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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 static android.annotation.SystemApi.Client.MODULE_LIBRARIES;
20 
21 import android.annotation.NonNull;
22 import android.annotation.Nullable;
23 import android.annotation.SystemApi;
24 import android.annotation.TestApi;
25 import android.compat.annotation.UnsupportedAppUsage;
26 import android.system.ErrnoException;
27 import android.system.Os;
28 import android.system.OsConstants;
29 import android.system.StructPollfd;
30 import android.util.Pair;
31 import android.webkit.WebViewZygote;
32 
33 import dalvik.system.VMRuntime;
34 
35 import libcore.io.IoUtils;
36 
37 import java.io.FileDescriptor;
38 import java.io.IOException;
39 import java.util.Map;
40 import java.util.concurrent.TimeoutException;
41 
42 /**
43  * Tools for managing OS processes.
44  */
45 public class Process {
46     private static final String LOG_TAG = "Process";
47 
48     /**
49      * An invalid UID value.
50      */
51     public static final int INVALID_UID = -1;
52 
53     /**
54      * Defines the root UID.
55      */
56     public static final int ROOT_UID = 0;
57 
58     /**
59      * Defines the UID/GID under which system code runs.
60      */
61     public static final int SYSTEM_UID = 1000;
62 
63     /**
64      * Defines the UID/GID under which the telephony code runs.
65      */
66     public static final int PHONE_UID = 1001;
67 
68     /**
69      * Defines the UID/GID for the user shell.
70      */
71     public static final int SHELL_UID = 2000;
72 
73     /**
74      * Defines the UID/GID for the log group.
75      * @hide
76      */
77     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
78     public static final int LOG_UID = 1007;
79 
80     /**
81      * Defines the UID/GID for the WIFI native processes like wificond, supplicant, hostapd,
82      * vendor HAL, etc.
83      */
84     public static final int WIFI_UID = 1010;
85 
86     /**
87      * Defines the UID/GID for the mediaserver process.
88      * @hide
89      */
90     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
91     public static final int MEDIA_UID = 1013;
92 
93     /**
94      * Defines the UID/GID for the DRM process.
95      * @hide
96      */
97     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
98     public static final int DRM_UID = 1019;
99 
100     /**
101      * Defines the GID for the group that allows write access to the internal media storage.
102      * @hide
103      */
104     public static final int SDCARD_RW_GID = 1015;
105 
106     /**
107      * Defines the UID/GID for the group that controls VPN services.
108      * @hide
109      */
110     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
111     @SystemApi(client = MODULE_LIBRARIES)
112     public static final int VPN_UID = 1016;
113 
114     /**
115      * Defines the UID/GID for keystore.
116      * @hide
117      */
118     public static final int KEYSTORE_UID = 1017;
119 
120     /**
121      * Defines the UID/GID for credstore.
122      * @hide
123      */
124     public static final int CREDSTORE_UID = 1076;
125 
126     /**
127      * Defines the UID/GID for the NFC service process.
128      * @hide
129      */
130     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
131     @TestApi
132     public static final int NFC_UID = 1027;
133 
134     /**
135      * Defines the UID/GID for the clatd process.
136      * @hide
137      * */
138     public static final int CLAT_UID = 1029;
139 
140     /**
141      * Defines the UID/GID for the Bluetooth service process.
142      */
143     public static final int BLUETOOTH_UID = 1002;
144 
145     /**
146      * Defines the GID for the group that allows write access to the internal media storage.
147      * @hide
148      */
149     public static final int MEDIA_RW_GID = 1023;
150 
151     /**
152      * Access to installed package details
153      * @hide
154      */
155     public static final int PACKAGE_INFO_GID = 1032;
156 
157     /**
158      * Defines the UID/GID for the shared RELRO file updater process.
159      * @hide
160      */
161     public static final int SHARED_RELRO_UID = 1037;
162 
163     /**
164      * Defines the UID/GID for the audioserver process.
165      * @hide
166      */
167     public static final int AUDIOSERVER_UID = 1041;
168 
169     /**
170      * Defines the UID/GID for the cameraserver process
171      * @hide
172      */
173     public static final int CAMERASERVER_UID = 1047;
174 
175     /**
176      * Defines the UID/GID for the tethering DNS resolver (currently dnsmasq).
177      * @hide
178      */
179     public static final int DNS_TETHER_UID = 1052;
180 
181     /**
182      * Defines the UID/GID for the WebView zygote process.
183      * @hide
184      */
185     public static final int WEBVIEW_ZYGOTE_UID = 1053;
186 
187     /**
188      * Defines the UID used for resource tracking for OTA updates.
189      * @hide
190      */
191     public static final int OTA_UPDATE_UID = 1061;
192 
193     /**
194      * Defines the UID used for statsd
195      * @hide
196      */
197     public static final int STATSD_UID = 1066;
198 
199     /**
200      * Defines the UID used for incidentd.
201      * @hide
202      */
203     public static final int INCIDENTD_UID = 1067;
204 
205     /**
206      * Defines the UID/GID for the Secure Element service process.
207      * @hide
208      */
209     public static final int SE_UID = 1068;
210 
211     /**
212      * Defines the UID/GID for the iorapd.
213      * @hide
214      */
215     public static final int IORAPD_UID = 1071;
216 
217     /**
218      * Defines the UID/GID for the NetworkStack app.
219      * @hide
220      */
221     public static final int NETWORK_STACK_UID = 1073;
222 
223     /**
224      * Defines the UID/GID for fs-verity certificate ownership in keystore.
225      * @hide
226      */
227     public static final int FSVERITY_CERT_UID = 1075;
228 
229     /**
230      * GID that gives access to USB OTG (unreliable) volumes on /mnt/media_rw/<vol name>
231      * @hide
232      */
233     public static final int EXTERNAL_STORAGE_GID = 1077;
234 
235     /**
236      * GID that gives write access to app-private data directories on external
237      * storage (used on devices without sdcardfs only).
238      * @hide
239      */
240     public static final int EXT_DATA_RW_GID = 1078;
241 
242     /**
243      * GID that gives write access to app-private OBB directories on external
244      * storage (used on devices without sdcardfs only).
245      * @hide
246      */
247     public static final int EXT_OBB_RW_GID = 1079;
248 
249     /**
250      * Defines the UID/GID for the Uwb service process.
251      * @hide
252      */
253     public static final int UWB_UID = 1083;
254 
255     /**
256      * GID that corresponds to the INTERNET permission.
257      * Must match the value of AID_INET.
258      * @hide
259      */
260     public static final int INET_GID = 3003;
261 
262     /** {@hide} */
263     public static final int NOBODY_UID = 9999;
264 
265     /**
266      * Defines the start of a range of UIDs (and GIDs), going from this
267      * number to {@link #LAST_APPLICATION_UID} that are reserved for assigning
268      * to applications.
