Poll (Apache Tomcat 8.0.15 API Documentation)

java.lang.Object
- org.apache.tomcat.jni.Poll

```
public class Poll
extends Object
```
Poll

Author:

Mladen Turk

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`APR_NO_DESC` Used in apr_pollfd_t to determine what the apr_descriptor is apr_datatype_e enum
`static int`	`APR_POLL_FILE` descriptor refers to a socket
`static int`	`APR_POLL_LASTDESC` descriptor refers to a file
`static int`	`APR_POLL_SOCKET` nothing here
`static int`	`APR_POLLERR` Pending error
`static int`	`APR_POLLHUP` Hangup occurred
`static int`	`APR_POLLIN` Can read without blocking
`static int`	`APR_POLLNVAL` Descriptor invalid
`static int`	`APR_POLLOUT` Can write without blocking
`static int`	`APR_POLLPRI` Priority data available
`static int`	`APR_POLLSET_THREADSAFE` Adding or Removing a Descriptor is thread safe

Constructor Summary

Constructors
Constructor and Description

Poll()

Constructors
Constructor and Description
`Poll()`

Method Summary

Methods
Modifier and Type	Method and Description
`static int`	`add(long pollset, long sock, int reqevents)` Add a socket to a pollset with the default timeout.
`static int`	`addWithTimeout(long pollset, long sock, int reqevents, long timeout)` Add a socket to a pollset with a specific timeout.
`static long`	`create(int size, long p, int flags, long ttl)` Setup a pollset object.
`static int`	`destroy(long pollset)` Destroy a pollset object
`static long`	`getTtl(long pollset)` Get the socket time to live.
`static int`	`interrupt(long pollset)` Make poll() return.
`static int`	`maintain(long pollset, long[] descriptors, boolean remove)` Maintain on the descriptor(s) in a pollset
`static int`	`poll(long pollset, long timeout, long[] descriptors, boolean remove)` Block for activity on the descriptor(s) in a pollset
`static int`	`pollset(long pollset, long[] descriptors)` Return all descriptor(s) in a pollset
`static int`	`remove(long pollset, long sock)` Remove a descriptor from a pollset
`static void`	`setTtl(long pollset, long ttl)` Set the socket time to live.
`static boolean`	`wakeable(long pollset)` Check if interrupt() is allowed.

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

- Field Detail
  - APR_POLLIN
```
public static final int APR_POLLIN
```
    Can read without blocking
    
    See Also:
    Constant Field Values
  - APR_POLLPRI
```
public static final int APR_POLLPRI
```
    Priority data available
    
    See Also:
    Constant Field Values
  - APR_POLLOUT
```
public static final int APR_POLLOUT
```
    Can write without blocking
    
    See Also:
    Constant Field Values
  - APR_POLLERR
```
public static final int APR_POLLERR
```
    Pending error
    
    See Also:
    Constant Field Values
  - APR_POLLHUP
```
public static final int APR_POLLHUP
```
    Hangup occurred
    
    See Also:
    Constant Field Values
  - APR_POLLNVAL
```
public static final int APR_POLLNVAL
```
    Descriptor invalid
    
    See Also:
    Constant Field Values
  - APR_POLLSET_THREADSAFE
```
public static final int APR_POLLSET_THREADSAFE
```
    Adding or Removing a Descriptor is thread safe
    
    See Also:
    Constant Field Values
  - APR_NO_DESC
```
public static final int APR_NO_DESC
```
    Used in apr_pollfd_t to determine what the apr_descriptor is apr_datatype_e enum
    
    See Also:
    Constant Field Values
  - APR_POLL_SOCKET
```
public static final int APR_POLL_SOCKET
```
    nothing here
    
    See Also:
    Constant Field Values
  - APR_POLL_FILE
```
public static final int APR_POLL_FILE
```
    descriptor refers to a socket
    
    See Also:
    Constant Field Values
  - APR_POLL_LASTDESC
```
public static final int APR_POLL_LASTDESC
```
    descriptor refers to a file
    
    See Also:
    Constant Field Values
- Constructor Detail
  - Poll
```
public Poll()
```
- Method Detail
  - create
```
public static long create(int size,
          long p,
          int flags,
          long ttl)
                   throws Error
```
    Setup a pollset object. If flags equals APR_POLLSET_THREADSAFE, then a pollset is created on which it is safe to make concurrent calls to apr_pollset_add(), apr_pollset_remove() and apr_pollset_poll() from separate threads. This feature is only supported on some platforms; the apr_pollset_create() call will fail with APR_ENOTIMPL on platforms where it is not supported.
    
