Hi,
On Wed, 2024-07-17 at 18:34 -0400, Aaron Merey wrote:
> From: Heather McIntyre <[email protected]>
>
> * libdw/libdw_findcu.c (__libdw_findcu): Use eu_tfind
> and dwarf_lock
> (__libdw_intern_next_unit): Use per-Dwarf_CU locks.
>
> Signed-off-by: Heather S. McIntyre <[email protected]>
> Signed-off-by: Aaron Merey <[email protected]>
> Signed-off-by: Mark Wielaard <[email protected]>
>
> ---
> v2 changes:
> Use per-Dwarf_CU lock instead of a global lock.
Are you sure this description and the ChangeLog entry are correct?
This patch doesn't contain a change to use eu_tfind (there is already
one). And it seems to use a per-Dwarf lock, not a per-Dwarf_CU lock.
> libdw/libdw_findcu.c | 47 ++++++++++++++++++++++++++++----------------
> 1 file changed, 30 insertions(+), 17 deletions(-)
>
> diff --git a/libdw/libdw_findcu.c b/libdw/libdw_findcu.c
> index 72cf261c..8acff448 100644
> --- a/libdw/libdw_findcu.c
> +++ b/libdw/libdw_findcu.c
> @@ -177,6 +177,8 @@ __libdw_intern_next_unit (Dwarf *dbg, bool debug_types)
> newp->startp = data->d_buf + newp->start;
> newp->endp = data->d_buf + newp->end;
> eu_search_tree_init (&newp->locs_tree);
> + rwlock_init (newp->abbrev_lock);
> + rwlock_init (newp->split_lock);
>
> /* v4 debug type units have version == 4 and unit_type == DW_UT_type. */
> if (debug_types)
Neither of these locks are used in the rest of the patch.
> @@ -243,27 +245,38 @@ __libdw_findcu (Dwarf *dbg, Dwarf_Off start, bool
> v4_debug_types)
> /* Maybe we already know that CU. */
> struct Dwarf_CU fake = { .start = start, .end = 0 };
> struct Dwarf_CU **found = eu_tfind (&fake, tree, findcu_cb);
> + struct Dwarf_CU *result = NULL;
> if (found != NULL)
> return *found;
>
> - if (start < *next_offset)
> - {
> - __libdw_seterrno (DWARF_E_INVALID_DWARF);
> - return NULL;
> - }
> + rwlock_wrlock (dbg->dwarf_lock);
>
> - /* No. Then read more CUs. */
> - while (1)
> - {
> - struct Dwarf_CU *newp = __libdw_intern_next_unit (dbg, v4_debug_types);
> - if (newp == NULL)
> - return NULL;
> -
> - /* Is this the one we are looking for? */
> - if (start < *next_offset || start == newp->start)
> - return newp;
> - }
> - /* NOTREACHED */
> + if (start < *next_offset)
> + __libdw_seterrno (DWARF_E_INVALID_DWARF);
> + else
> + {
> + /* No. Then read more CUs. */
> + while (1)
> + {
> + struct Dwarf_CU *newp = __libdw_intern_next_unit (dbg,
> + v4_debug_types);
> + if (newp == NULL)
> + {
> + result = NULL;
> + break;
> + }
> +
> + /* Is this the one we are looking for? */
> + if (start < *next_offset || start == newp->start)
> + {
> + result = newp;
> + break;
> + }
> + }
> + }
> +
> + rwlock_unlock (dbg->dwarf_lock);
> + return result;
> }
>
> struct Dwarf_CU *
This uses the global Dwarf structure lock, not a per Dwarf_CU lock.
Cheers,
Mark