269      */
270     public static final int FIRST_APPLICATION_UID = 10000;
271 
272     /**
273      * Last of application-specific UIDs starting at
274      * {@link #FIRST_APPLICATION_UID}.
275      */
276     public static final int LAST_APPLICATION_UID = 19999;
277 
278     /**
279      * First uid used for fully isolated sandboxed processes spawned from an app zygote
280      * @hide
281      */
282     @TestApi
283     public static final int FIRST_APP_ZYGOTE_ISOLATED_UID = 90000;
284 
285     /**
286      * Number of UIDs we allocate per application zygote
287      * @hide
288      */
289     @TestApi
290     public static final int NUM_UIDS_PER_APP_ZYGOTE = 100;
291 
292     /**
293      * Last uid used for fully isolated sandboxed processes spawned from an app zygote
294      * @hide
295      */
296     @TestApi
297     public static final int LAST_APP_ZYGOTE_ISOLATED_UID = 98999;
298 
299     /**
300      * First uid used for fully isolated sandboxed processes (with no permissions of their own)
301      * @hide
302      */
303     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
304     @TestApi
305     public static final int FIRST_ISOLATED_UID = 99000;
306 
307     /**
308      * Last uid used for fully isolated sandboxed processes (with no permissions of their own)
309      * @hide
310      */
311     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
312     @TestApi
313     public static final int LAST_ISOLATED_UID = 99999;
314 
315     /**
316      * Defines the gid shared by all applications running under the same profile.
317      * @hide
318      */
319     public static final int SHARED_USER_GID = 9997;
320 
321     /**
322      * First gid for applications to share resources. Used when forward-locking
323      * is enabled but all UserHandles need to be able to read the resources.
324      * @hide
325      */
326     public static final int FIRST_SHARED_APPLICATION_GID = 50000;
327 
328     /**
329      * Last gid for applications to share resources. Used when forward-locking
330      * is enabled but all UserHandles need to be able to read the resources.
331      * @hide
332      */
333     public static final int LAST_SHARED_APPLICATION_GID = 59999;
334 
335     /** {@hide} */
336     public static final int FIRST_APPLICATION_CACHE_GID = 20000;
337     /** {@hide} */
338     public static final int LAST_APPLICATION_CACHE_GID = 29999;
339 
340     /**
341      * Standard priority of application threads.
342      * Use with {@link #setThreadPriority(int)} and
343      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
344      * {@link java.lang.Thread} class.
345      */
346     public static final int THREAD_PRIORITY_DEFAULT = 0;
347 
348     /*
349      * ***************************************
350      * ** Keep in sync with utils/threads.h **
351      * ***************************************
352      */
353 
354     /**
355      * Lowest available thread priority.  Only for those who really, really
356      * don't want to run if anything else is happening.
357      * Use with {@link #setThreadPriority(int)} and
358      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
359      * {@link java.lang.Thread} class.
360      */
361     public static final int THREAD_PRIORITY_LOWEST = 19;
362 
363     /**
364      * Standard priority background threads.  This gives your thread a slightly
365      * lower than normal priority, so that it will have less chance of impacting
366      * the responsiveness of the user interface.
367      * Use with {@link #setThreadPriority(int)} and
368      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
369      * {@link java.lang.Thread} class.
370      */
371     public static final int THREAD_PRIORITY_BACKGROUND = 10;
372 
373     /**
374      * Standard priority of threads that are currently running a user interface
375      * that the user is interacting with.  Applications can not normally
376      * change to this priority; the system will automatically adjust your
377      * application threads as the user moves through the UI.
378      * Use with {@link #setThreadPriority(int)} and
379      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
380      * {@link java.lang.Thread} class.
381      */
382     public static final int THREAD_PRIORITY_FOREGROUND = -2;
383 
384     /**
385      * Standard priority of system display threads, involved in updating
386      * the user interface.  Applications can not
387      * normally change to this priority.
388      * Use with {@link #setThreadPriority(int)} and
389      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
390      * {@link java.lang.Thread} class.
391      */
392     public static final int THREAD_PRIORITY_DISPLAY = -4;
393 
394     /**
395      * Standard priority of the most important display threads, for compositing
396      * the screen and retrieving input events.  Applications can not normally
397      * change to this priority.
398      * Use with {@link #setThreadPriority(int)} and
399      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
400      * {@link java.lang.Thread} class.
401      */
402     public static final int THREAD_PRIORITY_URGENT_DISPLAY = -8;
403 
404     /**
405      * Standard priority of video threads.  Applications can not normally
406      * change to this priority.
407      * Use with {@link #setThreadPriority(int)} and
408      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
409      * {@link java.lang.Thread} class.
410      */
411     public static final int THREAD_PRIORITY_VIDEO = -10;
412 
413     /**
414      * Priority we boost main thread and RT of top app to.
415      * @hide
416      */
417     public static final int THREAD_PRIORITY_TOP_APP_BOOST = -10;
418 
419     /**
420      * Standard priority of audio threads.  Applications can not normally
421      * change to this priority.
422      * Use with {@link #setThreadPriority(int)} and
423      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
424      * {@link java.lang.Thread} class.
425      */
426     public static final int THREAD_PRIORITY_AUDIO = -16;
427 
428     /**
429      * Standard priority of the most important audio threads.
430      * Applications can not normally change to this priority.
431      * Use with {@link #setThreadPriority(int)} and
432      * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
433      * {@link java.lang.Thread} class.
434      */
435     public static final int THREAD_PRIORITY_URGENT_AUDIO = -19;
436 
437     /**
438      * Minimum increment to make a priority more favorable.
439      */
440     public static final int THREAD_PRIORITY_MORE_FAVORABLE = -1;
441 
442     /**
443      * Minimum increment to make a priority less favorable.
444      */
445     public static final int THREAD_PRIORITY_LESS_FAVORABLE = +1;
446 
447     /**
448      * Default scheduling policy
449      * @hide
450      */
451     public static final int SCHED_OTHER = 0;
452 
453     /**
454      * First-In First-Out scheduling policy
455      * @hide
456      */
457     public static final int SCHED_FIFO = 1;
458 
459     /**
460      * Round-Robin scheduling policy
461      * @hide
462      */
463     public static final int SCHED_RR = 2;
464 
465     /**
466      * Batch scheduling policy
467      * @hide
468      */
469     public static final int SCHED_BATCH = 3;
470 
471     /**
472      * Idle scheduling policy
473      * @hide
474      */
475     public static final int SCHED_IDLE = 5;
476 
477     /**
478      * Reset scheduler choice on fork.
