commit 46e22762fa51186a998bbf949028e3374d061869 Author: Sebastian Hahn sebastian@torproject.org Date: Fri Aug 28 18:18:48 2015 +0200

Keep unused smartlist storage zeroed

Helps catch bugs with our smartlist usage and shouldn't be too expensive. If it shows up in profiles we can re-investigate. --- changes/bug17026 | 5 +++++ src/common/container.c | 23 ++++++++++++++++++----- 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/changes/bug17026 b/changes/bug17026 new file mode 100644 index 0000000..8b1ce3c --- /dev/null +++ b/changes/bug17026 @@ -0,0 +1,5 @@ + o Minor features: + - Set unused entires in a smartlist to NULL. This helped catch a + (harmless) bug, and shouldn't affect performance too much. + Implements ticket 17026. + diff --git a/src/common/container.c b/src/common/container.c index 636dfb6..df4952f 100644 --- a/src/common/container.c +++ b/src/common/container.c @@ -55,6 +55,7 @@ smartlist_free,(smartlist_t *sl)) void smartlist_clear(smartlist_t *sl) { + memset(sl->list, 0, sizeof(void *) * sl->num_used); sl->num_used = 0; }

@@ -82,9 +83,10 @@ smartlist_ensure_capacity(smartlist_t *sl, int size) while (size > higher) higher *= 2; } - sl->capacity = higher; sl->list = tor_reallocarray(sl->list, sizeof(void *), - ((size_t)sl->capacity)); + ((size_t)higher)); + memset(sl->list + sl->capacity, 0, sizeof(void *) * (higher - sl->capacity)); + sl->capacity = higher; } #undef ASSERT_CAPACITY #undef MAX_CAPACITY @@ -123,6 +125,7 @@ smartlist_remove(smartlist_t *sl, const void *element) if (sl->list[i] == element) { sl->list[i] = sl->list[--sl->num_used]; /* swap with the end */ i--; /* so we process the new i'th element */ + sl->list[sl->num_used] = NULL; } }

@@ -132,9 +135,11 @@ void * smartlist_pop_last(smartlist_t *sl) { tor_assert(sl); - if (sl->num_used) - return sl->list[--sl->num_used]; - else + if (sl->num_used) { + void *tmp = sl->list[--sl->num_used]; + sl->list[sl->num_used] = NULL; + return tmp; + } else return NULL; }

@@ -165,6 +170,7 @@ smartlist_string_remove(smartlist_t *sl, const char *element) tor_free(sl->list[i]); sl->list[i] = sl->list[--sl->num_used]; /* swap with the end */ i--; /* so we process the new i'th element */ + sl->list[sl->num_used] = NULL; } } } @@ -321,6 +327,7 @@ smartlist_intersect(smartlist_t *sl1, const smartlist_t *sl2) if (!smartlist_contains(sl2, sl1->list[i])) { sl1->list[i] = sl1->list[--sl1->num_used]; /* swap with the end */ i--; /* so we process the new i'th element */ + sl1->list[sl1->num_used] = NULL; } }

@@ -345,6 +352,7 @@ smartlist_del(smartlist_t *sl, int idx) tor_assert(idx>=0); tor_assert(idx < sl->num_used); sl->list[idx] = sl->list[--sl->num_used]; + sl->list[sl->num_used] = NULL; }

/** Remove the <b>idx</b>th element of sl; if idx is not the last element, @@ -360,6 +368,7 @@ smartlist_del_keeporder(smartlist_t *sl, int idx) --sl->num_used; if (idx < sl->num_used) memmove(sl->list+idx, sl->list+idx+1, sizeof(void*)*(sl->num_used-idx)); + sl->list[sl->num_used] = NULL; }

/** Insert the value <b>val</b> as the new <b>idx</b>th element of @@ -937,9 +946,11 @@ smartlist_pqueue_pop(smartlist_t *sl, *IDXP(top)=-1; if (--sl->num_used) { sl->list[0] = sl->list[sl->num_used]; + sl->list[sl->num_used] = NULL; UPDATE_IDX(0); smartlist_heapify(sl, compare, idx_field_offset, 0); } + sl->list[sl->num_used] = NULL; return top; }

@@ -959,9 +970,11 @@ smartlist_pqueue_remove(smartlist_t *sl, --sl->num_used; *IDXP(item) = -1; if (idx == sl->num_used) { + sl->list[sl->num_used] = NULL; return; } else { sl->list[idx] = sl->list[sl->num_used]; + sl->list[sl->num_used] = NULL; UPDATE_IDX(idx); smartlist_heapify(sl, compare, idx_field_offset, idx); }