ThreadCpuTimer (Solr 9.6.1 core API)

java.lang.Object
- org.apache.solr.util.ThreadCpuTimer

```
@NotThreadSafe
public class ThreadCpuTimer
extends Object
```
Allows tracking information about the current thread using the JVM's built-in management bean ThreadMXBean.
Calling code should create an instance of this class when starting the operation, and then can get the getElapsedCpuMs() at any time thereafter.
This class is irrevocably not thread safe. Never allow instances of this class to be exposed to more than one thread. Acquiring an external lock will not be sufficient. This class can be considered "lock-hostile" due to its caching of timing information for a specific thread.

Field Summary

Fields
Modifier and Type Field Description

static String CPU_TIME

static String ENABLE_CPU_TIME

static String LOCAL_CPU_TIME

Constructor Summary

Constructors
Constructor Description

ThreadCpuTimer()
Create an instance to track the current thread's usage of CPU.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Optional<Long>`	`getElapsedCpuMs()`	Get the CPU usage information for the current thread since it created this `ThreadCpuTimer`.
`long`	`getElapsedCpuNs()`	Return CPU time consumed by this thread since the construction of this timer object.
`static boolean`	`isSupported()`
`String`	`toString()`

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

- Field Detail
  - CPU_TIME
```
public static final String CPU_TIME
```
    See Also:
    
    Constant Field Values
  - LOCAL_CPU_TIME
```
public static final String LOCAL_CPU_TIME
```
    See Also:
    
    Constant Field Values
  - ENABLE_CPU_TIME
```
public static final String ENABLE_CPU_TIME
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - ThreadCpuTimer
```
public ThreadCpuTimer()
```
    Create an instance to track the current thread's usage of CPU. Usage information can later be retrieved by calling getElapsedCpuMs(). Timing starts immediately upon construction.
- Method Detail
  - isSupported
```
public static boolean isSupported()
```
  - getElapsedCpuNs
```
public long getElapsedCpuNs()
```
    Return CPU time consumed by this thread since the construction of this timer object.
    
    Returns:
    
    current value, or UNSUPPORTED if not supported.
  - getElapsedCpuMs
```
public Optional<Long> getElapsedCpuMs()
```
    Get the CPU usage information for the current thread since it created this ThreadCpuTimer. The result is undefined if called by any other thread.
    
    Returns:
    
    the thread's cpu since the creation of this ThreadCpuTimer instance. If the VM's cpu tracking is disabled, returned value will be UNSUPPORTED.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object