479      * @hide
480      */
481     public static final int SCHED_RESET_ON_FORK = 0x40000000;
482 
483     // Keep in sync with SP_* constants of enum type SchedPolicy
484     // declared in system/core/include/cutils/sched_policy.h,
485     // except THREAD_GROUP_DEFAULT does not correspond to any SP_* value.
486 
487     /**
488      * Default thread group -
489      * has meaning with setProcessGroup() only, cannot be used with setThreadGroup().
490      * When used with setProcessGroup(), the group of each thread in the process
491      * is conditionally changed based on that thread's current priority, as follows:
492      * threads with priority numerically less than THREAD_PRIORITY_BACKGROUND
493      * are moved to foreground thread group.  All other threads are left unchanged.
494      * @hide
495      */
496     public static final int THREAD_GROUP_DEFAULT = -1;
497 
498     /**
499      * Background thread group - All threads in
500      * this group are scheduled with a reduced share of the CPU.
501      * Value is same as constant SP_BACKGROUND of enum SchedPolicy.
502      * @hide
503      */
504     public static final int THREAD_GROUP_BACKGROUND = 0;
505 
506     /**
507      * Foreground thread group - All threads in
508      * this group are scheduled with a normal share of the CPU.
509      * Value is same as constant SP_FOREGROUND of enum SchedPolicy.
510      * Not used at this level.
511      * @hide
512      **/
513     private static final int THREAD_GROUP_FOREGROUND = 1;
514 
515     /**
516      * System thread group.
517      * @hide
518      **/
519     public static final int THREAD_GROUP_SYSTEM = 2;
520 
521     /**
522      * Application audio thread group.
523      * @hide
524      **/
525     public static final int THREAD_GROUP_AUDIO_APP = 3;
526 
527     /**
528      * System audio thread group.
529      * @hide
530      **/
531     public static final int THREAD_GROUP_AUDIO_SYS = 4;
532 
533     /**
534      * Thread group for top foreground app.
535      * @hide
536      **/
537     public static final int THREAD_GROUP_TOP_APP = 5;
538 
539     /**
540      * Thread group for RT app.
541      * @hide
542      **/
543     public static final int THREAD_GROUP_RT_APP = 6;
544 
545     /**
546      * Thread group for bound foreground services that should
547      * have additional CPU restrictions during screen off
548      * @hide
549      **/
550     public static final int THREAD_GROUP_RESTRICTED = 7;
551 
552     public static final int SIGNAL_QUIT = 3;
553     public static final int SIGNAL_KILL = 9;
554     public static final int SIGNAL_USR1 = 10;
555 
556     private static long sStartElapsedRealtime;
557     private static long sStartUptimeMillis;
558 
559     private static final int PIDFD_UNKNOWN = 0;
560     private static final int PIDFD_SUPPORTED = 1;
561     private static final int PIDFD_UNSUPPORTED = 2;
562 
563     /**
564      * Whether or not the underlying OS supports pidfd
565      */
566     private static int sPidFdSupported = PIDFD_UNKNOWN;
567 
568     /**
569      * Value used to indicate that there is no special information about an application launch.  App
570      * launches with this policy will occur through the primary or secondary Zygote with no special
571      * treatment.
572      *
573      * @hide
574      */
575     public static final int ZYGOTE_POLICY_FLAG_EMPTY = 0;
576 
577     /**
578      * Flag used to indicate that an application launch is user-visible and latency sensitive.  Any
579      * launch with this policy will use a Unspecialized App Process Pool if the target Zygote
580      * supports it.
581      *
582      * @hide
583      */
584     public static final int ZYGOTE_POLICY_FLAG_LATENCY_SENSITIVE = 1 << 0;
585 
586     /**
587      * Flag used to indicate that the launch is one in a series of app launches that will be
588      * performed in quick succession.  For future use.
589      *
590      * @hide
591      */
592     public static final int ZYGOTE_POLICY_FLAG_BATCH_LAUNCH = 1 << 1;
593 
594     /**
595      * Flag used to indicate that the current launch event is for a system process.  All system
596      * processes are equally important, so none of them should be prioritized over the others.
597      *
598      * @hide
599      */
600     public static final int ZYGOTE_POLICY_FLAG_SYSTEM_PROCESS = 1 << 2;
601 
602     /**
603      * State associated with the zygote process.
604      * @hide
605      */
606     public static final ZygoteProcess ZYGOTE_PROCESS = new ZygoteProcess();
607 
608     /**
609      * Start a new process.
610      *
611      * <p>If processes are enabled, a new process is created and the
612      * static main() function of a <var>processClass</var> is executed there.
613      * The process will continue running after this function returns.
614      *
615      * <p>If processes are not enabled, a new thread in the caller's
616      * process is created and main() of <var>processClass</var> called there.
617      *
618      * <p>The niceName parameter, if not an empty string, is a custom name to
619      * give to the process instead of using processClass.  This allows you to
620      * make easily identifyable processes even if you are using the same base
621      * <var>processClass</var> to start them.
622      *
623      * When invokeWith is not null, the process will be started as a fresh app
624      * and not a zygote fork. Note that this is only allowed for uid 0 or when
625      * runtimeFlags contains DEBUG_ENABLE_DEBUGGER.
626      *
627      * @param processClass The class to use as the process's main entry
628      *                     point.
629      * @param niceName A more readable name to use for the process.
630      * @param uid The user-id under which the process will run.
631      * @param gid The group-id under which the process will run.
632      * @param gids Additional group-ids associated with the process.
633      * @param runtimeFlags Additional flags for the runtime.
634      * @param targetSdkVersion The target SDK version for the app.
635      * @param seInfo null-ok SELinux information for the new process.
636      * @param abi non-null the ABI this app should be started with.
637      * @param instructionSet null-ok the instruction set to use.
638      * @param appDataDir null-ok the data directory of the app.
639      * @param invokeWith null-ok the command to invoke with.
640      * @param packageName null-ok the name of the package this process belongs to.
641      * @param zygotePolicyFlags Flags used to determine how to launch the application
642      * @param isTopApp whether the process starts for high priority application.
643      * @param disabledCompatChanges null-ok list of disabled compat changes for the process being
644      *                             started.
645      * @param pkgDataInfoMap Map from related package names to private data directory
646      *                       volume UUID and inode number.
647      * @param whitelistedDataInfoMap Map from allowlisted package names to private data directory
648      *                       volume UUID and inode number.
649      * @param bindMountAppsData whether zygote needs to mount CE and DE data.
650      * @param bindMountAppStorageDirs whether zygote needs to mount Android/obb and Android/data.
651      * @param zygoteArgs Additional arguments to supply to the zygote process.
