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lix/boehmgc-coroutine-sp-fallback.diff
Matthew Bauer f4d7208e23 Update boehmgc-coroutine-sp-fallback.diff for darwin
The darwin_stop_world implementation is slightly different. sp goes to
altstack_lo instead of lo in this case. Assuming that is an
implementation detail.

But the fix is the same, when we detect alstack_lo outside of the
expected stack range, we reset it to hi - stack_limit.

Here stack_limit is calculated with pthread_get_stacksize_np since
that is the BSD equivalent to pthread_attr_getstacksize.
2022-09-01 11:48:50 -05:00

78 lines
3.5 KiB
Diff

diff --git a/darwin_stop_world.c b/darwin_stop_world.c
index 3dbaa3fb..36a1d1f7 100644
--- a/darwin_stop_world.c
+++ b/darwin_stop_world.c
@@ -352,6 +352,7 @@ GC_INNER void GC_push_all_stacks(void)
int nthreads = 0;
word total_size = 0;
mach_msg_type_number_t listcount = (mach_msg_type_number_t)THREAD_TABLE_SZ;
+ size_t stack_limit;
if (!EXPECT(GC_thr_initialized, TRUE))
GC_thr_init();
@@ -407,6 +408,19 @@ GC_INNER void GC_push_all_stacks(void)
GC_push_all_stack_sections(lo, hi, p->traced_stack_sect);
}
if (altstack_lo) {
+ // 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.
+ stack_limit = pthread_get_stacksize_np(p->id);
+ if (altstack_lo >= altstack_hi || altstack_lo < altstack_hi - stack_limit) { // sp outside stack
+ altstack_lo = altstack_hi - stack_limit;
+ }
+
total_size += altstack_hi - altstack_lo;
GC_push_all_stack(altstack_lo, altstack_hi);
}
diff --git a/pthread_stop_world.c b/pthread_stop_world.c
index 4b2c429..1fb4c52 100644
--- a/pthread_stop_world.c
+++ b/pthread_stop_world.c
@@ -673,6 +673,8 @@ GC_INNER void GC_push_all_stacks(void)
struct GC_traced_stack_sect_s *traced_stack_sect;
pthread_t self = pthread_self();
word total_size = 0;
+ size_t stack_limit;
+ pthread_attr_t pattr;
if (!EXPECT(GC_thr_initialized, TRUE))
GC_thr_init();
@@ -722,6 +724,31 @@ GC_INNER void GC_push_all_stacks(void)
hi = p->altstack + p->altstack_size;
/* FIXME: Need to scan the normal stack too, but how ? */
/* FIXME: Assume stack grows down */
+ } else {
+ if (pthread_getattr_np(p->id, &pattr)) {
+ ABORT("GC_push_all_stacks: pthread_getattr_np failed!");
+ }
+ 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
}
GC_push_all_stack_sections(lo, hi, traced_stack_sect);
# ifdef STACK_GROWS_UP