variable.c: fix thread + fork errors in autoload

This is fairly non-intrusive bugfix to prevent children
from trying to reach into thread stacks of the parent.
I will probably reuse this idea and redo r62934, too
(same bug).

* vm_core.h (typedef struct rb_vm_struct): add fork_gen counter
* thread.c (rb_thread_atfork_internal): increment fork_gen
* variable.c (struct autoload_data_i): store fork_gen
* variable.c (check_autoload_data): remove (replaced with get_...)
* variable.c (get_autoload_data): check fork_gen when retrieving
* variable.c (check_autoload_required): use get_autoload_data
* variable.c (rb_autoloading_value): ditto
* variable.c (rb_autoload_p): ditto
* variable.c (current_autoload_data): ditto
* variable.c (autoload_reset): reset fork_gen, adjust indent
* variable.c (rb_autoload_load): set fork_gen when setting state
* test/ruby/test_autoload.rb (test_autoload_fork): new test
  [ruby-core:86410] [Bug #14634]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63210 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 0 deletions

diff --git a/thread.c b/thread.c
index 1caea4976c..f0ace8326c 100644
--- a/thread.c
+++ b/thread.c
@@ -4216,6 +4216,7 @@ rb_thread_atfork_internal(rb_thread_t *th, void (*atfork)(rb_thread_t *, const r
     }
     rb_vm_living_threads_init(vm);
     rb_vm_living_threads_insert(vm, th);
+    vm->fork_gen++;
     rb_thread_sync_reset_all();
 
     vm->sleeper = 0;