feat: add dac-sum test

tst/52-dac-sum.c

@@ -0,0 +1,90 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include "thread.h"
+
+/* fibonacci.
+ *
+ * la durée doit être proportionnel à la valeur du résultat.
+ * valgrind doit être content.
+ * jusqu'à quelle valeur cela fonctionne-t-il ?
+ *
+ * support nécessaire:
+ * - thread_create()
+ * - thread_join() avec récupération de la valeur de retour
+ * - retour sans thread_exit()
+ */
+
+struct dac_in_t {
+    unsigned long* arr;
+    int st;
+    int end;
+};
+
+static void* s_dac_sum(void* _value)
+{
+  thread_t th, th2;
+  int err;
+  void *res = NULL, *res2 = NULL;
+  struct dac_in_t* in = (struct dac_in_t*) _value;
+  printf("%p %d %d\n", in->arr, in->st, in->end);
+
+  /* on passe un peu la main aux autres pour eviter de faire uniquement la partie gauche de l'arbre */
+  thread_yield();
+
+  if (in->end <= in->st + 1)
+    return (void*)in->arr[in->st];
+
+  size_t mid = (in->end + in->st) / 2;
+  struct dac_in_t in1 = {in->arr, in->st, mid};
+  struct dac_in_t in2 = {in->arr, mid, in->end};
+
+  err = thread_create(&th, s_dac_sum, (void*)&in1);
+  assert(!err);
+  err = thread_create(&th2, s_dac_sum, (void*)&in2);
+  assert(!err);
+
+  err = thread_join(th, &res);
+  assert(!err);
+  err = thread_join(th2, &res2);
+  assert(!err);
+
+  return (void*)((unsigned long) res + (unsigned long) res2);
+}
+
+int main(int argc, char *argv[])
+{
+  unsigned long res;
+  size_t n;
+  struct timeval tv1, tv2;
+  double s;
+
+  if (argc < 2) {
+    printf("argument manquant: entier n pour lequel dac_sum(n)\n");
+    return EXIT_FAILURE;
+  }
+
+  n = atoi(argv[1]);
+  unsigned long arr[n];
+  for (size_t i = 0 ; i < n ; ++i)
+      arr[i] = i + 1;
+
+  struct dac_in_t in = { arr, .st=0, .end=n };
+  gettimeofday(&tv1, NULL);
+  res = (unsigned long)s_dac_sum((void *)&in);
+  gettimeofday(&tv2, NULL);
+  s = (tv2.tv_sec-tv1.tv_sec) + (tv2.tv_usec-tv1.tv_usec) * 1e-6;
+
+  unsigned long expected = (n * (n + 1)) / 2;
+  if (res != expected) {
+    printf("dac(%lu) != %lu (FAILED)\n", res, expected);
+    printf("GRAPH;%lu;%lu;%e;%s\n", n, res, s, "FAILED" );
+    return EXIT_FAILURE;
+  } else {
+    printf("fibo(%lu) = %lu en %e s\n", n, res, s );
+    printf("GRAPH;%lu;%lu;%e;%s\n", n, res, s, "SUCCESS" );
+    return EXIT_SUCCESS;
+  }
+}