=begin
遠藤です。

fork の子プロセスから元プロセスの Fiber が呼べません。

$ ./ruby -e '
f = Fiber.new { }
fork { f.resume }
Process.waitpid
'
-e:3:in resume': fiber called across trap (FiberError) from -e:3:in block in '
from -e:3:in fork' from -e:3:in '

そういう仕様ならそういう仕様で別に構わないのですが、fiber
called across trap という例外メッセージはおかしい気がします。

ちなみに、trap をまたがって Fiber を呼ぶことは可能なようです。

$ ./ruby -e '
f = Fiber.new { p :ok }
trap(:USR1) { f.resume }
Process.kill :USR1, $$
sleep 0.2
'
:ok

$ ./ruby -e '
f = nil
trap(:USR1) { f = Fiber.new { p :ok } }
Process.kill :USR1, $$
sleep 0.2
f.resume
'
:ok

このチェックはもう必要ないのではないでしょうか。反対がなければ
コミットしようと思います。

diff --git a/cont.c b/cont.c
index a77f35e..932b10e 100644
--- a/cont.c
+++ b/cont.c
@@ -388,7 +388,6 @@ cont_restore_1(rb_context_t *cont)
th->state = sth->state;
th->status = sth->status;
th->tag = sth->tag;

• th->trap_tag = sth->trap_tag;
  th->errinfo = sth->errinfo;
  th->first_proc = sth->first_proc;

@@ -621,9 +620,6 @@ rb_cont_call(int argc, VALUE *argv, VALUE contval)
if (cont->saved_thread.self != th->self) {
rb_raise(rb_eRuntimeError, "continuation called across threads");
}

• if (cont->saved_thread.trap_tag != th->trap_tag) {

• rb_raise(rb_eRuntimeError, "continuation called across trap");

• }
  if (cont->saved_thread.fiber) {
  rb_fiber_t *fcont;
  GetFiberPtr(cont->saved_thread.fiber, fcont);
  @@ -940,9 +936,6 @@ fiber_switch(VALUE fibval, int argc, VALUE *argv,
  int is_resume)
  if (cont->saved_thread.self != th->self) {
  rb_raise(rb_eFiberError, "fiber called across threads");
  }

• else if (cont->saved_thread.trap_tag != th->trap_tag) {

• rb_raise(rb_eFiberError, "fiber called across trap");

• }
  else if (fib->status == TERMINATED) {
  value = rb_exc_new2(rb_eFiberError, "dead fiber called");
  if (th->fiber != fibval) rb_exc_raise(value);
  diff --git a/eval.c b/eval.c
  index c5a72dc..aa01d81 100644
  --- a/eval.c
  +++ b/eval.c
  @@ -677,19 +677,14 @@ rb_protect(VALUE (* proc) (VALUE), VALUE data,
  int * state)
  int status;
  rb_thread_t *th = GET_THREAD();
  rb_control_frame_t *cfp = th->cfp;

• struct rb_vm_trap_tag trap_tag;
  rb_jmpbuf_t org_jmpbuf;

• trap_tag.prev = th->trap_tag;

• PUSH_TAG();

• th->trap_tag = &trap_tag;
  MEMCPY(&org_jmpbuf, &(th)->root_jmpbuf, rb_jmpbuf_t, 1);
  if ((status = EXEC_TAG()) == 0) {
  SAVE_ROOT_JMPBUF(th, result = (*proc) (data));
  }
  MEMCPY(&(th)->root_jmpbuf, &org_jmpbuf, rb_jmpbuf_t, 1);

• th->trap_tag = trap_tag.prev;
  POP_TAG();

  if (state) {
  diff --git a/vm_core.h b/vm_core.h
  index b9b584a..b781765 100644
  --- a/vm_core.h
  +++ b/vm_core.h
  @@ -347,10 +347,6 @@ struct rb_vm_tag {
  struct rb_vm_tag *prev;
  };

-struct rb_vm_trap_tag {

• struct rb_vm_trap_tag *prev;
  -};

#define RUBY_VM_VALUE_CACHE_SIZE 0x1000
#define USE_VALUE_CACHE 0

@@ -414,7 +410,6 @@ typedef struct rb_thread_struct
int transition_for_lock;

  struct rb_vm_tag *tag;

• struct rb_vm_trap_tag *trap_tag;

  int parse_in_eval;
  int mild_compile_error;

--
Yusuke ENDOH mame@tsg.ne.jp
=end