Add a test for P1 that checks that multiple threads can properly wake

[pintos-anon] / src / tests / threads / alarm-simultaneous.c

diff --git a/src/tests/threads/alarm-simultaneous.c b/src/tests/threads/alarm-simultaneous.c
new file mode 100644 (file)
index 0000000..7db5418
--- /dev/null
+++ b/src/tests/threads/alarm-simultaneous.c
@@ -0,0 +1,94 @@
+/* Creates N threads, each of which sleeps a different, fixed
+   duration, M times.  Records the wake-up order and verifies
+   that it is valid. */
+
+#include <stdio.h>
+#include "tests/threads/tests.h"
+#include "threads/init.h"
+#include "threads/malloc.h"
+#include "threads/synch.h"
+#include "threads/thread.h"
+#include "devices/timer.h"
+
+static void test_sleep (int thread_cnt, int iterations);
+
+void
+test_alarm_simultaneous (void) 
+{
+  test_sleep (5, 5);
+}
+
+/* Information about the test. */
+struct sleep_test 
+  {
+    int64_t start;              /* Current time at start of test. */
+    int iterations;             /* Number of iterations per thread. */
+    int *output_pos;            /* Current position in output buffer. */
+  };
+
+static void sleeper (void *);
+
+/* Runs THREAD_CNT threads thread sleep ITERATIONS times each. */
+static void
+test_sleep (int thread_cnt, int iterations) 
+{
+  struct sleep_test test;
+  int *output;
+  int i;
+
+  /* This test does not work with the MLFQS. */
+  ASSERT (!enable_mlfqs);
+
+  msg ("Creating %d threads to sleep %d times each.", thread_cnt, iterations);
+  msg ("Each thread sleeps 10 ticks each time.");
+  msg ("Within an iteration, all threads should wake up on the same tick.");
+
+  /* Allocate memory. */
+  output = malloc (sizeof *output * iterations * thread_cnt * 2);
+  if (output == NULL)
+    PANIC ("couldn't allocate memory for test");
+
+  /* Initialize test. */
+  test.start = timer_ticks () + 100;
+  test.iterations = iterations;
+  test.output_pos = output;
+
+  /* Start threads. */
+  ASSERT (output != NULL);
+  for (i = 0; i < thread_cnt; i++)
+    {
+      char name[16];
+      snprintf (name, sizeof name, "thread %d", i);
+      thread_create (name, PRI_DEFAULT, sleeper, &test);
+    }
+  
+  /* Wait long enough for all the threads to finish. */
+  timer_sleep (100 + iterations * 10 + 100);
+
+  /* Print completion order. */
+  msg ("iteration 0, thread 0: woke up after %d ticks", output[0]);
+  for (i = 1; i < test.output_pos - output; i++) 
+    msg ("iteration %d, thread %d: woke up %d ticks later",
+         i / thread_cnt, i % thread_cnt, output[i] - output[i - 1]);
+  
+  free (output);
+}
+
+/* Sleeper thread. */
+static void
+sleeper (void *test_) 
+{
+  struct sleep_test *test = test_;
+  int i;
+
+  /* Make sure we're at the beginning of a timer tick. */
+  timer_sleep (1);
+
+  for (i = 1; i <= test->iterations; i++) 
+    {
+      int64_t sleep_until = test->start + i * 10;
+      timer_sleep (sleep_until - timer_ticks ());
+      *test->output_pos++ = timer_ticks () - test->start;
+      thread_yield ();
+    }
+}