Skip to content

Most visited

Recently visited

navigation
Added in API level 1

Process

public class Process
extends Object

java.lang.Object
   ↳ android.os.Process


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

static final long getElapsedCpuTime()

Returns elapsed milliseconds of the time this process has run.

static final int[] getExclusiveCores()

On some devices, the foreground process may have one or more CPU cores exclusively reserved for it.

static final int getGidForName(String name)

Returns the GID assigned to a particular user name, or -1 if there is none.

static final long getStartElapsedRealtime()

Return the elapsedRealtime() at which this process was started.

static final long getStartUptimeMillis()

Return the uptimeMillis() at which this process was started.

static final int getThreadPriority(int tid)

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

static final int getUidForName(String name)

Returns the UID assigned to a particular user name, or -1 if there is none.

static final boolean is64Bit()

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

static boolean isApplicationUid(int uid)

Returns whether the given uid belongs to an application.

static final void killProcess(int pid)

Kill the process with the given PID.

static final int myPid()

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

static final int myTid()

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

static final int myUid()

Returns the identifier of this process's uid.

static UserHandle myUserHandle()

Returns this process's user handle.

static final void sendSignal(int pid, int signal)

Send a signal to the given process.

static final void setThreadPriority(int tid, int priority)

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

static final void setThreadPriority(int priority)

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

static final boolean supportsProcesses()

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

Inherited methods

From class java.lang.Object

Constants

FIRST_APPLICATION_UID

Added in API level 1
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.

Constant Value: 10000 (0x00002710)

LAST_APPLICATION_UID

Added in API level 1
int LAST_APPLICATION_UID

Last of application-specific UIDs starting at FIRST_APPLICATION_UID.

Constant Value: 19999 (0x00004e1f)

PHONE_UID

Added in API level 1
int PHONE_UID

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

Constant Value: 1001 (0x000003e9)

SIGNAL_KILL

Added in API level 1
int SIGNAL_KILL

Constant Value: 9 (0x00000009)

SIGNAL_QUIT

Added in API level 1
int SIGNAL_QUIT

Constant Value: 3 (0x00000003)

SIGNAL_USR1

Added in API level 1
int SIGNAL_USR1

Constant Value: 10 (0x0000000a)

SYSTEM_UID

Added in API level 1
int SYSTEM_UID

Defines the UID/GID under which system code runs.

Constant Value: 1000 (0x000003e8)

THREAD_PRIORITY_AUDIO

Added in API level 1
int THREAD_PRIORITY_AUDIO

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)

THREAD_PRIORITY_BACKGROUND

Added in API level 1
int THREAD_PRIORITY_BACKGROUND

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)

THREAD_PRIORITY_DEFAULT

Added in API level 1
int THREAD_PRIORITY_DEFAULT

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

Constant Value: 0 (0x00000000)

THREAD_PRIORITY_DISPLAY

Added in API level 1
int THREAD_PRIORITY_DISPLAY

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)

THREAD_PRIORITY_FOREGROUND

Added in API level 1
int THREAD_PRIORITY_FOREGROUND

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)

THREAD_PRIORITY_LESS_FAVORABLE

Added in API level 1
int THREAD_PRIORITY_LESS_FAVORABLE

Minimum increment to make a priority less favorable.

Constant Value: 1 (0x00000001)

THREAD_PRIORITY_LOWEST

Added in API level 1
int THREAD_PRIORITY_LOWEST

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)

THREAD_PRIORITY_MORE_FAVORABLE

Added in API level 1
int THREAD_PRIORITY_MORE_FAVORABLE

Minimum increment to make a priority more favorable.

Constant Value: -1 (0xffffffff)

THREAD_PRIORITY_URGENT_AUDIO

Added in API level 1
int THREAD_PRIORITY_URGENT_AUDIO

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)

THREAD_PRIORITY_URGENT_DISPLAY

Added in API level 1
int THREAD_PRIORITY_URGENT_DISPLAY

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

Process

Added in API level 1
Process ()

Public methods

getElapsedCpuTime

Added in API level 1
long getElapsedCpuTime ()

Returns elapsed milliseconds of the time this process has run.

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

getExclusiveCores

Added in API level 24
int[] getExclusiveCores ()

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.

Returns
int[] 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.

getGidForName

Added in API level 1
int getGidForName (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.

Parameters
name String
Returns
int

getStartElapsedRealtime

Added in API level 24
long getStartElapsedRealtime ()

Return the elapsedRealtime() at which this process was started.

Returns
long

getStartUptimeMillis

Added in API level 24
long getStartUptimeMillis ()

Return the uptimeMillis() at which this process was started.

Returns
long

getThreadPriority

Added in API level 1
int getThreadPriority (int tid)

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.

getUidForName

Added in API level 1
int getUidForName (String name)

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

is64Bit

Added in API level 23
boolean is64Bit ()

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

Returns
boolean

isApplicationUid

Added in API level 24
boolean isApplicationUid (int uid)

Returns whether the given uid belongs to an application.

Parameters
uid int: A kernel uid.
Returns
boolean Whether the uid corresponds to an application sandbox running in a specific user.

killProcess

Added in API level 1
void killProcess (int pid)

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

myPid

Added in API level 1
int myPid ()

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

Returns
int

myTid

Added in API level 1
int myTid ()

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

Returns
int

myUid

Added in API level 2
int myUid ()

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

myUserHandle

Added in API level 17
UserHandle myUserHandle ()

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

sendSignal

Added in API level 1
void sendSignal (int pid, 
                int signal)

Send a signal to the given process.

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

setThreadPriority

Added in API level 1
void setThreadPriority (int tid, 
                int priority)

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.

setThreadPriority

Added in API level 1
void setThreadPriority (int priority)

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.

See also:

supportsProcesses

Added in API level 1
boolean supportsProcesses ()

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.
This site uses cookies to store your preferences for site-specific language and display options.

Hooray!

This class requires API level or higher

This doc is hidden because your selected API level for the documentation is . You can change the documentation API level with the selector above the left navigation.

For more information about specifying the API level your app requires, read Supporting Different Platform Versions.