/**
?*?@file
?*?UDP?protocol
?*/

#define?_BSD_SOURCE?????/*?Needed?for?using?struct?ip_mreq?with?recent?glibc?*/

/*
#include?“avformat.h“
#include?“avio_internal.h“
#include?“libavutil/parseutils.h“
#include?“libavutil/fifo.h“
#include?“libavutil/intreadwrite.h“
#include?“libavutil/avstring.h“
#include?“libavutil/opt.h“
#include?“libavutil/log.h“
#include?“libavutil/time.h“
#include?“internal.h“

#include?“os_support.h“
#include?“url.h“
*/

#include?
#include?
#include?
#include?
#include?
#include?
	???
#include?“udp.h“
#include?

#define?AVIO_FLAG_READ??1??????????????????????????????????????/**#define?AVIO_FLAG_WRITE?2??????????????????????????????????????/**#define?AVIO_FLAG_READ_WRITE?（AVIO_FLAG_READ|AVIO_FLAG_WRITE）??/**

/**
?*?Use?non-blocking?mode.
?*?If?this?flag?is?set?operations?on?the?context?will?return
?*?AVERROR（EAGAIN）?if?they?can?not?be?performed?immediately.
?*?If?this?flag?is?not?set?operations?on?the?context?will?never?return
?*?AVERROR（EAGAIN）.
?*?Note?that?this?flag?does?not?affect?the?opening/connecting?of?the
?*?context.?Connecting?a?protocol?will?always?block?if?necessary?（e.g.?on
?*?network?protocols）?but?never?hang?（e.g.?on?busy?devices）.
?*?Warning:?non-blocking?protocols?is?work-in-progress;?this?flag?may?be
?*?silently?ignored.
?*/
#define?AVIO_FLAG_NONBLOCK?8

/**
?*?Use?direct?mode.
?*?avio_read?and?avio_write?should?if?possible?be?satisfied?directly
?*?instead?of?going?through?a?buffer?and?avio_seek?will?always
?*?call?the?underlying?seek?function?directly.
?*/
#define?AVIO_FLAG_DIRECT?0x8000

#ifndef?HAVE_PTHREAD_CANCEL
#define?HAVE_PTHREAD_CANCEL?0
#endif

#ifndef?IPV6_ADD_MEMBERSHIP
#define?IPV6_ADD_MEMBERSHIP??IPV6_JOIN_GROUP
#define?IPV6_DROP_MEMBERSHIP?IPV6_LEAVE_GROUP
#endif


/*?error?handling?*/
#if?EDOM?>?0
#define?AVERROR（e）?（-（e））???///#define?AVUNERROR（e）?（-（e））?///#else
/*?Some?platforms?have?E*?and?errno?already?negated.?*/
#define?AVERROR（e）?（e）
#define?AVUNERROR（e）?（e）
#endif

#include?
static?int?ff_network_wait_fd（int?fd?int?write）
{
????int?ev?=?write???POLLOUT?:?POLLIN;
????struct?pollfd?p?=?{?.fd?=?fd?.events?=?ev?.revents?=?0?};
????int?ret;
????ret?=?poll（&p?1?100）;
	return?ret;
????//return?ret?}
//poll?返回?=0?代表超時
//poll?返回?>0?代表有ret個套接字有數據可以處理
//poll?返回?<0?代表出錯
//RETURN?VALUE
//???????On?success?a?positive?number?is?returned;?this?is?the?number?of?structures?which?have?non-zero?revents??fields
//???????（in?other?words?those?descriptors?with?events?or?errors?reported）.??A?value?of?0?indicates?that?the?call?timed
//???????out?and?no?file?descriptors?were?ready.?On?error?-1?is?returned?and?errno?is?set?ap

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????5513??2015-12-01?13:21??udp.h
?????文件???????29117??2015-12-02?17:16??udp.c