path: root/src/thread/cancellation.c
diff options
authorRich Felker <>2012-02-09 02:33:08 -0500
committerRich Felker <>2012-02-09 02:33:08 -0500
commitafc35d5efde48b82a7786d9c89b115965da6b637 (patch)
treed71e3007272b5eaa392feb84064459d8de9d82f5 /src/thread/cancellation.c
parented2911a11317729c1a13e779237fed736c676c1b (diff)
replace bad cancellation cleanup abi with a sane one
the old abi was intended to duplicate glibc's abi at the expense of being ugly and slow, but it turns out glib was not even using that abi except on non-gcc-compatible compilers (which it doesn't even support) and was instead using an exceptions-in-c/unwind-based approach whose abi we could not duplicate anyway without nasty dwarf2/unwind integration. the new abi is copied from a very old glibc abi, which seems to still be supported/present in current glibc. it avoids all unwinding, whether by sjlj or exceptions, and merely maintains a linked list of cleanup functions to be called from the context of pthread_exit. i've made some care to ensure that longjmp out of a cleanup function should work, even though it is not required to. this change breaks abi compatibility with programs which were using pthread cancellation, which is unfortunate, but that's why i'm making the change now rather than later. considering that most pthread features have not been usable until recently anyway, i don't see it as a major issue at this point.
Diffstat (limited to 'src/thread/cancellation.c')
1 files changed, 9 insertions, 12 deletions
diff --git a/src/thread/cancellation.c b/src/thread/cancellation.c
index b02cdfb0..967705a9 100644
--- a/src/thread/cancellation.c
+++ b/src/thread/cancellation.c
@@ -1,23 +1,20 @@
#include "pthread_impl.h"
-static void dummy(struct __ptcb *cb)
-weak_alias(dummy, __pthread_do_unwind);
-weak_alias(dummy, __pthread_do_register);
-weak_alias(dummy, __pthread_do_unregister);
+void __do_cleanup_push();
+void __do_cleanup_pop();
-void __pthread_unwind_next(struct __ptcb *cb)
+void _pthread_cleanup_push(struct __ptcb *cb, void (*f)(void *), void *x)
- __pthread_do_unwind(cb);
+ __do_cleanup_push(cb, f, x);
-void __pthread_register_cancel(struct __ptcb *cb)
+void _pthread_cleanup_pop(struct __ptcb *cb, int run)
- __pthread_do_register(cb);
+ __do_cleanup_pop(cb, run);
-void __pthread_unregister_cancel(struct __ptcb *cb)
+static void dummy()
- __pthread_do_unregister(cb);
+weak_alias(dummy, __do_cleanup_push);
+weak_alias(dummy, __do_cleanup_pop);