java.lang.Object
- org.wikidata.wdtk.util.Timer

```
public class Timer
extends Object
```
Class for keeping CPU and system times. Timers measure wall clock and/or CPU times (for specific threads). They can be started and stopped. Times between these two methods will be recorded and (when starting and stopping more than once) added up to total times. The number of start-stop measurements is recorded, and one can also query the average times. Finally, a timer can be reset. There are two main ways of accessing timers: by creating a Timer object directly or by using a global registry of timers. Registered timers are identified by their string name and thread id. The global registry is useful since it makes it much easier to re-integrate measurements taken in many threads. They also free the caller of the burden of keeping a reference to the Timer. The code in this file was adapted from the ElkTimer class of the ELK reasoner, with contributions from Yevgeny Kasakov and Pavel Klinov.

Author:

Markus Kroetzsch

Field Summary

Fields
Modifier and Type	Field	Description
`static int`	`RECORD_ALL`	Flag for indicating that all supported times should be taken.
`static int`	`RECORD_CPUTIME`	Flag for indicating that CPU time should be taken.
`static int`	`RECORD_NONE`	Flag for indicating that no times should be taken (just count runs).
`static int`	`RECORD_WALLTIME`	Flag for indicating that wall clock time should be taken.

Constructor Summary

Constructors
Constructor Description

Timer(String name, int todoFlags)
Constructor.

Timer(String name, int todoFlags, long threadId)
Constructor.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`equals(Object obj)`
`long`	`getAvgCpuTime()`	Return the average CPU time across all measurements.
`long`	`getAvgWallTime()`	Return the average wall clock time across all measurements.
`String`	`getName()`	Get the string name of the timer.
`static Timer`	`getNamedTimer(String timerName)`	Get a timer of the given string name that takes all possible times (todos) for the current thread.
`static Timer`	`getNamedTimer(String timerName, int todoFlags)`	Get a timer of the given string name and todos for the current thread.
`static Timer`	`getNamedTimer(String timerName, int todoFlags, long threadId)`	Get a timer of the given string name for the given thread.
`static Timer`	`getNamedTotalTimer(String timerName)`	Collect the total times measured by all known named timers of the given name.
`long`	`getThreadId()`	Get the ID of the thread for which this timer was created.
`long`	`getTotalCpuTime()`	Get the total recorded CPU time in nanoseconds.
`long`	`getTotalWallTime()`	Get the total recorded wall clock time in nanoseconds.
`int`	`hashCode()`
`boolean`	`isRunning()`	Return true if the timer is running.
`void`	`reset()`	Stop the timer (if running) and reset all recorded values.
`static void`	`resetNamedTimer(String timerName)`	Reset a timer of the given string name for all todos and the current thread.
`static void`	`resetNamedTimer(String timerName, int todoFlags)`	Reset a timer of the given string name for the current thread.
`static void`	`resetNamedTimer(String timerName, int todoFlags, long threadId)`	Reset a timer of the given string name for the given thread.
`void`	`start()`	Start the timer.
`static void`	`startNamedTimer(String timerName)`	Start a timer of the given string name for all todos and the current thread.
`static void`	`startNamedTimer(String timerName, int todoFlags)`	Start a timer of the given string name for the current thread.
`static void`	`startNamedTimer(String timerName, int todoFlags, long threadId)`	Start a timer of the given string name for the current thread.
`long`	`stop()`	Stop the timer and record the times that have passed since its start.
`static long`	`stopNamedTimer(String timerName)`	Stop a timer of the given string name for all todos and the current thread.
`static long`	`stopNamedTimer(String timerName, int todoFlags)`	Stop a timer of the given string name for the current thread.
`static long`	`stopNamedTimer(String timerName, int todoFlags, long threadId)`	Stop a timer of the given string name for the given thread.
`String`	`toString()`	The implementation of toString() generates a summary of the times recorded so far.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - RECORD_NONE
```
public static final int RECORD_NONE
```
    Flag for indicating that no times should be taken (just count runs).
    
    See Also:
    
    Constant Field Values
  - RECORD_CPUTIME
```
public static final int RECORD_CPUTIME
```
    Flag for indicating that CPU time should be taken.
    
