* vm_core.h (typedef struct rb_vm_struct): create a new

  'inhibit_thread_createion' field.
* thread.c (rb_thread_terminate_all): set inhibit_thread_creation.
* thread.c (thread_s_new): don't permit to create new thread
  if the VM is under destruction. Otherwise evil finalizer code
  can make SEGV. [Bug #4992][ruby-core:37858]

* bootstraptest/test_objectspace.rb: new test for this fix.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32492 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 5 insertions, 0 deletions

diff --git a/thread.c b/thread.c
index cd5b49b868..ac72d5d038 100644
--- a/thread.c
+++ b/thread.c
@@ -367,6 +367,7 @@ rb_thread_terminate_all(void)
 
     thread_debug("rb_thread_terminate_all (main thread: %p)\n", (void *)th);
     st_foreach(vm->living_threads, terminate_i, (st_data_t)th);
+    vm->inhibit_thread_creation = 1;
 
     while (!rb_thread_alone()) {
 	PUSH_TAG();
@@ -583,6 +584,10 @@ thread_s_new(int argc, VALUE *argv, VALUE klass)
 {
     rb_thread_t *th;
     VALUE thread = rb_thread_alloc(klass);
+
+    if (GET_VM()->inhibit_thread_creation)
+	rb_raise(rb_eThreadError, "can't alloc thread");
+
     rb_obj_call_init(thread, argc, argv);
     GetThreadPtr(thread, th);
     if (!th->first_args) {