Improve dudect test with memory leak fix

Valgrind inspection revealed memory leaks in the original code, with
43,632 bytes lost across 909 blocks per test. Analysis showed that the
initialization function was being called repeatedly within the testing
loop, each time reallocating the context array without any provision to
free prior memory allocations. This uncontrolled repetition caused
memory to accumulate not freed over multiple test iterations, leading to
the observed leaks. To correct this, the initialization process was
revised to execute only once before testing begins, and a cleanup was
added to release all allocated memory when testing concludes. To further
prevent memory-related issues, the measurement function was updated to
check all memory allocations, ensuring robustness against potential
failures.

Change-Id: If7001c1a719c6c353a37d10874c2a60e56f935d4

Author: HeatCrab

dudect/fixture.c

@@ -187,7 +187,7 @@ static bool doit(int mode)
     int64_t *percentiles = calloc(NUM_PERCENTILES, sizeof(int64_t));
 
     if (!before_ticks || !after_ticks || !exec_times || !classes ||
-        !input_data) {
+        !input_data || !percentiles) {
         die();
     }
 
@@ -213,18 +213,21 @@ static void init_once(void)
 {
     init_dut();
     for (size_t i = 0; i < DUDECT_TESTS; i++) {
-        ctxs[i] = malloc(sizeof(t_context_t));
-        t_init(ctxs[i]);
+        if (!ctxs[i]) {  // Avoid repeated allocation
+            ctxs[i] = malloc(sizeof(t_context_t));
+            t_init(ctxs[i]);
+        }
     }
 }
 
 static bool test_const(char *text, int mode)
 {
     bool result = false;
 
+    init_once();
+
     for (int cnt = 0; cnt < TEST_TRIES; ++cnt) {
         printf("Testing %s...(%d/%d)\n\n", text, cnt, TEST_TRIES);
-        init_once();
         for (int i = 0; i < ENOUGH_MEASURE / (N_MEASURES - DROP_SIZE * 2) + 1;
              ++i)
             result = doit(mode);
@@ -235,6 +238,7 @@ static bool test_const(char *text, int mode)
 
     for (size_t i = 0; i < DUDECT_TESTS; i++) {
         free(ctxs[i]);
+        ctxs[i] = NULL;
     }
 
     return result;