG_TAG, "Exception invoking static main on " 306 + className, ex); 307 308 throw new RuntimeException(ex); 309 } 310 311 } 312 313 /** retry interval for opening a zygote socket */ 314 static final int ZYGOTE_RETRY_MILLIS = 500; 315 316 /** 317 * Tries to open socket to Zygote process if not already open. If 318 * already open, does nothing. May block and retry. 319 */ 320 private static void openZygoteSocketIfNeeded() 321 throws ZygoteStartFailedEx { 322 323 int retryCount; 324 325 if (sPreviousZygoteOpenFailed) { 326 /* 327 * If we've failed before, expect that we'll fail again and 328 * don't pause for retries. 329 */ 330 retryCount = 0; 331 } else { 332 retryCount = 10; 333 } 334 335 /* 336 * See bug #811181: Sometimes runtime can make it up before zygote. 337 * Really, we'd like to do something better to avoid this condition, 338 * but for now just wait a bit... 339 */ 340 for (int retry = 0 341 ; (sZygoteSocket == null) && (retry < (retryCount + 1)) 342 ; retry++ ) { 343 344 if (retry > 0) { 345 try { 346 Log.i("Zygote", "Zygote not up yet, sleeping..."); 347 Thread.sleep(ZYGOTE_RETRY_MILLIS); 348 } catch (InterruptedException ex) { 349 // should never happen 350 } 351 } 352 353 try { 354 sZygoteSocket = new LocalSocket(); 355 356 sZygoteSocket.connect(new LocalSocketAddress(ZYGOTE_SOCKET, 357 LocalSocketAddress.Namespace.RESERVED)); 358 359 sZygoteInputStream 360 = new DataInputStream(sZygoteSocket.getInputStream()); 361 362 sZygoteWriter = 363 new BufferedWriter( 364 new OutputStreamWriter( 365 sZygoteSocket.getOutputStream()), 366 256); 367 368 Log.i("Zygote", "Process: zygote socket opened"); 369 370 sPreviousZygoteOpenFailed = false; 371 break; 372 } catch (IOException ex) { 373 if (sZygoteSocket != null) { 374 try { 375 sZygoteSocket.close(); 376 } catch (IOException ex2) { 377 Log.e(LOG_TAG,"I/O exception on close after exception", 378 ex2); 379 } 380 } 381 382 sZygoteSocket = null; 383 } 384 } 385 386 if (sZygoteSocket == null) { 387 sPreviousZygoteOpenFailed = true; 388 throw new ZygoteStartFailedEx("connect failed"); 389 } 390 } 391 392 /** 393 * Sends an argument list to the zygote process, which starts a new child 394 * and returns the child's pid. Please note: the present implementation 395 * replaces newlines in the argument list with spaces. 396 * @param args argument list 397 * @return PID of new child process 398 * @throws ZygoteStartFailedEx if process start failed for any reason 399 */ 400 private static int zygoteSendArgsAndGetPid(ArrayList<String> args) 401 throws ZygoteStartFailedEx { 402 403 int pid; 404 405 openZygoteSocketIfNeeded(); 406 407 try { 408 /** 409 * See com.android.internal.os.ZygoteInit.readArgumentList() 410 * Presently the wire format to the zygote process is: 411 * a) a count of arguments (argc, in essence) 412 * b) a number of newline-separated argument strings equal to count 413 * 414 * After the zygote process reads these it will write the pid of 415 * the child or -1 on failure. 416 */ 417 418 sZygoteWriter.write(Integer.toString(args.size())); 419 sZygoteWriter.newLine(); 420 421 int sz = args.size(); 422 for (int i = 0; i < sz; i++) { 423 String arg = args.get(i); 424 if (arg.indexOf('\n') >= 0) { 425 throw new ZygoteStartFailedEx( 426 "embedded newlines not allowed"); 427 } 428 sZygoteWriter.write(arg); 429 sZygoteWriter.newLine(); 430 } 431 432 sZygoteWriter.flush(); 433 434 // Should there be a timeout on this? 435 pid = sZygoteInputStream.readInt(); 436 437 if (pid < 0) { 438 throw new ZygoteStartFailedEx("fork() failed"); 439 } 440 } catch (IOException ex) { 441 try { 442 if (sZygoteSocket != null) { 443 sZygoteSocket.close(); 444 } 445 } catch (IOException ex2) { 446 // we're going to fail anyway 447 Log.e(LOG_TAG,"I/O exception on routine close", ex2); 448 } 449 450 sZygoteSocket = null; 451 452 throw new ZygoteStartFailedEx(ex); 453 } 454 455 return pid; 456 } 457 458 /** 459 * Starts a new process via the zygote mechanism. 460 * 461 * @param processClass Class name whose static main() to run 462 * @param niceName 'nice' process name to appear in ps 463 * @param uid a POSIX uid that the new process should setuid() to 464 * @param gid a POSIX gid that the new process shuold setgid() to 465 * @param gids null-ok; a list of supplementary group IDs that the 466 * new process should setgroup() to. 467 * @param enableDebugger True if debugging should be enabled for this process. 468 * @param extraArgs Additional arguments to supply to the zygote process. 