tdb2: failtest: use a linked list for history, not an array.

This avoids a silly realloc, but more importantly it gets us closer to
being runtime extensible, as each history element can be a different
size.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
(Imported from CCAN commit 9571a41e8494f3135557e3ec50c2de856392173e)

2 files changed, 26 insertions, 30 deletions

diff --git a/lib/tdb2/test/failtest_helper.c b/lib/tdb2/test/failtest_helper.c
index d24ac4c42b..f3ef09a6c3 100644
--- a/lib/tdb2/test/failtest_helper.c
+++ b/lib/tdb2/test/failtest_helper.c
@@ -26,12 +26,14 @@ bool failmatch(const struct failtest_call *call,
 }
 
 static const struct failtest_call *
-find_repeat(const struct failtest_call *start, const struct failtest_call *end,
+find_repeat(const struct tlist_calls *history,
 	    const struct failtest_call *call)
 {
 	const struct failtest_call *i;
 
-	for (i = start; i < end; i++) {
+	tlist_for_each(history, i, list) {
+		if (i != call)
+			continue;
 		if (failmatch(i, call->file, call->line, call->type))
 			return i;
 	}
@@ -49,32 +51,31 @@ static bool is_unlock(const struct failtest_call *call)
 		&& call->u.fcntl.arg.fl.l_type == F_UNLCK;
 }
 
-bool exit_check_log(struct failtest_call *history, unsigned num)
+bool exit_check_log(struct tlist_calls *history)
 {
-	unsigned int i;
+	const struct failtest_call *i;
 
-	for (i = 0; i < num; i++) {
-		if (!history[i].fail)
+	tlist_for_each(history, i, list) {
+		if (!i->fail)
 			continue;
 		/* Failing the /dev/urandom open doesn't count: we fall back. */
-		if (failmatch(&history[i], URANDOM_OPEN))
+		if (failmatch(i, URANDOM_OPEN))
 			continue;
 
 		/* Similarly with read fail. */
-		if (failmatch(&history[i], URANDOM_READ))
+		if (failmatch(i, URANDOM_READ))
 			continue;
 
 		/* Initial allocation of tdb doesn't log. */
-		if (failmatch(&history[i], INITIAL_TDB_MALLOC))
+		if (failmatch(i, INITIAL_TDB_MALLOC))
 			continue;
 
 		/* We don't block "failures" on non-blocking locks. */
-		if (is_nonblocking_lock(&history[i]))
+		if (is_nonblocking_lock(i))
 			continue;
 
 		if (!tap_log_messages)
-			diag("We didn't log for %u (%s:%u)",
-			     i, history[i].file, history[i].line);
+			diag("We didn't log for %s:%u", i->file, i->line);
 		return tap_log_messages != 0;
 	}
 	return true;
@@ -82,9 +83,11 @@ bool exit_check_log(struct failtest_call *history, unsigned num)
 
 /* Some places we soldier on despite errors: only fail them once. */
 enum failtest_result
-block_repeat_failures(struct failtest_call *history, unsigned num)
+block_repeat_failures(struct tlist_calls *history)
 {
-	const struct failtest_call *i, *last = &history[num-1];
+	const struct failtest_call *i, *last;
+
+	last = tlist_tail(history, struct failtest_call, list);
 
 	if (failtest_suppress)
 		return FAIL_DONT_FAIL;
@@ -92,7 +95,7 @@ block_repeat_failures(struct failtest_call *history, unsigned num)
 	if (failmatch(last, INITIAL_TDB_MALLOC)
 	    || failmatch(last, URANDOM_OPEN)
 	    || failmatch(last, URANDOM_READ)) {
-		if (find_repeat(history, last, last))
+		if (find_repeat(history, last))
 			return FAIL_DONT_FAIL;
 		return FAIL_PROBE;
 	}
@@ -100,21 +103,15 @@ block_repeat_failures(struct failtest_call *history, unsigned num)
 	/* Unlock or non-blocking lock is fail-once. */
 	if (is_unlock(last)) {
 		/* Find a previous unlock at this point? */
-		for (i = find_repeat(history, last, last);
-		     i;
-		     i = find_repeat(history, i, last)) {
-			if (is_unlock(i))
-				return FAIL_DONT_FAIL;
-		}
+		i = find_repeat(history, last);
+		if (i && is_unlock(i))
+			return FAIL_DONT_FAIL;
 		return FAIL_PROBE;
 	} else if (is_nonblocking_lock(last)) {
 		/* Find a previous non-blocking lock at this point? */
-		for (i = find_repeat(history, last, last);
-		     i;
-		     i = find_repeat(history, i, last)) {
-			if (is_nonblocking_lock(i))
-				return FAIL_DONT_FAIL;
-		}
+		i = find_repeat(history, last);
+		if (i && is_nonblocking_lock(i))
+			return FAIL_DONT_FAIL;
 		return FAIL_PROBE;
 	}
 
diff --git a/lib/tdb2/test/failtest_helper.h b/lib/tdb2/test/failtest_helper.h
index 7f912bb5e9..a3c680885d 100644
--- a/lib/tdb2/test/failtest_helper.h
+++ b/lib/tdb2/test/failtest_helper.h
@@ -8,11 +8,10 @@
 #define URANDOM_OPEN		"open.c", 62, FAILTEST_OPEN
 #define URANDOM_READ		"open.c", 42, FAILTEST_READ
 
-bool exit_check_log(struct failtest_call *history, unsigned num);
+bool exit_check_log(struct tlist_calls *history);
 bool failmatch(const struct failtest_call *call,
 	       const char *file, int line, enum failtest_call_type type);
-enum failtest_result
-block_repeat_failures(struct failtest_call *history, unsigned num);
+enum failtest_result block_repeat_failures(struct tlist_calls *history);
 
 /* Set this to suppress failure. */
 extern bool failtest_suppress;