Also test the higher part of the confidence interval

(cherry picked from commit 8d3220643c42d77decca49d6f39cef69cc6ce7bf)

diff --git a/lib/isc/tests/random_test.c b/lib/isc/tests/random_test.c
index af7c408acd9f5de4311b5503f9eb2f927c83d648..4a7bb288da7af177818eaec36d1aa079131d4905 100644 (file)
--- a/lib/isc/tests/random_test.c
+++ b/lib/isc/tests/random_test.c
@@ -256,13 +256,14 @@ random_test(pvalue_func_t *func) {
        isc_rng_t *rng;
        isc_uint32_t m;
        isc_uint32_t j;
-       isc_uint32_t histogram[11];
+       isc_uint32_t histogram[11] = { 0 };
        isc_uint32_t passed;
        double proportion;
        double p_hat;
-       double lower_confidence;
+       double lower_confidence, higher_confidence;
        double chi_square;
        double p_value_t;
+       double alpha;
 
        tables_init();
 
@@ -276,9 +277,6 @@ random_test(pvalue_func_t *func) {
        m = 1000;
        passed = 0;
 
-       for (j = 0; j < 11; j++)
-               histogram[j] = 0;
-
        for (j = 0; j < m; j++) {
                isc_uint32_t i;
                isc_uint16_t values[REPS];
@@ -288,8 +286,9 @@ random_test(pvalue_func_t *func) {
                        values[i] = isc_rng_random(rng);
 
                p_value = (*func)(mctx, values, REPS);
-               if (p_value >= 0.01)
+               if (p_value >= 0.01) {
                        passed++;
+               }
 
                ATF_REQUIRE(p_value >= 0.0);
                ATF_REQUIRE(p_value <= 1.0);
@@ -300,32 +299,35 @@ random_test(pvalue_func_t *func) {
 
        isc_rng_detach(&rng);
 
-       /* Fold histogram[10] (p_value = 1.0) into histogram[9] for
-        * interval [0.9, 1.0]
-        */
-       histogram[9] += histogram[10];
-       histogram[10] = 0;
-
        /*
         * Check proportion of sequences passing a test (see section
         * 4.2.1 in NIST SP 800-22).
         */
+       alpha = 0.01; /* the significance level */
        proportion = (double) passed / (double) m;
-       p_hat = 1 - 0.01; /* alpha is 0.01 in the NIST tests */
-       lower_confidence = p_hat - (3.0 * sqrt((p_hat * (1 - p_hat)) / m));
+       p_hat = 1.0 - alpha;
+       lower_confidence = p_hat - (3.0 * sqrt((p_hat * (1.0 - p_hat)) / m));
+       higher_confidence = p_hat + (3.0 * sqrt((p_hat * (1.0 - p_hat)) / m));
 
        /* Debug message, not displayed when running via atf-run */
        printf("passed=%u/1000\n", passed);
-       printf("lower_confidence=%f, proportion=%f\n",
-              lower_confidence, proportion);
+       printf("higher_confidence=%f, lower_confidence=%f, proportion=%f\n",
+              higher_confidence, lower_confidence, proportion);
 
        ATF_REQUIRE(proportion >= lower_confidence);
+       ATF_REQUIRE(proportion <= higher_confidence);
 
        /*
         * Check uniform distribution of p-values (see section 4.2.2 in
         * NIST SP 800-22).
         */
 
+       /* Fold histogram[10] (p_value = 1.0) into histogram[9] for
+        * interval [0.9, 1.0]
+        */
+       histogram[9] += histogram[10];
+       histogram[10] = 0;
+
        /* Pre-requisite that at least 55 sequences are processed. */
        ATF_REQUIRE(m >= 55);