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-rw-r--r--src/basic/static-destruct.h92
1 files changed, 67 insertions, 25 deletions
diff --git a/src/basic/static-destruct.h b/src/basic/static-destruct.h
index 97baac7abb..2ffc6516f8 100644
--- a/src/basic/static-destruct.h
+++ b/src/basic/static-destruct.h
@@ -4,15 +4,46 @@
#include "alloc-util.h"
#include "macro.h"
+#include "memory-util.h"
/* A framework for registering static variables that shall be freed on shutdown of a process. It's a bit like gcc's
* destructor attribute, but allows us to precisely schedule when we want to free the variables. This is supposed to
* feel a bit like the gcc cleanup attribute, but for static variables. Note that this does not work for static
* variables declared in .so's, as the list is private to the same linking unit. But maybe that's a good thing. */
-typedef struct StaticDestructor {
+#define _common_static_destruct_attrs_ \
+ /* Older compilers don't know "retain" attribute. */ \
+ _Pragma("GCC diagnostic ignored \"-Wattributes\"") \
+ /* The actual destructor structure we place in a special section to find it. */ \
+ _section_("SYSTEMD_STATIC_DESTRUCT") \
+ /* Use pointer alignment, since that is apparently what gcc does for static variables. */ \
+ _alignptr_ \
+ /* Make sure this is not dropped from the image despite not being explicitly referenced. */ \
+ _used_ \
+ /* Prevent garbage collection by the linker. */ \
+ _retain_ \
+ /* Make sure that AddressSanitizer doesn't pad this variable: we want everything in this section
+ * packed next to each other so that we can enumerate it. */ \
+ _variable_no_sanitize_address_
+
+typedef enum StaticDestructorType {
+ STATIC_DESTRUCTOR_SIMPLE,
+ STATIC_DESTRUCTOR_ARRAY,
+ _STATIC_DESTRUCTOR_TYPE_MAX,
+ _STATIC_DESTRUCTOR_INVALID = -EINVAL,
+} StaticDestructorType;
+
+typedef struct SimpleCleanup {
void *data;
free_func_t destroy;
+} SimpleCleanup;
+
+typedef struct StaticDestructor {
+ StaticDestructorType type;
+ union {
+ SimpleCleanup simple;
+ ArrayCleanup array;
+ };
} StaticDestructor;
#define STATIC_DESTRUCTOR_REGISTER(variable, func) \
@@ -24,40 +55,51 @@ typedef struct StaticDestructor {
typeof(variable) *q = p; \
func(q); \
} \
- /* Older compilers don't know "retain" attribute. */ \
- _Pragma("GCC diagnostic ignored \"-Wattributes\"") \
- /* The actual destructor structure we place in a special section to find it. */ \
- _section_("SYSTEMD_STATIC_DESTRUCT") \
- /* Use pointer alignment, since that is apparently what gcc does for static variables. */ \
- _alignptr_ \
- /* Make sure this is not dropped from the image despite not being explicitly referenced. */ \
- _used_ \
- /* Prevent garbage collection by the linker. */ \
- _retain_ \
- /* Make sure that AddressSanitizer doesn't pad this variable: we want everything in this section
- * packed next to each other so that we can enumerate it. */ \
- _variable_no_sanitize_address_ \
+ _common_static_destruct_attrs_ \
static const StaticDestructor UNIQ_T(static_destructor_entry, uq) = { \
- .data = &(variable), \
- .destroy = UNIQ_T(static_destructor_wrapper, uq), \
+ .type = STATIC_DESTRUCTOR_SIMPLE, \
+ .simple.data = &(variable), \
+ .simple.destroy = UNIQ_T(static_destructor_wrapper, uq), \
}
+#define STATIC_ARRAY_DESTRUCTOR_REGISTER(a, n, func) \
+ _STATIC_ARRAY_DESTRUCTOR_REGISTER(UNIQ, a, n, func)
+
+#define _STATIC_ARRAY_DESTRUCTOR_REGISTER(uq, a, n, func) \
+ /* Type-safety check */ \
+ _unused_ static void (* UNIQ_T(static_destructor_wrapper, uq))(typeof(a[0]) *x, size_t y) = (func); \
+ _common_static_destruct_attrs_ \
+ static const StaticDestructor UNIQ_T(static_destructor_entry, uq) = { \
+ .type = STATIC_DESTRUCTOR_ARRAY, \
+ .array.parray = (void**) &(a), \
+ .array.pn = &(n), \
+ .array.pfunc = (free_array_func_t) (func), \
+ };
+
/* Beginning and end of our section listing the destructors. We define these as weak as we want this to work
* even if no destructors are defined and the section is missing. */
-extern const struct StaticDestructor _weak_ __start_SYSTEMD_STATIC_DESTRUCT[];
-extern const struct StaticDestructor _weak_ __stop_SYSTEMD_STATIC_DESTRUCT[];
+extern const StaticDestructor _weak_ __start_SYSTEMD_STATIC_DESTRUCT[];
+extern const StaticDestructor _weak_ __stop_SYSTEMD_STATIC_DESTRUCT[];
/* The function to destroy everything. (Note that this must be static inline, as it's key that it remains in
* the same linking unit as the variables we want to destroy.) */
static inline void static_destruct(void) {
- const StaticDestructor *d;
-
if (!__start_SYSTEMD_STATIC_DESTRUCT)
return;
- d = ALIGN_PTR(__start_SYSTEMD_STATIC_DESTRUCT);
- while (d < __stop_SYSTEMD_STATIC_DESTRUCT) {
- d->destroy(d->data);
- d = ALIGN_PTR(d + 1);
- }
+ for (const StaticDestructor *d = ALIGN_PTR(__start_SYSTEMD_STATIC_DESTRUCT);
+ d < __stop_SYSTEMD_STATIC_DESTRUCT;
+ d = ALIGN_PTR(d + 1))
+ switch (d->type) {
+ case STATIC_DESTRUCTOR_SIMPLE:
+ d->simple.destroy(d->simple.data);
+ break;
+
+ case STATIC_DESTRUCTOR_ARRAY:
+ array_cleanup(&d->array);
+ break;
+
+ default:
+ assert_not_reached();
+ }
}