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25 
26 package sun.nio.ch;
27 
28 import sun.misc.*;
29 
30 
31 /**
32  * Manipulates a native array of pollfd structs.
33  *
34  * @author Mike McCloskey
35  * @since 1.4
36  */
37 
38 public abstract class AbstractPollArrayWrapper {
39 
40     // Miscellaneous constants
41     static final short SIZE_POLLFD   = 8;
42     static final short FD_OFFSET     = 0;
43     static final short EVENT_OFFSET  = 4;
44     static final short REVENT_OFFSET = 6;
45 
46     // The poll fd array
47     protected AllocatedNativeObject pollArray;
48 
49     // Number of valid entries in the pollArray
50     protected int totalChannels = 0;
51 
52     // Base address of the native pollArray
53     protected long pollArrayAddress;
54 
55     // Access methods for fd structures
getEventOps(int i)56     int getEventOps(int i) {
57         int offset = SIZE_POLLFD * i + EVENT_OFFSET;
58         return pollArray.getShort(offset);
59     }
60 
getReventOps(int i)61     int getReventOps(int i) {
62         int offset = SIZE_POLLFD * i + REVENT_OFFSET;
63         return pollArray.getShort(offset);
64     }
65 
getDescriptor(int i)66     int getDescriptor(int i) {
67         int offset = SIZE_POLLFD * i + FD_OFFSET;
68         return pollArray.getInt(offset);
69     }
70 
putEventOps(int i, int event)71     void putEventOps(int i, int event) {
72         int offset = SIZE_POLLFD * i + EVENT_OFFSET;
73         pollArray.putShort(offset, (short)event);
74     }
75 
putReventOps(int i, int revent)76     void putReventOps(int i, int revent) {
77         int offset = SIZE_POLLFD * i + REVENT_OFFSET;
78         pollArray.putShort(offset, (short)revent);
79     }
80 
putDescriptor(int i, int fd)81     void putDescriptor(int i, int fd) {
82         int offset = SIZE_POLLFD * i + FD_OFFSET;
83         pollArray.putInt(offset, fd);
84     }
85 
86 }
87