![The following code is an implementation of the producer consumer problem using a software
locking mechanism. Your tasks here require you to debug the code with the intent of achieving
the following tasks:
Task 1: Identifying the critical section
Task 2: Identify the software locks and replace them with a simplified mutex lock and unlock.
HINT: The code provided relies heavily on the in and out pointers of the buffer. You should
make the code run on a single count variable.
#include
#include
#include
#include
#define MAXSIZE 100
#define ITERATIONS 1000
int buffer[MAXSIZE]; // buffer
int nextp, nextc; // temporary storage
int count=0;
void printfunction(void * ptr)
{
int count = *(int *) ptr;
if (count==0)
{
printf("All items produced are consumed by the consumer ");
}
else
{
for (int i=0; i<=count; i=i+1)
{
printf("%d, t",buffer[i]);
}
printf(" ");
}
}
void *producer(void *ptr)
{
int item, flag=0;](https://image.slidesharecdn.com/thefollowingcodeisanimplementationoftheproducerconsumerpro-230709035614-620fa3e2/85/The-following-code-is-an-implementation-of-the-producer-consumer-pro-pdf-1-320.jpg)
![int in = *(int *) ptr;
do
{
item = (rand()%7)%10;
flag=flag+1;
nextp=item;
buffer[in]=nextp;
in=((in+1)%MAXSIZE);
while(count <= MAXSIZE)
{
count=count+1;
printf("Count = %d - incremented at producer ", count);
}
} while (flag<=ITERATIONS);
pthread_exit(NULL);
}
void *consumer(void *ptr)
{
int item, flag=ITERATIONS;
int out = *(int *) ptr;
do
{
while (count >0)
{
nextc = buffer[out];
out=(out+1)%MAXSIZE;
printf("tCount = %d - decremented at consumer ", count, flag);
count = count-1;
flag=flag-1;
}
if (count <= 0)
{
printf("consumer made to wait...faster than producer. ");
}
}while (flag>=0);
pthread_exit(NULL);](https://image.slidesharecdn.com/thefollowingcodeisanimplementationoftheproducerconsumerpro-230709035614-620fa3e2/85/The-following-code-is-an-implementation-of-the-producer-consumer-pro-pdf-2-320.jpg)
![}
int main(void)
{
int in=0, out=0; //pointers
pthread_t pro, con;
// Spawn threads
pthread_create(&pro, NULL, producer, &count);
pthread_create(&con, NULL, consumer, &count);
if (rc1)
{
printf("ERROR; return code from pthread_create() is %d ", rc1);
exit(-1);
}
if (rc2)
{
printf("ERROR; return code from pthread_create() is %d ", rc2);
exit(-1);
}
// Wait for the threads to finish
// Otherwise main might run to the end
// and kill the entire process when it exits.
pthread_join(pro, NULL);
pthread_join(con, NULL);
printfunction(&count);
}
Solution
#include
#include
#include
#include
#define MAXSIZE 100
#define ITERATIONS 1000
int buffer[MAXSIZE]; // buffer
int nextp, nextc; // temporary storage](https://image.slidesharecdn.com/thefollowingcodeisanimplementationoftheproducerconsumerpro-230709035614-620fa3e2/85/The-following-code-is-an-implementation-of-the-producer-consumer-pro-pdf-3-320.jpg)
![int count=0;
void printfunction(void * ptr)
{
int count = *(int *) ptr;
if (count==0)
{
printf("All items produced are consumed by the consumer ");
}
else
{
for (int i=0; i<=count; i=i+1)
{
printf("%d, t",buffer[i]);
}
printf(" ");
}
}
void *producer(void *ptr)
{
int item, flag=0;
int in = *(int *) ptr;
do
{
item = (rand()%7)%10;
flag=flag+1;
nextp=item;
buffer[in]=nextp;
in=((in+1)%MAXSIZE);
while(count <= MAXSIZE)
{
count=count+1;
printf("Count = %d - incremented at producer ", count);
}
} while (flag<=ITERATIONS);
pthread_exit(NULL);
}](https://image.slidesharecdn.com/thefollowingcodeisanimplementationoftheproducerconsumerpro-230709035614-620fa3e2/85/The-following-code-is-an-implementation-of-the-producer-consumer-pro-pdf-4-320.jpg)
![void *consumer(void *ptr)
{
int item, flag=ITERATIONS;
int out = *(int *) ptr;
do
{
while (count >0)
{
nextc = buffer[out];
out=(out+1)%MAXSIZE;
printf("tCount = %d - decremented at consumer ", count, flag);
count = count-1;
flag=flag-1;
}
if (count <= 0)
{
printf("consumer made to wait...faster than producer. ");
}
}while (flag>=0);
pthread_exit(NULL);
}
int main(void)
{
int in=0, out=0; //pointers
pthread_t pro, con;
// Spawn threads
pthread_create(&pro, NULL, producer, &count);
pthread_create(&con, NULL, consumer, &count);
if (rc1)
