[OpenWrt-Devel] [PATCH] iwinfo: add channel survey

[Koen Vandeputte]

On 2018-06-05 10:23, Nick wrote:
> ....
>>   
>> +static char * format_channel_time(uint64_t time)
>> +{
>> +	static char buf[30];
>> +
>> +	if (!time)
>> +		snprintf(buf, sizeof(buf), "unknown");
>> +	else
>> +		snprintf(buf, sizeof(buf), "%llu ms", time);
>> +
>> +	return buf;
>> +}
>> +

Out of curiosity:


Any reason to use a static char buffer inside this function instead of 
using some char buffer provided by the caller?
This would:

- Avoid using slow heap memory and use faster stack memory (if the 
caller allocates it on stack)
- Automatically makes the function re-entrant & threadsafe this way


>>   static char * format_noise(int noise)
>>   {
>>   	static char buf[10];
>> @@ -531,6 +543,19 @@ static char * print_phyname(const struct iwinfo_ops *iw, const char *ifname)
>>   	return "?";
>>   }
>>   
>> +static void print_survey(const struct iwinfo_ops *iw, const char *ifname)
>> +{
>> +	struct iwinfo_survey_entry entry;
>> +	iw->survey(ifname, &entry);
>> +	printf("%s\tESSID:\t\t\t\t%s\n", ifname, print_ssid(iw, ifname));
>> +	printf("\tChannel:\t\t\t%s (%s)\n", print_channel(iw, ifname), format_frequency(entry.frequency));
>> +	printf("\tNoise:\t\t\t\t%s\n", format_noise(entry.noise));
>> +	printf("\tchannel Active Time:\t\t%s\n", format_channel_time(entry.channel_time));
>> +	printf("\tChannel Busy Time:\t\t%s\n",format_channel_time(entry.channel_time_busy));
>> +	printf("\tExtension Channel Busy Time:\t%s\n",format_channel_time(entry.channel_time_ext_busy));
>> +	printf("\tChannel Receive Time:\t\t%s\n",format_channel_time(entry.channel_time_rx));
>> +	printf("\tChannel Transmit Time:\t\t%s\n",format_channel_time(entry.channel_time_tx));
>> +}
>>   ...
Koen



_______________________________________________
openwrt-devel mailing list
openwrt-devel at lists.openwrt.org
https://lists.openwrt.org/listinfo/openwrt-devel