lix/boehmgc-coroutine-sp-fallback.diff
Pierre Bourdon f7b6552699 [resubmit] flake: update nixpkgs pin 23.11->24.05 (+ boehmgc compat changes)
-- message from cl/1418 --

The boehmgc changes are bundled into this commit because doing otherwise
would require an annoying dance of "adding compatibility for < 8.2.6 and
>= 8.2.6" then updating the pin then removing the (now unneeded)
compatibility. It doesn't seem worth the trouble to me given the low
complexity of said changes.

Rebased coroutine-sp-fallback.diff patch taken from https://github.com/NixOS/nixpkgs/pull/317227

-- jade resubmit changes --

This is a resubmission of https://gerrit.lix.systems/c/lix/+/1418, which
was reverted in https://gerrit.lix.systems/c/lix/+/1432 for breaking CI
evaluation without being detected.

I have run `nix flake check -Lv` on this one before submission and it
passes on my machine and crucially without eval errors, so the CI result
should be accurate.

It seems like someone renamed forbiddenDependenciesRegex to
forbiddenDependenciesRegexes in nixpkgs and also changed the type
incompatibly. That's pretty silly, but at least it's just an eval error.

Also, `xonsh` regressed the availability of `xonsh-unwrapped`, but it
was fixed by us in https://github.com/NixOS/nixpkgs/pull/317636, which
is now in our channel, so we update nixpkgs compared to the original
iteration of this to simply get that.

We originally had a regression related to some reorganization of the
nixpkgs lib test suite in which there was broken parameter passing.
This, too, we got quickfixed in nixpkgs, so we don't need any changes
for it: https://github.com/NixOS/nixpkgs/pull/317772

Related: https://gerrit.lix.systems/c/lix/+/1428
Fixes: #385

Change-Id: I26d41ea826fec900ebcad0f82a727feb6bcd28f3
2024-06-12 15:34:22 -07:00

55 lines
2.3 KiB
Diff

diff --git a/pthread_stop_world.c b/pthread_stop_world.c
index 2b45489..0e6d8ef 100644
--- a/pthread_stop_world.c
+++ b/pthread_stop_world.c
@@ -776,6 +776,8 @@ STATIC void GC_restart_handler(int sig)
/* world is stopped. Should not fail if it isn't. */
GC_INNER void GC_push_all_stacks(void)
{
+ size_t stack_limit;
+ pthread_attr_t pattr;
GC_bool found_me = FALSE;
size_t nthreads = 0;
int i;
@@ -868,6 +870,40 @@ GC_INNER void GC_push_all_stacks(void)
hi = p->altstack + p->altstack_size;
# endif
/* FIXME: Need to scan the normal stack too, but how ? */
+ } else {
+ #ifdef HAVE_PTHREAD_ATTR_GET_NP
+ if (pthread_attr_init(&pattr) != 0) {
+ ABORT("GC_push_all_stacks: pthread_attr_init failed!");
+ }
+ if (pthread_attr_get_np(p->id, &pattr) != 0) {
+ ABORT("GC_push_all_stacks: pthread_attr_get_np failed!");
+ }
+ #else
+ if (pthread_getattr_np(p->id, &pattr)) {
+ ABORT("GC_push_all_stacks: pthread_getattr_np failed!");
+ }
+ #endif
+ if (pthread_attr_getstacksize(&pattr, &stack_limit)) {
+ ABORT("GC_push_all_stacks: pthread_attr_getstacksize failed!");
+ }
+ if (pthread_attr_destroy(&pattr)) {
+ ABORT("GC_push_all_stacks: pthread_attr_destroy failed!");
+ }
+ // When a thread goes into a coroutine, we lose its original sp until
+ // control flow returns to the thread.
+ // While in the coroutine, the sp points outside the thread stack,
+ // so we can detect this and push the entire thread stack instead,
+ // as an approximation.
+ // We assume that the coroutine has similarly added its entire stack.
+ // This could be made accurate by cooperating with the application
+ // via new functions and/or callbacks.
+ #ifndef STACK_GROWS_UP
+ if (lo >= hi || lo < hi - stack_limit) { // sp outside stack
+ lo = hi - stack_limit;
+ }
+ #else
+ #error "STACK_GROWS_UP not supported in boost_coroutine2 (as of june 2021), so we don't support it in Nix."
+ #endif
}
# ifdef STACKPTR_CORRECTOR_AVAILABLE
if (GC_sp_corrector != 0)