/* * Copyright (C) 2006 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.os; import static android.annotation.SystemApi.Client.MODULE_LIBRARIES; import android.annotation.ElapsedRealtimeLong; import android.annotation.FlaggedApi; import android.annotation.IntRange; import android.annotation.NonNull; import android.annotation.Nullable; import android.annotation.SuppressLint; import android.annotation.SystemApi; import android.annotation.TestApi; import android.annotation.UptimeMillisLong; import android.compat.annotation.UnsupportedAppUsage; import android.os.Build.VERSION_CODES; import android.ravenwood.annotation.RavenwoodKeep; import android.ravenwood.annotation.RavenwoodKeepPartialClass; import android.ravenwood.annotation.RavenwoodRedirect; import android.ravenwood.annotation.RavenwoodRedirectionClass; import android.ravenwood.annotation.RavenwoodReplace; import android.sysprop.MemoryProperties; import android.system.ErrnoException; import android.system.Os; import android.system.OsConstants; import android.system.StructPollfd; import android.util.Pair; import android.webkit.WebViewZygote; import com.android.sdksandbox.flags.Flags; import dalvik.system.VMDebug; import dalvik.system.VMRuntime; import libcore.io.IoUtils; import java.io.FileDescriptor; import java.io.IOException; import java.util.Map; import java.util.NoSuchElementException; import java.util.concurrent.TimeoutException; /** * Tools for managing OS processes. */ @RavenwoodKeepPartialClass @RavenwoodRedirectionClass("Process_ravenwood") public class Process { private static final String LOG_TAG = "Process"; /** * An invalid UID value. */ public static final int INVALID_UID = -1; /** * Defines the root UID. */ public static final int ROOT_UID = 0; /** * Defines the UID/GID under which system code runs. */ public static final int SYSTEM_UID = 1000; /** * Defines the UID/GID under which the telephony code runs. */ public static final int PHONE_UID = 1001; /** * Defines the UID/GID for the user shell. */ public static final int SHELL_UID = 2000; /** * Defines the UID/GID for the log group. * @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int LOG_UID = 1007; /** * Defines the UID/GID for the WIFI native processes like wificond, supplicant, hostapd, * vendor HAL, etc. */ public static final int WIFI_UID = 1010; /** * Defines the UID/GID for the mediaserver process. * @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int MEDIA_UID = 1013; /** * Defines the UID/GID for the DRM process. * @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int DRM_UID = 1019; /** * Defines the GID for the group that allows write access to the internal media storage. * @hide */ public static final int SDCARD_RW_GID = 1015; /** * Defines the UID/GID for the group that controls VPN services. * @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) @SystemApi(client = MODULE_LIBRARIES) public static final int VPN_UID = 1016; /** * Defines the UID/GID for keystore. * @hide */ public static final int KEYSTORE_UID = 1017; /** * Defines the UID/GID for credstore. * @hide */ public static final int CREDSTORE_UID = 1076; /** * Defines the UID/GID for the NFC service process. * @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) @TestApi @SystemApi(client = MODULE_LIBRARIES) public static final int NFC_UID = 1027; /** * Defines the UID/GID for the clatd process. * @hide * */ public static final int CLAT_UID = 1029; /** * Defines the UID/GID for the Bluetooth service process. */ public static final int BLUETOOTH_UID = 1002; /** * Defines the GID for the group that allows write access to the internal media storage. * @hide */ public static final int MEDIA_RW_GID = 1023; /** * Access to installed package details * @hide */ public static final int PACKAGE_INFO_GID = 1032; /** * Defines the UID/GID for the shared RELRO file updater process. * @hide */ public static final int SHARED_RELRO_UID = 1037; /** * Defines the UID/GID for the audioserver process. * @hide */ public static final int AUDIOSERVER_UID = 1041; /** * Defines the UID/GID for the cameraserver process * @hide */ public static final int CAMERASERVER_UID = 1047; /** * Defines the UID/GID for the tethering DNS resolver (currently dnsmasq). * @hide */ public static final int DNS_TETHER_UID = 1052; /** * Defines the UID/GID for the WebView zygote process. * @hide */ public static final int WEBVIEW_ZYGOTE_UID = 1053; /** * Defines the UID used for resource tracking for OTA updates. * @hide */ public static final int OTA_UPDATE_UID = 1061; /** * Defines the UID used for statsd * @hide */ public static final int STATSD_UID = 1066; /** * Defines the UID used for incidentd. * @hide */ public static final int INCIDENTD_UID = 1067; /** * Defines the UID/GID for the Secure Element service process. * @hide */ public static final int SE_UID = 1068; /** * Defines the UID/GID for the NetworkStack app. * @hide */ public static final int NETWORK_STACK_UID = 1073; /** * Defines the UID/GID for fs-verity certificate ownership in keystore. * @hide */ public static final int FSVERITY_CERT_UID = 1075; /** * GID that gives access to USB OTG (unreliable) volumes on /mnt/media_rw/ * @hide */ public static final int EXTERNAL_STORAGE_GID = 1077; /** * GID that gives write access to app-private data directories on external * storage (used on devices without sdcardfs only). * @hide */ public static final int EXT_DATA_RW_GID = 1078; /** * GID that gives write access to app-private OBB directories on external * storage (used on devices without sdcardfs only). * @hide */ public static final int EXT_OBB_RW_GID = 1079; /** * Defines the UID/GID for the Uwb service process. * @hide */ public static final int UWB_UID = 1083; /** * Defines a virtual UID that is used to aggregate data related to SDK sandbox UIDs. * {@see SdkSandboxManager} * @hide */ @TestApi public static final int SDK_SANDBOX_VIRTUAL_UID = 1090; /** * GID that corresponds to the INTERNET permission. * Must match the value of AID_INET. * @hide */ public static final int INET_GID = 3003; /** * Defines the UID/GID for the vendor based data process. * This is used to register AIDL service from vendor app context. * @hide */ public static final int VENDOR_DATA_UID = 2918; /** {@hide} */ public static final int NOBODY_UID = 9999; /** * Defines the start of a range of UIDs (and GIDs), going from this * number to {@link #LAST_APPLICATION_UID} that are reserved for assigning * to applications. */ public static final int FIRST_APPLICATION_UID = 10000; /** * Last of application-specific UIDs