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      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 
     17 package android.os;
     18 
     19 import android.net.LocalSocket;
     20 import android.net.LocalSocketAddress;
     21 import android.system.Os;
     22 import android.util.Log;
     23 import com.android.internal.os.Zygote;
     24 import java.io.BufferedWriter;
     25 import java.io.DataInputStream;
     26 import java.io.IOException;
     27 import java.io.OutputStreamWriter;
     28 import java.nio.charset.StandardCharsets;
     29 import java.util.ArrayList;
     30 import java.util.Arrays;
     31 import java.util.List;
     32 
     33 /*package*/ class ZygoteStartFailedEx extends Exception {
     34     ZygoteStartFailedEx(String s) {
     35         super(s);
     36     }
     37 
     38     ZygoteStartFailedEx(Throwable cause) {
     39         super(cause);
     40     }
     41 
     42     ZygoteStartFailedEx(String s, Throwable cause) {
     43         super(s, cause);
     44     }
     45 }
     46 
     47 /**
     48  * Tools for managing OS processes.
     49  */
     50 public class Process {
     51     private static final String LOG_TAG = "Process";
     52 
     53     /**
     54      * @hide for internal use only.
     55      */
     56     public static final String ZYGOTE_SOCKET = "zygote";
     57 
     58     /**
     59      * @hide for internal use only.
     60      */
     61     public static final String SECONDARY_ZYGOTE_SOCKET = "zygote_secondary";
     62 
     63     /**
     64      * Defines the root UID.
     65      * @hide
     66      */
     67     public static final int ROOT_UID = 0;
     68 
     69     /**
     70      * Defines the UID/GID under which system code runs.
     71      */
     72     public static final int SYSTEM_UID = 1000;
     73 
     74     /**
     75      * Defines the UID/GID under which the telephony code runs.
     76      */
     77     public static final int PHONE_UID = 1001;
     78 
     79     /**
     80      * Defines the UID/GID for the user shell.
     81      * @hide
     82      */
     83     public static final int SHELL_UID = 2000;
     84 
     85     /**
     86      * Defines the UID/GID for the log group.
     87      * @hide
     88      */
     89     public static final int LOG_UID = 1007;
     90 
     91     /**
     92      * Defines the UID/GID for the WIFI supplicant process.
     93      * @hide
     94      */
     95     public static final int WIFI_UID = 1010;
     96 
     97     /**
     98      * Defines the UID/GID for the mediaserver process.
     99      * @hide
    100      */
    101     public static final int MEDIA_UID = 1013;
    102 
    103     /**
    104      * Defines the UID/GID for the DRM process.
    105      * @hide
    106      */
    107     public static final int DRM_UID = 1019;
    108 
    109     /**
    110      * Defines the UID/GID for the group that controls VPN services.
    111      * @hide
    112      */
    113     public static final int VPN_UID = 1016;
    114 
    115     /**
    116      * Defines the UID/GID for the NFC service process.
    117      * @hide
    118      */
    119     public static final int NFC_UID = 1027;
    120 
    121     /**
    122      * Defines the UID/GID for the Bluetooth service process.
    123      * @hide
    124      */
    125     public static final int BLUETOOTH_UID = 1002;
    126 
    127     /**
    128      * Defines the GID for the group that allows write access to the internal media storage.
    129      * @hide
    130      */
    131     public static final int MEDIA_RW_GID = 1023;
    132 
    133     /**
    134      * Access to installed package details
    135      * @hide
    136      */
    137     public static final int PACKAGE_INFO_GID = 1032;
    138 
    139     /**
    140      * Defines the UID/GID for the shared RELRO file updater process.
    141      * @hide
    142      */
    143     public static final int SHARED_RELRO_UID = 1037;
    144 
    145     /**
    146      * Defines the start of a range of UIDs (and GIDs), going from this
    147      * number to {@link #LAST_APPLICATION_UID} that are reserved for assigning
    148      * to applications.
    149      */
    150     public static final int FIRST_APPLICATION_UID = 10000;
    151 
    152     /**
    153      * Last of application-specific UIDs starting at
    154      * {@link #FIRST_APPLICATION_UID}.
    155      */
    156     public static final int LAST_APPLICATION_UID = 19999;
    157 
    158     /**
    159      * First uid used for fully isolated sandboxed processes (with no permissions of their own)
    160      * @hide
    161      */
    162     public static final int FIRST_ISOLATED_UID = 99000;
    163 
    164     /**
    165      * Last uid used for fully isolated sandboxed processes (with no permissions of their own)
    166      * @hide
    167      */
    168     public static final int LAST_ISOLATED_UID = 99999;
    169 
    170     /**
    171      * Defines the gid shared by all applications running under the same profile.
    172      * @hide
    173      */
    174     public static final int SHARED_USER_GID = 9997;
    175 
    176     /**
    177      * First gid for applications to share resources. Used when forward-locking
    178      * is enabled but all UserHandles need to be able to read the resources.
    179      * @hide
    180      */
    181     public static final int FIRST_SHARED_APPLICATION_GID = 50000;
    182 
    183     /**
    184      * Last gid for applications to share resources. Used when forward-locking
    185      * is enabled but all UserHandles need to be able to read the resources.
