Android APIs
public class

Process

extends Object
java.lang.Object
   ↳ android.os.Process

Class Overview

Tools for managing OS processes.

Summary

Constants
int FIRST_APPLICATION_UID Defines the start of a range of UIDs (and GIDs), going from this number to LAST_APPLICATION_UID that are reserved for assigning to applications.
int LAST_APPLICATION_UID Last of application-specific UIDs starting at FIRST_APPLICATION_UID.
int PHONE_UID Defines the UID/GID under which the telephony code runs.
int SIGNAL_KILL
int SIGNAL_QUIT
int SIGNAL_USR1
int SYSTEM_UID Defines the UID/GID under which system code runs.
int THREAD_PRIORITY_AUDIO Standard priority of audio threads.
int THREAD_PRIORITY_BACKGROUND Standard priority background threads.
int THREAD_PRIORITY_DEFAULT Standard priority of application threads.
int THREAD_PRIORITY_DISPLAY Standard priority of system display threads, involved in updating the user interface.
int THREAD_PRIORITY_FOREGROUND Standard priority of threads that are currently running a user interface that the user is interacting with.
int THREAD_PRIORITY_LESS_FAVORABLE Minimum increment to make a priority less favorable.
int THREAD_PRIORITY_LOWEST Lowest available thread priority.
int THREAD_PRIORITY_MORE_FAVORABLE Minimum increment to make a priority more favorable.
int THREAD_PRIORITY_URGENT_AUDIO Standard priority of the most important audio threads.
int THREAD_PRIORITY_URGENT_DISPLAY Standard priority of the most important display threads, for compositing the screen and retrieving input events.
Public Constructors
Process()
Public Methods
final static long getElapsedCpuTime()
Returns elapsed milliseconds of the time this process has run.
final static int getGidForName(String name)
Returns the GID assigned to a particular user name, or -1 if there is none.
final static int getThreadPriority(int tid)
Return the current priority of a thread, based on Linux priorities.
final static int getUidForName(String name)
Returns the UID assigned to a particular user name, or -1 if there is none.
final static boolean is64Bit()
Returns true if the current process is a 64-bit runtime.
final static void killProcess(int pid)
Kill the process with the given PID.
final static int myPid()
Returns the identifier of this process, which can be used with killProcess(int) and sendSignal(int, int).
final static int myTid()
Returns the identifier of the calling thread, which be used with setThreadPriority(int, int).
final static int myUid()
Returns the identifier of this process's uid.
final static UserHandle myUserHandle()
Returns this process's user handle.
final static void sendSignal(int pid, int signal)
Send a signal to the given process.
final static void setThreadPriority(int tid, int priority)
Set the priority of a thread, based on Linux priorities.
final static void setThreadPriority(int priority)
Set the priority of the calling thread, based on Linux priorities.
final static boolean supportsProcesses()
This method was deprecated in API level 14. This method always returns true. Do not use.
[Expand]
Inherited Methods
From class java.lang.Object

Constants

public static final int FIRST_APPLICATION_UID

Added in API level 1

Defines the start of a range of UIDs (and GIDs), going from this number to LAST_APPLICATION_UID that are reserved for assigning to applications.

Constant Value: 10000 (0x00002710)

public static final int LAST_APPLICATION_UID

Added in API level 1

Last of application-specific UIDs starting at FIRST_APPLICATION_UID.

Constant Value: 19999 (0x00004e1f)

public static final int PHONE_UID

Added in API level 1

Defines the UID/GID under which the telephony code runs.

Constant Value: 1001 (0x000003e9)

public static final int SIGNAL_KILL

Added in API level 1

Constant Value: 9 (0x00000009)

public static final int SIGNAL_QUIT

Added in API level 1

Constant Value: 3 (0x00000003)

public static final int SIGNAL_USR1

Added in API level 1

Constant Value: 10 (0x0000000a)

public static final int SYSTEM_UID

Added in API level 1

Defines the UID/GID under which system code runs.

Constant Value: 1000 (0x000003e8)

public static final int THREAD_PRIORITY_AUDIO

Added in API level 1

Standard priority of audio threads. Applications can not normally change to this priority. Use with setThreadPriority(int) and setThreadPriority(int, int), not with the normal Thread class.

Constant Value: -16 (0xfffffff0)

public static final int THREAD_PRIORITY_BACKGROUND

Added in API level 1

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 setThreadPriority(int) and setThreadPriority(int, int), not with the normal Thread class.