starting at * {@link #FIRST_APPLICATION_UID}. */ public static final int LAST_APPLICATION_UID = 19999; /** * Defines the start of a range of UIDs going from this number to * {@link #LAST_SDK_SANDBOX_UID} that are reserved for assigning to * sdk sandbox processes. There is a 1-1 mapping between a sdk sandbox * process UID and the app that it belongs to, which can be computed by * subtracting (FIRST_SDK_SANDBOX_UID - FIRST_APPLICATION_UID) from the * uid of a sdk sandbox process. * * Note that there are no GIDs associated with these processes; storage * attribution for them will be done using project IDs. * @hide */ public static final int FIRST_SDK_SANDBOX_UID = 20000; /** * Last UID that is used for sdk sandbox processes. * @hide */ public static final int LAST_SDK_SANDBOX_UID = 29999; /** * First uid used for fully isolated sandboxed processes spawned from an app zygote * @hide */ @TestApi public static final int FIRST_APP_ZYGOTE_ISOLATED_UID = 90000; /** * Number of UIDs we allocate per application zygote * @hide */ @TestApi public static final int NUM_UIDS_PER_APP_ZYGOTE = 100; /** * Last uid used for fully isolated sandboxed processes spawned from an app zygote * @hide */ @TestApi public static final int LAST_APP_ZYGOTE_ISOLATED_UID = 98999; /** * First uid used for fully isolated sandboxed processes (with no permissions of their own) * @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) @TestApi public static final int FIRST_ISOLATED_UID = 99000; /** * Last uid used for fully isolated sandboxed processes (with no permissions of their own) * @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) @TestApi public static final int LAST_ISOLATED_UID = 99999; /** * Defines the gid shared by all applications running under the same profile. * @hide */ public static final int SHARED_USER_GID = 9997; /** * First gid for applications to share resources. Used when forward-locking * is enabled but all UserHandles need to be able to read the resources. * @hide */ public static final int FIRST_SHARED_APPLICATION_GID = 50000; /** * Last gid for applications to share resources. Used when forward-locking * is enabled but all UserHandles need to be able to read the resources. * @hide */ public static final int LAST_SHARED_APPLICATION_GID = 59999; /** {@hide} */ public static final int FIRST_APPLICATION_CACHE_GID = 20000; /** {@hide} */ public static final int LAST_APPLICATION_CACHE_GID = 29999; /** * An invalid PID value. */ public static final int INVALID_PID = -1; /** * Standard priority of application threads. * Use with {@link #setThreadPriority(int)} and * {@link #setThreadPriority(int, int)}, not with the normal * {@link java.lang.Thread} class. */ public static final int THREAD_PRIORITY_DEFAULT = 0; /* * *************************************** * ** Keep in sync with utils/threads.h ** * *************************************** */ /** * Lowest available thread priority. Only for those who really, really * don't want to run if anything else is happening. * Use with {@link #setThreadPriority(int)} and * {@link #setThreadPriority(int, int)}, not with the normal * {@link java.lang.Thread} class. */ public static final int THREAD_PRIORITY_LOWEST = 19; /** * Standard priority background threads. This gives your thread a slightly * lower than normal priority, so that it will have less chance of impacting * the responsiveness of the user interface. * Use with {@link #setThreadPriority(int)} and * {@link #setThreadPriority(int, int)}, not with the normal * {@link java.lang.Thread} class. */ public static final int THREAD_PRIORITY_BACKGROUND = 10; /** * Standard priority of threads that are currently running a user interface * that the user is interacting with. Applications can not normally * change to this priority; the system will automatically adjust your * application threads as the user moves through the UI. * Use with {@link #setThreadPriority(int)} and * {@link #setThreadPriority(int, int)}, not with the normal * {@link java.lang.Thread} class. */ public static final int THREAD_PRIORITY_FOREGROUND = -2; /** * Standard priority of system display threads, involved in updating * the user interface. Applications can not * normally change to this priority. * Use with {@link #setThreadPriority(int)} and * {@link #setThreadPriority(int, int)}, not with the normal * {@link java.lang.Thread} class. */ public static final int THREAD_PRIORITY_DISPLAY = -4; /** * Standard priority of the most important display threads, for compositing * the screen and retrieving input events. Applications can not normally * change to this priority. * Use with {@link #setThreadPriority(int)} and * {@link #setThreadPriority(int, int)}, not with the normal * {@link java.lang.Thread} class. */ public static final int THREAD_PRIORITY_URGENT_DISPLAY = -8; /** * Standard priority of video threads. Applications can not normally * change to this priority. * Use with {@link #setThreadPriority(int)} and * {@link #setThreadPriority(int, int)}, not with the normal * {@link java.lang.Thread} class. */ public static final int THREAD_PRIORITY_VIDEO = -10; /** * Priority we boost main thread and RT of top app to. * @hide */ public static final int THREAD_PRIORITY_TOP_APP_BOOST = -10; /** * Standard priority of audio threads. Applications can not normally * change to this priority. * Use with {@link #setThreadPriority(int)} and * {@link #setThreadPriority(int, int)}, not with the normal * {@link java.lang.Thread} class. */ public static final int THREAD_PRIORITY_AUDIO = -16; /** * Standard priority of the most important audio threads. * Applications can not normally change to this priority. * Use with {@link #setThreadPriority(int)} and * {@link #setThreadPriority(int, int)}, not with the normal * {@link java.lang.Thread} class. */ public static final int THREAD_PRIORITY_URGENT_AUDIO = -19; /** * Minimum increment to make a priority more favorable. */ public static final int THREAD_PRIORITY_MORE_FAVORABLE = -1; /** * Minimum increment to make a priority less favorable. */ public static final int THREAD_PRIORITY_LESS_FAVORABLE = +1; /** * Default scheduling policy * @hide */ public static final int SCHED_OTHER = 0; /** * First-In First-Out scheduling policy * @hide */ public static final int SCHED_FIFO = 1; /** * Round-Robin scheduling policy * @hide */ public static final int SCHED_RR = 2; /** * Batch scheduling policy * @hide */ public static final int SCHED_BATCH = 3; /** * Idle scheduling policy * @hide */ public static final int SCHED_IDLE = 5; /** * Reset scheduler