[PATCH i-g-t 12/17] lib/ktap: Use IGT linked lists for storing KTAP results

[Janusz Krzysztofik <janusz.krzysztofik@xxxxxxxxxxxxxxx>]

For code simplicity and clarity, use existing IGT linked lists library
instead of open coding a custom implementation of a list of KTAP results.

While being at it, flatten the code by inverting a check for pending
results.

Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@xxxxxxxxxxxxxxx>
---
 lib/igt_kmod.c | 28 ++++++++++++++++------------
 lib/igt_ktap.c | 25 +++++--------------------
 lib/igt_ktap.h |  6 ++++--
 3 files changed, 25 insertions(+), 34 deletions(-)

diff --git a/lib/igt_kmod.c b/lib/igt_kmod.c
index 988ac164cb..c692954911 100644
--- a/lib/igt_kmod.c
+++ b/lib/igt_kmod.c
@@ -760,7 +760,6 @@ static void __igt_kunit(struct igt_ktest *tst, const char *opts)
 	struct kmod_module *kunit_kmod;
 	bool is_builtin;
 	struct ktap_test_results *results;
-	struct ktap_test_results_element *temp;
 	unsigned long taints;
 	int flags, ret;
 
@@ -784,28 +783,33 @@ static void __igt_kunit(struct igt_ktest *tst, const char *opts)
 		igt_skip("Unable to load %s module\n", tst->module_name);
 	}
 
-	while (READ_ONCE(results->still_running) || READ_ONCE(results->head) != NULL)
+	while (READ_ONCE(results->still_running) || !igt_list_empty(&results->list))
 	{
+		struct ktap_test_results_element *result;
+
 		if (igt_kernel_tainted(&taints)) {
 			ktap_parser_cancel();
 			break;
 		}
 
-		if (READ_ONCE(results->head) != NULL) {
-			pthread_mutex_lock(&results->mutex);
+		pthread_mutex_lock(&results->mutex);
+		if (igt_list_empty(&results->list)) {
+			pthread_mutex_unlock(&results->mutex);
+			continue;
+		}
 
-			igt_dynamic(results->head->test_name) {
-				igt_assert(READ_ONCE(results->head->passed));
+		result = igt_list_first_entry(&results->list, result, link);
 
-				igt_fail_on(igt_kernel_tainted(&taints));
-			}
+		igt_list_del(&result->link);
+		pthread_mutex_unlock(&results->mutex);
 
-			temp = results->head;
-			results->head = results->head->next;
-			free(temp);
+		igt_dynamic(result->test_name) {
+			igt_assert(READ_ONCE(result->passed));
 
-			pthread_mutex_unlock(&results->mutex);
+			igt_fail_on(igt_kernel_tainted(&taints));
 		}
+
+		free(result);
 	}
 
 	ret = ktap_parser_stop();
diff --git a/lib/igt_ktap.c b/lib/igt_ktap.c
index 165f6b2cce..5e9967f980 100644
--- a/lib/igt_ktap.c
+++ b/lib/igt_ktap.c
@@ -12,6 +12,7 @@
 #include "igt_aux.h"
 #include "igt_core.h"
 #include "igt_ktap.h"
+#include "igt_list.h"
 
 #define DELIMITER "-"
 
@@ -335,7 +336,7 @@ static int parse_tap_level(int fd, char *base_test_name, int test_count, bool *f
 			   bool *found_tests, bool is_builtin)
 {
 	char record[BUF_LEN + 1];
-	struct ktap_test_results_element *r, *temp;
+	struct ktap_test_results_element *r;
 	int internal_test_count;
 	char test_name[BUF_LEN + 1];
 	char base_test_name_for_next_level[BUF_LEN + 1];
@@ -403,17 +404,9 @@ static int parse_tap_level(int fd, char *base_test_name, int test_count, bool *f
 			r->test_name[BUF_LEN] = '\0';
 
 			r->passed = false;
-			r->next = NULL;
 
 			pthread_mutex_lock(&results.mutex);
-			if (results.head == NULL) {
-				results.head = r;
-			} else {
-				temp = results.head;
-				while (temp->next != NULL)
-					temp = temp->next;
-				temp->next = r;
-			}
+			igt_list_add_tail(&r->link, &results.list);
 			pthread_mutex_unlock(&results.mutex);
 
 			test_name[0] = '\0';
@@ -431,17 +424,9 @@ static int parse_tap_level(int fd, char *base_test_name, int test_count, bool *f
 			r->test_name[BUF_LEN] = '\0';
 
 			r->passed = true;
-			r->next = NULL;
 
 			pthread_mutex_lock(&results.mutex);
-			if (results.head == NULL) {
-				results.head = r;
-			} else {
-				temp = results.head;
-				while (temp->next != NULL)
-					temp = temp->next;
-				temp->next = r;
-			}
+			igt_list_add_tail(&r->link, &results.list);
 			pthread_mutex_unlock(&results.mutex);
 
 			test_name[0] = '\0';
@@ -523,7 +508,7 @@ static pthread_t ktap_parser_thread;
 
 struct ktap_test_results *ktap_parser_start(int fd, bool is_builtin)
 {
-	results.head = NULL;
+	IGT_INIT_LIST_HEAD(&results.list);
 	pthread_mutex_init(&results.mutex, NULL);
 	results.still_running = true;
 
diff --git a/lib/igt_ktap.h b/lib/igt_ktap.h
index 991800e912..b4d7a6dbc7 100644
--- a/lib/igt_ktap.h
+++ b/lib/igt_ktap.h
@@ -28,16 +28,18 @@
 
 #include <pthread.h>
 
+#include "igt_list.h"
+
 void *igt_ktap_parser(void *unused);
 
 typedef struct ktap_test_results_element {
 	char test_name[BUF_LEN + 1];
 	bool passed;
-	struct ktap_test_results_element *next;
+	struct igt_list_head link;
 } ktap_test_results_element;
 
 struct ktap_test_results {
-	ktap_test_results_element *head;
+	struct igt_list_head list;
 	pthread_mutex_t mutex;
 	bool still_running;
 };
-- 
2.41.0