Constant Value: 10 (0x0000000a)

public static final int THREAD_PRIORITY_DEFAULT

Added in API level 1

Standard priority of application threads. Use with setThreadPriority(int) and setThreadPriority(int, int), not with the normal Thread class.

Constant Value: 0 (0x00000000)

public static final int THREAD_PRIORITY_DISPLAY

Added in API level 1

Standard priority of system display threads, involved in updating the user interface. Applications can not normally change to this priority. Use with setThreadPriority(int) and setThreadPriority(int, int), not with the normal Thread class.

Constant Value: -4 (0xfffffffc)

public static final int THREAD_PRIORITY_FOREGROUND

Added in API level 1

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 setThreadPriority(int) and setThreadPriority(int, int), not with the normal Thread class.

Constant Value: -2 (0xfffffffe)

public static final int THREAD_PRIORITY_LESS_FAVORABLE

Added in API level 1

Minimum increment to make a priority less favorable.

Constant Value: 1 (0x00000001)

public static final int THREAD_PRIORITY_LOWEST

Added in API level 1

Lowest available thread priority. Only for those who really, really don't want to run if anything else is happening. Use with setThreadPriority(int) and setThreadPriority(int, int), not with the normal Thread class.

Constant Value: 19 (0x00000013)

public static final int THREAD_PRIORITY_MORE_FAVORABLE

Added in API level 1

Minimum increment to make a priority more favorable.

Constant Value: -1 (0xffffffff)

public static final int THREAD_PRIORITY_URGENT_AUDIO

Added in API level 1

Standard priority of the most important audio threads. Applications can not normally change to this priority. Use with setThreadPriority(int) and setThreadPriority(int, int), not with the normal Thread class.

Constant Value: -19 (0xffffffed)

public static final int THREAD_PRIORITY_URGENT_DISPLAY

Added in API level 1

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 setThreadPriority(int) and setThreadPriority(int, int), not with the normal Thread class.

Constant Value: -8 (0xfffffff8)

Public Constructors

public Process ()

Added in API level 1

Public Methods

public static final long getElapsedCpuTime ()

Added in API level 1

Returns elapsed milliseconds of the time this process has run.

Returns
long Returns the number of milliseconds this process has return.

public static final int getGidForName (String name)

Added in API level 1

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.

Parameters
name String
Returns
int

public static final int getThreadPriority (int tid)

Added in API level 1

Return the current priority of a thread, based on Linux priorities.

Parameters
tid int: The identifier of the thread/process to change.
Returns
int 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.

public static final int getUidForName (String name)

Added in API level 1

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.

Parameters
name String
Returns
int

public static final boolean is64Bit ()

Added in API level 23

Returns true if the current process is a 64-bit runtime.

Returns
boolean

public static final void killProcess (int pid)

Added in API level 1

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.

Parameters
pid int

public static final int myPid ()

Added in API level 1

Returns the identifier of this process, which can be used with killProcess(int) and sendSignal(int, int).

Returns
int

public static final int myTid ()

Added in API level 1

Returns the identifier of the calling thread, which be used with setThreadPriority(int, int).

Returns
int

public static final int myUid ()

Added in API level 2

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 myUserHandle() in that a uid identifies a specific app sandbox in a specific user.

Returns
int

public static final UserHandle myUserHandle ()

Added in API level 17

Returns this process's user handle. This is the user the process is running under. It is distinct from myUid() in that a particular user will have multiple distinct apps running under it each with their own uid.

Returns
UserHandle

public static final void sendSignal (int pid, int signal)

Added in API level 1

Send a signal to the given process.

Parameters
pid int: The pid of the target process.
signal int: The signal to send.

public static final void setThreadPriority (int tid, int priority)

Added in API level 1

Set the priority of a thread, based on Linux priorities.

Parameters
tid int: The identifier of the thread/process to change.
priority int: 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.
SecurityException Throws SecurityException if your process does not have permission to modify the given thread, or to use the given priority.

public static final void setThreadPriority (int priority)

Added in API level 1

Set the priority of the calling thread, based on Linux priorities. See setThreadPriority(int, int) for more information.

Parameters
priority int: 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.
SecurityException Throws SecurityException if your process does not have permission to modify the given thread, or to use the given priority.

public static final boolean supportsProcesses ()

Added in API level 1

This method was deprecated in API level 14.
This method always returns true. Do not use.

Determine whether the current environment supports multiple processes.

Returns
boolean Returns true if the system can run in multiple processes, else false if everything is running in a single process.