652      * @return An object that describes the result of the attempt to start the process.
653      * @throws RuntimeException on fatal start failure
654      *
655      * {@hide}
656      */
start(@onNull final String processClass, @Nullable final String niceName, int uid, int gid, @Nullable int[] gids, int runtimeFlags, int mountExternal, int targetSdkVersion, @Nullable String seInfo, @NonNull String abi, @Nullable String instructionSet, @Nullable String appDataDir, @Nullable String invokeWith, @Nullable String packageName, int zygotePolicyFlags, boolean isTopApp, @Nullable long[] disabledCompatChanges, @Nullable Map<String, Pair<String, Long>> pkgDataInfoMap, @Nullable Map<String, Pair<String, Long>> whitelistedDataInfoMap, boolean bindMountAppsData, boolean bindMountAppStorageDirs, @Nullable String[] zygoteArgs)657     public static ProcessStartResult start(@NonNull final String processClass,
658                                            @Nullable final String niceName,
659                                            int uid, int gid, @Nullable int[] gids,
660                                            int runtimeFlags,
661                                            int mountExternal,
662                                            int targetSdkVersion,
663                                            @Nullable String seInfo,
664                                            @NonNull String abi,
665                                            @Nullable String instructionSet,
666                                            @Nullable String appDataDir,
667                                            @Nullable String invokeWith,
668                                            @Nullable String packageName,
669                                            int zygotePolicyFlags,
670                                            boolean isTopApp,
671                                            @Nullable long[] disabledCompatChanges,
672                                            @Nullable Map<String, Pair<String, Long>>
673                                                    pkgDataInfoMap,
674                                            @Nullable Map<String, Pair<String, Long>>
675                                                    whitelistedDataInfoMap,
676                                            boolean bindMountAppsData,
677                                            boolean bindMountAppStorageDirs,
678                                            @Nullable String[] zygoteArgs) {
679         return ZYGOTE_PROCESS.start(processClass, niceName, uid, gid, gids,
680                     runtimeFlags, mountExternal, targetSdkVersion, seInfo,
681                     abi, instructionSet, appDataDir, invokeWith, packageName,
682                     zygotePolicyFlags, isTopApp, disabledCompatChanges,
683                     pkgDataInfoMap, whitelistedDataInfoMap, bindMountAppsData,
684                     bindMountAppStorageDirs, zygoteArgs);
685     }
686 
687     /** @hide */
startWebView(@onNull final String processClass, @Nullable final String niceName, int uid, int gid, @Nullable int[] gids, int runtimeFlags, int mountExternal, int targetSdkVersion, @Nullable String seInfo, @NonNull String abi, @Nullable String instructionSet, @Nullable String appDataDir, @Nullable String invokeWith, @Nullable String packageName, @Nullable long[] disabledCompatChanges, @Nullable String[] zygoteArgs)688     public static ProcessStartResult startWebView(@NonNull final String processClass,
689                                                   @Nullable final String niceName,
690                                                   int uid, int gid, @Nullable int[] gids,
691                                                   int runtimeFlags,
692                                                   int mountExternal,
693                                                   int targetSdkVersion,
694                                                   @Nullable String seInfo,
695                                                   @NonNull String abi,
696                                                   @Nullable String instructionSet,
697                                                   @Nullable String appDataDir,
698                                                   @Nullable String invokeWith,
699                                                   @Nullable String packageName,
700                                                   @Nullable long[] disabledCompatChanges,
701                                                   @Nullable String[] zygoteArgs) {
702         // Webview zygote can't access app private data files, so doesn't need to know its data
703         // info.
704         return WebViewZygote.getProcess().start(processClass, niceName, uid, gid, gids,
705                     runtimeFlags, mountExternal, targetSdkVersion, seInfo,
706                     abi, instructionSet, appDataDir, invokeWith, packageName,
707                     /*zygotePolicyFlags=*/ ZYGOTE_POLICY_FLAG_EMPTY, /*isTopApp=*/ false,
708                 disabledCompatChanges, /* pkgDataInfoMap */ null,
709                 /* whitelistedDataInfoMap */ null, false, false, zygoteArgs);
710     }
711 
712     /**
713      * Returns elapsed milliseconds of the time this process has run.
714      * @return  Returns the number of milliseconds this process has return.
715      */
getElapsedCpuTime()716     public static final native long getElapsedCpuTime();
717 
718     /**
719      * Return the {@link SystemClock#elapsedRealtime()} at which this process was started.
720      */
getStartElapsedRealtime()721     public static final long getStartElapsedRealtime() {
722         return sStartElapsedRealtime;
723     }
724 
725     /**
726      * Return the {@link SystemClock#uptimeMillis()} at which this process was started.
727      */
getStartUptimeMillis()728     public static final long getStartUptimeMillis() {
729         return sStartUptimeMillis;
730     }
731 
732     /** @hide */
setStartTimes(long elapsedRealtime, long uptimeMillis)733     public static final void setStartTimes(long elapsedRealtime, long uptimeMillis) {
734         sStartElapsedRealtime = elapsedRealtime;
735         sStartUptimeMillis = uptimeMillis;
736     }
737 
738     /**
739      * Returns true if the current process is a 64-bit runtime.
740      */
is64Bit()741     public static final boolean is64Bit() {
742         return VMRuntime.getRuntime().is64Bit();
743     }
744 
745     /**
746      * Returns the identifier of this process, which can be used with
747      * {@link #killProcess} and {@link #sendSignal}.
748      */
myPid()749     public static final int myPid() {
750         return Os.getpid();
751     }
752 
753     /**
754      * Returns the identifier of this process' parent.
755      * @hide
756      */
757     @UnsupportedAppUsage(trackingBug = 171962076)
myPpid()758     public static final int myPpid() {
759         return Os.getppid();
760     }
761 
762     /**
763      * Returns the identifier of the calling thread, which be used with
764      * {@link #setThreadPriority(int, int)}.
765      */
myTid()766     public static final int myTid() {
767         return Os.gettid();
768     }
769 
770     /**
771      * Returns the identifier of this process's uid.  This is the kernel uid
772      * that the process is running under, which is the identity of its
773      * app-specific sandbox.  It is different from {@link #myUserHandle} in that
774      * a uid identifies a specific app sandbox in a specific user.
775      */
myUid()776     public static final int myUid() {
777         return Os.getuid();
778     }
779 
780     /**
781      * Returns this process's user handle.  This is the
782      * user the process is running under.  It is distinct from
783      * {@link #myUid()} in that a particular user will have multiple
784      * distinct apps running under it each with their own uid.
785      */
myUserHandle()786     public static UserHandle myUserHandle() {
787         return UserHandle.of(UserHandle.getUserId(myUid()));
788     }
789 
790     /**
791      * Returns whether the given uid belongs to a system core component or not.