    See Also:
    
    Constant Field Values
  - RECORD_WALLTIME
```
public static final int RECORD_WALLTIME
```
    Flag for indicating that wall clock time should be taken.
    
    See Also:
    
    Constant Field Values
  - RECORD_ALL
```
public static final int RECORD_ALL
```
    Flag for indicating that all supported times should be taken.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - Timer
```
public Timer(String name,
             int todoFlags,
             long threadId)
```
    Constructor. Every timer is identified by three things: a string name, an integer for flagging its tasks (todos), and a thread id (long). Tasks can be flagged by a disjunction of constants like RECORD_CPUTIME and RECORD_WALLTIME. Only times for which an according flag is set will be recorded. The thread id can be the actual id of the thread that is measured, or 0 (invalid id) to not assign the timer to any thread. In this case, no CPU time measurement is possible since Java does not allow us to measure the total CPU time across all threads.
    
    Parameters:
    
    name - a string that identifies the timer
    
    todoFlags - flags to define what the timer will measure
    
    threadId - the id of the thread for measuring CPU time or 0 if not measuring
  - Timer
```
public Timer(String name,
             int todoFlags)
```
    Constructor. Same as Timer(String, int, long), but using the current thread instead of a freely specified thread.
    
    Parameters:
    
    name - a string that identifies the timer
    
    todoFlags - flags to define what the timer will measure
- Method Detail
  - getName
```
public String getName()
```
    Get the string name of the timer.
    
    Returns:
    
    string name
  - getThreadId
```
public long getThreadId()
```
    Get the ID of the thread for which this timer was created.
    
    Returns:
    
    thread ID
  - isRunning
```
public boolean isRunning()
```
    Return true if the timer is running.
    
    Returns:
    
    true if running
  - getTotalCpuTime
```
public long getTotalCpuTime()
```
    Get the total recorded CPU time in nanoseconds.
    
    Returns:
    
    recorded CPU time in nanoseconds
  - getAvgCpuTime
```
public long getAvgCpuTime()
```
    Return the average CPU time across all measurements.
    
    Returns:
    
    the average CPU time across all measurements
  - getTotalWallTime
```
public long getTotalWallTime()
```
    Get the total recorded wall clock time in nanoseconds.
    
    Returns:
    
    recorded wall time in nanoseconds
  - getAvgWallTime
```
public long getAvgWallTime()
```
    Return the average wall clock time across all measurements.
    
    Returns:
    
    the average wall clock time across all measurements
  - start
```
public void start()
```
    Start the timer.
  - reset
```
public void reset()
```
    Stop the timer (if running) and reset all recorded values.
  - stop
```
public long stop()
```
    Stop the timer and record the times that have passed since its start. The times that have passed are added to the internal state and can be retrieved with getTotalCpuTime() etc. If CPU times are recorded, then the method returns the CPU time that has passed since the timer was last started; otherwise -1 is returned.
    
    Returns:
    
    CPU time that the timer was running, or -1 if timer not running or CPU time unavailable for other reasons
  - toString
```
public String toString()
```
    The implementation of toString() generates a summary of the times recorded so far. If the timer is still running, then it will not be stopped to add the currently measured time to the output but a warning will added.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    string description of the timer results and state
  - startNamedTimer
```
public static void startNamedTimer(String timerName)
```
    Start a timer of the given string name for all todos and the current thread. If no such timer exists yet, then it will be newly created.
    
    Parameters:
    
    timerName - the name of the timer
  - startNamedTimer
```
public static void startNamedTimer(String timerName,
                                   int todoFlags)
```
    Start a timer of the given string name for the current thread. If no such timer exists yet, then it will be newly created.
    
    Parameters:
    
    timerName - the name of the timer
    
    todoFlags -
  - startNamedTimer
```
public static void startNamedTimer(String timerName,
                                   int todoFlags,
                                   long threadId)
```
    Start a timer of the given string name for the current thread. If no such timer exists yet, then it will be newly created.
    
    Parameters:
    
    timerName - the name of the timer
    
    todoFlags -
    
    threadId - of the thread to track, or 0 if only system clock should be tracked
  - stopNamedTimer
```
public static long stopNamedTimer(String timerName)
```
    Stop a timer of the given string name for all todos and the current thread. If no such timer exists, -1 will be returned. Otherwise the return value is the CPU time that was measured.
    