choice on fork. * @hide */ public static final int SCHED_RESET_ON_FORK = 0x40000000; // Keep in sync with SP_* constants of enum type SchedPolicy // declared in system/core/include/cutils/sched_policy.h, // except THREAD_GROUP_DEFAULT does not correspond to any SP_* value. /** * Default thread group - * has meaning with setProcessGroup() only, cannot be used with setThreadGroup(). * When used with setProcessGroup(), the group of each thread in the process * is conditionally changed based on that thread's current priority, as follows: * threads with priority numerically less than THREAD_PRIORITY_BACKGROUND * are moved to foreground thread group. All other threads are left unchanged. * @hide */ public static final int THREAD_GROUP_DEFAULT = -1; /** * Background thread group - All threads in * this group are scheduled with a reduced share of the CPU. * Value is same as constant SP_BACKGROUND of enum SchedPolicy. * @hide */ public static final int THREAD_GROUP_BACKGROUND = 0; /** * Foreground thread group - All threads in * this group are scheduled with a normal share of the CPU. * Value is same as constant SP_FOREGROUND of enum SchedPolicy. * Not used at this level. * @hide **/ private static final int THREAD_GROUP_FOREGROUND = 1; /** * System thread group. * @hide **/ public static final int THREAD_GROUP_SYSTEM = 2; /** * Application audio thread group. * @hide **/ public static final int THREAD_GROUP_AUDIO_APP = 3; /** * System audio thread group. * @hide **/ public static final int THREAD_GROUP_AUDIO_SYS = 4; /** * Thread group for top foreground app. * @hide **/ public static final int THREAD_GROUP_TOP_APP = 5; /** * Thread group for RT app. * @hide **/ public static final int THREAD_GROUP_RT_APP = 6; /** * Thread group for bound foreground services that should * have additional CPU restrictions during screen off * @hide **/ public static final int THREAD_GROUP_RESTRICTED = 7; /** @hide */ public static final int SIGNAL_DEFAULT = 0; public static final int SIGNAL_QUIT = 3; public static final int SIGNAL_KILL = 9; public static final int SIGNAL_USR1 = 10; /** * When the process started and ActivityThread.handleBindApplication() was executed. */ private static long sStartElapsedRealtime; /** * When the process started and ActivityThread.handleBindApplication() was executed. */ private static long sStartUptimeMillis; /** * When the activity manager was about to ask zygote to fork. */ private static long sStartRequestedElapsedRealtime; /** * When the activity manager was about to ask zygote to fork. */ private static long sStartRequestedUptimeMillis; private static final int PIDFD_UNKNOWN = 0; private static final int PIDFD_SUPPORTED = 1; private static final int PIDFD_UNSUPPORTED = 2; /** * Whether or not the underlying OS supports pidfd */ private static int sPidFdSupported = PIDFD_UNKNOWN; /** * Value used to indicate that there is no special information about an application launch. App * launches with this policy will occur through the primary or secondary Zygote with no special * treatment. * * @hide */ public static final int ZYGOTE_POLICY_FLAG_EMPTY = 0; /** * Flag used to indicate that an application launch is user-visible and latency sensitive. Any * launch with this policy will use a Unspecialized App Process Pool if the target Zygote * supports it. * * @hide */ public static final int ZYGOTE_POLICY_FLAG_LATENCY_SENSITIVE = 1 << 0; /** * Flag used to indicate that the launch is one in a series of app launches that will be * performed in quick succession. For future use. * * @hide */ public static final int ZYGOTE_POLICY_FLAG_BATCH_LAUNCH = 1 << 1; /** * Flag used to indicate that the current launch event is for a system process. All system * processes are equally important, so none of them should be prioritized over the others. * * @hide */ public static final int ZYGOTE_POLICY_FLAG_SYSTEM_PROCESS = 1 << 2; /** * State associated with the zygote process. * @hide */ public static final ZygoteProcess ZYGOTE_PROCESS = new ZygoteProcess(); /** * The process name set via {@link #setArgV0(String)}. */ private static String sArgV0; /** * Start a new process. * *

If processes are enabled, a new process is created and the * static main() function of a processClass is executed there. * The process will continue running after this function returns. * *

If processes are not enabled, a new thread in the caller's * process is created and main() of processClass called there. * *

The niceName parameter, if not an empty string, is a custom name to * give to the process instead of using processClass. This allows you to * make easily identifyable processes even if you are using the same base * processClass to start them. * * When invokeWith is not null, the process will be started as a fresh app * and not a zygote fork. Note that this is only allowed for uid 0 or when * runtimeFlags contains DEBUG_ENABLE_DEBUGGER. * * @param processClass The class to use as the process's main entry * point. * @param niceName A more readable name to use for the process. * @param uid The user-id under which the process will run. * @param gid The group-id under which the process will run. * @param gids Additional group-ids associated with the process. * @param runtimeFlags Additional flags for the runtime. * @param targetSdkVersion The target SDK version for the app. * @param seInfo null-ok SELinux information for the new process. * @param abi non-null the ABI this app should be started with. * @param instructionSet null-ok the instruction set to use. * @param appDataDir null-ok the data directory of the app. * @param invokeWith null-ok the command to invoke with. * @param packageName null-ok the name of the package this process belongs to. * @param zygotePolicyFlags Flags used to determine how to launch the application * @param isTopApp whether the process starts for high priority application. * @param disabledCompatChanges null-ok list of disabled compat changes for the process being * started. * @param pkgDataInfoMap Map from related package names to private data directory * volume UUID and inode number. * @param whitelistedDataInfoMap Map from allowlisted package names to private data directory * volume UUID and inode number. * @param bindMountAppsData whether zygote needs to mount CE and DE data. * @param bindMountAppStorageDirs whether zygote needs to mount Android/obb and Android/data. * @param zygoteArgs Additional arguments to supply to the zygote process. * @return An object that describes the result of the attempt to start the process. * @throws