feat: project 1

project1/phase3/phase3.c

@@ -0,0 +1,105 @@
+#include <errno.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#define NUM_ACCOUNTS 5
+#define NUM_TRANSFERS 5
+
+// Monetary value in cents
+typedef long currency;
+
+void sprintf_currency(char *buffer, currency c) {
+  if (c < 0) {
+    c = -c;
+    sprintf(buffer, "-");
+    buffer += sizeof(char);
+  }
+  sprintf(buffer, "$%ld.%.2ld", c / 100, c % 100);
+}
+
+void printf_currency(currency c) {
+  if (c < 0) {
+    c = -c;
+    printf("-");
+  }
+  printf("$%ld.%.2ld", c / 100, c % 100);
+}
+
+// Accounts (shared resource)
+typedef struct account {
+  int account_id;
+  currency balance;
+  int transaction_count;
+  pthread_mutex_t lock; // Account access mutex
+} account;
+
+// Global account array
+account accounts[NUM_ACCOUNTS];
+
+// Threads
+
+pthread_t transfers[NUM_TRANSFERS];
+
+typedef struct transfer_args {
+  int transfer_id;
+  account *from;
+  account *to;
+  currency amount;
+} transfer_args;
+
+void *transfer_thread(void *arg) {
+  transfer_args *args = (transfer_args *)arg;
+  int id = args->transfer_id;
+  account *from = args->from;
+  account *to = args->to;
+  currency amount = args->amount;
+
+  pthread_mutex_lock(&from->lock);
+  printf("Thread %u: Locked account %d\n", id, from->account_id);
+
+  usleep(100); // Delay to account for other threads
+
+  pthread_mutex_lock(&to->lock);
+  printf("Thread %u: Locked account %d\n", id, to->account_id);
+
+  from->balance -= amount;
+  to->balance += amount;
+  from->transaction_count++;
+  to->transaction_count++;
+
+  printf("Thread %u: Unlocked account %u\n", id, from->account_id);
+  printf("Thread %u: Unlocked account %u\n", id, to->account_id);
+  pthread_mutex_unlock(&to->lock);
+  pthread_mutex_unlock(&from->lock);
+
+  return NULL;
+}
+
+int main() {
+  // Initialize all accounts with 0 balance
+  for (int i = 0; i < NUM_ACCOUNTS; i++) {
+    accounts[i] = (account){.account_id = i, .balance = 0};
+    pthread_mutex_init(&accounts[i].lock, NULL);
+  }
+
+  // Initialize transfers
+  transfer_args args[NUM_TRANSFERS];
+  for (int i = 0; i < NUM_TRANSFERS; i++) {
+    args[i] = (transfer_args){.transfer_id = i,
+                              .from = &accounts[i % NUM_ACCOUNTS],
+                              .to = &accounts[(i + 1) % NUM_ACCOUNTS],
+                              .amount = 1000};
+    pthread_create(&transfers[i], NULL, transfer_thread, &args[i]);
+  }
+
+  // Wait for all threads to finish
+  for (int i = 0; i < NUM_TRANSFERS; i++) {
+    pthread_join(transfers[i], NULL);
+  }
+
+  return 0;
+}