469 * @return PID 470 * @throws ZygoteStartFailedEx if process start failed for any reason 471 */ 472 private static int startViaZygote(final String processClass, 473 final String niceName, 474 final int uid, final int gid, 475 final int[] gids, 476 int debugFlags, 477 String[] extraArgs) 478 throws ZygoteStartFailedEx { 479 int pid; 480 481 synchronized(Process.class) { 482 ArrayList<String> argsForZygote = new ArrayList<String>(); 483 484 // --runtime-init, --setuid=, --setgid=, 485 // and --setgroups= must go first 486 argsForZygote.add("--runtime-init"); 487 argsForZygote.add("--setuid=" + uid); 488 argsForZygote.add("--setgid=" + gid); 489 if ((debugFlags & Zygote.DEBUG_ENABLE_DEBUGGER) != 0) { 490 argsForZygote.add("--enable-debugger"); 491 } 492 if ((debugFlags & Zygote.DEBUG_ENABLE_CHECKJNI) != 0) { 493 argsForZygote.add("--enable-checkjni"); 494 } 495 if ((debugFlags & Zygote.DEBUG_ENABLE_ASSERT) != 0) { 496 argsForZygote.add("--enable-assert"); 497 } 498 499 //TODO optionally enable debuger 500 //argsForZygote.add("--enable-debugger"); 501 502 // --setgroups is a comma-separated list 503 if (gids != null && gids.length > 0) { 504 StringBuilder sb = new StringBuilder(); 505 sb.append("--setgroups="); 506 507 int sz = gids.length; 508 for (int i = 0; i < sz; i++) { 509 if (i != 0) { 510 sb.append(','); 511 } 512 sb.append(gids[i]); 513 } 514 515 argsForZygote.add(sb.toString()); 516 } 517 518 if (niceName != null) { 519 argsForZygote.add("--nice-name=" + niceName); 520 } 521 522 argsForZygote.add(processClass); 523 524 if (extraArgs != null) { 525 for (String arg : extraArgs) { 526 argsForZygote.add(arg); 527 } 528 } 529 530 pid = zygoteSendArgsAndGetPid(argsForZygote); 531 } 532 533 if (pid <= 0) { 534 throw new ZygoteStartFailedEx("zygote start failed:" + pid); 535 } 536 537 return pid; 538 } 539 540 /** 541 * Returns elapsed milliseconds of the time this process has run. 542 * @return Returns the number of milliseconds this process has return. 543 */ 544 public static final native long getElapsedCpuTime(); 545 546 /** 547 * Returns the identifier of this process, which can be used with 548 * {@link #killProcess} and {@link #sendSignal}. 549 */ 550 public static final native int myPid(); 551 552 /** 553 * Returns the identifier of the calling thread, which be used with 554 * {@link #setThreadPriority(int, int)}. 555 */ 556 public static final native int myTid(); 557 558 /** 559 * Returns the identifier of this process's user. 560 */ 561 public static final native int myUid(); 562 563 /** 564 * Returns the UID assigned to a particular user name, or -1 if there is 565 * none. If the given string consists of only numbers, it is converted 566 * directly to a uid. 567 */ 568 public static final native int getUidForName(String name); 569 570 /** 571 * Returns the GID assigned to a particular user name, or -1 if there is 572 * none. If the given string consists of only numbers, it is converted 573 * directly to a gid. 574 */ 575 public static final native int getGidForName(String name); 576 577 /** 578 * Set the priority of a thread, based on Linux priorities. 579 * 580 * @param tid The identifier of the thread/process to change. 581 * @param priority A Linux priority level, from -20 for highest scheduling 582 * priority to 19 for lowest scheduling priority. 583 * 584 * @throws IllegalArgumentException Throws IllegalArgumentException if 585 * <var>tid</var> does not exist. 586 * @throws SecurityException Throws SecurityException if your process does 587 * not have permission to modify the given thread, or to use the given 588 * priority. 589 */ 590 public static final native void setThreadPriority(int tid, int priority) 591 throws IllegalArgumentException, SecurityException; 592 593 /** 594 * Sets the scheduling group for a thread. 595 * @hide 596 * @param tid The indentifier of the thread/process to change. 597 * @param group The target group for this thread/process. 598 * 599 * @throws IllegalArgumentException Throws IllegalArgumentException if 600 * <var>tid</var> does not exist. 601 * @throws SecurityException Throws SecurityException if your process does 602 * not have permission to modify the given thread, or to use the given 603 * priority. 604 */ 605 public static final native void setThreadGroup(int tid, int group) 606 throws IllegalArgumentException, SecurityException; 607 608 /** 609 * Set the priority of the calling thread, based on Linux priorities. See 610 * {@link #setThreadPriority(int, int)} for more information. 611 * 612 * @param priority A Linux priority level, from -20 for highest scheduling 613 * priority to 19 for lowest scheduling priority. 