RuntimeException on fatal start failure * * {@hide} */ public static ProcessStartResult start(@NonNull 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> pkgDataInfoMap, @Nullable Map> whitelistedDataInfoMap, boolean bindMountAppsData, boolean bindMountAppStorageDirs, boolean bindMountSystemOverrides, @Nullable String[] zygoteArgs) { return ZYGOTE_PROCESS.start(processClass, niceName, uid, gid, gids, runtimeFlags, mountExternal, targetSdkVersion, seInfo, abi, instructionSet, appDataDir, invokeWith, packageName, zygotePolicyFlags, isTopApp, disabledCompatChanges, pkgDataInfoMap, whitelistedDataInfoMap, bindMountAppsData, bindMountAppStorageDirs, bindMountSystemOverrides, zygoteArgs); } /** @hide */ public static ProcessStartResult startWebView(@NonNull 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) { // Webview zygote can't access app private data files, so doesn't need to know its data // info. return WebViewZygote.getProcess().start(processClass, niceName, uid, gid, gids, runtimeFlags, mountExternal, targetSdkVersion, seInfo, abi, instructionSet, appDataDir, invokeWith, packageName, /*zygotePolicyFlags=*/ ZYGOTE_POLICY_FLAG_EMPTY, /*isTopApp=*/ false, disabledCompatChanges, /* pkgDataInfoMap */ null, /* whitelistedDataInfoMap */ null, /* bindMountAppsData */ false, /* bindMountAppStorageDirs */ false, /* bindMountSyspropOverrides */ false, zygoteArgs); } /** * Returns elapsed milliseconds of the time this process has run. * @return Returns the number of milliseconds this process has return. */ public static final native long getElapsedCpuTime(); /** * Return the {@link SystemClock#elapsedRealtime()} at which this process was started, * but before any of the application code was executed. */ @ElapsedRealtimeLong public static long getStartElapsedRealtime() { return sStartElapsedRealtime; } /** * Return the {@link SystemClock#uptimeMillis()} at which this process was started, * but before any of the application code was executed. */ @UptimeMillisLong public static long getStartUptimeMillis() { return sStartUptimeMillis; } /** * Return the {@link SystemClock#elapsedRealtime()} at which the system was about to * start this process. i.e. before a zygote fork. * *

More precisely, the system may start app processes before there's a start request, * in order to reduce the process start up latency, in which case this is set when the system * decides to "specialize" the process into a requested app. */ @ElapsedRealtimeLong public static long getStartRequestedElapsedRealtime() { return sStartRequestedElapsedRealtime; } /** * Return the {@link SystemClock#uptimeMillis()} at which the system was about to * start this process. i.e. before a zygote fork. * *

More precisely, the system may start app processes before there's a start request, * in order to reduce the process start up latency, in which case this is set when the system * decides to "specialize" the process into a requested app. */ @UptimeMillisLong public static long getStartRequestedUptimeMillis() { return sStartRequestedUptimeMillis; } /** @hide */ public static final void setStartTimes(long elapsedRealtime, long uptimeMillis, long startRequestedElapsedRealtime, long startRequestedUptime) { sStartElapsedRealtime = elapsedRealtime; sStartUptimeMillis = uptimeMillis; sStartRequestedElapsedRealtime = startRequestedElapsedRealtime; sStartRequestedUptimeMillis = startRequestedUptime; } /** * Returns true if the current process is a 64-bit runtime. */ @RavenwoodKeep public static final boolean is64Bit() { return VMRuntime.getRuntime().is64Bit(); } /** * Returns the identifier of this process, which can be used with * {@link #killProcess} and {@link #sendSignal}. */ @RavenwoodKeep public static final int myPid() { return Os.getpid(); } /** * Returns the identifier of this process' parent. * @hide */ @UnsupportedAppUsage(trackingBug = 171962076) public static final int myPpid() { return Os.getppid(); } /** * Returns the identifier of the calling thread, which be used with * {@link #setThreadPriority(int, int)}. */ @RavenwoodKeep public static final int myTid() { return Os.gettid(); } /** * Returns the identifier of this process's uid. This is the kernel uid * that the process is running under, which is the identity of its * app-specific sandbox. It is different from {@link #myUserHandle} in that * a uid identifies a specific app sandbox in a specific user. */ @RavenwoodKeep public static final int myUid() { return Os.getuid(); } /** * Returns this process's user handle. This is the * user the process is running under. It is distinct from * {@link #myUid()} in that a particular user will have multiple * distinct apps running under it each with their own uid. */ @RavenwoodKeep public static UserHandle myUserHandle() { return UserHandle.of(UserHandle.getUserId(myUid())); } /** * Returns whether the given uid belongs to a system core component or not. * @hide */ @RavenwoodKeep public static boolean isCoreUid(int uid) { return UserHandle.isCore(uid); } /** * Returns whether the given uid belongs to an application. * @param uid A kernel uid. * @return Whether the uid corresponds to an application sandbox running in * a specific user. */ @RavenwoodKeep public static boolean isApplicationUid(int uid) { return UserHandle.isApp(uid); } /** * Returns whether the current process is in an isolated sandbox. */ @RavenwoodKeep public static final boolean isIsolated() { return isIsolated(myUid()); } /** * @deprecated Use {@link #isIsolatedUid(int)} instead. * {@hide} */ @Deprecated @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.TIRAMISU, publicAlternatives = "Use {@link #isIsolatedUid(int)} instead.") @RavenwoodKeep public static final boolean isIsolated(int uid) { return isIsolatedUid(uid); } /** * Returns whether the process with the given {@code uid} is an isolated sandbox. */ @RavenwoodKeep public static final boolean isIsolatedUid(int uid) { uid = UserHandle.getAppId(uid); return (uid >= FIRST_ISOLATED_UID && uid <= LAST_ISOLATED_UID) || (uid >= FIRST_APP_ZYGOTE_ISOLATED_UID && uid <= LAST_APP_ZYGOTE_ISOLATED_UID); } /** * Returns whether the provided UID belongs to an sdk sandbox process * @see android.app.sdksandbox.SdkSandboxManager */ @SuppressLint("UnflaggedApi") // promoting from @SystemApi. @RavenwoodKeep public static final boolean isSdkSandboxUid(int uid) { uid = UserHandle.getAppId(uid); return (uid >= FIRST_SDK_SANDBOX_UID && uid <= LAST_SDK_SANDBOX_UID); } /** * Returns the app uid corresponding to an sdk sandbox uid. * @see android.app.sdksandbox.SdkSandboxManager * * @param uid the sdk sandbox uid * @return the app uid for the given sdk sandbox uid * * @throws IllegalArgumentException if input is not an sdk sandbox uid */ @SuppressLint("UnflaggedApi") // promoting from @SystemApi. @RavenwoodKeep public static final int getAppUidForSdkSandboxUid(int uid) { if (!isSdkSandboxUid(uid)) { throw new IllegalArgumentException("Input UID is not an SDK sandbox UID"); } return uid - (FIRST_SDK_SANDBOX_UID - FIRST_APPLICATION_UID); } /** * * Returns the sdk sandbox process corresponding to an app process. * * @hide */ @SystemApi(client = MODULE_LIBRARIES) @TestApi @RavenwoodKeep // TODO(b/318651609): Deprecate once Process#getSdkSandboxUidForAppUid is rolled out to 100% public static final int toSdkSandboxUid(int uid) { return uid + (FIRST_SDK_SANDBOX_UID - FIRST_APPLICATION_UID); } /** * Returns the sdk sandbox uid corresponding to an app uid. * @see android.app.sdksandbox.SdkSandboxManager * * @param uid the app uid * @return the sdk sandbox uid for the given app uid * * @throws IllegalArgumentException if input is not an app uid */ @FlaggedApi(Flags.FLAG_SDK_SANDBOX_UID_TO_APP_UID_API) @RavenwoodKeep public static final int getSdkSandboxUidForAppUid(int uid) { if (!isApplicationUid(uid)) { throw new IllegalArgumentException("Input UID is not an app UID"); } return uid + (FIRST_SDK_SANDBOX_UID - FIRST_APPLICATION_UID); } /** * Returns whether the current process is a sdk sandbox process. */ @RavenwoodKeep public static final boolean isSdkSandbox() { return isSdkSandboxUid(myUid()); } /** * Returns the UID assigned to a particular user name, or -1 if there is * none. If the given string consists of only numbers, it is converted * directly to a uid. */ public static final native int getUidForName(String name); /** * Returns the GID assigned to a particular user name, or -1 if there is * none. If the given string consists of only numbers, it is converted * directly to a gid. */ public static final native int getGidForName(String name); /** * Returns a uid for a currently running process. * @param pid the process id * @return the uid of the process, or -1 if the process is not running. * @hide pending API council review */ @UnsupportedAppUsage public static final int getUidForPid(int pid) { String[] procStatusLabels = { "Uid:" }; long[] procStatusValues = new long[1]; procStatusValues[0] = -1; Process.readProcLines("/proc/" + pid + "/status", procStatusLabels, procStatusValues); return (int) procStatusValues[0]; } /** * Returns the parent process id for a currently running process. * @param pid the process id * @return the parent process id of the process, or -1 if the process is not running. * @hide */ @UnsupportedAppUsage public static final int getParentPid(int pid) { String[] procStatusLabels = { "PPid:" }; long[] procStatusValues = new long[1]; procStatusValues[0] = -1; Process.readProcLines("/proc/" + pid + "/status", procStatusLabels, procStatusValues); return (int) procStatusValues[0]; } /** * Returns the thread group leader id for a currently running thread. * @param tid the thread id * @return the thread group leader id of the thread, or -1 if the thread is not running. * This is same as what getpid(2) would return if called by tid. * @hide */ public static final int getThreadGroupLeader(int tid) { String[] procStatusLabels = { "Tgid:" }; long[] procStatusValues = new long[1]; procStatusValues[0] = -1; Process.readProcLines("/proc/" + tid + "/status", procStatusLabels, procStatusValues); return (int) procStatusValues[0]; } /** * Set the priority of a thread, based on Linux priorities. * * @param tid The identifier of the thread/process to change. * @param priority A Linux priority level, from -20 for highest scheduling * priority to 19 for lowest scheduling priority. * * @throws IllegalArgumentException Throws IllegalArgumentException if * tid does not exist. * @throws SecurityException Throws SecurityException if your process does * not have permission to modify the given thread, or to use the given * priority. */ @RavenwoodRedirect public static final native void setThreadPriority(int tid, @IntRange(from = -20, to = THREAD_PRIORITY_LOWEST) int priority) throws IllegalArgumentException, SecurityException; /** * Call with 'false' to cause future calls to {@link #setThreadPriority(int)} to * throw an exception if passed a background-level thread priority. This is only * effective if the JNI layer is built with GUARD_THREAD_PRIORITY defined to 1. * * @hide */ @RavenwoodRedirect public static final native void setCanSelfBackground(boolean backgroundOk); /** * Sets the scheduling group for a thread. * @hide * @param tid The identifier of the thread to change. * @param group The target group for this thread from THREAD_GROUP_*. * * @throws IllegalArgumentException Throws IllegalArgumentException if * tid does not exist. * @throws SecurityException Throws SecurityException if your process does * not have permission to modify the given thread, or to use the given * priority. * If the thread is a thread group leader, that is it's gettid() == getpid(), * then the other threads in the same thread group are _not_ affected. * * Does not set cpuset for some historical reason, just calls * libcutils::set_sched_policy(). */ public static final native void setThreadGroup(int tid, int group) throws IllegalArgumentException, SecurityException; /** * Sets the scheduling group and the corresponding cpuset group * @hide * @param tid The identifier of the thread to change. * @param group The target group for this thread from THREAD_GROUP_*. * * @throws IllegalArgumentException Throws IllegalArgumentException if * tid does not exist. * @throws SecurityException Throws SecurityException if your process does * not have permission to modify the given thread, or to use the given * priority. */ public static final native void setThreadGroupAndCpuset(int tid, int group) throws IllegalArgumentException, SecurityException; /** * Sets the scheduling group for a process and all child threads * @hide * @param pid The identifier of the process to change. * @param group The target group for this process from THREAD_GROUP_*. * * @throws IllegalArgumentException Throws IllegalArgumentException if * tid does not exist. * @throws SecurityException Throws SecurityException if your process does * not have permission to modify the given thread, or to use the given * priority. * * group == THREAD_GROUP_DEFAULT means to move all non-background priority * threads to the foreground scheduling group, but to leave