vm*: doubly-linked list from ccan to manage vm->living_threads

A doubly-linked list for tracking living threads guarantees
constant-time insert/delete performance with no corner cases of a
hash table.  I chose this ccan implementation of doubly-linked
lists over the BSD sys/queue.h implementation since:

1) insertion and removal are both branchless
2) locality is improved if a struct may be a member of multiple lists
   (0002 patch in Feature 9632 will introduce a secondary list
   for waiting FDs)

This also increases cache locality during iteration: improving
performance in a new IO#close benchmark with many sleeping threads
while still scanning the same number of threads.

	vm_thread_close 1.762

* vm_core.h (rb_vm_t): list_head and counter for living_threads
  (rb_thread_t): vmlt_node for living_threads linkage
  (rb_vm_living_threads_init): new function wrapper
  (rb_vm_living_threads_insert): ditto
  (rb_vm_living_threads_remove): ditto
* vm.c (rb_vm_living_threads_foreach): new function wrapper
* thread.c (terminate_i, thread_start_func_2, thread_create_core,
  thread_fd_close_i, thread_fd_close): update to use new APIs
* vm.c (vm_mark_each_thread_func, rb_vm_mark, ruby_vm_destruct,
  vm_memsize, vm_init2, Init_VM): ditto
* vm_trace.c (clear_trace_func_i, rb_clear_trace_func): ditto
* benchmark/bm_vm_thread_close.rb: added to show improvement
* ccan/build_assert/build_assert.h: added as a dependency of list.h
* ccan/check_type/check_type.h: ditto
* ccan/container_of/container_of.h: ditto
* ccan/licenses/BSD-MIT: ditto
* ccan/licenses/CC0: ditto
* ccan/str/str.h: ditto (stripped of unused macros)
* ccan/list/list.h: ditto
* common.mk: add CCAN_LIST_INCLUDES
  [ruby-core:61871][Feature 9632 (part 1)]

Apologies for the size of this commit, but I think a good
doubly-linked list will be useful for future features, too.
This may be used to add ordering to a container_of-based hash
table to preserve compatibility if required (e.g. feature 9614).

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45913 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 2 insertions, 4 deletions

diff --git a/vm_trace.c b/vm_trace.c
index db4b908181..dd1a082e4a 100644
--- a/vm_trace.c
+++ b/vm_trace.c
@@ -213,10 +213,8 @@ rb_remove_event_hook_with_data(rb_event_hook_func_t func, VALUE data)
 }
 
 static int
-clear_trace_func_i(st_data_t key, st_data_t val, st_data_t flag)
+clear_trace_func_i(rb_thread_t *th, void *unused)
 {
-    rb_thread_t *th;
-    GetThreadPtr((VALUE)key, th);
     rb_threadptr_remove_event_hook(th, 0, Qundef);
     return ST_CONTINUE;
 }
@@ -224,7 +222,7 @@ clear_trace_func_i(st_data_t key, st_data_t val, st_data_t flag)
 void
 rb_clear_trace_func(void)
 {
-    st_foreach(GET_VM()->living_threads, clear_trace_func_i, (st_data_t) 0);
+    rb_vm_living_threads_foreach(GET_VM(), clear_trace_func_i, 0);
     rb_remove_event_hook(0);
 }