    186      * @hide
    187      */
    188     public static final int LAST_SHARED_APPLICATION_GID = 59999;
    189 
    190     /**
    191      * Standard priority of application threads.
    192      * Use with {@link #setThreadPriority(int)} and
    193      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
    194      * {@link java.lang.Thread} class.
    195      */
    196     public static final int THREAD_PRIORITY_DEFAULT = 0;
    197 
    198     /*
    199      * ***************************************
    200      * ** Keep in sync with utils/threads.h **
    201      * ***************************************
    202      */
    203 
    204     /**
    205      * Lowest available thread priority.  Only for those who really, really
    206      * don't want to run if anything else is happening.
    207      * Use with {@link #setThreadPriority(int)} and
    208      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
    209      * {@link java.lang.Thread} class.
    210      */
    211     public static final int THREAD_PRIORITY_LOWEST = 19;
    212 
    213     /**
    214      * Standard priority background threads.  This gives your thread a slightly
    215      * lower than normal priority, so that it will have less chance of impacting
    216      * the responsiveness of the user interface.
    217      * Use with {@link #setThreadPriority(int)} and
    218      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
    219      * {@link java.lang.Thread} class.
    220      */
    221     public static final int THREAD_PRIORITY_BACKGROUND = 10;
    222 
    223     /**
    224      * Standard priority of threads that are currently running a user interface
    225      * that the user is interacting with.  Applications can not normally
    226      * change to this priority; the system will automatically adjust your
    227      * application threads as the user moves through the UI.
    228      * Use with {@link #setThreadPriority(int)} and
    229      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
    230      * {@link java.lang.Thread} class.
    231      */
    232     public static final int THREAD_PRIORITY_FOREGROUND = -2;
    233 
    234     /**
    235      * Standard priority of system display threads, involved in updating
    236      * the user interface.  Applications can not
    237      * normally change to this priority.
    238      * Use with {@link #setThreadPriority(int)} and
    239      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
    240      * {@link java.lang.Thread} class.
    241      */
    242     public static final int THREAD_PRIORITY_DISPLAY = -4;
    243 
    244     /**
    245      * Standard priority of the most important display threads, for compositing
    246      * the screen and retrieving input events.  Applications can not normally
    247      * change to this priority.
    248      * Use with {@link #setThreadPriority(int)} and
    249      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
    250      * {@link java.lang.Thread} class.
    251      */
    252     public static final int THREAD_PRIORITY_URGENT_DISPLAY = -8;
    253 
    254     /**
    255      * Standard priority of audio threads.  Applications can not normally
    256      * change to this priority.
    257      * Use with {@link #setThreadPriority(int)} and
    258      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
    259      * {@link java.lang.Thread} class.
    260      */
    261     public static final int THREAD_PRIORITY_AUDIO = -16;
    262 
    263     /**
    264      * Standard priority of the most important audio threads.
    265      * Applications can not normally change to this priority.
    266      * Use with {@link #setThreadPriority(int)} and
    267      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
    268      * {@link java.lang.Thread} class.
    269      */
    270     public static final int THREAD_PRIORITY_URGENT_AUDIO = -19;
    271 
    272     /**
    273      * Minimum increment to make a priority more favorable.
    274      */
    275     public static final int THREAD_PRIORITY_MORE_FAVORABLE = -1;
    276 
    277     /**
    278      * Minimum increment to make a priority less favorable.
    279      */
    280     public static final int THREAD_PRIORITY_LESS_FAVORABLE = +1;
    281 
    282     /**
    283      * Default scheduling policy
    284      * @hide
    285      */
    286     public static final int SCHED_OTHER = 0;
    287 
    288     /**
    289      * First-In First-Out scheduling policy
    290      * @hide
    291      */
    292     public static final int SCHED_FIFO = 1;
    293 
    294     /**
    295      * Round-Robin scheduling policy
    296      * @hide
    297      */
    298     public static final int SCHED_RR = 2;
    299 
    300     /**
    301      * Batch scheduling policy
    302      * @hide
    303      */
    304     public static final int SCHED_BATCH = 3;
    305 
    306     /**
    307      * Idle scheduling policy
    308      * @hide
    309      */
    310     public static final int SCHED_IDLE = 5;
    311 
    312     // Keep in sync with SP_* constants of enum type SchedPolicy
    313     // declared in system/core/include/cutils/sched_policy.h,
    314     // except THREAD_GROUP_DEFAULT does not correspond to any SP_* value.
    315 
    316     /**
    317      * Default thread group -
    318      * has meaning with setProcessGroup() only, cannot be used with setThreadGroup().
    319      * When used with setProcessGroup(), the group of each thread in the process
    320      * is conditionally changed based on that thread's current priority, as follows:
    321      * threads with priority numerically less than THREAD_PRIORITY_BACKGROUND
    322      * are moved to foreground thread group.  All other threads are left unchanged.
    323      * @hide
    324      */
    325     public static final int THREAD_GROUP_DEFAULT = -1;
    326 
    327     /**
    328      * Background thread group - All threads in
    329      * this group are scheduled with a reduced share of the CPU.
