javax.realtime
Class RealtimeSystem
java.lang.Object
|
+--javax.realtime.RealtimeSystem
- public final class RealtimeSystem
- extends java.lang.Object
RealtimeSystem
provides a means for tuning the behavior of the
implementation by specifying parameters such as the maximum number of
locks that can be in use concurrently, and the monitor control policy.
In addition, RealtimeSystem
provides a mechanism for obtaining access to
the security manager, garbage collector and scheduler, to make queries
from them or to set parameters.
Method Summary |
static GarbageCollector |
currentGC()
Return a reference to the currently active garbage collector
for the heap. |
static int |
getConcurrentLocksUsed()
Get the maximum number of locks that have been used concurrently. |
static int |
getMaximumConcurrentLocks()
Get the maximum number of locks that can be used concurrently without
incurring an execution time increase
as set by the setMaximumConcurrentLocks() methods. |
static RealtimeSecurity |
getSecurityManager()
Get a reference to the security manager used to control
access to real-time system features such as access to
physical memory. |
static void |
setMaximumConcurrentLocks(int numLocks)
Set the anticipated maximum number of locks that may be held
or waited on concurrently. |
static void |
setMaximumConcurrentLocks(int number,
boolean hard)
Set the anticipated maximum number of locks that may be held
or waited on concurrently. |
static void |
setSecurityManager(RealtimeSecurity manager)
Set a new real-time security manager. |
Methods inherited from class java.lang.Object |
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait |
BIG_ENDIAN
public static final byte BIG_ENDIAN
LITTLE_ENDIAN
public static final byte LITTLE_ENDIAN
BYTE_ORDER
public static final byte BYTE_ORDER
RealtimeSystem
public RealtimeSystem()
currentGC
public static GarbageCollector currentGC()
- Return a reference to the currently active garbage collector
for the heap.
- Returns:
- A
GarbageCollector
object which is the current collector collecting
objects on the traditional Java heap.
getConcurrentLocksUsed
public static int getConcurrentLocksUsed()
- Get the maximum number of locks that have been used concurrently.
This value can be used for tuning the concurrent locks parameter, which
is used as a hint by systems that use a monitor cache.
- Returns:
- An int whose value is the number of locks in use at the
time of the invocation of the method.
getMaximumConcurrentLocks
public static int getMaximumConcurrentLocks()
- Get the maximum number of locks that can be used concurrently without
incurring an execution time increase
as set by the
setMaximumConcurrentLocks()
methods.
- Returns:
- An int whose value is the maximum number of locks that can be in simultaneous use.
getSecurityManager
public static RealtimeSecurity getSecurityManager()
- Get a reference to the security manager used to control
access to real-time system features such as access to
physical memory.
- Returns:
- A
RealtimeSecurity
object representing the default real-time security manager.
setMaximumConcurrentLocks
public static void setMaximumConcurrentLocks(int numLocks)
- Set the anticipated maximum number of locks that may be held
or waited on concurrently. Provide a hint to systems that
use a monitor cache as to how much space to dedicate to the cache.
- Parameters:
number
- An integer whose value becomes the number of locks that
can be in simultaneous use without incurring an execution time increase.
If number
is less than or equal to zero nothing happens.
setMaximumConcurrentLocks
public static void setMaximumConcurrentLocks(int number,
boolean hard)
- Set the anticipated maximum number of locks that may be held
or waited on concurrently. Provide a limit for the size of
the monitor cache on systems that provide one if hard is true.
- Parameters:
number
- The maximum number of locks that can be in simultaneous
use without incurring an execution time increase.
If number
is less than or equal to zero nothing happens.hard
- If true, number
sets a limit. If a lock is attempted which would cause the
number of locks to exceed number
then a ResourceLimitError
is thrown.
setSecurityManager
public static void setSecurityManager(RealtimeSecurity manager)
- Set a new real-time security manager.
- Parameters:
manager
- A RealtimeSecurity
object which will become the new security manager.- Throws:
- java.lang.SecurityException - Thrown if security manager has already been set.