792      * @hide
793      */
isCoreUid(int uid)794     public static boolean isCoreUid(int uid) {
795         return UserHandle.isCore(uid);
796     }
797 
798     /**
799      * Returns whether the given uid belongs to an application.
800      * @param uid A kernel uid.
801      * @return Whether the uid corresponds to an application sandbox running in
802      *     a specific user.
803      */
isApplicationUid(int uid)804     public static boolean isApplicationUid(int uid) {
805         return UserHandle.isApp(uid);
806     }
807 
808     /**
809      * Returns whether the current process is in an isolated sandbox.
810      */
isIsolated()811     public static final boolean isIsolated() {
812         return isIsolated(myUid());
813     }
814 
815     /** {@hide} */
816     @UnsupportedAppUsage
isIsolated(int uid)817     public static final boolean isIsolated(int uid) {
818         uid = UserHandle.getAppId(uid);
819         return (uid >= FIRST_ISOLATED_UID && uid <= LAST_ISOLATED_UID)
820                 || (uid >= FIRST_APP_ZYGOTE_ISOLATED_UID && uid <= LAST_APP_ZYGOTE_ISOLATED_UID);
821     }
822 
823     /**
824      * Returns the UID assigned to a particular user name, or -1 if there is
825      * none.  If the given string consists of only numbers, it is converted
826      * directly to a uid.
827      */
getUidForName(String name)828     public static final native int getUidForName(String name);
829 
830     /**
831      * Returns the GID assigned to a particular user name, or -1 if there is
832      * none.  If the given string consists of only numbers, it is converted
833      * directly to a gid.
834      */
getGidForName(String name)835     public static final native int getGidForName(String name);
836 
837     /**
838      * Returns a uid for a currently running process.
839      * @param pid the process id
840      * @return the uid of the process, or -1 if the process is not running.
841      * @hide pending API council review
842      */
843     @UnsupportedAppUsage
getUidForPid(int pid)844     public static final int getUidForPid(int pid) {
845         String[] procStatusLabels = { "Uid:" };
846         long[] procStatusValues = new long[1];
847         procStatusValues[0] = -1;
848         Process.readProcLines("/proc/" + pid + "/status", procStatusLabels, procStatusValues);
849         return (int) procStatusValues[0];
850     }
851 
852     /**
853      * Returns the parent process id for a currently running process.
854      * @param pid the process id
855      * @return the parent process id of the process, or -1 if the process is not running.
856      * @hide
857      */
858     @UnsupportedAppUsage
getParentPid(int pid)859     public static final int getParentPid(int pid) {
860         String[] procStatusLabels = { "PPid:" };
861         long[] procStatusValues = new long[1];
862         procStatusValues[0] = -1;
863         Process.readProcLines("/proc/" + pid + "/status", procStatusLabels, procStatusValues);
864         return (int) procStatusValues[0];
865     }
866 
867     /**
868      * Returns the thread group leader id for a currently running thread.
869      * @param tid the thread id
870      * @return the thread group leader id of the thread, or -1 if the thread is not running.
871      *         This is same as what getpid(2) would return if called by tid.
872      * @hide
873      */
getThreadGroupLeader(int tid)874     public static final int getThreadGroupLeader(int tid) {
875         String[] procStatusLabels = { "Tgid:" };
876         long[] procStatusValues = new long[1];
877         procStatusValues[0] = -1;
878         Process.readProcLines("/proc/" + tid + "/status", procStatusLabels, procStatusValues);
879         return (int) procStatusValues[0];
880     }
881 
882     /**
883      * Set the priority of a thread, based on Linux priorities.
884      *
885      * @param tid The identifier of the thread/process to change.
886      * @param priority A Linux priority level, from -20 for highest scheduling
887      * priority to 19 for lowest scheduling priority.
888      *
889      * @throws IllegalArgumentException Throws IllegalArgumentException if
890      * <var>tid</var> does not exist.
891      * @throws SecurityException Throws SecurityException if your process does
892      * not have permission to modify the given thread, or to use the given
893      * priority.
894      */
setThreadPriority(int tid, int priority)895     public static final native void setThreadPriority(int tid, int priority)
896             throws IllegalArgumentException, SecurityException;
897 
898     /**
899      * Call with 'false' to cause future calls to {@link #setThreadPriority(int)} to
900      * throw an exception if passed a background-level thread priority.  This is only
901      * effective if the JNI layer is built with GUARD_THREAD_PRIORITY defined to 1.
902      *
903      * @hide
904      */
setCanSelfBackground(boolean backgroundOk)905     public static final native void setCanSelfBackground(boolean backgroundOk);
906 
907     /**
908      * Sets the scheduling group for a thread.
909      * @hide
910      * @param tid The identifier of the thread to change.
911      * @param group The target group for this thread from THREAD_GROUP_*.
912      *
913      * @throws IllegalArgumentException Throws IllegalArgumentException if
914      * <var>tid</var> does not exist.
915      * @throws SecurityException Throws SecurityException if your process does
916      * not have permission to modify the given thread, or to use the given
917      * priority.
918      * If the thread is a thread group leader, that is it's gettid() == getpid(),
919      * then the other threads in the same thread group are _not_ affected.
920      *
921      * Does not set cpuset for some historical reason, just calls
922      * libcutils::set_sched_policy().
923      */
setThreadGroup(int tid, int group)924     public static final native void setThreadGroup(int tid, int group)
925             throws IllegalArgumentException, SecurityException;
926 
927     /**
928      * Sets the scheduling group and the corresponding cpuset group
929      * @hide
930      * @param tid The identifier of the thread to change.
931      * @param group The target group for this thread from THREAD_GROUP_*.
932      *
933      * @throws IllegalArgumentException Throws IllegalArgumentException if
934      * <var>tid</var> does not exist.
935      * @throws SecurityException Throws SecurityException if your process does
936      * not have permission to modify the given thread, or to use the given
937      * priority.
938      */
setThreadGroupAndCpuset(int tid, int group)939     public static final native void setThreadGroupAndCpuset(int tid, int group)
940             throws IllegalArgumentException, SecurityException;
941 
942     /**
943      * Sets the scheduling group for a process and all child threads
944      * @hide
945      * @param pid The identifier of the process to change.
946      * @param group The target group for this process from THREAD_GROUP_*.
947      *
948      * @throws IllegalArgumentException Throws IllegalArgumentException if
949      * <var>tid</var> does not exist.
950      * @throws SecurityException Throws SecurityException if your process does
951      * not have permission to modify the given thread, or to use the given
952      * priority.
