Code cleanup and commentary

src/consumer.cpp

@@ -1,5 +1,4 @@
-#include <semaphore.h>
-#include <unistd.h>
+#include <semaphore.h> // POSIX semaphores!
 #include "list.hpp"    // list implementation
 #include "globals.hpp" // lists, sems, muts
 #include "consumer.hpp"
@@ -7,7 +6,7 @@
 int consume(block* c);
 
 void *consumer (void *) {
-   block* c;
+   block *c;
    while (true) {
       // wait for element on list2
       wait(sem_list2);
@@ -31,7 +30,6 @@ void *consumer (void *) {
       signal(sem_freelist_minus_1);
       // signal new element on freelist
       signal(sem_freelist);
-
    }
    return nullptr;
 }

src/main.cpp

@@ -1,13 +1,12 @@
-#include <semaphore.h>
-#include <pthread.h>
-#include <unistd.h>
-#include <stdint.h>
-#include <stdio.h>
-#include "list.hpp"
-#include "globals.hpp"
-#include "producer.hpp"
-#include "consumer.hpp"
-#include "transformer.hpp"
+#include <semaphore.h>  // POSIX semaphores!
+#include <pthread.h>    // POSIX threads!
+#include <unistd.h>     // usleep
+#include <stdio.h>      // printf
+#include "list.hpp"     // list implementation
+#include "globals.hpp"  // globals/CPP defines
+#include "producer.hpp" // Thread-1
+#include "consumer.hpp" // Thread-3
+#include "transformer.hpp" // Thread-2
 
 // Create all of memory
 block memory[N] = {0};
@@ -24,7 +23,7 @@ int main (int argc, char* argv[]) {
    // initialize the freelist
    list_init(freelist, memory, N);
 
-   //TODO: Implement a semaphore solution to the problem
+   //* Implement a semaphore solution to the problem
    // counting semaphores measure the length
    sem_init(&sem_freelist, 0, freelist->length);
    sem_init(&sem_freelist_minus_1, 0, freelist->length-1);
@@ -38,18 +37,19 @@ int main (int argc, char* argv[]) {
    //* Use pthreads to split execution
    // Make some pthreads
    pthread_t thread1, thread2, thread3;
-
    // Create thread1 as producer
    pthread_create(&thread1, NULL, producer, NULL);
    // Create thread2 as transformer
    pthread_create(&thread2, NULL, transformer, NULL);
    // Create thread3 as consumer
    pthread_create(&thread3, NULL, consumer, NULL);
-
+   // print some information about the 3 lists
    while (true) {
-      printf("\033c");
+      printf("\033cfreelist: ");
       list_print(freelist);
+      printf("   list1: ");
       list_print(list1);
+      printf("   list2: ");
       list_print(list2);
       usleep(timescale);
    }

src/producer.cpp

@@ -1,5 +1,4 @@
-#include <semaphore.h>
-#include <unistd.h>
+#include <semaphore.h> // POSIX semaphores!
 #include "list.hpp"    // list implementation
 #include "globals.hpp" // lists, sems, muts
 #include "producer.hpp"

src/transformer.cpp

@@ -1,10 +1,9 @@
-#include <semaphore.h>
-#include <unistd.h>
+#include <semaphore.h> // POSIX semaphores!
 #include "list.hpp"    // list implementation
 #include "globals.hpp" // lists, sems, muts
 #include "transformer.hpp"
 
-void transform(block* x, block* y);
+void transform(block *x, block *y);
 
 void *transformer (void *) {
    block *x, *y;
@@ -47,12 +46,10 @@ void *transformer (void *) {
       signal(mut_list2);
       // signal new element on list2
       signal(sem_list2);
-
    }
    return nullptr;
 }
 
 void transform(block *x, block *y) {
-   usleep(timescale);
    return;
 }