Discussion:
[Pixman] [PATCH] Add destructor function to free pixman_implementation_t structs on exit
Siarhei Siamashka
2017-09-18 10:46:06 UTC
Permalink
This fixes a few small memory leaks detected by valgrind. This memory
was allocated once on pixman library load and never freed (but still
was reachable). The fix only helps if the compiler has support for
__attribute__((constructor)) and __attribute__((destructor))
function attributes.

Reported-by: Emil Velikov <***@gmail.com>
Signed-off-by: Siarhei Siamashka <***@gmail.com>
---
configure.ac | 1 +
pixman/pixman.c | 12 ++++++++++++
2 files changed, 13 insertions(+)

diff --git a/configure.ac b/configure.ac
index e833e45..a592cba 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1047,6 +1047,7 @@ AC_LINK_IFELSE([AC_LANG_SOURCE([[
*/
static int x = 1;
static void __attribute__((constructor)) constructor_function () { x = 0; }
+static void __attribute__((destructor)) destructor_function () { x = 0; }
int main (void) { return x; }
#else
#error not gcc or gcc version is older than 2.7
diff --git a/pixman/pixman.c b/pixman/pixman.c
index f932eac..0bcc832 100644
--- a/pixman/pixman.c
+++ b/pixman/pixman.c
@@ -38,6 +38,18 @@ pixman_constructor (void)
{
global_implementation = _pixman_choose_implementation ();
}
+
+static void __attribute__((destructor))
+pixman_destructor (void)
+{
+ pixman_implementation_t *imp = global_implementation;
+ while (imp)
+ {
+ pixman_implementation_t *fallback = imp->fallback;
+ free (imp);
+ imp = fallback;
+ }
+}
#endif

typedef struct operator_info_t operator_info_t;
--
2.7.3
Pekka Paalanen
2017-09-18 11:09:26 UTC
Permalink
On Mon, 18 Sep 2017 13:46:06 +0300
Post by Siarhei Siamashka
This fixes a few small memory leaks detected by valgrind. This memory
was allocated once on pixman library load and never freed (but still
was reachable). The fix only helps if the compiler has support for
__attribute__((constructor)) and __attribute__((destructor))
function attributes.
---
configure.ac | 1 +
pixman/pixman.c | 12 ++++++++++++
2 files changed, 13 insertions(+)
diff --git a/configure.ac b/configure.ac
index e833e45..a592cba 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1047,6 +1047,7 @@ AC_LINK_IFELSE([AC_LANG_SOURCE([[
*/
static int x = 1;
static void __attribute__((constructor)) constructor_function () { x = 0; }
+static void __attribute__((destructor)) destructor_function () { x = 0; }
int main (void) { return x; }
#else
#error not gcc or gcc version is older than 2.7
diff --git a/pixman/pixman.c b/pixman/pixman.c
index f932eac..0bcc832 100644
--- a/pixman/pixman.c
+++ b/pixman/pixman.c
@@ -38,6 +38,18 @@ pixman_constructor (void)
{
global_implementation = _pixman_choose_implementation ();
}
+
+static void __attribute__((destructor))
+pixman_destructor (void)
+{
+ pixman_implementation_t *imp = global_implementation;
+ while (imp)
+ {
+ pixman_implementation_t *fallback = imp->fallback;
+ free (imp);
+ imp = fallback;
+ }
+}
#endif
typedef struct operator_info_t operator_info_t;
Hi,

looks good to me.
Reviewed-by: Pekka Paalanen <***@collabora.co.uk>

Didn't test.


Thanks,
pq
Emil Velikov
2017-09-18 12:48:02 UTC
Permalink
On 18 September 2017 at 11:46, Siarhei Siamashka
Post by Siarhei Siamashka
This fixes a few small memory leaks detected by valgrind. This memory
was allocated once on pixman library load and never freed (but still
was reachable). The fix only helps if the compiler has support for
__attribute__((constructor)) and __attribute__((destructor))
function attributes.
Looks and works like a charm. FWIW

Reviewed-by: Emil Velikov <***@collabora.com>
Tested-by: Emil Velikov <***@collabora.com>

-Emil

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