1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<HTML> 3<HEAD> 4<META http-equiv="Content-Type" content="text/html; charset=windows-1252"> 5<META name="GENERATOR" content="IBM WebSphere Studio Homepage Builder Version 7.0.0.0 for Windows"> 6<META http-equiv="Content-Style-Type" content="text/css"> 7<TITLE>OS_PollEvent</TITLE> 8<LINK rel="stylesheet" href="../../css/nitro.css" type="text/css"> 9</HEAD> 10<BODY> 11<H1 align="left">OS_PollEvent* <IMG src="../../image/NTR.gif" align=middle><IMG src="../../image/TWL.gif" align=middle></H1> 12<H2>Syntax</H2> 13<DL> 14 <DD> 15 <PRE><CODE>#include <nitro/os.h></CODE></PRE> 16 <PRE><CODE>u32 OS_PollEvent( OSEvent* event, 17 u32 pattern, 18 OSEventMode mode ); 19 20u32 OS_PollEventEx( OSEvent* event, 21 u32 pattern, 22 OSEventMode mode, 23 u32 clearBit ); 24 25(Inline functions) 26static inline 27u32 OS_PollEvent_And( OSEvent* event, 28 u32 pattern ); 29 30static inline 31u32 OS_PollEvent_Or( OSEvent* event, 32 u32 pattern ); 33 34static inline 35u32 OS_PollEventEx_And( OSEvent* event, 36 u32 pattern, 37 u32 clearBit ); 38 39static inline 40u32 OS_PollEventEx_Or( OSEvent* event, 41 u32 pattern, 42 u32 clearBit );</CODE></PRE> 43</DL> 44<H2>Arguments</H2> 45<TABLE border="1" width="100%"> 46 <TBODY> 47 <TR> 48 <TD width="13%"><EM><STRONG>event</STRONG></EM></TD> 49 <TD width="87%">Pointer to an event structure.</TD> 50 </TR> 51 <TR> 52 <TD><EM><STRONG>pattern</STRONG></EM></TD> 53 <TD>Event flag bit pattern. Takes the form of the pattern that ends waiting for events.</TD> 54 </TR> 55 <TR> 56 <TD><EM><STRONG>mode</STRONG></EM></TD> 57 <TD>Matching mode. Indicates the event flag bit pattern's conditions for conformance.</TD> 58 </TR> 59 <TR> 60 <TD width="13%"><EM><STRONG>clearBit</STRONG></EM></TD> 61 <TD width="87%">Bits to clear from the event flag after the conditions are fulfilled.</TD> 62 </TR> 63 </TBODY> 64</TABLE> 65<H2>Return Values</H2> 66<P>If 0, indicates that the conditions have not been met.<BR>A nonzero value indicates that the conditions are met, and it will be the value of the event flag. If <B><I>clearBit</I></B> is specified, this function will return the value of the event flag before the bits were cleared.</P> 67<H2>Description</H2> 68<P>Finds out whether the event structure meets the completion conditions that have been set for waiting for events.</P> 69<P><EM><B>event</B></EM> is a pointer to an event structure. This <B><I>event</I></B> argument is is initialized by <CODE><A href="OS_InitEvent.html">OS_InitEvent()</A></CODE> and is used to have threads wait for events. In the <CODE>OS_PollEvent*</CODE> functions, it is also used to find out whether the event completion conditions have been met.</P> 70<P>Unlike the function to wait for events (<CODE><A href="OS_WaitEvent.html">OS_WaitEvent*()</A></CODE>), control will return from this function immediately regardless of whether the event completion conditions are met. Thread functions are not called, so the system will not switch threads.</P> 71<P>The completion conditions are indicated by <B><I>pattern</I></B> and <B><I>mode</I></B>. For more information, see <CODE><A href="OS_WaitEvent.html">OS_WaitEvent*()</A></CODE>.</P> 72<P>Returns a nonzero event flag value if the completion conditions have been met, and returns 0 if the conditions have not been met.</P> 73<P>In <CODE>OS_PollEventEx()</CODE>, when the completion conditions have been met, the bits indicated in <B><I>clearBit</I></B> will be cleared from the event flag. The return value will be the value of the event flag before it is cleared.</P> 74<P><CODE>OS_PollEvent<FONT color="#ff0000">_And</FONT>( event, pattern )</CODE> is the same as <CODE>OS_PollEvent( event, pattern, <FONT color="#ff0000">OS_EVENT_MODE_AND</FONT> )</CODE>.</P> 75<P><CODE>OS_PollEvent<FONT color="#ff0000">_Or</FONT>( event, pattern )</CODE> is the same as <CODE>OS_PollEvent( event, pattern, <FONT color="#ff0000">OS_EVENT_MODE_OR</FONT> )</CODE>.</P> 76<P><CODE>OS_PollEventEx<FONT color="#ff0000">_And</FONT>( event, pattern, clearBit )</CODE> is the same as <CODE>OS_PollEventEx( event, pattern, <FONT color="#ff0000">OS_EVENT_MODE_AND</FONT>, clearBit )</CODE>.</P> 77<P><CODE>OS_PollEventEx<FONT color="#ff0000">_Or</FONT>( event, pattern, clearBit )</CODE> is the same as <CODE>OS_PollEventEx( event, pattern, <FONT color="#ff0000">OS_EVENT_MODE_OR</FONT>, clearBit )</CODE>.</P> 78<H2>See Also</H2> 79<P><CODE><A href="OS_InitEvent.html">OS_InitEvent</A>, <A href="OS_WaitEvent.html">OS_WaitEvent*</A>, <A href="OS_SignalEvent.html">OS_SignalEvent</A>, <A href="OS_ClearEvent.html">OS_Clear*Event</A>, <A href="about_Event.html">OS Overview (Events)</A><BR></CODE></P> 80<H2>Revision History</H2> 81<P>2007/12/04 Initial version.</P> 82<hr><p>CONFIDENTIAL</p></body> 83</HTML>