background * priority threads alone. group == THREAD_GROUP_BACKGROUND moves all * threads, regardless of priority, to the background scheduling group. * group == THREAD_GROUP_FOREGROUND is not allowed. * * Always sets cpusets. */ @UnsupportedAppUsage public static final native void setProcessGroup(int pid, int group) throws IllegalArgumentException, SecurityException; /** * Freeze or unfreeze the specified process. * * @param pid Identifier of the process to freeze or unfreeze. * @param uid Identifier of the user the process is running under. * @param frozen Specify whether to free (true) or unfreeze (false). * * @hide */ public static final native void setProcessFrozen(int pid, int uid, boolean frozen); /** * Return the scheduling group of requested process. * * @hide */ public static final native int getProcessGroup(int pid) throws IllegalArgumentException, SecurityException; /** * * Create a new process group in the cgroup uid/pid hierarchy * * @return <0 in case of error * * @hide */ public static final native int createProcessGroup(int uid, int pid); /** * On some devices, the foreground process may have one or more CPU * cores exclusively reserved for it. This method can be used to * retrieve which cores that are (if any), so the calling process * can then use sched_setaffinity() to lock a thread to these cores. * Note that the calling process must currently be running in the * foreground for this method to return any cores. * * The CPU core(s) exclusively reserved for the foreground process will * stay reserved for as long as the process stays in the foreground. * * As soon as a process leaves the foreground, those CPU cores will * no longer be reserved for it, and will most likely be reserved for * the new foreground process. It's not necessary to change the affinity * of your process when it leaves the foreground (if you had previously * set it to use a reserved core); the OS will automatically take care * of resetting the affinity at that point. * * @return an array of integers, indicating the CPU cores exclusively * reserved for this process. The array will have length zero if no * CPU cores are exclusively reserved for this process at this point * in time. */ public static final native int[] getExclusiveCores(); /** * Set the priority of the calling thread, based on Linux priorities. See * {@link #setThreadPriority(int, int)} for more information. * * @param priority A Linux priority level, from -20 for highest scheduling * priority to 19 for lowest scheduling priority. * * @throws IllegalArgumentException Throws IllegalArgumentException if * tid does not exist. * @throws SecurityException Throws SecurityException if your process does * not have permission to modify the given thread, or to use the given * priority. * * @see #setThreadPriority(int, int) */ @RavenwoodReplace public static final native void setThreadPriority( @IntRange(from = -20, to = THREAD_PRIORITY_LOWEST) int priority) throws IllegalArgumentException, SecurityException; private static void setThreadPriority$ravenwood(int priority) { setThreadPriority(myTid(), priority); } /** * Return the current priority of a thread, based on Linux priorities. * * @param tid The identifier of the thread/process. If tid equals zero, the priority of the * calling process/thread will be returned. * * @return Returns the current priority, as a Linux priority level, * from -20 for highest scheduling priority to 19 for lowest scheduling * priority. * * @throws IllegalArgumentException Throws IllegalArgumentException if * tid does not exist. */ @RavenwoodRedirect @IntRange(from = -20, to = THREAD_PRIORITY_LOWEST) public static final native int getThreadPriority(int tid) throws IllegalArgumentException; /** * Return the current scheduling policy of a thread, based on Linux. * * @param tid The identifier of the thread/process to get the scheduling policy. * * @throws IllegalArgumentException Throws IllegalArgumentException if * tid does not exist, or if priority is out of range for the policy. * @throws SecurityException Throws SecurityException if your process does * not have permission to modify the given thread, or to use the given * scheduling policy or priority. * * {@hide} */ @TestApi public static final native int getThreadScheduler(int tid) throws IllegalArgumentException; /** * Set the scheduling policy and priority of a thread, based on Linux. * * @param tid The identifier of the thread/process to change. * @param policy A Linux scheduling policy such as SCHED_OTHER etc. * @param priority A Linux priority level in a range appropriate for the given policy. * * @throws IllegalArgumentException Throws IllegalArgumentException if * tid does not exist, or if priority is out of range for the policy. * @throws SecurityException Throws SecurityException if your process does * not have permission to modify the given thread, or to use the given * scheduling policy or priority. * * {@hide} */ public static final native void setThreadScheduler(int tid, int policy, int priority) throws IllegalArgumentException; /** * Determine whether the current environment supports multiple processes. * * @return Returns true if the system can run in multiple processes, else * false if everything is running in a single process. * * @deprecated This method always returns true. Do not use. */ @Deprecated public static final boolean supportsProcesses() { return true; } /** * Adjust the swappiness level for a process. * * @param pid The process identifier to set. * @param is_increased Whether swappiness should be increased or default. * * @return Returns true if the underlying system supports this * feature, else false. * * {@hide} */ public static final native boolean setSwappiness(int pid, boolean is_increased); /** * Change this process's argv[0] parameter. This can be useful to show * more descriptive information in things like the 'ps' command. * * @param text The new name of this process. * * {@hide} */ @UnsupportedAppUsage(maxTargetSdk = VERSION_CODES.S, publicAlternatives = "Do not try to " + "change the process name. (If you must, you could use {@code pthread_setname_np(3)}, " + "but this could confuse the system)") public static void setArgV0(@NonNull String text) { sArgV0 = text; setArgV0Native(text); VMDebug.setCurrentProcessName(text); } private static native void setArgV0Native(String text); /** * Return the name of this process. By default, the process name is the same as the app's * package name, but this can be changed using {@code android:process}. */ @NonNull public static