From: Nobuyoshi Nakada <nobu@...>
Date: 2008-03-27T14:26:51+09:00
Subject: Re: some Enumerable methods slower in 1.9 on OS X after revision 15124

Hi,

At Thu, 27 Mar 2008 05:20:57 +0900,
Yukihiro Matsumoto wrote in [ruby-core:16037]:
> |I just wanted to make sure core had seen this blog post (with comments
> |narrowing down the scope) about #inject, #each, and #times (at least)
> |being slower on OS X (http://antoniocangiano.com/2008/03/25/inject-
> |each-and-times-methods-much-slower-in-ruby-19/). I believe I'm correct
> |in finding that revision 15124 is when those methods went from faster
> |than 1.8.6 to much slower.
> 
> It seems that sigsetjmp() is significantly slower on OS X.  I
> contacted Nobu about this issue.  I believe he will address soon.

No, r15124 changed to use setjmp instead of _setjmp if
sigsetjmp exists, so sigsetjmp isn't used as well as earlier.

Citing from http://developer.apple.com/documentation/Darwin/Reference/ManPages/man3/setjmp.3.html:

     The setjmp()/longjmp() pairs save and restore the signal mask while
     _setjmp()/_longjmp() pairs save and restore only the register set and the
     stack.  (See sigprocmask(2).)

also:

     The sigsetjmp()/siglongjmp() function pairs save and restore the signal
     mask if the argument savemask is non-zero; otherwise, only the register
     set and the stack are saved.

Should the priority be _setjmp > sigsetjmp > setjmp?


Index: trunk/vm_core.h
===================================================================
--- trunk/vm_core.h	(revision 15843)
+++ trunk/vm_core.h	(working copy)
@@ -347,5 +347,20 @@ enum rb_thread_status {
 };
 
+#if defined(_setjmp) && !defined(HAVE__SETJMP)
+#define HAVE__SETJMP 1
+#endif
+#if defined(sigsetjmp) && !defined(HAVE_SIGSETJMP)
+#define HAVE_SIGSETJMP 1
+#endif
+#if defined(HAVE__SETJMP) || !defined(HAVE_SIGSETJMP)
+#define RUBY_USE_SIGSETJMP 0
+#else
+#define RUBY_USE_SIGSETJMP 1
+#endif
+#if RUBY_USE_SIGSETJMP
+typedef sigjmp_buf rb_jmpbuf_t;
+#else
 typedef jmp_buf rb_jmpbuf_t;
+#endif
 
 struct rb_vm_tag {
Index: trunk/gc.c
===================================================================
--- trunk/gc.c	(revision 15843)
+++ trunk/gc.c	(working copy)
@@ -53,7 +53,6 @@
 int rb_io_fptr_finalize(struct rb_io_t*);
 
-#if !defined(setjmp) && defined(HAVE__SETJMP) && !defined(sigsetjmp) && !defined(HAVE_SIGSETJMP)
-#define setjmp(env) _setjmp(env)
-#endif
+#define rb_setjmp(env) ruby_setjmp(env)
+#define rb_jmp_buf rb_jmpbuf_t
 
 /* Make alloca work the best possible way.  */
@@ -1428,4 +1427,6 @@ obj_free(VALUE obj)
 #ifdef __GNUC__
 #if defined(__human68k__) || defined(DJGPP)
+#undef rb_setjmp
+#undef rb_jmp_buf
 #if defined(__human68k__)
 typedef unsigned long rb_jmp_buf[8];
@@ -1436,7 +1437,4 @@ _rb_setjmp:\n\
 	moveq.l	#0,d0\n\
 	rts");
-#ifdef setjmp
-#undef setjmp
-#endif
 #else
 #if defined(DJGPP)
@@ -1459,6 +1457,4 @@ _rb_setjmp:\n\
 #endif
 int rb_setjmp (rb_jmp_buf);
-#define jmp_buf rb_jmp_buf
-#define setjmp rb_setjmp
 #endif /* __human68k__ or DJGPP */
 #endif /* __GNUC__ */
@@ -1471,5 +1467,5 @@ static void
 mark_current_machine_context(rb_thread_t *th)
 {
-    jmp_buf save_regs_gc_mark;
+    rb_jmp_buf save_regs_gc_mark;
     VALUE *stack_start, *stack_end;
 
@@ -1494,5 +1490,5 @@ mark_current_machine_context(rb_thread_t
     FLUSH_REGISTER_WINDOWS;
     /* This assumes that all registers are saved into the jmp_buf (and stack) */
-    setjmp(save_regs_gc_mark);
+    rb_setjmp(save_regs_gc_mark);
     mark_locations_array((VALUE*)save_regs_gc_mark,
 			 sizeof(save_regs_gc_mark) / sizeof(VALUE));
Index: trunk/eval_intern.h
===================================================================
--- trunk/eval_intern.h	(revision 15843)
+++ trunk/eval_intern.h	(working copy)
@@ -82,7 +82,11 @@ char *strrchr(const char *, const char);
 #endif
 
