EDU.oswego.cs.dl.util.concurrent
public abstract class SemaphoreControlledChannel extends java.lang.Object implements BoundedChannel
Modifier and Type | Field and Description |
---|---|
protected int |
capacity_ |
protected Semaphore |
putGuard_ |
protected Semaphore |
takeGuard_ |
Constructor and Description |
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SemaphoreControlledChannel(int capacity)
Create a channel with the given capacity and default
semaphore implementation
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SemaphoreControlledChannel(int capacity,
java.lang.Class semaphoreClass)
Create a channel with the given capacity and
semaphore implementations instantiated from the supplied class
|
Modifier and Type | Method and Description |
---|---|
int |
capacity()
Return the maximum number of elements that can be held.
|
protected abstract java.lang.Object |
extract()
Internal mechanics of take.
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protected abstract void |
insert(java.lang.Object x)
Internal mechanics of put.
|
boolean |
offer(java.lang.Object x,
long msecs)
Place item in channel only if it can be accepted within
msecs milliseconds.
|
java.lang.Object |
poll(long msecs)
Return and remove an item from channel only if one is available within
msecs milliseconds.
|
void |
put(java.lang.Object x)
Place item in the channel, possibly waiting indefinitely until
it can be accepted.
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int |
size()
Return the number of elements in the buffer.
|
java.lang.Object |
take()
Return and remove an item from channel,
possibly waiting indefinitely until
such an item exists.
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protected final Semaphore putGuard_
protected final Semaphore takeGuard_
protected int capacity_
public SemaphoreControlledChannel(int capacity) throws java.lang.IllegalArgumentException
java.lang.IllegalArgumentException
- if capacity less or equal to zeropublic SemaphoreControlledChannel(int capacity, java.lang.Class semaphoreClass) throws java.lang.IllegalArgumentException, java.lang.NoSuchMethodException, java.lang.SecurityException, java.lang.InstantiationException, java.lang.IllegalAccessException, java.lang.reflect.InvocationTargetException
java.lang.IllegalArgumentException
- if capacity less or equal to zero.java.lang.NoSuchMethodException
- If class does not have constructor
that intializes permitsjava.lang.SecurityException
- if constructor information
not accessiblejava.lang.InstantiationException
- if semaphore class is abstractjava.lang.IllegalAccessException
- if constructor cannot be calledjava.lang.reflect.InvocationTargetException
- if semaphore constructor throws an
exceptionpublic int capacity()
BoundedChannel
capacity
in interface BoundedChannel
public int size()
protected abstract void insert(java.lang.Object x)
protected abstract java.lang.Object extract()
public void put(java.lang.Object x) throws java.lang.InterruptedException
Channel
put
in interface Channel
put
in interface Puttable
x
- the element to be inserted. Should be non-null.java.lang.InterruptedException
- if the current thread has
been interrupted at a point at which interruption
is detected, in which case the element is guaranteed not
to be inserted. Otherwise, on normal return, the element is guaranteed
to have been inserted.public boolean offer(java.lang.Object x, long msecs) throws java.lang.InterruptedException
Channel
offer
in interface Channel
offer
in interface Puttable
x
- the element to be inserted. Should be non-null.msecs
- the number of milliseconds to wait. If less than
or equal to zero, the method does not perform any timed waits,
but might still require
access to a synchronization lock, which can impose unbounded
delay if there is a lot of contention for the channel.java.lang.InterruptedException
- if the current thread has
been interrupted at a point at which interruption
is detected, in which case the element is guaranteed not
to be inserted (i.e., is equivalent to a false return).public java.lang.Object take() throws java.lang.InterruptedException
Channel
take
in interface Channel
take
in interface Takable
java.lang.InterruptedException
- if the current thread has
been interrupted at a point at which interruption
is detected, in which case state of the channel is unchanged.public java.lang.Object poll(long msecs) throws java.lang.InterruptedException
Channel
poll
in interface Channel
poll
in interface Takable
msecs
- the number of milliseconds to wait. If less than
or equal to zero, the operation does not perform any timed waits,
but might still require
access to a synchronization lock, which can impose unbounded
delay if there is a lot of contention for the channel.java.lang.InterruptedException
- if the current thread has
been interrupted at a point at which interruption
is detected, in which case state of the channel is unchanged
(i.e., equivalent to a null return).