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Commit bc1ebe80 authored by Rusty Russell's avatar Rusty Russell
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dgraph: add dgraph_check and CCAN_DGRAPH_DEBUG 

This is good form for datastructures, so caller can track weird bugs.
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 02358a94
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Showing with 275 additions and 9 deletions
ccan/dgraph/dgraph.c
View file @ bc1ebe80
/* Licensed under LGPLv2.1+ - see LICENSE file for details */
#include <ccan/dgraph/dgraph.h>
#include <stdlib.h>
#include <stdio.h>
void dgraph_init_node(struct dgraph_node *n)
{
......@@ -22,6 +23,7 @@ void dgraph_clear_node(struct dgraph_node *n)
struct dgraph_edge *e;
unsigned int i;
(void)dgraph_debug(n);
for (i = DGRAPH_FROM; i <= DGRAPH_TO; i++) {
while ((e = tlist_top(&n->edge[i], list[i])) != NULL) {
assert(e->n[i] == n);
......@@ -33,6 +35,9 @@ void dgraph_clear_node(struct dgraph_node *n)
void dgraph_add_edge(struct dgraph_node *from, struct dgraph_node *to)
{
struct dgraph_edge *e = malloc(sizeof(*e));
(void)dgraph_debug(from);
(void)dgraph_debug(to);
e->n[DGRAPH_FROM] = from;
e->n[DGRAPH_TO] = to;
tlist_add(&from->edge[DGRAPH_FROM], e, list[DGRAPH_FROM]);
......@@ -43,6 +48,8 @@ bool dgraph_del_edge(struct dgraph_node *from, struct dgraph_node *to)
{
struct dgraph_edge *e, *next;
(void)dgraph_debug(from);
(void)dgraph_debug(to);
dgraph_for_each_edge_safe(from, e, next, DGRAPH_FROM) {
if (e->n[DGRAPH_TO] == to) {
free_edge(e);
......@@ -59,22 +66,110 @@ static bool traverse_depth_first(struct dgraph_node *n,
{
struct dgraph_edge *e, *next;
dgraph_for_each_edge_safe(n, e, next, dir) {
/* dgraph_for_each_edge_safe, without dgraph_debug() */
tlist_for_each_safe(&n->edge[dir], e, next, list[dir]) {
if (!traverse_depth_first(e->n[!dir], dir, fn, data))
return false;
}
return fn(n, (void *)data);
}
void dgraph_traverse(struct dgraph_node *n,
void dgraph_traverse(const struct dgraph_node *n,
enum dgraph_dir dir,
bool (*fn)(struct dgraph_node *, void *),
const void *data)
{
struct dgraph_edge *e, *next;
dgraph_for_each_edge_safe(n, e, next, dir) {
/* dgraph_for_each_edge_safe, without dgraph_debug() */
tlist_for_each_safe(&n->edge[dir], e, next, list[dir]) {
if (!traverse_depth_first(e->n[!dir], dir, fn, data))
break;
}
}
struct check_info {
const struct dgraph_node *ret;
const char *abortstr;
};
static bool find_backedge(const struct dgraph_node *from,
const struct dgraph_node *to,
enum dgraph_dir dir)
{
struct dgraph_edge *e;
tlist_for_each(&from->edge[dir], e, list[dir]) {
if (e->n[!dir] == to)
return true;
}
return false;
}
static bool dgraph_check_node(struct dgraph_node *n, void *info_)
{
struct check_info *info = info_;
unsigned int dir;
struct dgraph_edge *e;
for (dir = DGRAPH_FROM; dir <= DGRAPH_TO; dir++) {
/* First, check edges list. */
if (!tlist_check(&n->edge[dir], info->abortstr)) {
info->ret = NULL;
return false;
}
/* dgraph_for_each_edge() without check! */
tlist_for_each(&n->edge[dir], e, list[dir]) {
if (e->n[dir] == n) {
if (find_backedge(e->n[!dir], n, !dir))
continue;
if (info->abortstr) {
fprintf(stderr,
"%s: node %p %s edge doesnt"
" point back to %p\n",
info->abortstr, e->n[!dir],
!dir == DGRAPH_FROM
? "DGRAPH_FROM" : "DGRAPH_TO",
n);
abort();
}
info->ret = NULL;
return false;
}
if (info->abortstr) {
fprintf(stderr,
"%s: node %p %s edge %p points"
" to %p\n",
info->abortstr, n,
dir == DGRAPH_FROM
? "DGRAPH_FROM" : "DGRAPH_TO",
e, e->n[dir]);
abort();
}
info->ret = NULL;
return false;
}
}
return true;
}
