add: project 2

project2/src/lottery.c

@@ -0,0 +1,52 @@
+#include "lottery.h"
+#include "main.h"
+#include <stdlib.h>
+#include <time.h>
+
+void lottery_run(process processes[], int num_processes) {
+  unsigned int seed = time(NULL);
+
+  process *ready_queue[num_processes];
+  int num_ready = 0;
+  int num_processed = 0;
+  int num_run = 0;
+  cpu_time_t next_free = 0;
+  while (num_run < num_processes) {
+    // Add new arrivals to ready queue
+    for (int i = num_processed;
+         i < num_processes && processes[i].arrival <= next_free; i++) {
+      ready_queue[num_ready] = &processes[i];
+      num_ready++;
+      num_processed++;
+    }
+
+    // Idle if ready queue is empty
+    if (num_ready == 0) {
+      next_free = processes[num_processed].arrival;
+      continue;
+    }
+
+    // Remove random process
+    int next_i = rand_r(&seed) % num_ready;
+    process *next = ready_queue[next_i];
+    num_ready--;
+    for (int i = next_i; i < num_ready; i++) {
+      ready_queue[i] = ready_queue[i + 1];
+    }
+
+    // Run process
+    next->num_schedules = 1;
+    next->starts = malloc(sizeof(cpu_time_t));
+    next->starts[0] = next_free;
+    next->durations = malloc(sizeof(cpu_time_t));
+    next->durations[0] = next->burst;
+    num_run++;
+
+    next_free = next->starts[0] + next->burst;
+  }
+}
+
+scheduler lottery = (scheduler){.name = "lottery",
+                                .description = NULL,
+                                .run = lottery_run,
+                                .uses_priority = 0};