libjava/gnu/java/nio/natSelectorImplPosix.cc

   1 // natSelectorImplPosix.cc
   2
   3 /* Copyright (C) 2002, 2003  Free Software Foundation
   4
   5    This file is part of libgcj.
   6
   7 This software is copyrighted work licensed under the terms of the
   8 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   9 details.  */
  10
  11 #include <config.h>
  12 #include <platform.h>
  13
  14 #include <errno.h>
  15 #include <string.h>
  16
  17 #include <gnu/java/nio/SelectorImpl.h>
  18 #include <java/io/InterruptedIOException.h>
  19 #include <java/io/IOException.h>
  20 #include <java/lang/Thread.h>
  21
  22 static void
  23 helper_put_filedescriptors (jintArray fdArray, fd_set& fds, int& max_fd)
  24 {
  25   jint* tmpFDArray = elements (fdArray);
  26
  27   for (int index = 0; index < JvGetArrayLength (fdArray); index++)
  28     {
  29       int fd = tmpFDArray [index];
  30       if (fd > 0)
  31         {
  32           FD_SET (tmpFDArray [index], &fds);
  33
  34           if (tmpFDArray [index] > max_fd)
  35             max_fd = tmpFDArray [index];
  36         }
  37     }
  38 }
  39
  40 static void
  41 helper_get_filedescriptors (jintArray& fdArray, fd_set fds)
  42 {
  43   jint* tmpFDArray = elements (fdArray);
  44
  45   for (int index = 0; index < JvGetArrayLength (fdArray); index++)
  46     {
  47       int fd = tmpFDArray [index];
  48       if (fd < 0 || !FD_ISSET (fd, &fds))
  49         tmpFDArray [index] = 0;
  50     }
  51 }
  52
  53 static void
  54 helper_reset (jintArray& fdArray)
  55 {
  56   jint* tmpFDArray = elements (fdArray);
  57
  58   for (int index = 0; index < JvGetArrayLength (fdArray); index++)
  59     tmpFDArray [index] = 0;
  60 }
  61
  62 jint
  63 gnu::java::nio::SelectorImpl::implSelect (jintArray read, jintArray write,
  64                                           jintArray except, jlong timeout)
  65 {
  66   jint result;
  67   int max_fd = 0;
  68   fd_set read_fds;
  69   fd_set write_fds;
  70   fd_set except_fds;
  71   struct timeval real_time_data;
  72   struct timeval *time_data = NULL;
  73
  74   // If a legal timeout value isn't given, use NULL.
  75   // This means an infinite timeout. The specification
  76   // also says that a zero timeout should be treated
  77   // as infinite. Otherwise (if the timeout value is legal),
  78   // fill our timeval struct and use it for the select.
  79   if (timeout > 0)
  80     {
  81       real_time_data.tv_sec = timeout / 1000;
  82       real_time_data.tv_usec = (timeout % 1000) * 1000;
  83       time_data = &real_time_data;
  84     }
  85
  86   // Reset all fd_set structures
  87   FD_ZERO (&read_fds);
  88   FD_ZERO (&write_fds);
  89   FD_ZERO (&except_fds);
  90
  91   // Fill the fd_set data structures for the _Jv_select() call.
  92   helper_put_filedescriptors (read, read_fds, max_fd);
  93   helper_put_filedescriptors (write, write_fds, max_fd);
  94   helper_put_filedescriptors (except, except_fds, max_fd);
  95
  96   // Actually do the select
  97   try
  98     {
  99       result = _Jv_select (max_fd + 1, &read_fds, &write_fds,
 100                            &except_fds, time_data);
 101     }
 102   catch (::java::io::InterruptedIOException *e)
 103     {
 104       // The behavior of JRE 1.4.1 is that no exception is thrown
 105       // when the thread is interrupted, but the thread's interrupt
 106       // status is set. Clear all of our select sets and return 0,
 107       // indicating that nothing was selected.
 108       ::java::lang::Thread::currentThread ()->interrupt ();
 109        helper_reset (read);
 110        helper_reset (write);
 111        helper_reset (except);
 112        return 0;
 113     }
 114
 115   if (result < 0)
 116     {
 117       char* strerr = strerror (errno);
 118       throw new ::java::io::IOException (JvNewStringUTF (strerr));
 119     }
 120
 121   // Set the file descriptors according to the values returned from select().
 122   helper_get_filedescriptors (read, read_fds);
 123   helper_get_filedescriptors (write, write_fds);
 124   helper_get_filedescriptors (except, except_fds);
 125
 126   return result;
 127 }