    330      * Value is same as constant SP_BACKGROUND of enum SchedPolicy.
    331      * FIXME rename to THREAD_GROUP_BACKGROUND.
    332      * @hide
    333      */
    334     public static final int THREAD_GROUP_BG_NONINTERACTIVE = 0;
    335 
    336     /**
    337      * Foreground thread group - All threads in
    338      * this group are scheduled with a normal share of the CPU.
    339      * Value is same as constant SP_FOREGROUND of enum SchedPolicy.
    340      * Not used at this level.
    341      * @hide
    342      **/
    343     private static final int THREAD_GROUP_FOREGROUND = 1;
    344 
    345     /**
    346      * System thread group.
    347      * @hide
    348      **/
    349     public static final int THREAD_GROUP_SYSTEM = 2;
    350 
    351     /**
    352      * Application audio thread group.
    353      * @hide
    354      **/
    355     public static final int THREAD_GROUP_AUDIO_APP = 3;
    356 
    357     /**
    358      * System audio thread group.
    359      * @hide
    360      **/
    361     public static final int THREAD_GROUP_AUDIO_SYS = 4;
    362 
    363     public static final int SIGNAL_QUIT = 3;
    364     public static final int SIGNAL_KILL = 9;
    365     public static final int SIGNAL_USR1 = 10;
    366 
    367     /**
    368      * State for communicating with the zygote process.
    369      *
    370      * @hide for internal use only.
    371      */
    372     public static class ZygoteState {
    373         final LocalSocket socket;
    374         final DataInputStream inputStream;
    375         final BufferedWriter writer;
    376         final List<String> abiList;
    377 
    378         boolean mClosed;
    379 
    380         private ZygoteState(LocalSocket socket, DataInputStream inputStream,
    381                 BufferedWriter writer, List<String> abiList) {
    382             this.socket = socket;
    383             this.inputStream = inputStream;
    384             this.writer = writer;
    385             this.abiList = abiList;
    386         }
    387 
    388         public static ZygoteState connect(String socketAddress) throws IOException {
    389             DataInputStream zygoteInputStream = null;
    390             BufferedWriter zygoteWriter = null;
    391             final LocalSocket zygoteSocket = new LocalSocket();
    392 
    393             try {
    394                 zygoteSocket.connect(new LocalSocketAddress(socketAddress,
    395                         LocalSocketAddress.Namespace.RESERVED));
    396 
    397                 zygoteInputStream = new DataInputStream(zygoteSocket.getInputStream());
    398 
    399                 zygoteWriter = new BufferedWriter(new OutputStreamWriter(
    400                         zygoteSocket.getOutputStream()), 256);
    401             } catch (IOException ex) {
    402                 try {
    403                     zygoteSocket.close();
    404                 } catch (IOException ignore) {
    405                 }
    406 
    407                 throw ex;
    408             }
    409 
    410             String abiListString = getAbiList(zygoteWriter, zygoteInputStream);
    411             Log.i("Zygote", "Process: zygote socket opened, supported ABIS: " + abiListString);
    412 
    413             return new ZygoteState(zygoteSocket, zygoteInputStream, zygoteWriter,
    414                     Arrays.asList(abiListString.split(",")));
    415         }
    416 
    417         boolean matches(String abi) {
    418             return abiList.contains(abi);
    419         }
    420 
    421         public void close() {
    422             try {
    423                 socket.close();
    424             } catch (IOException ex) {
    425                 Log.e(LOG_TAG,"I/O exception on routine close", ex);
    426             }
    427 
    428             mClosed = true;
    429         }
    430 
    431         boolean isClosed() {
    432             return mClosed;
    433         }
    434     }
    435 
    436     /**
    437      * The state of the connection to the primary zygote.
    438      */
    439     static ZygoteState primaryZygoteState;
    440 
    441     /**
    442      * The state of the connection to the secondary zygote.
    443      */
    444     static ZygoteState secondaryZygoteState;
    445 
    446     /**
    447      * Start a new process.
    448      *
    449      * <p>If processes are enabled, a new process is created and the
    450      * static main() function of a <var>processClass</var> is executed there.
    451      * The process will continue running after this function returns.
    452      *
    453      * <p>If processes are not enabled, a new thread in the caller's
    454      * process is created and main() of <var>processClass</var> called there.
    455      *
    456      * <p>The niceName parameter, if not an empty string, is a custom name to
    457      * give to the process instead of using processClass.  This allows you to
    458      * make easily identifyable processes even if you are using the same base
    459      * <var>processClass</var> to start them.
    460      *
    461      * @param processClass The class to use as the process's main entry
    462      *                     point.
    463      * @param niceName A more readable name to use for the process.
    464      * @param uid The user-id under which the process will run.
    465      * @param gid The group-id under which the process will run.
    466      * @param gids Additional group-ids associated with the process.
    467      * @param debugFlags Additional flags.
    468      * @param targetSdkVersion The target SDK version for the app.
    469      * @param seInfo null-ok SELinux information for the new process.
    470      * @param abi non-null the ABI this app should be started with.
    471      * @param instructionSet null-ok the instruction set to use.
