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Re: [lwip-devel] Upgrading from v1.3.0 to 1.4.0 - sys_now()

From: address@hidden
Subject: Re: [lwip-devel] Upgrading from v1.3.0 to 1.4.0 - sys_now()
Date: Mon, 16 May 2011 20:41:33 +0200
User-agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; de; rv: Gecko/20110414 Thunderbird/3.1.10

Phil Perryman wrote:
I'm currently porting my Xilinx drivers from lwip 1.3.0 to 1.4.0 and have
found that the latest version now uses a sys_now() function which was not
used/needed previously.  Why is this now needed
sys_now() is only referenced if NO_SYS==1 and LWIP_TIMERS==1. It is used by sys_check_timeouts() for an automatic timer implementation: previously, a NO_SYS==1 port had to call the various timer functions at the correct interval (e.g. tcp_tmr, etharp_tmr, ip_reass_tmr, etc.).

Now you may simply call sys_check_timeouts() in your main loop: no matter at which interval this function is called, it will know when to call which timers based on the return value of sys_now().

and what should the
frequency of the returned timestamp be (assuming it is just a 32-bit count

As the comment above the function declaration says, it should return milliseconds:

/** Returns the current time in milliseconds,
 * may be the same as sys_jiffies or at least based on it. */


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