953      *
954      * group == THREAD_GROUP_DEFAULT means to move all non-background priority
955      * threads to the foreground scheduling group, but to leave background
956      * priority threads alone.  group == THREAD_GROUP_BACKGROUND moves all
957      * threads, regardless of priority, to the background scheduling group.
958      * group == THREAD_GROUP_FOREGROUND is not allowed.
959      *
960      * Always sets cpusets.
961      */
962     @UnsupportedAppUsage
setProcessGroup(int pid, int group)963     public static final native void setProcessGroup(int pid, int group)
964             throws IllegalArgumentException, SecurityException;
965 
966     /**
967      * Freeze or unfreeze the specified process.
968      *
969      * @param pid Identifier of the process to freeze or unfreeze.
970      * @param uid Identifier of the user the process is running under.
971      * @param frozen Specify whether to free (true) or unfreeze (false).
972      *
973      * @hide
974      */
setProcessFrozen(int pid, int uid, boolean frozen)975     public static final native void setProcessFrozen(int pid, int uid, boolean frozen);
976 
977     /**
978      * Enable or disable the freezer. When enable == false all frozen processes are unfrozen,
979      * but aren't removed from the freezer. While in this state, processes can be added or removed
980      * by using setProcessFrozen, but they won't actually be frozen until the freezer is enabled
981      * again. If enable == true the freezer is enabled again, and all processes
982      * in the freezer (including the ones added while the freezer was disabled) are frozen.
983      *
984      * @param enable Specify whether to enable (true) or disable (false) the freezer.
985      *
986      * @hide
987      */
enableFreezer(boolean enable)988     public static final native void enableFreezer(boolean enable);
989 
990     /**
991      * Return the scheduling group of requested process.
992      *
993      * @hide
994      */
getProcessGroup(int pid)995     public static final native int getProcessGroup(int pid)
996             throws IllegalArgumentException, SecurityException;
997 
998     /**
999      *
1000      * Create a new process group in the cgroup uid/pid hierarchy
1001      *
1002      * @return <0 in case of error
1003      *
1004      * @hide
1005      */
createProcessGroup(int uid, int pid)1006     public static final native int createProcessGroup(int uid, int pid);
1007 
1008     /**
1009      * On some devices, the foreground process may have one or more CPU
1010      * cores exclusively reserved for it. This method can be used to
1011      * retrieve which cores that are (if any), so the calling process
1012      * can then use sched_setaffinity() to lock a thread to these cores.
1013      * Note that the calling process must currently be running in the
1014      * foreground for this method to return any cores.
1015      *
1016      * The CPU core(s) exclusively reserved for the foreground process will
1017      * stay reserved for as long as the process stays in the foreground.
1018      *
1019      * As soon as a process leaves the foreground, those CPU cores will
1020      * no longer be reserved for it, and will most likely be reserved for
1021      * the new foreground process. It's not necessary to change the affinity
1022      * of your process when it leaves the foreground (if you had previously
1023      * set it to use a reserved core); the OS will automatically take care
1024      * of resetting the affinity at that point.
1025      *
1026      * @return an array of integers, indicating the CPU cores exclusively
1027      * reserved for this process. The array will have length zero if no
1028      * CPU cores are exclusively reserved for this process at this point
1029      * in time.
1030      */
getExclusiveCores()1031     public static final native int[] getExclusiveCores();
1032 
1033     /**
1034      * Set the priority of the calling thread, based on Linux priorities.  See
1035      * {@link #setThreadPriority(int, int)} for more information.
1036      *
1037      * @param priority A Linux priority level, from -20 for highest scheduling
1038      * priority to 19 for lowest scheduling priority.
1039      *
1040      * @throws IllegalArgumentException Throws IllegalArgumentException if
1041      * <var>tid</var> does not exist.
1042      * @throws SecurityException Throws SecurityException if your process does
1043      * not have permission to modify the given thread, or to use the given
1044      * priority.
1045      *
1046      * @see #setThreadPriority(int, int)
1047      */
setThreadPriority(int priority)1048     public static final native void setThreadPriority(int priority)
1049             throws IllegalArgumentException, SecurityException;
1050 
1051     /**
1052      * Return the current priority of a thread, based on Linux priorities.
1053      *
1054      * @param tid The identifier of the thread/process. If tid equals zero, the priority of the
1055      * calling process/thread will be returned.
1056      *
1057      * @return Returns the current priority, as a Linux priority level,
1058      * from -20 for highest scheduling priority to 19 for lowest scheduling
1059      * priority.
1060      *
1061      * @throws IllegalArgumentException Throws IllegalArgumentException if
1062      * <var>tid</var> does not exist.
1063      */
getThreadPriority(int tid)1064     public static final native int getThreadPriority(int tid)
1065             throws IllegalArgumentException;
1066 
1067     /**
1068      * Return the current scheduling policy of a thread, based on Linux.
1069      *
1070      * @param tid The identifier of the thread/process to get the scheduling policy.
1071      *
1072      * @throws IllegalArgumentException Throws IllegalArgumentException if
1073      * <var>tid</var> does not exist, or if <var>priority</var> is out of range for the policy.
1074      * @throws SecurityException Throws SecurityException if your process does
1075      * not have permission to modify the given thread, or to use the given
1076      * scheduling policy or priority.
1077      *
1078      * {@hide}
1079      */
1080 
1081     @TestApi
getThreadScheduler(int tid)1082     public static final native int getThreadScheduler(int tid)
1083             throws IllegalArgumentException;
1084 
1085     /**
1086      * Set the scheduling policy and priority of a thread, based on Linux.
1087      *
1088      * @param tid The identifier of the thread/process to change.
1089      * @param policy A Linux scheduling policy such as SCHED_OTHER etc.
1090      * @param priority A Linux priority level in a range appropriate for the given policy.
1091      *
1092      * @throws IllegalArgumentException Throws IllegalArgumentException if
1093      * <var>tid</var> does not exist, or if <var>priority</var> is out of range for the policy.
1094      * @throws SecurityException Throws SecurityException if your process does
1095      * not have permission to modify the given thread, or to use the given
1096      * scheduling policy or priority.
1097      *
1098      * {@hide}
1099      */
1100 
setThreadScheduler(int tid, int policy, int priority)1101     public static final native void setThreadScheduler(int tid, int policy, int priority)
1102             throws IllegalArgumentException;
1103 
1104     /**
1105      * Determine whether the current environment supports multiple processes.
1106      *
1107      * @return Returns true if the system can run in multiple processes, else
1108      * false if everything is running in a single process.
1109      *
1110      * @deprecated This method always returns true.  Do not use.
1111      */
1112     @Deprecated
supportsProcesses()1113     public static final boolean supportsProcesses() {
1114         return true;
1115     }
1116 
1117     /**
1118      * Adjust the swappiness level for a process.
