tjh.dev
1diff --git a/pthread_stop_world.c b/pthread_stop_world.c
2index 2b45489..0e6d8ef 100644
3--- a/pthread_stop_world.c
4+++ b/pthread_stop_world.c
5@@ -776,6 +776,8 @@
6 /* world is stopped. Should not fail if it isn't. */
7 GC_INNER void GC_push_all_stacks(void)
8 {
9+ size_t stack_limit;
10+ pthread_attr_t pattr;
11 GC_bool found_me = FALSE;
12 size_t nthreads = 0;
13 int i;
14@@ -868,6 +870,45 @@
15 hi = p->altstack + p->altstack_size;
16 # endif
17 /* FIXME: Need to scan the normal stack too, but how ? */
18+ } else {
19+ #if defined(HAVE_PTHREAD_ATTR_GET_NP)
20+ if (pthread_attr_init(&pattr) != 0) {
21+ ABORT("GC_push_all_stacks: pthread_attr_init failed!");
22+ }
23+ if (pthread_attr_get_np(p->id, &pattr) != 0) {
24+ ABORT("GC_push_all_stacks: pthread_attr_get_np failed!");
25+ }
26+ #elif defined(HAVE_PTHREAD_GETATTR_NP)
27+ if (pthread_getattr_np(p->id, &pattr)) {
28+ ABORT("GC_push_all_stacks: pthread_getattr_np failed!");
29+ }
30+ #else
31+ /* assume default */
32+ if (pthread_attr_init(&pattr) != 0) {
33+ ABORT("GC_push_all_stacks: pthread_attr_init failed!");
34+ }
35+ #endif
36+ if (pthread_attr_getstacksize(&pattr, &stack_limit)) {
37+ ABORT("GC_push_all_stacks: pthread_attr_getstacksize failed!");
38+ }
39+ if (pthread_attr_destroy(&pattr)) {
40+ ABORT("GC_push_all_stacks: pthread_attr_destroy failed!");
41+ }
42+ // When a thread goes into a coroutine, we lose its original sp until
43+ // control flow returns to the thread.
44+ // While in the coroutine, the sp points outside the thread stack,
45+ // so we can detect this and push the entire thread stack instead,
46+ // as an approximation.
47+ // We assume that the coroutine has similarly added its entire stack.
48+ // This could be made accurate by cooperating with the application
49+ // via new functions and/or callbacks.
50+ #ifndef STACK_GROWS_UP
51+ if (lo >= hi || lo < hi - stack_limit) { // sp outside stack
52+ lo = hi - stack_limit;
53+ }
54+ #else
55+ #error "STACK_GROWS_UP not supported in boost_coroutine2 (as of june 2021), so we don't support it in Nix."
56+ #endif
57 }
58 # ifdef STACKPTR_CORRECTOR_AVAILABLE
59 if (GC_sp_corrector != 0)