-#if !defined(setjmp) && defined(HAVE__SETJMP) && !defined(sigsetjmp) && !defined(HAVE_SIGSETJMP)
+#if RUBY_USE_SIGSETJMP
+#define ruby_setjmp(env) sigsetjmp((env), 0)
+#define ruby_longjmp(env,val) siglongjmp(env,val)
+#elif defined(_setjmp) || defined(HAVE__SETJMP)
 #define ruby_setjmp(env) _setjmp(env)
 #define ruby_longjmp(env,val) _longjmp(env,val)
+int _setjmp(), _longjmp();
 #else
 #define ruby_setjmp(env) setjmp(env)
Index: stable/eval.c
===================================================================
--- stable/eval.c	(revision 15843)
+++ stable/eval.c	(working copy)
@@ -194,8 +194,13 @@ static int volatile freebsd_clear_carry_
      (j)->status)
 #else
-#  if !defined(setjmp) && defined(HAVE__SETJMP) && !defined(sigsetjmp) && !defined(HAVE_SIGSETJMP)
+#  if RUBY_USE_SIGSETJMP
+#    define ruby_setjmp(just_before_setjmp, env) \
+       ((just_before_setjmp), sigsetjmp((env), 0))
+#    define ruby_longjmp(env,val) siglongjmp(env,val)
+#  elif defined(_setjmp) || defined(HAVE__SETJMP)
 #    define ruby_setjmp(just_before_setjmp, env) \
        ((just_before_setjmp), _setjmp(env))
 #    define ruby_longjmp(env,val) _longjmp(env,val)
+int _setjmp(), _longjmp();
 #  else
 #    define ruby_setjmp(just_before_setjmp, env) \
Index: stable/gc.c
===================================================================
--- stable/gc.c	(revision 15843)
+++ stable/gc.c	(working copy)
@@ -38,7 +38,12 @@ void re_free_registers _((struct re_regi
 void rb_io_fptr_finalize _((struct OpenFile*));
 
-#if !defined(setjmp) && defined(HAVE__SETJMP) && !defined(sigsetjmp) && !defined(HAVE_SIGSETJMP)
-#define setjmp(env) _setjmp(env)
+#if RUBY_USE_SIGSETJMP
+#define rb_setjmp(env) sigsetjmp((env), 0)
+#elif defined(_setjmp) || defined(HAVE__SETJMP)
+#define rb_setjmp(env) _setjmp(env)
+#else
+#define rb_setjmp(env) setjmp(env)
 #endif
+#define rb_jmp_buf rb_jmpbuf_t
 
 /* Make alloca work the best possible way.  */
@@ -1284,4 +1289,6 @@ rb_gc_mark_frame(frame)
 #ifdef __GNUC__
 #if defined(__human68k__) || defined(DJGPP)
+#undef rb_setjmp
+#undef rb_jmp_buf
 #if defined(__human68k__)
 typedef unsigned long rb_jmp_buf[8];
@@ -1292,7 +1299,4 @@ _rb_setjmp:\n\
 	moveq.l	#0,d0\n\
 	rts");
-#ifdef setjmp
-#undef setjmp
-#endif
 #else
 #if defined(DJGPP)
@@ -1315,6 +1319,4 @@ _rb_setjmp:\n\
 #endif
 int rb_setjmp (rb_jmp_buf);
-#define jmp_buf rb_jmp_buf
-#define setjmp rb_setjmp
 #endif /* __human68k__ or DJGPP */
 #endif /* __GNUC__ */
@@ -1365,5 +1367,5 @@ garbage_collect()
     FLUSH_REGISTER_WINDOWS;
     /* This assumes that all registers are saved into the jmp_buf (and stack) */
-    setjmp(save_regs_gc_mark);
+    rb_setjmp(save_regs_gc_mark);
     mark_locations_array((VALUE*)save_regs_gc_mark, sizeof(save_regs_gc_mark) / sizeof(VALUE *));
 #if STACK_GROW_DIRECTION < 0
Index: stable/node.h
===================================================================
--- stable/node.h	(revision 15843)
+++ stable/node.h	(working copy)
@@ -388,6 +388,21 @@ typedef struct {
 } rb_jmpbuf_t[1];
 #else
+#if defined(_setjmp) && !defined(HAVE__SETJMP)
+#define HAVE__SETJMP 1
+#endif
+#if defined(sigsetjmp) && !defined(HAVE_SIGSETJMP)
+#define HAVE_SIGSETJMP 1
+#endif
+#if defined(HAVE__SETJMP) || !defined(HAVE_SIGSETJMP)
+#define RUBY_USE_SIGSETJMP 0
+#else
+#define RUBY_USE_SIGSETJMP 1
+#endif
+#if RUBY_USE_SIGSETJMP
+typedef sigjmp_buf rb_jmpbuf_t;
+#else
 typedef jmp_buf rb_jmpbuf_t;
 #endif
+#endif
 
 enum rb_thread_status {


-- 
Nobu Nakada