1119      *
1120      * @param pid The process identifier to set.
1121      * @param is_increased Whether swappiness should be increased or default.
1122      *
1123      * @return Returns true if the underlying system supports this
1124      *         feature, else false.
1125      *
1126      * {@hide}
1127      */
setSwappiness(int pid, boolean is_increased)1128     public static final native boolean setSwappiness(int pid, boolean is_increased);
1129 
1130     /**
1131      * Change this process's argv[0] parameter.  This can be useful to show
1132      * more descriptive information in things like the 'ps' command.
1133      *
1134      * @param text The new name of this process.
1135      *
1136      * {@hide}
1137      */
1138     @UnsupportedAppUsage
setArgV0(String text)1139     public static final native void setArgV0(String text);
1140 
1141     /**
1142      * Kill the process with the given PID.
1143      * Note that, though this API allows us to request to
1144      * kill any process based on its PID, the kernel will
1145      * still impose standard restrictions on which PIDs you
1146      * are actually able to kill.  Typically this means only
1147      * the process running the caller's packages/application
1148      * and any additional processes created by that app; packages
1149      * sharing a common UID will also be able to kill each
1150      * other's processes.
1151      */
killProcess(int pid)1152     public static final void killProcess(int pid) {
1153         sendSignal(pid, SIGNAL_KILL);
1154     }
1155 
1156     /** @hide */
setUid(int uid)1157     public static final native int setUid(int uid);
1158 
1159     /** @hide */
setGid(int uid)1160     public static final native int setGid(int uid);
1161 
1162     /**
1163      * Send a signal to the given process.
1164      *
1165      * @param pid The pid of the target process.
1166      * @param signal The signal to send.
1167      */
sendSignal(int pid, int signal)1168     public static final native void sendSignal(int pid, int signal);
1169 
1170     /**
1171      * @hide
1172      * Private impl for avoiding a log message...  DO NOT USE without doing
1173      * your own log, or the Android Illuminati will find you some night and
1174      * beat you up.
1175      */
killProcessQuiet(int pid)1176     public static final void killProcessQuiet(int pid) {
1177         sendSignalQuiet(pid, SIGNAL_KILL);
1178     }
1179 
1180     /**
1181      * @hide
1182      * Private impl for avoiding a log message...  DO NOT USE without doing
1183      * your own log, or the Android Illuminati will find you some night and
1184      * beat you up.
1185      */
1186     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
sendSignalQuiet(int pid, int signal)1187     public static final native void sendSignalQuiet(int pid, int signal);
1188 
1189     /** @hide */
1190     @UnsupportedAppUsage
getFreeMemory()1191     public static final native long getFreeMemory();
1192 
1193     /** @hide */
1194     @UnsupportedAppUsage
getTotalMemory()1195     public static final native long getTotalMemory();
1196 
1197     /** @hide */
1198     @UnsupportedAppUsage
readProcLines(String path, String[] reqFields, long[] outSizes)1199     public static final native void readProcLines(String path,
1200             String[] reqFields, long[] outSizes);
1201 
1202     /** @hide */
1203     @UnsupportedAppUsage
getPids(String path, int[] lastArray)1204     public static final native int[] getPids(String path, int[] lastArray);
1205 
1206     /** @hide */
1207     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
1208     public static final int PROC_TERM_MASK = 0xff;
1209     /** @hide */
1210     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
1211     public static final int PROC_ZERO_TERM = 0;
1212     /** @hide */
1213     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
1214     public static final int PROC_SPACE_TERM = (int)' ';
1215     /** @hide */
1216     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
1217     public static final int PROC_TAB_TERM = (int)'\t';
1218     /** @hide */
1219     public static final int PROC_NEWLINE_TERM = (int) '\n';
1220     /** @hide */
1221     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
1222     public static final int PROC_COMBINE = 0x100;
1223     /** @hide */
1224     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
1225     public static final int PROC_PARENS = 0x200;
1226     /** @hide */
1227     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
1228     public static final int PROC_QUOTES = 0x400;
1229     /** @hide */
1230     public static final int PROC_CHAR = 0x800;
1231     /** @hide */
1232     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
1233     public static final int PROC_OUT_STRING = 0x1000;
1234     /** @hide */
1235     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
1236     public static final int PROC_OUT_LONG = 0x2000;
1237     /** @hide */
1238     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
1239     public static final int PROC_OUT_FLOAT = 0x4000;
1240 
1241     /**
1242      * Read and parse a {@code proc} file in the given format.
1243      *
1244      * <p>The format is a list of integers, where every integer describes a variable in the file. It
1245      * specifies how the variable is syntactically terminated (e.g. {@link Process#PROC_SPACE_TERM},
1246      * {@link Process#PROC_TAB_TERM}, {@link Process#PROC_ZERO_TERM}, {@link
1247      * Process#PROC_NEWLINE_TERM}).
1248      *
1249      * <p>If the variable should be parsed and returned to the caller, the termination type should
1250      * be binary OR'd with the type of output (e.g. {@link Process#PROC_OUT_STRING}, {@link
1251      * Process#PROC_OUT_LONG}, {@link Process#PROC_OUT_FLOAT}.
1252      *
1253      * <p>If the variable is wrapped in quotation marks it should be binary OR'd with {@link
1254      * Process#PROC_QUOTES}. If the variable is wrapped in parentheses it should be binary OR'd with
1255      * {@link Process#PROC_PARENS}.
1256      *
1257      * <p>If the variable is not formatted as a string and should be cast directly from characters
1258      * to a long, the {@link Process#PROC_CHAR} integer should be binary OR'd.
1259      *
1260      * <p>If the terminating character can be repeated, the {@link Process#PROC_COMBINE} integer
1261      * should be binary OR'd.
1262      *
1263      * @param file the path of the {@code proc} file to read
1264      * @param format the format of the file
1265      * @param outStrings the parsed {@code String}s from the file
1266      * @param outLongs the parsed {@code long}s from the file
1267      * @param outFloats the parsed {@code float}s from the file
1268      * @hide
1269      */
1270     @UnsupportedAppUsage
readProcFile(String file, int[] format, String[] outStrings, long[] outLongs, float[] outFloats)1271     public static final native boolean readProcFile(String file, int[] format,
1272             String[] outStrings, long[] outLongs, float[] outFloats);
1273 
1274     /** @hide */
1275     @UnsupportedAppUsage
parseProcLine(byte[] buffer, int startIndex, int endIndex, int[] format, String[] outStrings, long[] outLongs, float[] outFloats)1276     public static final native boolean parseProcLine(byte[] buffer, int startIndex,
1277             int endIndex, int[] format, String[] outStrings, long[] outLongs, float[] outFloats);
1278 
1279     /** @hide */
1280     @UnsupportedAppUsage
getPidsForCommands(String[] cmds)1281     public static final native int[] getPidsForCommands(String[] cmds);
1282 
1283     /**
1284      * Gets the total Pss value for a given process, in bytes.