struct dgraph_node *dgraph_check(const struct dgraph_node *n,
const char *abortstr)
{
struct check_info info;
/* This gets set to NULL by dgraph_check_node on failure. */
info.ret = n;
info.abortstr = abortstr;
dgraph_check_node((struct dgraph_node *)info.ret, &info);
if (info.ret)
dgraph_traverse(n, DGRAPH_FROM, dgraph_check_node, &info);
if (info.ret)
dgraph_traverse(n, DGRAPH_TO, dgraph_check_node, &info);
return (void *)info.ret;
}
ccan/dgraph/dgraph.h
View file @ bc1ebe80
......@@ -40,28 +40,46 @@ void dgraph_clear_node(struct dgraph_node *n);
void dgraph_add_edge(struct dgraph_node *from, struct dgraph_node *to);
bool dgraph_del_edge(struct dgraph_node *from, struct dgraph_node *to);
#ifdef CCAN_DGRAPH_DEBUG
#define dgraph_debug(n) dgraph_check((n), __func__)
#else
#define dgraph_debug(n) (n)
#endif
/* You can dgraph_clear_node() the node you're on safely. */
#define dgraph_traverse_from(n, fn, arg) \
dgraph_traverse((n), DGRAPH_FROM, \
dgraph_traverse(dgraph_debug(n), DGRAPH_FROM, \
typesafe_cb_preargs(bool, void *, (fn), (arg), \
struct dgraph_node *), \
(arg))
#define dgraph_traverse_to(n, fn, arg) \
dgraph_traverse((n), DGRAPH_TO, \
dgraph_traverse(dgraph_debug(n), DGRAPH_TO, \
typesafe_cb_preargs(bool, void *, (fn), (arg), \
struct dgraph_node *), \
(arg))
void dgraph_traverse(struct dgraph_node *n,
void dgraph_traverse(const struct dgraph_node *n,
enum dgraph_dir dir,
bool (*fn)(struct dgraph_node *from, void *data),
const void *data);
#define dgraph_for_each_edge(n, i, dir) \
tlist_for_each(&(n)->edge[dir], i, list[dir])
tlist_for_each(&dgraph_debug(n)->edge[dir], i, list[dir])
#define dgraph_for_each_edge_safe(n, i, next, dir) \
tlist_for_each_safe(&(n)->edge[dir], i, next, list[dir])
tlist_for_each_safe(&dgraph_debug(n)->edge[dir], i, next, list[dir])
/**
* dgraph_check - check a graph for consistency
* @n: the dgraph_node to check.
* @abortstr: the string to print on aborting, or NULL.
*
* Returns @n if the list is consistent, NULL if not (it can never
* return NULL if @abortstr is set).
*
* See also: tlist_check()
*/
struct dgraph_node *dgraph_check(const struct dgraph_node *n,
const char *abortstr);
#endif /* CCAN_DGRAPH_H */
ccan/dgraph/test/run-debug.c 0 → 100644
View file @ bc1ebe80
#define CCAN_DGRAPH_DEBUG 1
#include <ccan/dgraph/dgraph.h>
/* Include the C files directly. */
#include <ccan/dgraph/dgraph.c>
#include <ccan/tap/tap.h>
static bool count_nodes(struct dgraph_node *n, unsigned int *count)
{
(*count)++;
return true;
}
static bool stop_traverse(struct dgraph_node *n, unsigned int *count)
{
if (--(*count) == 0)
return false;
return true;
}
int main(void)
{
struct dgraph_node n1, n2, n3;
unsigned int count = 0;
/* This is how many tests you plan to run */
plan_tests(42);
dgraph_init_node(&n1);
ok1(dgraph_check(&n1, NULL) == &n1);
count = 0;
dgraph_traverse_from(&n1, count_nodes, &count);
ok1(count == 0);
count = 0;
dgraph_traverse_to(&n1, count_nodes, &count);
ok1(count == 0);
dgraph_init_node(&n2);
ok1(dgraph_check(&n2, NULL) == &n2);
dgraph_add_edge(&n1, &n2);
ok1(dgraph_check(&n1, NULL) == &n1);
ok1(dgraph_check(&n2, NULL) == &n2);
count = 0;
dgraph_traverse_from(&n1, count_nodes, &count);
ok1(count == 1);
count = 0;
dgraph_traverse_to(&n1, count_nodes, &count);
ok1(count == 0);
count = 0;
dgraph_traverse_from(&n2, count_nodes, &count);
ok1(count == 0);
count = 0;
dgraph_traverse_to(&n2, count_nodes, &count);
ok1(count == 1);
dgraph_init_node(&n3);
ok1(dgraph_check(&n3, NULL) == &n3);
dgraph_add_edge(&n2, &n3);
ok1(dgraph_check(&n1, NULL) == &n1);
ok1(dgraph_check(&n2, NULL) == &n2);