    472      * @param appDataDir null-ok the data directory of the app.
    473      * @param zygoteArgs Additional arguments to supply to the zygote process.
    474      *
    475      * @return An object that describes the result of the attempt to start the process.
    476      * @throws RuntimeException on fatal start failure
    477      *
    478      * {@hide}
    479      */
    480     public static final ProcessStartResult start(final String processClass,
    481                                   final String niceName,
    482                                   int uid, int gid, int[] gids,
    483                                   int debugFlags, int mountExternal,
    484                                   int targetSdkVersion,
    485                                   String seInfo,
    486                                   String abi,
    487                                   String instructionSet,
    488                                   String appDataDir,
    489                                   String[] zygoteArgs) {
    490         try {
    491             return startViaZygote(processClass, niceName, uid, gid, gids,
    492                     debugFlags, mountExternal, targetSdkVersion, seInfo,
    493                     abi, instructionSet, appDataDir, zygoteArgs);
    494         } catch (ZygoteStartFailedEx ex) {
    495             Log.e(LOG_TAG,
    496                     "Starting VM process through Zygote failed");
    497             throw new RuntimeException(
    498                     "Starting VM process through Zygote failed", ex);
    499         }
    500     }
    501 
    502     /** retry interval for opening a zygote socket */
    503     static final int ZYGOTE_RETRY_MILLIS = 500;
    504 
    505     /**
    506      * Queries the zygote for the list of ABIS it supports.
    507      *
    508      * @throws ZygoteStartFailedEx if the query failed.
    509      */
    510     private static String getAbiList(BufferedWriter writer, DataInputStream inputStream)
    511             throws IOException {
    512         // Each query starts with the argument count (1 in this case)
    513         writer.write("1");
    514         // ... followed by a new-line.
    515         writer.newLine();
    516         // ... followed by our only argument.
    517         writer.write("--query-abi-list");
    518         writer.newLine();
    519         writer.flush();
    520 
    521         // The response is a length prefixed stream of ASCII bytes.
    522         int numBytes = inputStream.readInt();
    523         byte[] bytes = new byte[numBytes];
    524         inputStream.readFully(bytes);
    525 
    526         return new String(bytes, StandardCharsets.US_ASCII);
    527     }
    528 
    529     /**
    530      * Sends an argument list to the zygote process, which starts a new child
    531      * and returns the child's pid. Please note: the present implementation
    532      * replaces newlines in the argument list with spaces.
    533      *
    534      * @throws ZygoteStartFailedEx if process start failed for any reason
    535      */
    536     private static ProcessStartResult zygoteSendArgsAndGetResult(
    537             ZygoteState zygoteState, ArrayList<String> args)
    538             throws ZygoteStartFailedEx {
    539         try {
    540             /**
    541              * See com.android.internal.os.ZygoteInit.readArgumentList()
    542              * Presently the wire format to the zygote process is:
    543              * a) a count of arguments (argc, in essence)
    544              * b) a number of newline-separated argument strings equal to count
    545              *
    546              * After the zygote process reads these it will write the pid of
    547              * the child or -1 on failure, followed by boolean to
    548              * indicate whether a wrapper process was used.
    549              */
    550             final BufferedWriter writer = zygoteState.writer;
    551             final DataInputStream inputStream = zygoteState.inputStream;
    552 
    553             writer.write(Integer.toString(args.size()));
    554             writer.newLine();
    555 
    556             int sz = args.size();
    557             for (int i = 0; i < sz; i++) {
    558                 String arg = args.get(i);
    559                 if (arg.indexOf('\n') >= 0) {
    560                     throw new ZygoteStartFailedEx(
    561                             "embedded newlines not allowed");
    562                 }
    563                 writer.write(arg);
    564                 writer.newLine();
    565             }
    566 
    567             writer.flush();
    568 
    569             // Should there be a timeout on this?
    570             ProcessStartResult result = new ProcessStartResult();
    571             result.pid = inputStream.readInt();
    572             if (result.pid < 0) {
    573                 throw new ZygoteStartFailedEx("fork() failed");
    574             }
    575             result.usingWrapper = inputStream.readBoolean();
    576             return result;
    577         } catch (IOException ex) {
    578             zygoteState.close();
    579             throw new ZygoteStartFailedEx(ex);
    580         }
    581     }
    582 
    583     /**
    584      * Starts a new process via the zygote mechanism.
    585      *
    586      * @param processClass Class name whose static main() to run
    587      * @param niceName 'nice' process name to appear in ps
    588      * @param uid a POSIX uid that the new process should setuid() to
    589      * @param gid a POSIX gid that the new process shuold setgid() to
    590      * @param gids null-ok; a list of supplementary group IDs that the
    591      * new process should setgroup() to.
    592      * @param debugFlags Additional flags.
    593      * @param targetSdkVersion The target SDK version for the app.
    594      * @param seInfo null-ok SELinux information for the new process.
    595      * @param abi the ABI the process should use.
    596      * @param instructionSet null-ok the instruction set to use.
    597      * @param appDataDir null-ok the data directory of the app.
    598      * @param extraArgs Additional arguments to supply to the zygote process.