    Parameters:
    size - The maximum number of descriptors that this pollset can hold
    p - The pool from which to allocate the pollset
    flags - Optional flags to modify the operation of the pollset.
    ttl - Maximum time to live for a particular socket.
    
    Returns:
    The pointer in which to return the newly created object
    
    Throws:
    
    Error
  - destroy
```
public static int destroy(long pollset)
```
    Destroy a pollset object
    
    Parameters:
    pollset - The pollset to destroy
  - add
```
public static int add(long pollset,
      long sock,
      int reqevents)
```
    Add a socket to a pollset with the default timeout.
    
    Parameters:
    pollset - The pollset to which to add the socket
    sock - The sockets to add
    reqevents - requested events
  - addWithTimeout
```
public static int addWithTimeout(long pollset,
                 long sock,
                 int reqevents,
                 long timeout)
```
    Add a socket to a pollset with a specific timeout.
    
    Parameters:
    pollset - The pollset to which to add the socket
    sock - The sockets to add
    reqevents - requested events
    timeout - requested timeout in microseconds (-1 for infinite)
  - remove
```
public static int remove(long pollset,
         long sock)
```
    Remove a descriptor from a pollset
    
    Parameters:
    pollset - The pollset from which to remove the descriptor
    sock - The socket to remove
  - poll
```
public static int poll(long pollset,
       long timeout,
       long[] descriptors,
       boolean remove)
```
    Block for activity on the descriptor(s) in a pollset
    Parameters:
    pollset - The pollset to use
    timeout - Timeout in microseconds
    descriptors - Array of signaled descriptors (output parameter) The descriptor array must be two times the size of pollset. and are populated as follows:
    descriptors[2n + 0] -> returned events descriptors[2n + 1] -> socket
    remove - Remove signaled descriptors from pollset
    
    Returns:
    Number of signaled descriptors (output parameter) or negative APR error code.
  - maintain
```
public static int maintain(long pollset,
           long[] descriptors,
           boolean remove)
```
    Maintain on the descriptor(s) in a pollset
    Parameters:
    pollset - The pollset to use
    descriptors - Array of signaled descriptors (output parameter) The descriptor array must be the size of pollset. and are populated as follows:
    descriptors[n] -> socket
    remove - Remove signaled descriptors from pollset
    
    Returns:
    Number of signaled descriptors (output parameter) or negative APR error code.
  - setTtl
```
public static void setTtl(long pollset,
          long ttl)
```
    Set the socket time to live.
    
    Parameters:
    pollset - The pollset to use
    ttl - Timeout in microseconds
  - getTtl
```
public static long getTtl(long pollset)
```
    Get the socket time to live.
    
    Parameters:
    pollset - The pollset to use
    
    Returns:
    Timeout in microseconds
  - pollset
```
public static int pollset(long pollset,
          long[] descriptors)
```
    Return all descriptor(s) in a pollset
    Parameters:
    pollset - The pollset to use
    descriptors - Array of descriptors (output parameter) The descriptor array must be two times the size of pollset. and are populated as follows:
    descriptors[2n + 0] -> returned events descriptors[2n + 1] -> socket
    Returns:
    Number of descriptors (output parameter) in the Poll or negative APR error code.
  - interrupt
```
public static int interrupt(long pollset)
```
    Make poll() return.
    
    Parameters:
    pollset -
    
    Returns:
    Negative APR error code
  - wakeable
```
public static boolean wakeable(long pollset)
```
    Check if interrupt() is allowed.
    
    Parameters:
    pollset -
    
    Returns:
    true if interrupt(long) is allowed, else false

Class Poll

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

APR_POLLIN

APR_POLLPRI

APR_POLLOUT

APR_POLLERR

APR_POLLHUP

APR_POLLNVAL

APR_POLLSET_THREADSAFE

APR_NO_DESC

APR_POLL_SOCKET

APR_POLL_FILE

APR_POLL_LASTDESC

Constructor Detail

Poll

Method Detail

create

destroy

add

addWithTimeout

remove

poll

maintain

setTtl

getTtl

pollset

interrupt

wakeable