Semaphore

java.lang.Object
- BSsync.Semaphore

```
public class Semaphore
extends java.lang.Object
```
Base class for counting semaphores. Conceptually, a semaphore maintains a set of permits. Each acquire() blocks if necessary until a permit is available, and then takes it. Each release adds a permit. However, no actual permit objects are used; the Semaphore just keeps a count of the number available and acts accordingly.
A semaphore initialized to 1 can serve as a mutual exclusion lock.
This implementation makes NO guarantees about the order in which threads will acquire permits

Field Summary

Fields
Modifier and Type Field Description

protected int permits_
current number of available permits

static boolean verbose
Set this variable to true for debugging output

Constructor Summary

Constructors
Constructor	Description
`Semaphore(int initialPermits)`	Create a Semaphore with the given initial number of permits.
`Semaphore(int initialPermits, java.lang.String name)`	Create a named Semaphore with the given initial number of permits.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description

void acquire()
Wait until a permit is available, and take one

void release()
Release a permit
- Methods inherited from class java.lang.Object
  clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - verbose
```
public static boolean verbose
```
    Set this variable to true for debugging output
  - permits_
```
protected int permits_
```
    current number of available permits
- Constructor Detail
  - Semaphore
```
public Semaphore(int initialPermits)
```
    Create a Semaphore with the given initial number of permits. Using a seed of one makes the semaphore act as a mutual exclusion lock. Negative seeds are also allowed, in which case no acquires will proceed until the number of releases has pushed the number of permits past 0.
    
    Parameters:
    
    initialPermits - initial value of the Semaphore
  - Semaphore
```
public Semaphore(int initialPermits,
                 java.lang.String name)
```
    Create a named Semaphore with the given initial number of permits. the name is only used for debugging output. Using a seed of one makes the semaphore act as a mutual exclusion lock. Negative seeds are also allowed, in which case no acquires will proceed until the number of releases has pushed the number of permits past 0.
    
    Parameters:
    
    initialPermits - initial value of the Semaphore
    
    name - name of the Semaphore
- Method Detail
  - acquire
```
public void acquire()
```
    Wait until a permit is available, and take one
  - release
```
public void release()
```
    Release a permit