614 * 615 * @throws IllegalArgumentException Throws IllegalArgumentException if 616 * <var>tid</var> does not exist. 617 * @throws SecurityException Throws SecurityException if your process does 618 * not have permission to modify the given thread, or to use the given 619 * priority. 620 * 621 * @see #setThreadPriority(int, int) 622 */ 623 public static final native void setThreadPriority(int priority) 624 throws IllegalArgumentException, SecurityException; 625 626 /** 627 * Return the current priority of a thread, based on Linux priorities. 628 * 629 * @param tid The identifier of the thread/process to change. 630 * 631 * @return Returns the current priority, as a Linux priority level, 632 * from -20 for highest scheduling priority to 19 for lowest scheduling 633 * priority. 634 * 635 * @throws IllegalArgumentException Throws IllegalArgumentException if 636 * <var>tid</var> does not exist. 637 */ 638 public static final native int getThreadPriority(int tid) 639 throws IllegalArgumentException; 640 641 /** 642 * Determine whether the current environment supports multiple processes. 643 * 644 * @return Returns true if the system can run in multiple processes, else 645 * false if everything is running in a single process. 646 */ 647 public static final native boolean supportsProcesses(); 648 649 /** 650 * Set the out-of-memory badness adjustment for a process. 651 * 652 * @param pid The process identifier to set. 653 * @param amt Adjustment value -- linux allows -16 to +15. 654 * 655 * @return Returns true if the underlying system supports this 656 * feature, else false. 657 * 658 * {@hide} 659 */ 660 public static final native boolean setOomAdj(int pid, int amt); 661 662 /** 663 * Change this process's argv[0] parameter. This can be useful to show 664 * more descriptive information in things like the 'ps' command. 665 * 666 * @param text The new name of this process. 667 * 668 * {@hide} 669 */ 670 public static final native void setArgV0(String text); 671 672 /** 673 * Kill the process with the given PID. 674 * Note that, though this API allows us to request to 675 * kill any process based on its PID, the kernel will 676 * still impose standard restrictions on which PIDs you 677 * are actually able to kill. Typically this means only 678 * the process running the caller's packages/application 679 * and any additional processes created by that app; packages 680 * sharing a common UID will also be able to kill each 681 * other's processes. 682 */ 683 public static final void killProcess(int pid) { 684 sendSignal(pid, SIGNAL_KILL); 685 } 686 687 /** @hide */ 688 public static final native int setUid(int uid); 689 690 /** @hide */ 691 public static final native int setGid(int uid); 692 693 /** 694 * Send a signal to the given process. 695 * 696 * @param pid The pid of the target process. 697 * @param signal The signal to send. 698 */ 699 public static final native void sendSignal(int pid, int signal); 700 701 /** @hide */ 702 public static final native int getFreeMemory(); 703 704 /** @hide */ 705 public static final native void readProcLines(String path, 706 String[] reqFields, long[] outSizes); 707 708 /** @hide */ 709 public static final native int[] getPids(String path, int[] lastArray); 710 711 /** @hide */ 712 public static final int PROC_TERM_MASK = 0xff; 713 /** @hide */ 714 public static final int PROC_ZERO_TERM = 0; 715 /** @hide */ 716 public static final int PROC_SPACE_TERM = (int)' '; 717 /** @hide */ 718 public static final int PROC_TAB_TERM = (int)'\t'; 719 /** @hide */ 720 public static final int PROC_COMBINE = 0x100; 721 /** @hide */ 722 public static final int PROC_PARENS = 0x200; 723 /** @hide */ 724 public static final int PROC_OUT_STRING = 0x1000; 725 /** @hide */ 726 public static final int PROC_OUT_LONG = 0x2000; 727 /** @hide */ 728 public static final int PROC_OUT_FLOAT = 0x4000; 729 730 /** @hide */ 731 public static final native boolean readProcFile(String file, int[] format, 732 String[] outStrings, long[] outLongs, float[] outFloats); 733 734 /** @hide */ 735 public static final native boolean parseProcLine(byte[] buffer, int startIndex, 736 int endIndex, int[] format, String[] outStrings, long[] outLongs, float[] outFloats); 737 738 /** 739 * Gets the total Pss value for a given process, in bytes. 740 * 741 * @param pid the process to the Pss for 742 * @return the total Pss value for the given process in bytes, 743 * or -1 if the value cannot be determined 744 * @hide 745 */ 746 public static final native long getPss(int pid); 747} 748