String myProcessName() { // Note this could be different from the actual process name if someone changes the // process name using native code (using pthread_setname_np()). But sArgV0 // is the name that the system thinks this process has. return sArgV0; } /** * Kill the process with the given PID. * Note that, though this API allows us to request to * kill any process based on its PID, the kernel will * still impose standard restrictions on which PIDs you * are actually able to kill. Typically this means only * the process running the caller's packages/application * and any additional processes created by that app; packages * sharing a common UID will also be able to kill each * other's processes. */ public static final void killProcess(int pid) { sendSignal(pid, SIGNAL_KILL); } /** * Check the tgid and tid pair to see if the tid still exists and belong to the tgid. * * TOCTOU warning: the status of the tid can change at the time this method returns. This should * be used in very rare cases such as checking if a (tid, tgid) pair that is known to exist * recently no longer exists now. As the possibility of the same tid to be reused under the same * tgid during a short window is rare. And even if it happens the caller logic should be robust * to handle it without error. * * @throws IllegalArgumentException if tgid or tid is not positive. * @throws SecurityException if the caller doesn't have the permission, this method is expected * to be used by system process with {@link #SYSTEM_UID} because it * internally uses tkill(2). * @throws NoSuchElementException if the Linux process with pid as the tid has exited or it * doesn't belong to the tgid. * @hide */ public static final void checkTid(int tgid, int tid) throws IllegalArgumentException, SecurityException, NoSuchElementException { sendTgSignalThrows(tgid, tid, SIGNAL_DEFAULT); } /** * Check if the pid still exists. * * TOCTOU warning: the status of the pid can change at the time this method returns. This should * be used in very rare cases such as checking if a pid that belongs to an isolated process of a * uid known to exist recently no longer exists now. As the possibility of the same pid to be * reused again under the same uid during a short window is rare. And even if it happens the * caller logic should be robust to handle it without error. * * @throws IllegalArgumentException if pid is not positive. * @throws SecurityException if the caller doesn't have the permission, this method is expected * to be used by system process with {@link #SYSTEM_UID} because it * internally uses kill(2). * @throws NoSuchElementException if the Linux process with the pid has exited. * @hide */ public static final void checkPid(int pid) throws IllegalArgumentException, SecurityException, NoSuchElementException { sendSignalThrows(pid, SIGNAL_DEFAULT); } /** @hide */ public static final native int setUid(int uid); /** @hide */ public static final native int setGid(int uid); /** * Send a signal to the given process. * * @param pid The pid of the target process. * @param signal The signal to send. */ public static final native void sendSignal(int pid, int signal); private static native void sendSignalThrows(int pid, int signal) throws IllegalArgumentException, SecurityException, NoSuchElementException; private static native void sendTgSignalThrows(int pid, int tgid, int signal) throws IllegalArgumentException, SecurityException, NoSuchElementException; /** * @hide * Private impl for avoiding a log message... DO NOT USE without doing * your own log, or the Android Illuminati will find you some night and * beat you up. */ public static final void killProcessQuiet(int pid) { sendSignalQuiet(pid, SIGNAL_KILL); } /** * @hide * Private impl for avoiding a log message... DO NOT USE without doing * your own log, or the Android Illuminati will find you some night and * beat you up. */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P) public static final native void sendSignalQuiet(int pid, int signal); /** * @return The advertised memory of the system, as the end user would encounter in a retail * display environment. If the advertised memory is not defined, it returns * {@code getTotalMemory()} rounded. * * @hide */ public static final long getAdvertisedMem() { String formatSize = MemoryProperties.memory_ddr_size().orElse("0KB"); long memSize = FileUtils.parseSize(formatSize); if (memSize <= 0) { return FileUtils.roundStorageSize(getTotalMemory()); } return memSize; } /** @hide */ @UnsupportedAppUsage public static final native long getFreeMemory(); /** @hide */ @UnsupportedAppUsage public static final native long getTotalMemory(); /** @hide */ @UnsupportedAppUsage public static final native void readProcLines(String path, String[] reqFields, long[] outSizes); /** @hide */ @UnsupportedAppUsage public static final native int[] getPids(String path, int[] lastArray); /** @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int PROC_TERM_MASK = 0xff; /** @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int PROC_ZERO_TERM = 0; /** @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int PROC_SPACE_TERM = (int)' '; /** @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int PROC_TAB_TERM = (int)'\t'; /** @hide */ public static final int PROC_NEWLINE_TERM = (int) '\n'; /** @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int PROC_COMBINE = 0x100; /** @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int PROC_PARENS = 0x200; /** @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int PROC_QUOTES = 0x400; /** @hide */ public static final int PROC_CHAR = 0x800; /** @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int PROC_OUT_STRING = 0x1000; /** @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int PROC_OUT_LONG = 0x2000; /** @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) public static final int PROC_OUT_FLOAT = 0x4000; /** * Read and parse a {@code proc} file in the given format. * *

The format is a list of integers, where every integer describes a variable in the file. It * specifies how the variable is syntactically terminated (e.g. {@link Process#PROC_SPACE_TERM}, * {@link Process#PROC_TAB_TERM}, {@link Process#PROC_ZERO_TERM}, {@link * Process#PROC_NEWLINE_TERM}). * *

If the variable should be parsed and returned to the caller, the termination type should * be binary OR'd with the type of output (e.g. {@link Process#PROC_OUT_STRING}, {@link * Process#PROC_OUT_LONG}, {@link Process#PROC_OUT_FLOAT}. * *