1285      *
1286      * @param pid the process to the Pss for
1287      * @return the total Pss value for the given process in bytes,
1288      *  or -1 if the value cannot be determined
1289      * @hide
1290      */
1291     @UnsupportedAppUsage
getPss(int pid)1292     public static final native long getPss(int pid);
1293 
1294     /** @hide */
getRss(int pid)1295     public static final native long[] getRss(int pid);
1296 
1297     /**
1298      * Specifies the outcome of having started a process.
1299      * @hide
1300      */
1301     public static final class ProcessStartResult {
1302         /**
1303          * The PID of the newly started process.
1304          * Always >= 0.  (If the start failed, an exception will have been thrown instead.)
1305          */
1306         public int pid;
1307 
1308         /**
1309          * True if the process was started with a wrapper attached.
1310          */
1311         public boolean usingWrapper;
1312     }
1313 
1314     /**
1315      * Kill all processes in a process group started for the given
1316      * pid.
1317      * @hide
1318      */
killProcessGroup(int uid, int pid)1319     public static final native int killProcessGroup(int uid, int pid);
1320 
1321     /**
1322      * Remove all process groups.  Expected to be called when ActivityManager
1323      * is restarted.
1324      * @hide
1325      */
removeAllProcessGroups()1326     public static final native void removeAllProcessGroups();
1327 
1328     /**
1329      * Check to see if a thread belongs to a given process. This may require
1330      * more permissions than apps generally have.
1331      * @return true if this thread belongs to a process
1332      * @hide
1333      */
isThreadInProcess(int tid, int pid)1334     public static final boolean isThreadInProcess(int tid, int pid) {
1335         StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
1336         try {
1337             if (Os.access("/proc/" + tid + "/task/" + pid, OsConstants.F_OK)) {
1338                 return true;
1339             } else {
1340                 return false;
1341             }
1342         } catch (Exception e) {
1343             return false;
1344         } finally {
1345             StrictMode.setThreadPolicy(oldPolicy);
1346         }
1347 
1348     }
1349 
1350     /**
1351      * Wait for the death of the given process.
1352      *
1353      * @param pid The process ID to be waited on
1354      * @param timeout The maximum time to wait in milliseconds, or -1 to wait forever
1355      * @hide
1356      */
waitForProcessDeath(int pid, int timeout)1357     public static void waitForProcessDeath(int pid, int timeout)
1358             throws InterruptedException, TimeoutException {
1359         boolean fallback = supportsPidFd();
1360         if (!fallback) {
1361             FileDescriptor pidfd = null;
1362             try {
1363                 final int fd = nativePidFdOpen(pid, 0);
1364                 if (fd >= 0) {
1365                     pidfd = new FileDescriptor();
1366                     pidfd.setInt$(fd);
1367                 } else {
1368                     fallback = true;
1369                 }
1370                 if (pidfd != null) {
1371                     StructPollfd[] fds = new StructPollfd[] {
1372                         new StructPollfd()
1373                     };
1374                     fds[0].fd = pidfd;
1375                     fds[0].events = (short) OsConstants.POLLIN;
1376                     fds[0].revents = 0;
1377                     fds[0].userData = null;
1378                     int res = Os.poll(fds, timeout);
1379                     if (res > 0) {
1380                         return;
1381                     } else if (res == 0) {
1382                         throw new TimeoutException();
1383                     } else {
1384                         // We should get an ErrnoException now
1385                     }
1386                 }
1387             } catch (ErrnoException e) {
1388                 if (e.errno == OsConstants.EINTR) {
1389                     throw new InterruptedException();
1390                 }
1391                 fallback = true;
1392             } finally {
1393                 if (pidfd != null) {
1394                     IoUtils.closeQuietly(pidfd);
1395                 }
1396             }
1397         }
1398         if (fallback) {
1399             boolean infinity = timeout < 0;
1400             long now = System.currentTimeMillis();
1401             final long end = now + timeout;
1402             while (infinity || now < end) {
1403                 try {
1404                     Os.kill(pid, 0);
1405                 } catch (ErrnoException e) {
1406                     if (e.errno == OsConstants.ESRCH) {
1407                         return;
1408                     }
1409                 }
1410                 Thread.sleep(1);
1411                 now = System.currentTimeMillis();
1412             }
1413         }
1414         throw new TimeoutException();
1415     }
1416 
1417     /**
1418      * Determine whether the system supports pidfd APIs
1419      *
1420      * @return Returns true if the system supports pidfd APIs
1421      * @hide
1422      */
1423     public static boolean supportsPidFd() {
1424         if (sPidFdSupported == PIDFD_UNKNOWN) {
1425             int fd = -1;
1426             try {
1427                 fd = nativePidFdOpen(myPid(), 0);
1428                 sPidFdSupported = PIDFD_SUPPORTED;
1429             } catch (ErrnoException e) {
1430                 sPidFdSupported = e.errno != OsConstants.ENOSYS
1431                         ? PIDFD_SUPPORTED : PIDFD_UNSUPPORTED;
1432             } finally {
1433                 if (fd >= 0) {
1434                     final FileDescriptor f = new FileDescriptor();
1435                     f.setInt$(fd);
1436                     IoUtils.closeQuietly(f);
1437                 }
1438             }
1439         }
1440         return sPidFdSupported == PIDFD_SUPPORTED;
1441     }
1442 
1443     /**
1444      * Open process file descriptor for given pid.
1445      *
1446      * @param pid The process ID to open for
1447      * @param flags Reserved, unused now, must be 0
1448      * @return The process file descriptor for given pid
1449      * @throws IOException if it can't be opened
1450      *
1451      * @hide
1452      */
1453     public static @Nullable FileDescriptor openPidFd(int pid, int flags) throws IOException {
1454         if (!supportsPidFd()) {
1455             return null;
1456         }
1457         if (flags != 0) {
1458             throw new IllegalArgumentException();
1459         }
1460         try {
1461             FileDescriptor pidfd = new FileDescriptor();
1462             pidfd.setInt$(nativePidFdOpen(pid, flags));
1463             return pidfd;
1464         } catch (ErrnoException e) {
1465             IOException ex = new IOException();
1466             ex.initCause(e);
1467             throw ex;
1468         }
1469     }
1470 
1471     private static native int nativePidFdOpen(int pid, int flags) throws ErrnoException;
1472 }
1473