org.apache.cassandra.net

Class ResourceLimits.Basic

java.lang.Object

org.apache.cassandra.net.ResourceLimits.Basic

All Implemented Interfaces:

ResourceLimits.Limit

Enclosing class:

ResourceLimits

public static class ResourceLimits.Basic
extends java.lang.Object
implements ResourceLimits.Limit

A cheaper, thread-unsafe permit container to be used for unshared limits.

Constructor Summary

Constructors

Constructor and Description
Basic(long limit)

Method Summary

Modifier and Type	Method and Description
void	allocate(long amount) Allocates an amount independent of permits available from this limit.
long	limit()
ResourceLimits.Outcome	release(long amount)
long	remaining()
long	setLimit(long newLimit) Sets the total amount of permits represented by this ResourceLimits.Limit - the capacity If the old limit has been reached and the new limit is large enough to allow for more permits to be aqcuired, subsequent calls to ResourceLimits.Limit.allocate(long) or ResourceLimits.Limit.tryAllocate(long) will succeed.
boolean	tryAllocate(long amount) Attempts to allocate an amount of permits from this limit.
long	using()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Basic

public Basic(long limit)

Method Detail

limit

public long limit()

Specified by:

limit in interface ResourceLimits.Limit

Returns:

total amount of permits represented by this ResourceLimits.Limit - the capacity

setLimit

public long setLimit(long newLimit)

Description copied from interface: ResourceLimits.Limit

Sets the total amount of permits represented by this ResourceLimits.Limit - the capacity If the old limit has been reached and the new limit is large enough to allow for more permits to be aqcuired, subsequent calls to ResourceLimits.Limit.allocate(long) or ResourceLimits.Limit.tryAllocate(long) will succeed. If the new limit is lower than the current amount of allocated permits then subsequent calls to ResourceLimits.Limit.allocate(long) or ResourceLimits.Limit.tryAllocate(long) will block or fail respectively.

Specified by:

setLimit in interface ResourceLimits.Limit

Returns:

the old limit

remaining

public long remaining()

Specified by:

remaining in interface ResourceLimits.Limit

Returns:

remaining, unallocated permit amount

using

public long using()

Specified by:

using in interface ResourceLimits.Limit

Returns:

amount of permits currently in use

tryAllocate

public boolean tryAllocate(long amount)

Description copied from interface: ResourceLimits.Limit

Attempts to allocate an amount of permits from this limit. If allocated, MUST eventually be released back with ResourceLimits.Limit.release(long).

Specified by:

tryAllocate in interface ResourceLimits.Limit

Returns:

true if the allocation was successful, false otherwise

allocate

public void allocate(long amount)

Description copied from interface: ResourceLimits.Limit

Allocates an amount independent of permits available from this limit. MUST eventually be released back with ResourceLimits.Limit.release(long).

Specified by:

allocate in interface ResourceLimits.Limit

release

public ResourceLimits.Outcome release(long amount)

Specified by:

release in interface ResourceLimits.Limit

Parameters:

amount - return the amount of permits back to this limit

Returns:

ABOVE_LIMIT if there aren't enough permits available even after the release, or BELOW_LIMIT if there are enough permits available after the releaese.