    599      * @return An object that describes the result of the attempt to start the process.
    600      * @throws ZygoteStartFailedEx if process start failed for any reason
    601      */
    602     private static ProcessStartResult startViaZygote(final String processClass,
    603                                   final String niceName,
    604                                   final int uid, final int gid,
    605                                   final int[] gids,
    606                                   int debugFlags, int mountExternal,
    607                                   int targetSdkVersion,
    608                                   String seInfo,
    609                                   String abi,
    610                                   String instructionSet,
    611                                   String appDataDir,
    612                                   String[] extraArgs)
    613                                   throws ZygoteStartFailedEx {
    614         synchronized(Process.class) {
    615             ArrayList<String> argsForZygote = new ArrayList<String>();
    616 
    617             // --runtime-init, --setuid=, --setgid=,
    618             // and --setgroups= must go first
    619             argsForZygote.add("--runtime-init");
    620             argsForZygote.add("--setuid=" + uid);
    621             argsForZygote.add("--setgid=" + gid);
    622             if ((debugFlags & Zygote.DEBUG_ENABLE_JNI_LOGGING) != 0) {
    623                 argsForZygote.add("--enable-jni-logging");
    624             }
    625             if ((debugFlags & Zygote.DEBUG_ENABLE_SAFEMODE) != 0) {
    626                 argsForZygote.add("--enable-safemode");
    627             }
    628             if ((debugFlags & Zygote.DEBUG_ENABLE_DEBUGGER) != 0) {
    629                 argsForZygote.add("--enable-debugger");
    630             }
    631             if ((debugFlags & Zygote.DEBUG_ENABLE_CHECKJNI) != 0) {
    632                 argsForZygote.add("--enable-checkjni");
    633             }
    634             if ((debugFlags & Zygote.DEBUG_ENABLE_ASSERT) != 0) {
    635                 argsForZygote.add("--enable-assert");
    636             }
    637             if (mountExternal == Zygote.MOUNT_EXTERNAL_MULTIUSER) {
    638                 argsForZygote.add("--mount-external-multiuser");
    639             } else if (mountExternal == Zygote.MOUNT_EXTERNAL_MULTIUSER_ALL) {
    640                 argsForZygote.add("--mount-external-multiuser-all");
    641             }
    642             argsForZygote.add("--target-sdk-version=" + targetSdkVersion);
    643 
    644             //TODO optionally enable debuger
    645             //argsForZygote.add("--enable-debugger");
    646 
    647             // --setgroups is a comma-separated list
    648             if (gids != null && gids.length > 0) {
    649                 StringBuilder sb = new StringBuilder();
    650                 sb.append("--setgroups=");
    651 
    652                 int sz = gids.length;
    653                 for (int i = 0; i < sz; i++) {
    654                     if (i != 0) {
    655                         sb.append(',');
    656                     }
    657                     sb.append(gids[i]);
    658                 }
    659 
    660                 argsForZygote.add(sb.toString());
    661             }
    662 
    663             if (niceName != null) {
    664                 argsForZygote.add("--nice-name=" + niceName);
    665             }
    666 
    667             if (seInfo != null) {
    668                 argsForZygote.add("--seinfo=" + seInfo);
    669             }
    670 
    671             if (instructionSet != null) {
    672                 argsForZygote.add("--instruction-set=" + instructionSet);
    673             }
    674 
    675             if (appDataDir != null) {
    676                 argsForZygote.add("--app-data-dir=" + appDataDir);
    677             }
    678 
    679             argsForZygote.add(processClass);
    680 
    681             if (extraArgs != null) {
    682                 for (String arg : extraArgs) {
    683                     argsForZygote.add(arg);
    684                 }
    685             }
    686 
    687             return zygoteSendArgsAndGetResult(openZygoteSocketIfNeeded(abi), argsForZygote);
    688         }
    689     }
    690 
    691     /**
    692      * Tries to open socket to Zygote process if not already open. If
    693      * already open, does nothing.  May block and retry.
    694      */
    695     private static ZygoteState openZygoteSocketIfNeeded(String abi) throws ZygoteStartFailedEx {
    696         if (primaryZygoteState == null || primaryZygoteState.isClosed()) {
    697             try {
    698                 primaryZygoteState = ZygoteState.connect(ZYGOTE_SOCKET);
    699             } catch (IOException ioe) {
    700                 throw new ZygoteStartFailedEx("Error connecting to primary zygote", ioe);
    701             }
    702         }
    703 
    704         if (primaryZygoteState.matches(abi)) {
    705             return primaryZygoteState;
    706         }
    707 
    708         // The primary zygote didn't match. Try the secondary.
    709         if (secondaryZygoteState == null || secondaryZygoteState.isClosed()) {
    710             try {
    711             secondaryZygoteState = ZygoteState.connect(SECONDARY_ZYGOTE_SOCKET);
    712             } catch (IOException ioe) {
    713                 throw new ZygoteStartFailedEx("Error connecting to secondary zygote", ioe);
    714             }
    715         }
    716 
    717         if (secondaryZygoteState.matches(abi)) {
    718             return secondaryZygoteState;
    719         }
    720 
    721         throw new ZygoteStartFailedEx("Unsupported zygote ABI: " + abi);
    722     }
    723 
    724     /**
    725      * Returns elapsed milliseconds of the time this process has run.
