Disabled external gits

cs453-ca/CS453-2021-project/sync-examples/procon2.c

@@ -0,0 +1,97 @@
+#include <pthread.h>
+#include <inttypes.h>
+#include <assert.h>
+#include <stdio.h>
+#include <stdatomic.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include "lock.h"
+
+#define RUNS 4096
+#define THREADS 4
+#define DATA_TEXT_SIZE 1024
+#define BUFFER_SIZE 1024
+
+struct data {
+  char text[DATA_TEXT_SIZE];
+};
+
+static struct lock_t lock;
+
+bool are_same(struct data* a, struct data* b) {
+  for (int i = 0; i < DATA_TEXT_SIZE; i++)
+    if (a->text[i] != b->text[i]) return false;
+  return true;
+}
+
+struct data buffer[BUFFER_SIZE] = { 0 };
+
+int produced_until = 0;
+int consumed_until = 0;
+
+struct data produced[RUNS] = { 0 }; // used to check correctness
+struct data consumed[RUNS] = { 0 }; // used to check correctness
+
+void* produce(void* null) {
+  for (int r = 0; r < RUNS; r++) {
+    while (true) {
+      lock_acquire(&lock);
+      if (consumed_until + BUFFER_SIZE > r) break;
+      lock_release(&lock);
+    }
+    printf("can produce %d\n", r);
+    for (int i = 0; i < DATA_TEXT_SIZE; i++)
+      produced[r].text[i] = rand();
+    buffer[r % BUFFER_SIZE] = produced[r];
+    produced_until++;
+    lock_release(&lock);
+    // Correct: we wait until nobody consumed data anymore and correctly release
+    // (prevent reordering) thanks to the lock.
+  }
+}
+
+void* consume(void* null) {
+  for (int r = 0; r < RUNS; r++) {
+    while (true) {
+      lock_acquire(&lock);
+      if (produced_until > r) break;
+      lock_release(&lock);
+    }
+    printf("can consume %d\n", r);
+    consumed[r] = buffer[r % BUFFER_SIZE];
+    consumed_until++;
+    lock_release(&lock);
+    // Correct: we wait until nobody produces data anymore and correctly acquire
+    // + release (prevent reordering) thanks to the lock.
+  }
+}
+
+int main() {
+  lock_init(&lock);
+  int res;
+  pthread_t producer;
+  res = pthread_create(&producer, NULL, produce, NULL);
+  assert(!res);
+
+  pthread_t consumer;
+  res = pthread_create(&consumer, NULL, consume, NULL);
+  assert(!res);
+
+  res = pthread_join(consumer, NULL);
+  assert(!res);
+
+  res = pthread_join(producer, NULL);
+  assert(!res);
+
+  int r = 0;
+  for (; r < RUNS; r++) {
+    if (!are_same(&produced[r], &consumed[r])) {
+      printf("Consumed the wrong data on round %d.\n", r);
+      break;
+    }
+  }
+  if (r == RUNS) {
+    printf("Looks correct to me! :)\n");
+  }
+}