Sun Aug 6 15:15:13 2006

Asterisk developer's documentation

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poll.c File Reference

#include <unistd.h>
#include <sys/types.h>
#include <sys/time.h>
#include <assert.h>
#include <string.h>
#include "asterisk/poll-compat.h"

Include dependency graph for poll.c:

Go to the source code of this file.

Defines
#define	MAX(a, b)   ((a) > (b) ? (a) : (b))
Functions
static int	map_poll_spec (struct pollfd *pArray, unsigned long n_fds, fd_set *pReadSet, fd_set *pWriteSet, fd_set *pExceptSet)
static void	map_select_results (struct pollfd *pArray, unsigned long n_fds, fd_set *pReadSet, fd_set *pWriteSet, fd_set *pExceptSet)
static struct timeval *	map_timeout (int poll_timeout, struct timeval *pSelTimeout)
int	poll (structpollfd *pArray, unsigned long n_fds, int timeout)

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Define Documentation

#define MAX (  a, b   )     ((a) > (b) ? (a) : (b))

Definition at line 87 of file poll.c. Referenced by handle_response_register(), map_poll_spec(), and sound_thread().

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Function Documentation

static int map_poll_spec (  struct pollfd *  pArray, unsigned long  n_fds, fd_set *  pReadSet, fd_set *  pWriteSet, fd_set *  pExceptSet )  [static]

Definition at line 103 of file poll.c. References pollfd::events, pollfd::fd, MAX, POLLIN, POLLOUT, and POLLPRI. Referenced by poll(). { register unsigned long i; /* loop control */ register struct pollfd *pCur; /* current array element */ register int max_fd = -1; /* return value */ /* Map the poll() structures into the file descriptor sets required by select(). */ for (i = 0, pCur = pArray; i < n_fds; i++, pCur++) { /* Skip any bad FDs in the array. */ if (pCur->fd < 0) continue; if (pCur->events & POLLIN) { /* "Input Ready" notification desired. */ FD_SET (pCur->fd, pReadSet); } if (pCur->events & POLLOUT) { /* "Output Possible" notification desired. */ FD_SET (pCur->fd, pWriteSet); } if (pCur->events & POLLPRI) { /* "Exception Occurred" notification desired. (Exceptions include out of band data. */ FD_SET (pCur->fd, pExceptSet); } max_fd = MAX (max_fd, pCur->fd); } return max_fd; }

static void map_select_results (  struct pollfd *  pArray, unsigned long  n_fds, fd_set *  pReadSet, fd_set *  pWriteSet, fd_set *  pExceptSet )  [static]

Definition at line 221 of file poll.c. References pollfd::fd, POLLIN, POLLOUT, POLLPRI, and pollfd::revents. Referenced by poll(). { register unsigned long i; /* loop control */ register struct pollfd *pCur; /* current array element */ for (i = 0, pCur = pArray; i < n_fds; i++, pCur++) { /* Skip any bad FDs in the array. */ if (pCur->fd < 0) continue; /* Exception events take priority over input events. */ pCur->revents = 0; if (FD_ISSET (pCur->fd, pExceptSet)) pCur->revents |= POLLPRI; else if (FD_ISSET (pCur->fd, pReadSet)) pCur->revents |= POLLIN; if (FD_ISSET (pCur->fd, pWriteSet)) pCur->revents |= POLLOUT; } return; }

static struct timeval* map_timeout (  int  poll_timeout, struct timeval *  pSelTimeout )  [static]

Definition at line 157 of file poll.c. Referenced by poll(). { struct timeval *pResult; /* Map the poll() timeout value into a select() timeout. The possible values of the poll() timeout value, and their meanings, are: VALUE MEANING -1 wait indefinitely (until signal occurs) 0 return immediately, don't block >0 wait specified number of milliseconds select() uses a "struct timeval", which specifies the timeout in seconds and microseconds, so the milliseconds value has to be mapped accordingly. */ assert (pSelTimeout != (struct timeval *) NULL); switch (poll_timeout) { case -1: /* A NULL timeout structure tells select() to wait indefinitely. */ pResult = (struct timeval *) NULL; break; case 0: /* "Return immediately" (test) is specified by all zeros in a timeval structure. */ pSelTimeout->tv_sec = 0; pSelTimeout->tv_usec = 0; pResult = pSelTimeout; break; default: /* Wait the specified number of milliseconds. */ pSelTimeout->tv_sec = poll_timeout / 1000; /* get seconds */ poll_timeout %= 1000; /* remove seconds */ pSelTimeout->tv_usec = poll_timeout * 1000; /* get microseconds */ pResult = pSelTimeout; break; } return pResult; }

int poll (  struct pollfd *  pArray, unsigned long  n_fds, int  timeout )

Definition at line 264 of file poll.c. References map_poll_spec(), map_select_results(), and map_timeout(). Referenced by ast_carefulwrite(), ast_el_read_char(), ast_io_wait(), ast_remotecontrol(), ast_wait_for_input(), ast_waitfor_n_fd(), ast_waitfor_nandfds(), do_monitor(), get_input(), launch_netscript(), listener(), main(), netconsole(), timed_read(), zt_sendtext(), and zt_setoption(). { fd_set read_descs; /* input file descs */ fd_set write_descs; /* output file descs */ fd_set except_descs; /* exception descs */ struct timeval stime; /* select() timeout value */ int ready_descriptors; /* function result */ int max_fd; /* maximum fd value */ struct timeval *pTimeout; /* actually passed */ FD_ZERO (&read_descs); FD_ZERO (&write_descs); FD_ZERO (&except_descs); assert (pArray != (struct pollfd *) NULL); /* Map the poll() file descriptor list in the select() data structures. */ max_fd = map_poll_spec (pArray, n_fds, &read_descs, &write_descs, &except_descs); /* Map the poll() timeout value in the select() timeout structure. */ pTimeout = map_timeout (timeout, &stime); /* Make the select() call. */ ready_descriptors = select (max_fd + 1, &read_descs, &write_descs, &except_descs, pTimeout); if (ready_descriptors >= 0) { map_select_results (pArray, n_fds, &read_descs, &write_descs, &except_descs); } return ready_descriptors; }

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