    726      * @return  Returns the number of milliseconds this process has return.
    727      */
    728     public static final native long getElapsedCpuTime();
    729 
    730     /**
    731      * Returns the identifier of this process, which can be used with
    732      * {@link #killProcess} and {@link #sendSignal}.
    733      */
    734     public static final int myPid() {
    735         return Os.getpid();
    736     }
    737 
    738     /**
    739      * Returns the identifier of this process' parent.
    740      * @hide
    741      */
    742     public static final int myPpid() {
    743         return Os.getppid();
    744     }
    745 
    746     /**
    747      * Returns the identifier of the calling thread, which be used with
    748      * {@link #setThreadPriority(int, int)}.
    749      */
    750     public static final int myTid() {
    751         return Os.gettid();
    752     }
    753 
    754     /**
    755      * Returns the identifier of this process's uid.  This is the kernel uid
    756      * that the process is running under, which is the identity of its
    757      * app-specific sandbox.  It is different from {@link #myUserHandle} in that
    758      * a uid identifies a specific app sandbox in a specific user.
    759      */
    760     public static final int myUid() {
    761         return Os.getuid();
    762     }
    763 
    764     /**
    765      * Returns this process's user handle.  This is the
    766      * user the process is running under.  It is distinct from
    767      * {@link #myUid()} in that a particular user will have multiple
    768      * distinct apps running under it each with their own uid.
    769      */
    770     public static final UserHandle myUserHandle() {
    771         return new UserHandle(UserHandle.getUserId(myUid()));
    772     }
    773 
    774     /**
    775      * Returns whether the current process is in an isolated sandbox.
    776      * @hide
    777      */
    778     public static final boolean isIsolated() {
    779         int uid = UserHandle.getAppId(myUid());
    780         return uid >= FIRST_ISOLATED_UID && uid <= LAST_ISOLATED_UID;
    781     }
    782 
    783     /**
    784      * Returns the UID assigned to a particular user name, or -1 if there is
    785      * none.  If the given string consists of only numbers, it is converted
    786      * directly to a uid.
    787      */
    788     public static final native int getUidForName(String name);
    789 
    790     /**
    791      * Returns the GID assigned to a particular user name, or -1 if there is
    792      * none.  If the given string consists of only numbers, it is converted
    793      * directly to a gid.
    794      */
    795     public static final native int getGidForName(String name);
    796 
    797     /**
    798      * Returns a uid for a currently running process.
    799      * @param pid the process id
    800      * @return the uid of the process, or -1 if the process is not running.
    801      * @hide pending API council review
    802      */
    803     public static final int getUidForPid(int pid) {
    804         String[] procStatusLabels = { "Uid:" };
    805         long[] procStatusValues = new long[1];
    806         procStatusValues[0] = -1;
    807         Process.readProcLines("/proc/" + pid + "/status", procStatusLabels, procStatusValues);
    808         return (int) procStatusValues[0];
    809     }
    810 
    811     /**
    812      * Returns the parent process id for a currently running process.
    813      * @param pid the process id
    814      * @return the parent process id of the process, or -1 if the process is not running.
    815      * @hide
    816      */
    817     public static final int getParentPid(int pid) {
    818         String[] procStatusLabels = { "PPid:" };
    819         long[] procStatusValues = new long[1];
    820         procStatusValues[0] = -1;
    821         Process.readProcLines("/proc/" + pid + "/status", procStatusLabels, procStatusValues);
    822         return (int) procStatusValues[0];
    823     }
    824 
    825     /**
    826      * Returns the thread group leader id for a currently running thread.
    827      * @param tid the thread id
    828      * @return the thread group leader id of the thread, or -1 if the thread is not running.
    829      *         This is same as what getpid(2) would return if called by tid.
    830      * @hide
    831      */
    832     public static final int getThreadGroupLeader(int tid) {
    833         String[] procStatusLabels = { "Tgid:" };
    834         long[] procStatusValues = new long[1];
    835         procStatusValues[0] = -1;
    836         Process.readProcLines("/proc/" + tid + "/status", procStatusLabels, procStatusValues);
    837         return (int) procStatusValues[0];
    838     }
    839 
    840     /**
    841      * Set the priority of a thread, based on Linux priorities.
    842      *
    843      * @param tid The identifier of the thread/process to change.
    844      * @param priority A Linux priority level, from -20 for highest scheduling
    845      * priority to 19 for lowest scheduling priority.
    846      *
    847      * @throws IllegalArgumentException Throws IllegalArgumentException if
    848      * <var>tid</var> does not exist.
    849      * @throws SecurityException Throws SecurityException if your process does
    850      * not have permission to modify the given thread, or to use the given
    851      * priority.
    852      */
    853     public static final native void setThreadPriority(int tid, int priority)
    854             throws IllegalArgumentException, SecurityException;
    855 
    856     /**
    857      * Call with 'false' to cause future calls to {@link #setThreadPriority(int)} to
    858      * throw an exception if passed a background-level thread priority.  This is only
    859      * effective if the JNI layer is built with GUARD_THREAD_PRIORITY defined to 1.
