jonas.elofsson wrote:
>
> Ok, tried some other stuff, see test code below. When the counter 'i' reaches
> 128 (* 8 = 1024 files opened and closed) i get bad printouts from the open
> and read calls.
>
>
> My test code:
>
> (panna.c)
>
> #include <stdio.h>
> #include <fcntl.h>
>
> void msDelay(int ms)
> {
> int i,a;
> int delayvar=10;
>
> for (a=0;a<ms;a++)
> {
> for (i=0;i<33084;i++)
> {
> delayvar*=2;
> delayvar/=2;
> }
> }
> }
>
> float readtemp(char* pin)
> {
> int fil;
> char filename[100];
> float tot = 0, high = 0, temp, dc;
>
> char c;
>
> sprintf(filename, "/proc/diskstats");
>
> fil = open(filename, O_RDONLY);
>
> if(fil < 0) printf("Open error!");
>
> if(read(fil, &c, 1) != 1) printf("Read error!");
close(file);
>
> if(tot == 0)
> {
return 0; // file handle lost
> }
>
> dc = high/tot;
>
> temp = (dc - 0.32) / 0.0047;
>
/* close(fil); */
>
> return temp;
> }
>
> int main(void)
> {
> //printf("\x1B[1;0;0;10;31;14;4;0;0Q");
> //printf("\x1B[2J\x1B[4;8H=)\x1B[2;3HJonas \x01 Emma");
>
> float temp[8];
> char* pins[8] = {"PG01", "PG02", "PG03", "PG04", "PG05", "PG16",
> "PG17", "PG18"};
> int i, j = 0;
>
> printf("\x1B[2J"); //ClrScr
>
> while(1)
> {
> for(i = 0; i <= 7; i++)
> {
> temp[i] = readtemp(pins[i]);
> }
>
> j++;
>
> printf("\x1B[0;0H"); //GotoXY 0,0
>
> printf(" %02.0f %02.0f %02.0f %02.0f %02.0f\n", temp[0],
> temp[1], temp[2], temp[3], temp[4]);
> printf(" %02.0f %02.0f %04.1f\n", temp[5], temp[6], temp[7]);
> printf(" %d", j);
>
> fflush(stdout);
>
> msDelay(10);
>
> }
>
> return 0;
>
> }
>
> Makefile:
>
> AXIS_USABLE_LIBS = UCLIBC GLIBC
> include $(AXIS_TOP_DIR)/tools/build/Rules.axis
>
> PROGS = panna
>
> all: $(PROGS)
> $(PROGS): $(PROGS).o
> $(CC) $(LDFLAGS) $^ $(LDLIBS) -o $@
>
> clean:
> rm -f $(PROGS) *.o core
>
>
> Best regards, Jonas
>
> --- In [email protected], j...@... wrote:
>> on proc you should use open() close() read()
>>
>> please post the complete code
>>
>>
>>
>>
>> Quoting "jonas.elofsson" <jelofs...@...>:
>>
>>> Hi!
>>>
>>> I have a problem reading files in the /proc directory in C.
>>>
>>> I made a module for reading SMARTTEMP temperature sensors, and it
>>> works great. I made it to create one file for each I/O pin under
>>> /proc/smarttemp/. Working beautifully.
>>>
>>> I also made a module for controlling my LCD display, and that to
>>> works like a charm.
>>>
>>> I put together a small test program to read 8 different temperaturs
>>> from different sensors and then display them on the display updating
>>> once every second.
>>>
>>> Works great, for two minutes...
>>>
>>> Then, when one of the /proc files is read for the 1024:th time
>>> problems occurs. It turns out the file descriptors are out..! They
>>> don't seem to get relesaed when I do a fclose (I use fopen and
>>> fclose on them, is this a problem?).
>>>
>>> I get no problems if I change the program to read from a file on the
>>> normal FS instead.
>>>
>>> If I try to read some other file in /proc i get the same error after
>>> 1024 loops... So it seems it's not in my driver code.
>>>
>>> I tried to do a system("cp /proc/smarrtemp/PG01 /var/temp"); for
>>> each measurement and then reading the file in /var instead, trying
>>> to fool it a bit, just for testing. But after about 1024 copies I
>>> still get problems.
>>>
>>> I would be very thankful for any ideas about why this is and how to
>>> get it working.
>>>
>>> I use the image on ACMEs homepage, 2.6 something. =)
>>>
>>> Best regards, Jonas
>>>
>>>
>>>
>>>
>>
>>
>> --
>> John Crispin
>> hacking, coding, etc
>> blogic on irc
>>
>> _______ ________ __
>> | |.-----.-----.-----.| | | |.----.| |_
>> | - || _ | -__| || | | || _|| _|
>> |_______|| __|_____|__|__||________||__| |____|
>> |__| W I R E L E S S F R E E D O M
>> KAMIKAZE (bleeding edge) -----------------------
>> * 10 oz Vodka Shake well with ice and strain
>> * 10 oz Triple sec mixture into 10 shot glasses.
>> * 10 oz lime juice Salute!
>> ---------------------------------------------------
>>
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