Your program must first open the directory passed to it as a command line argument $($for

example, $./$hw$2$ directoryName threadNumber$).$ The program is to use threads to compute the

number of prime numbers in each file and print thread by thread. The number of active threads

at a time is to be limited to threadNumber.

Hint$1$: use a semaphore $($mutex$)$ to limit the number of simultaneously active threads

$($threadNumber$).$ Create a threads whenever an active thread terminates. Your program must

work for any number of files.

Hint$2$: you may heck number of active threads per process by executing $$ps $-$eLf$$ command in

a second terminal window under NLWP column, after your program starts execution.

Notes about the problem: you may think of this problem as if an unknown number of students

are queued in front of an instructor$$s office to see their exam papers. But he instructor$$s office

can only host at most n $($threadNumber$)$ students. So$,$ the new student can enter the room, only

when one of the students inside leaves the room.

Execute your program observing time data:

time $./$hw$2$ myDir $1$

time $./$hw$2$ myDir $2$

$...$

Thread $1$ has found $6454$ primes in file$1.$txt

$...$

Thread $5$ has found $23935$ primes in file$2.$txt

$...$

real $0$m$54\mathrm{.}277$s

user $1$m$48\mathrm{.}500$s

sys $0$m$0.$

Here is my code:

#include

#include

#include

#include

#include

#include

#define MAX$\_$THREADS $100$

$//$ Global variables

int active$\_$threads $=0$;

sem$\_$t mutex;

$//$ Function to count prime numbers in a file

void $*$count$\_$primes$($void $*$arg$)\{$

$//$ Extract file$-$specific information from the argument

char $*$filename $=(($char $**)$arg$)[0]$;

int thread$\_$number $=*(($int $*)((($char $**)$arg$)[1]))$;

$//$ Implementation of prime counting in a file

$//$ This is a placeholder. Replace it with actual prime counting logic.

printf$("$Thread $\%$d has found some primes in $\%$s

$",$ thread$\_$number, filename$)$;

$//$ Increment active$\_$threads when entering

sem$\_$wait$($&mutex$)$;

active$\_$threads$++$;

sem$\_$post$($&mutex$)$;

$//$ Critical section $-$ process the file

$//$ Count primes in the file

$//$ Decrement active$\_$threads when leaving

sem$\_$wait$($&mutex$)$;

active$\_$threads$--$;

sem$\_$post$($&mutex$)$;

free$($arg$)$; $//$ Free memory allocated for the argument

pthread$\_$exit$($NULL$)$;

$\}$

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

$//$ Check command$-$line arguments

if $($argc $!=3)\{$

fprintf$($stderr$,$ "Usage: $\%$s directoryName threadNumber

$",$ argv$[0])$;

return EXIT$\_$FAILURE;

$\}$

$//$ Open the directory

DIR $*$dir;

struct dirent $*$ent;

if $(($dir $=$ opendir$($argv$[1]))==$ NULL$)\{$

perror$("$Error opening directory"$)$;

return EXIT$\_$FAILURE;

$\}$

$//$ Initialize semaphore

sem$\_$init$($&mutex, $0,$ atoi$($argv$[2]))$;

$//$ Loop through files in the directory

int thread$\_$number $=1$; $//$ Initialize thread number

while $(($ent $=$ readdir$($dir$))!=$ NULL$)\{$

$//$ Skip $"."$ and $".."$ directories

if $($strcmp$($ent$->$d$\_$name, $".")==0||$ strcmp$($ent$->$d$\_$name, $"..")==0)\{$

continue;

$\}$

$//$ Construct argument for the thread

char $**$arg $=$ malloc$(2*$ sizeof$($char $*))$;

arg$[0]=$ ent$->$d$\_$name;

arg$[1]=($char $*)$malloc$($sizeof$($int$))$;

$*(($int $*)$arg$[1])=$ thread$\_$number;

$//$ Create a new thread to count primes in the file

pthread$\_$t tid;

pthread$\_$create$($&tid, NULL, count$\_$primes, arg$)$;

$//$ Increment thread number

thread$\_$number$++$;

$//$ Wait if the maximum number of active threads is reached

while $($active$\_$threads $>=$ atoi$($argv$[2]))\{$

$//$ Implement wait logic here

$\}$

$\}$

$//$ Close directory

closedir$($dir$)$;

$//$ Destroy semaphore

sem$\_$destroy$($&mutex$)$;

return EXIT$\_$SUCCESS;

$\}$

and here is output of this code :

Thread $1$ has found some primes in file$1.$txt

Thread $2$ has found some primes in file$10.$txt

Thread $3$ has found some primes in file$11.$txt

Thread $4$ has found some primes in file$12.$txt$...$

real $0$m$0\mathrm{.}006$s

user $0$m$0\mathrm{.}003$s

sys $0$m$0\mathrm{.}000$s;

Can you modify my code so its counting the primes in the files like below

Thread $1$ has found $6454$ primes in file$1.$txt

$...$

Thread $5$ has found $23935$ primes in file$2.$txt