    860      *
    861      * @hide
    862      */
    863     public static final native void setCanSelfBackground(boolean backgroundOk);
    864 
    865     /**
    866      * Sets the scheduling group for a thread.
    867      * @hide
    868      * @param tid The identifier of the thread to change.
    869      * @param group The target group for this thread from THREAD_GROUP_*.
    870      *
    871      * @throws IllegalArgumentException Throws IllegalArgumentException if
    872      * <var>tid</var> does not exist.
    873      * @throws SecurityException Throws SecurityException if your process does
    874      * not have permission to modify the given thread, or to use the given
    875      * priority.
    876      * If the thread is a thread group leader, that is it's gettid() == getpid(),
    877      * then the other threads in the same thread group are _not_ affected.
    878      */
    879     public static final native void setThreadGroup(int tid, int group)
    880             throws IllegalArgumentException, SecurityException;
    881 
    882     /**
    883      * Sets the scheduling group for a process and all child threads
    884      * @hide
    885      * @param pid The identifier of the process to change.
    886      * @param group The target group for this process from THREAD_GROUP_*.
    887      *
    888      * @throws IllegalArgumentException Throws IllegalArgumentException if
    889      * <var>tid</var> does not exist.
    890      * @throws SecurityException Throws SecurityException if your process does
    891      * not have permission to modify the given thread, or to use the given
    892      * priority.
    893      *
    894      * group == THREAD_GROUP_DEFAULT means to move all non-background priority
    895      * threads to the foreground scheduling group, but to leave background
    896      * priority threads alone.  group == THREAD_GROUP_BG_NONINTERACTIVE moves all
    897      * threads, regardless of priority, to the background scheduling group.
    898      * group == THREAD_GROUP_FOREGROUND is not allowed.
    899      */
    900     public static final native void setProcessGroup(int pid, int group)
    901             throws IllegalArgumentException, SecurityException;
    902 
    903     /**
    904      * Return the scheduling group of requested process.
    905      *
    906      * @hide
    907      */
    908     public static final native int getProcessGroup(int pid)
    909             throws IllegalArgumentException, SecurityException;
    910 
    911     /**
    912      * Set the priority of the calling thread, based on Linux priorities.  See
    913      * {@link #setThreadPriority(int, int)} for more information.
    914      *
    915      * @param priority A Linux priority level, from -20 for highest scheduling
    916      * priority to 19 for lowest scheduling priority.
    917      *
    918      * @throws IllegalArgumentException Throws IllegalArgumentException if
    919      * <var>tid</var> does not exist.
    920      * @throws SecurityException Throws SecurityException if your process does
    921      * not have permission to modify the given thread, or to use the given
    922      * priority.
    923      *
    924      * @see #setThreadPriority(int, int)
    925      */
    926     public static final native void setThreadPriority(int priority)
    927             throws IllegalArgumentException, SecurityException;
    928 
    929     /**
    930      * Return the current priority of a thread, based on Linux priorities.
    931      *
    932      * @param tid The identifier of the thread/process to change.
    933      *
    934      * @return Returns the current priority, as a Linux priority level,
    935      * from -20 for highest scheduling priority to 19 for lowest scheduling
    936      * priority.
    937      *
    938      * @throws IllegalArgumentException Throws IllegalArgumentException if
    939      * <var>tid</var> does not exist.
    940      */
    941     public static final native int getThreadPriority(int tid)
    942             throws IllegalArgumentException;
    943 
    944     /**
    945      * Set the scheduling policy and priority of a thread, based on Linux.
    946      *
    947      * @param tid The identifier of the thread/process to change.
    948      * @param policy A Linux scheduling policy such as SCHED_OTHER etc.
    949      * @param priority A Linux priority level in a range appropriate for the given policy.
    950      *
    951      * @throws IllegalArgumentException Throws IllegalArgumentException if
    952      * <var>tid</var> does not exist, or if <var>priority</var> is out of range for the policy.
    953      * @throws SecurityException Throws SecurityException if your process does
    954      * not have permission to modify the given thread, or to use the given
    955      * scheduling policy or priority.
    956      *
    957      * {@hide}
    958      */
    959     public static final native void setThreadScheduler(int tid, int policy, int priority)
    960             throws IllegalArgumentException;
    961 
    962     /**
    963      * Determine whether the current environment supports multiple processes.
    964      *
    965      * @return Returns true if the system can run in multiple processes, else
    966      * false if everything is running in a single process.
    967      *
    968      * @deprecated This method always returns true.  Do not use.
    969      */
    970     @Deprecated
    971     public static final boolean supportsProcesses() {
    972         return true;
    973     }
    974 
    975     /**
    976      * Adjust the swappiness level for a process.
    977      *
    978      * @param pid The process identifier to set.
    979      * @param is_increased Whether swappiness should be increased or default.
    980      *
    981      * @return Returns true if the underlying system supports this
    982      *         feature, else false.