ok1(dgraph_check(&n3, NULL) == &n3);
count = 0;
dgraph_traverse_from(&n1, count_nodes, &count);
ok1(count == 2);
count = 0;
dgraph_traverse_to(&n1, count_nodes, &count);
ok1(count == 0);
count = 0;
dgraph_traverse_from(&n2, count_nodes, &count);
ok1(count == 1);
count = 0;
dgraph_traverse_to(&n2, count_nodes, &count);
ok1(count == 1);
count = 0;
dgraph_traverse_from(&n3, count_nodes, &count);
ok1(count == 0);
count = 0;
dgraph_traverse_to(&n3, count_nodes, &count);
ok1(count == 2);
/* Check stopping traverse. */
count = 1;
dgraph_traverse_from(&n1, stop_traverse, &count);
ok1(count == 0);
count = 2;
dgraph_traverse_from(&n1, stop_traverse, &count);
ok1(count == 0);
count = 3;
dgraph_traverse_from(&n1, stop_traverse, &count);
ok1(count == 1);
dgraph_clear_node(&n1);
ok1(dgraph_check(&n1, NULL) == &n1);
ok1(dgraph_check(&n2, NULL) == &n2);
ok1(dgraph_check(&n3, NULL) == &n3);
count = 0;
dgraph_traverse_from(&n2, count_nodes, &count);
ok1(count == 1);
count = 0;
dgraph_traverse_to(&n2, count_nodes, &count);
ok1(count == 0);
count = 0;
dgraph_traverse_from(&n3, count_nodes, &count);
ok1(count == 0);
count = 0;
dgraph_traverse_to(&n3, count_nodes, &count);
ok1(count == 1);
ok1(dgraph_del_edge(&n2, &n3));
count = 0;
dgraph_traverse_from(&n2, count_nodes, &count);
ok1(count == 0);
count = 0;
dgraph_traverse_to(&n2, count_nodes, &count);
ok1(count == 0);
count = 0;
dgraph_traverse_from(&n3, count_nodes, &count);
ok1(count == 0);
count = 0;
dgraph_traverse_to(&n3, count_nodes, &count);
ok1(count == 0);
ok1(dgraph_check(&n1, NULL) == &n1);
ok1(dgraph_check(&n2, NULL) == &n2);
ok1(dgraph_check(&n3, NULL) == &n3);
ok1(!dgraph_del_edge(&n2, &n3));
dgraph_clear_node(&n2);
ok1(dgraph_check(&n1, NULL) == &n1);
ok1(dgraph_check(&n2, NULL) == &n2);
ok1(dgraph_check(&n3, NULL) == &n3);
/* This exits depending on whether all tests passed */
return exit_status();
}
ccan/dgraph/test/run.c
View file @ bc1ebe80
......@@ -22,9 +22,10 @@ int main(void)
unsigned int count = 0;
/* This is how many tests you plan to run */
plan_tests(25);
plan_tests(42);
dgraph_init_node(&n1);
ok1(dgraph_check(&n1, NULL) == &n1);
count = 0;
dgraph_traverse_from(&n1, count_nodes, &count);
ok1(count == 0);
......@@ -33,7 +34,10 @@ int main(void)
ok1(count == 0);
dgraph_init_node(&n2);
ok1(dgraph_check(&n2, NULL) == &n2);
dgraph_add_edge(&n1, &n2);
ok1(dgraph_check(&n1, NULL) == &n1);
ok1(dgraph_check(&n2, NULL) == &n2);
count = 0;
dgraph_traverse_from(&n1, count_nodes, &count);
ok1(count == 1);
......@@ -48,7 +52,11 @@ int main(void)
ok1(count == 1);
dgraph_init_node(&n3);
ok1(dgraph_check(&n3, NULL) == &n3);
dgraph_add_edge(&n2, &n3);
ok1(dgraph_check(&n1, NULL) == &n1);
ok1(dgraph_check(&n2, NULL) == &n2);
ok1(dgraph_check(&n3, NULL) == &n3);
count = 0;
dgraph_traverse_from(&n1, count_nodes, &count);
ok1(count == 2);
......@@ -80,6 +88,9 @@ int main(void)
ok1(count == 1);
dgraph_clear_node(&n1);
ok1(dgraph_check(&n1, NULL) == &n1);
ok1(dgraph_check(&n2, NULL) == &n2);
ok1(dgraph_check(&n3, NULL) == &n3);
count = 0;
dgraph_traverse_from(&n2, count_nodes, &count);
......@@ -107,10 +118,17 @@ int main(void)
count = 0;
dgraph_traverse_to(&n3, count_nodes, &count);
ok1(count == 0);
ok1(dgraph_check(&n1, NULL) == &n1);
ok1(dgraph_check(&n2, NULL) == &n2);
ok1(dgraph_check(&n3, NULL) == &n3);
ok1(!dgraph_del_edge(&n2, &n3));
dgraph_clear_node(&n2);
ok1(dgraph_check(&n1, NULL) == &n1);
ok1(dgraph_check(&n2, NULL) == &n2);
ok1(dgraph_check(&n3, NULL) == &n3);
/* This exits depending on whether all tests passed */
return exit_status();
}
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