diff options
Diffstat (limited to 'source4/lib')
| -rw-r--r-- | source4/lib/talloc.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/source4/lib/talloc.c b/source4/lib/talloc.c index ce8f1c5272..55b97717c7 100644 --- a/source4/lib/talloc.c +++ b/source4/lib/talloc.c @@ -124,6 +124,41 @@ void talloc_increase_ref_count(const void *ptr) tc->ref_count++; } +/* + helper for talloc_reference() +*/ +static int talloc_reference_destructor(void *ptr) +{ + void **handle = ptr; + talloc_free(*handle); + return 0; +} + +/* + make a secondary reference to a pointer, hanging off the given context. + the pointer remains valid until both the original caller and this given + context are freed. + + the major use for this is when two different structures need to reference the + same underlying data, and you want to be able to free the two instances separately, + and in either order +*/ +void *talloc_reference(const void *context, const void *ptr) +{ + void **handle; + handle = _talloc(context, sizeof(void *)); + if (handle == NULL) { + return NULL; + } + /* note that we hang the destructor off the handle, not the + main context as that allows the caller to still setup their + own destructor on the context if they want to */ + talloc_set_destructor(handle, talloc_reference_destructor); + talloc_increase_ref_count(ptr); + *handle = discard_const(ptr); + return *handle; +} + /* add a name to an existing pointer - va_list version |