    983      *
    984      * {@hide}
    985      */
    986     public static final native boolean setSwappiness(int pid, boolean is_increased);
    987 
    988     /**
    989      * Change this process's argv[0] parameter.  This can be useful to show
    990      * more descriptive information in things like the 'ps' command.
    991      *
    992      * @param text The new name of this process.
    993      *
    994      * {@hide}
    995      */
    996     public static final native void setArgV0(String text);
    997 
    998     /**
    999      * Kill the process with the given PID.
   1000      * Note that, though this API allows us to request to
   1001      * kill any process based on its PID, the kernel will
   1002      * still impose standard restrictions on which PIDs you
   1003      * are actually able to kill.  Typically this means only
   1004      * the process running the caller's packages/application
   1005      * and any additional processes created by that app; packages
   1006      * sharing a common UID will also be able to kill each
   1007      * other's processes.
   1008      */
   1009     public static final void killProcess(int pid) {
   1010         sendSignal(pid, SIGNAL_KILL);
   1011     }
   1012 
   1013     /** @hide */
   1014     public static final native int setUid(int uid);
   1015 
   1016     /** @hide */
   1017     public static final native int setGid(int uid);
   1018 
   1019     /**
   1020      * Send a signal to the given process.
   1021      *
   1022      * @param pid The pid of the target process.
   1023      * @param signal The signal to send.
   1024      */
   1025     public static final native void sendSignal(int pid, int signal);
   1026 
   1027     /**
   1028      * @hide
   1029      * Private impl for avoiding a log message...  DO NOT USE without doing
   1030      * your own log, or the Android Illuminati will find you some night and
   1031      * beat you up.
   1032      */
   1033     public static final void killProcessQuiet(int pid) {
   1034         sendSignalQuiet(pid, SIGNAL_KILL);
   1035     }
   1036 
   1037     /**
   1038      * @hide
   1039      * Private impl for avoiding a log message...  DO NOT USE without doing
   1040      * your own log, or the Android Illuminati will find you some night and
   1041      * beat you up.
   1042      */
   1043     public static final native void sendSignalQuiet(int pid, int signal);
   1044 
   1045     /** @hide */
   1046     public static final native long getFreeMemory();
   1047 
   1048     /** @hide */
   1049     public static final native long getTotalMemory();
   1050 
   1051     /** @hide */
   1052     public static final native void readProcLines(String path,
   1053             String[] reqFields, long[] outSizes);
   1054 
   1055     /** @hide */
   1056     public static final native int[] getPids(String path, int[] lastArray);
   1057 
   1058     /** @hide */
   1059     public static final int PROC_TERM_MASK = 0xff;
   1060     /** @hide */
   1061     public static final int PROC_ZERO_TERM = 0;
   1062     /** @hide */
   1063     public static final int PROC_SPACE_TERM = (int)' ';
   1064     /** @hide */
   1065     public static final int PROC_TAB_TERM = (int)'\t';
   1066     /** @hide */
   1067     public static final int PROC_COMBINE = 0x100;
   1068     /** @hide */
   1069     public static final int PROC_PARENS = 0x200;
   1070     /** @hide */
   1071     public static final int PROC_QUOTES = 0x400;
   1072     /** @hide */
   1073     public static final int PROC_OUT_STRING = 0x1000;
   1074     /** @hide */
   1075     public static final int PROC_OUT_LONG = 0x2000;
   1076     /** @hide */
   1077     public static final int PROC_OUT_FLOAT = 0x4000;
   1078 
   1079     /** @hide */
   1080     public static final native boolean readProcFile(String file, int[] format,
   1081             String[] outStrings, long[] outLongs, float[] outFloats);
   1082 
   1083     /** @hide */
   1084     public static final native boolean parseProcLine(byte[] buffer, int startIndex,
   1085             int endIndex, int[] format, String[] outStrings, long[] outLongs, float[] outFloats);
   1086 
   1087     /** @hide */
   1088     public static final native int[] getPidsForCommands(String[] cmds);
   1089 
   1090     /**
   1091      * Gets the total Pss value for a given process, in bytes.
   1092      *
   1093      * @param pid the process to the Pss for
   1094      * @return the total Pss value for the given process in bytes,
   1095      *  or -1 if the value cannot be determined
   1096      * @hide
   1097      */
   1098     public static final native long getPss(int pid);
   1099 
   1100     /**
   1101      * Specifies the outcome of having started a process.
   1102      * @hide
   1103      */
   1104     public static final class ProcessStartResult {
   1105         /**
   1106          * The PID of the newly started process.
   1107          * Always >= 0.  (If the start failed, an exception will have been thrown instead.)
   1108          */
   1109         public int pid;
   1110 
   1111         /**
   1112          * True if the process was started with a wrapper attached.
   1113          */
   1114         public boolean usingWrapper;
   1115     }
   1116 
   1117     /**
   1118      * Kill all processes in a process group started for the given
   1119      * pid.
   1120      * @hide
   1121      */
   1122     public static final native int killProcessGroup(int uid, int pid);
   1123 
   1124     /**
   1125      * Remove all process groups.  Expected to be called when ActivityManager
   1126      * is restarted.
   1127      * @hide
   1128      */
   1129     public static final native void removeAllProcessGroups();
   1130 }
   1131