    Parameters:
    
    timerName - the name of the timer
    
    Returns:
    
    CPU time if timer existed and was running, and -1 otherwise
  - stopNamedTimer
```
public static long stopNamedTimer(String timerName,
                                  int todoFlags)
```
    Stop a timer of the given string name for the current thread. If no such timer exists, -1 will be returned. Otherwise the return value is the CPU time that was measured.
    
    Parameters:
    
    timerName - the name of the timer
    
    todoFlags -
    
    Returns:
    
    CPU time if timer existed and was running, and -1 otherwise
  - stopNamedTimer
```
public static long stopNamedTimer(String timerName,
                                  int todoFlags,
                                  long threadId)
```
    Stop a timer of the given string name for the given thread. If no such timer exists, -1 will be returned. Otherwise the return value is the CPU time that was measured.
    
    Parameters:
    
    timerName - the name of the timer
    
    todoFlags -
    
    threadId - of the thread to track, or 0 if only system clock should be tracked
    
    Returns:
    
    CPU time if timer existed and was running, and -1 otherwise
  - resetNamedTimer
```
public static void resetNamedTimer(String timerName)
```
    Reset a timer of the given string name for all todos and the current thread. If no such timer exists yet, then it will be newly created.
    
    Parameters:
    
    timerName - the name of the timer
  - resetNamedTimer
```
public static void resetNamedTimer(String timerName,
                                   int todoFlags)
```
    Reset a timer of the given string name for the current thread. If no such timer exists yet, then it will be newly created.
    
    Parameters:
    
    timerName - the name of the timer
    
    todoFlags -
  - resetNamedTimer
```
public static void resetNamedTimer(String timerName,
                                   int todoFlags,
                                   long threadId)
```
    Reset a timer of the given string name for the given thread. If no such timer exists yet, then it will be newly created.
    
    Parameters:
    
    timerName - the name of the timer
    
    todoFlags -
    
    threadId - of the thread to track, or 0 if only system clock should be tracked
  - getNamedTimer
```
public static Timer getNamedTimer(String timerName)
```
    Get a timer of the given string name that takes all possible times (todos) for the current thread. If no such timer exists yet, then it will be newly created.
    
    Parameters:
    
    timerName - the name of the timer
    
    Returns:
    
    timer
  - getNamedTimer
```
public static Timer getNamedTimer(String timerName,
                                  int todoFlags)
```
    Get a timer of the given string name and todos for the current thread. If no such timer exists yet, then it will be newly created.
    
    Parameters:
    
    timerName - the name of the timer
    
    todoFlags -
    
    Returns:
    
    timer
  - getNamedTimer
```
public static Timer getNamedTimer(String timerName,
                                  int todoFlags,
                                  long threadId)
```
    Get a timer of the given string name for the given thread. If no such timer exists yet, then it will be newly created.
    
    Parameters:
    
    timerName - the name of the timer
    
    todoFlags -
    
    threadId - of the thread to track, or 0 if only system clock should be tracked
    
    Returns:
    
    timer
  - getNamedTotalTimer
```
public static Timer getNamedTotalTimer(String timerName)
```
    Collect the total times measured by all known named timers of the given name. This is useful to add up times that were collected across separate threads.
    
    Parameters:
    
    timerName -
    
    Returns:
    
    timer
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object obj)
```
    Overrides:
    
    equals in class Object

Constructor	Description
`Timer(String name, int todoFlags)`	Constructor.
`Timer(String name, int todoFlags, long threadId)`	Constructor.

Class Timer

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

RECORD_NONE

RECORD_CPUTIME

RECORD_WALLTIME

RECORD_ALL

Constructor Detail

Timer

Timer

Method Detail

getName

getThreadId

isRunning

getTotalCpuTime

getAvgCpuTime

getTotalWallTime

getAvgWallTime

start

reset

stop

toString

startNamedTimer

startNamedTimer

startNamedTimer

stopNamedTimer

stopNamedTimer

stopNamedTimer

resetNamedTimer

resetNamedTimer

resetNamedTimer

getNamedTimer

getNamedTimer

getNamedTimer

getNamedTotalTimer

hashCode

equals