$[$Counting$]$ Consider the following program using pthread.

#include

#include

#include

#include "common.h$"$

#include "common$\_$threads.h$"$

int max;

volatile int counter $=0$; $//$ shared global variable

void mythread$($void arg$)\{$

char $*$letter $=$ arg;

int i; $//$ stack $($private per thread$)$

printf$("\%$s: begin $[$addr of i: $\%$p$]$

$",$ letter, &i$)$; $//$Line $1$

for $($i $=0$; i $<$ max; i$++)\{$

counter $=$ counter $+1$; $//$ shared: only one

$\}$

printf$("\%$s: done

$",$ letter$)$;

return NULL;

$\}$

int main$($int argc, char $*$argv$[])\{$

if $($argc $!=2)\{$

fprintf$($stderr$,$ "usage: main$-$first loopcount

$")$;

exit$(1)$;

$\}$

max $=$ atoi$($argv$[1])$;

pthread$\_$t p$1,$ p$2$;

printf$("$main: begin $[$counter $=\%$d$]$

$",$ counter,

$($unsigned int$)$ &counter$)$;

Pthread$\_$create$($&p$1,$ NULL, mythread, $"$A$")$;

Pthread$\_$create$($&p$2,$ NULL, mythread, $"$B$")$;

$//$ join waits for the threads to finish

Pthread$\_$join$($p$1,$ NULL$)$;

Pthread$\_$join$($p$2,$ NULL$)$;

printf$("$main: done

$[$counter: $\%$d$]$

$[$should: $\%$d$]$

$",$

counter, max$*2)$; $//$Line $2$

return $0$;

$\}$

$1.$ Suppose in a run, we get the output. Corresponding to Line $1,$ we get the output from one

thread as follows:

A: begin $[$addr of i: $0$x$700004788$f$9$c$]$

Can you infer the output from the other thread corresponding to Line $1?$ If$,$ show

the output. If not, explain why.

$2.$ This program takes the input from the command line for "max". In this run, we

have max as $1000000.$ What is the output corresponding to Line $2?$

$3.$ Does the above program have any problem? If no$,$ explain your reasoning. If yes, show

your solution to fix that $($you can copy and modify the code above with your changes briefly