If the variable is wrapped in quotation marks it should be binary OR'd with {@link * Process#PROC_QUOTES}. If the variable is wrapped in parentheses it should be binary OR'd with * {@link Process#PROC_PARENS}. * *

If the variable is not formatted as a string and should be cast directly from characters * to a long, the {@link Process#PROC_CHAR} integer should be binary OR'd. * *

If the terminating character can be repeated, the {@link Process#PROC_COMBINE} integer * should be binary OR'd. * * @param file the path of the {@code proc} file to read * @param format the format of the file * @param outStrings the parsed {@code String}s from the file * @param outLongs the parsed {@code long}s from the file * @param outFloats the parsed {@code float}s from the file * @hide */ @UnsupportedAppUsage public static final native boolean readProcFile(String file, int[] format, String[] outStrings, long[] outLongs, float[] outFloats); /** @hide */ @UnsupportedAppUsage public static final native boolean parseProcLine(byte[] buffer, int startIndex, int endIndex, int[] format, String[] outStrings, long[] outLongs, float[] outFloats); /** @hide */ @UnsupportedAppUsage public static final native int[] getPidsForCommands(String[] cmds); /** * Gets the total Pss value for a given process, in bytes. * * @param pid the process to the Pss for * @return the total Pss value for the given process in bytes, * or -1 if the value cannot be determined * @hide */ @UnsupportedAppUsage public static final native long getPss(int pid); /** * Gets the total Rss value for a given process, in bytes. * * @param pid the process to the Rss for * @return an ordered array containing multiple values, they are: * [total_rss, file, anon, swap, shmem]. * or NULL if the value cannot be determined * @hide */ public static final native long[] getRss(int pid); /** * Specifies the outcome of having started a process. * @hide */ public static final class ProcessStartResult { /** * The PID of the newly started process. * Always >= 0. (If the start failed, an exception will have been thrown instead.) */ public int pid; /** * True if the process was started with a wrapper attached. */ public boolean usingWrapper; } /** * Kill all processes in a process group started for the given * pid. * @hide */ public static final native int killProcessGroup(int uid, int pid); /** * Send a signal to all processes in a group under the given PID, but do not wait for the * processes to be fully cleaned up, or for the cgroup to be removed before returning. * Callers should also ensure that killProcessGroup is called later to ensure the cgroup is * fully removed, otherwise system resources may leak. * @hide */ public static final native boolean sendSignalToProcessGroup(int uid, int pid, int signal); /** * Freeze the cgroup for the given UID. * This cgroup may contain child cgroups which will also be frozen. If this cgroup or its * children contain processes with Binder interfaces, those interfaces should be frozen before * the cgroup to avoid blocking synchronous callers indefinitely. * * @param uid The UID to be frozen * @param freeze true = freeze; false = unfreeze * @hide */ public static final native void freezeCgroupUid(int uid, boolean freeze); /** * Remove all process groups. Expected to be called when ActivityManager * is restarted. * @hide */ public static final native void removeAllProcessGroups(); /** * Check to see if a thread belongs to a given process. This may require * more permissions than apps generally have. * @return true if this thread belongs to a process * @hide */ public static final boolean isThreadInProcess(int tid, int pid) { StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads(); try { if (Os.access("/proc/" + tid + "/task/" + pid, OsConstants.F_OK)) { return true; } else { return false; } } catch (Exception e) { return false; } finally { StrictMode.setThreadPolicy(oldPolicy); } } /** * Wait for the death of the given process. * * @param pid The process ID to be waited on * @param timeout The maximum time to wait in milliseconds, or -1 to wait forever * @hide */ public static void waitForProcessDeath(int pid, int timeout) throws InterruptedException, TimeoutException { boolean fallback = supportsPidFd(); if (!fallback) { FileDescriptor pidfd = null; try { final int fd = nativePidFdOpen(pid, 0); if (fd >= 0) { pidfd = new FileDescriptor(); pidfd.setInt$(fd); } else { fallback = true; } if (pidfd != null) { StructPollfd[] fds = new StructPollfd[] { new StructPollfd() }; fds[0].fd = pidfd; fds[0].events = (short) OsConstants.POLLIN; fds[0].revents = 0; fds[0].userData = null; int res = Os.poll(fds, timeout); if (res > 0) { return; } else if (res == 0) { throw new TimeoutException(); } else { // We should get an ErrnoException now } } } catch (ErrnoException e) { if (e.errno == OsConstants.EINTR) { throw new InterruptedException(); } fallback = true; } finally { if (pidfd != null) { IoUtils.closeQuietly(pidfd); } } } if (fallback) { boolean infinity = timeout < 0; long now = System.currentTimeMillis(); final long end = now + timeout; while (infinity || now < end) { try { Os.kill(pid, 0); } catch (ErrnoException e) { if (e.errno == OsConstants.ESRCH) { return; } } Thread.sleep(1); now = System.currentTimeMillis(); } } throw new TimeoutException(); } /** * Determine whether the system supports pidfd APIs * * @return Returns true if the system supports pidfd APIs * @hide */ public static boolean supportsPidFd() { if (sPidFdSupported == PIDFD_UNKNOWN) { int fd = -1; try { fd = nativePidFdOpen(myPid(), 0); sPidFdSupported = PIDFD_SUPPORTED; } catch (ErrnoException e) { sPidFdSupported = e.errno != OsConstants.ENOSYS ? PIDFD_SUPPORTED : PIDFD_UNSUPPORTED; } finally { if (fd >= 0) { final FileDescriptor f = new FileDescriptor(); f.setInt$(fd); IoUtils.closeQuietly(f); } } } return sPidFdSupported == PIDFD_SUPPORTED; } /** * Open process file descriptor for given pid. * * @param pid The process ID to open for * @param flags Reserved, unused now, must be 0 * @return The process file descriptor for given pid * @throws IOException if it can't be opened * * @hide */ public static @Nullable FileDescriptor openPidFd(int pid, int flags) throws IOException { if (!supportsPidFd()) { return null; } if (flags != 0) { throw new IllegalArgumentException(); } try { FileDescriptor pidfd = new FileDescriptor(); pidfd.setInt$(nativePidFdOpen(pid, flags)); return pidfd; } catch (ErrnoException e) { IOException ex = new IOException(); ex.initCause(e); throw ex; } } private static native int nativePidFdOpen(int pid, int flags) throws ErrnoException; }