{
printf("ERROR; return code from pthread_create() is %d ", rc1);
exit(-1);
}
if (rc2)
{
printf("ERROR; return code from pthread_create() is %d ", rc2);](https://image.slidesharecdn.com/thefollowingcodeisanimplementationoftheproducerconsumerpro-230709035614-620fa3e2/85/The-following-code-is-an-implementation-of-the-producer-consumer-pro-pdf-5-320.jpg)
The following code is an implementation of the producer consumer pro.pdf
- 1. The following code is an implementation of the producer consumer problem using a software locking mechanism. Your tasks here require you to debug the code with the intent of achieving the following tasks: Task 1: Identifying the critical section Task 2: Identify the software locks and replace them with a simplified mutex lock and unlock. HINT: The code provided relies heavily on the in and out pointers of the buffer. You should make the code run on a single count variable. #include #include #include #include #define MAXSIZE 100 #define ITERATIONS 1000 int buffer[MAXSIZE]; // buffer int nextp, nextc; // temporary storage int count=0; void printfunction(void * ptr) { int count = *(int *) ptr; if (count==0) { printf("All items produced are consumed by the consumer "); } else { for (int i=0; i<=count; i=i+1) { printf("%d, t",buffer[i]); } printf(" "); } } void *producer(void *ptr) { int item, flag=0;
- 2. int in = *(int *) ptr; do { item = (rand()%7)%10; flag=flag+1; nextp=item; buffer[in]=nextp; in=((in+1)%MAXSIZE); while(count <= MAXSIZE) { count=count+1; printf("Count = %d - incremented at producer ", count); } } while (flag<=ITERATIONS); pthread_exit(NULL); } void *consumer(void *ptr) { int item, flag=ITERATIONS; int out = *(int *) ptr; do { while (count >0) { nextc = buffer[out]; out=(out+1)%MAXSIZE; printf("tCount = %d - decremented at consumer ", count, flag); count = count-1; flag=flag-1; } if (count <= 0) { printf("consumer made to wait...faster than producer. "); } }while (flag>=0); pthread_exit(NULL);
- 3. } int main(void) { int in=0, out=0; //pointers pthread_t pro, con; // Spawn threads pthread_create(&pro, NULL, producer, &count); pthread_create(&con, NULL, consumer, &count); if (rc1) { printf("ERROR; return code from pthread_create() is %d ", rc1); exit(-1); } if (rc2) { printf("ERROR; return code from pthread_create() is %d ", rc2); exit(-1); } // Wait for the threads to finish // Otherwise main might run to the end // and kill the entire process when it exits. pthread_join(pro, NULL); pthread_join(con, NULL); printfunction(&count); } Solution #include #include #include #include #define MAXSIZE 100 #define ITERATIONS 1000 int buffer[MAXSIZE]; // buffer int nextp, nextc; // temporary storage
- 4. int count=0; void printfunction(void * ptr) { int count = *(int *) ptr; if (count==0) { printf("All items produced are consumed by the consumer "); } else { for (int i=0; i<=count; i=i+1) { printf("%d, t",buffer[i]); } printf(" "); } } void *producer(void *ptr) { int item, flag=0; int in = *(int *) ptr; do { item = (rand()%7)%10; flag=flag+1; nextp=item; buffer[in]=nextp; in=((in+1)%MAXSIZE); while(count <= MAXSIZE) { count=count+1; printf("Count = %d - incremented at producer ", count); } } while (flag<=ITERATIONS); pthread_exit(NULL); }
- 5. void *consumer(void *ptr) { int item, flag=ITERATIONS; int out = *(int *) ptr; do { while (count >0) { nextc = buffer[out]; out=(out+1)%MAXSIZE; printf("tCount = %d - decremented at consumer ", count, flag); count = count-1; flag=flag-1; } if (count <= 0) { printf("consumer made to wait...faster than producer. "); } }while (flag>=0); pthread_exit(NULL); } int main(void) { int in=0, out=0; //pointers pthread_t pro, con; // Spawn threads pthread_create(&pro, NULL, producer, &count); pthread_create(&con, NULL, consumer, &count); if (rc1) { printf("ERROR; return code from pthread_create() is %d ", rc1); exit(-1); } if (rc2) { printf("ERROR; return code from pthread_create() is %d ", rc2);
- 6. exit(-1); } // Wait for the threads to finish // Otherwise main might run to the end // and kill the entire process when it exits. pthread_join(pro, NULL); pthread_join(con, NULL); printfunction(&count); }