pkgs/tools/package-management/nix/patches/boehmgc-coroutine-sp-fallback.patch

   1 diff --git a/pthread_stop_world.c b/pthread_stop_world.c
   2 index 2b45489..0e6d8ef 100644
   3 --- a/pthread_stop_world.c
   4 +++ b/pthread_stop_world.c
   5 @@ -776,6 +776,8 @@ STATIC void GC_restart_handler(int sig)
   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 +870,40 @@ GC_INNER void GC_push_all_stacks(void)
  15              hi = p->altstack + p->altstack_size;
  16  #         endif
  17            /* FIXME: Need to scan the normal stack too, but how ? */
  18 +        } else {
  19 +          #ifdef 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 +          #else
  27 +          if (pthread_getattr_np(p->id, &pattr)) {
  28 +            ABORT("GC_push_all_stacks: pthread_getattr_np failed!");
  29 +          }
  30 +          #endif
  31 +          if (pthread_attr_getstacksize(&pattr, &stack_limit)) {
  32 +            ABORT("GC_push_all_stacks: pthread_attr_getstacksize failed!");
  33 +          }
  34 +          if (pthread_attr_destroy(&pattr)) {
  35 +            ABORT("GC_push_all_stacks: pthread_attr_destroy failed!");
  36 +          }
  37 +          // When a thread goes into a coroutine, we lose its original sp until
  38 +          // control flow returns to the thread.
  39 +          // While in the coroutine, the sp points outside the thread stack,
  40 +          // so we can detect this and push the entire thread stack instead,
  41 +          // as an approximation.
  42 +          // We assume that the coroutine has similarly added its entire stack.
  43 +          // This could be made accurate by cooperating with the application
  44 +          // via new functions and/or callbacks.
  45 +          #ifndef STACK_GROWS_UP
  46 +            if (lo >= hi || lo < hi - stack_limit) { // sp outside stack
  47 +              lo = hi - stack_limit;
  48 +            }
  49 +          #else
  50 +          #error "STACK_GROWS_UP not supported in boost_coroutine2 (as of june 2021), so we don't support it in Nix."
  51 +          #endif
  52          }
  53  #       ifdef STACKPTR_CORRECTOR_AVAILABLE
  54            if (GC_sp_corrector != 0)