Enable method cache by default.

Introduced `MRB_NO_METHOD_CACHE` which is inverse of `MRB_METHOD_CACHE`
that should be enabled intestinally. In addition, the default cache is
made bigger (128 -> 256).

8 files changed, 23 insertions, 28 deletions

diff --git a/doc/guides/mrbconf.md b/doc/guides/mrbconf.md
index 1e1a5afcf..003c2b300 100644
--- a/doc/guides/mrbconf.md
+++ b/doc/guides/mrbconf.md
@@ -163,12 +163,12 @@ largest value of required alignment.
 * Default value is `128`.
 * Specifies initial capacity of `RString` created by `mrb_str_buf_new` function..
 
-`MRB_METHOD_CACHE`
-* Improve performance for method dispatch.
+`MRB_NO_METHOD_CACHE`
+* Disable method cache to save memory.
 
 `MRB_METHOD_CACHE_SIZE`
-* Default value is `128`.
-* Ignored if `MRB_METHOD_CACHE` is not defined.
+* Default value is `256`.
+* Ignored if `MRB_NO_METHOD_CACHE` is defined.
 * Need to be the power of 2.
 
 `MRB_METHOD_T_STRUCT`
diff --git a/include/mrbconf.h b/include/mrbconf.h
index 2b1adb24e..81ab36977 100644
--- a/include/mrbconf.h
+++ b/include/mrbconf.h
@@ -31,10 +31,10 @@
 /* exclude floating point numbers */
 //#define MRB_WITHOUT_FLOAT
 
-/* add -DMRB_METHOD_CACHE to use method cache to improve performance */
-//#define MRB_METHOD_CACHE
+/* add -DMRB_NO_METHOD_CACHE to disable method cache to save memory */
+//#define MRB_NO_METHOD_CACHE
 /* size of the method cache (need to be the power of 2) */
-//#define MRB_METHOD_CACHE_SIZE (1<<7)
+//#define MRB_METHOD_CACHE_SIZE (1<<8)
 
 /* add -DMRB_METHOD_T_STRUCT on machines that use higher bits of pointers */
 /* no MRB_METHOD_T_STRUCT requires highest 2 bits of function pointers to be zero */
@@ -160,6 +160,10 @@
 
 /* A profile for micro controllers */
 #if defined(MRB_CONSTRAINED_BASELINE_PROFILE)
+# ifndef MRB_NO_METHOD_CACHE
+#  define MRB_NO_METHOD_CACHE
+# endif
+
 # ifndef KHASH_DEFAULT_SIZE
 #  define KHASH_DEFAULT_SIZE 16
 # endif
@@ -177,10 +181,6 @@
 
 /* A profile for desktop computers or workstations; rich memory! */
 #elif defined(MRB_MAIN_PROFILE)
-# ifndef MRB_METHOD_CACHE
-#  define MRB_METHOD_CACHE
-# endif
-
 # ifndef MRB_METHOD_CACHE_SIZE
 #  define MRB_METHOD_CACHE_SIZE (1<<10)
 # endif
@@ -195,10 +195,6 @@
 
 /* A profile for server; mruby vm is long life */
 #elif defined(MRB_HIGH_PROFILE)
-# ifndef MRB_METHOD_CACHE
-#  define MRB_METHOD_CACHE
-# endif
-
 # ifndef MRB_METHOD_CACHE_SIZE
 #  define MRB_METHOD_CACHE_SIZE (1<<12)
 # endif
diff --git a/include/mruby.h b/include/mruby.h
index 27c428e85..c9425e8a7 100644
--- a/include/mruby.h
+++ b/include/mruby.h
@@ -188,11 +188,11 @@ struct mrb_context {
 };
 
 #ifdef MRB_METHOD_CACHE_SIZE
-# define MRB_METHOD_CACHE
+# undef MRB_NO_METHOD_CACHE
 #else
-/* default method cache size: 128 */
+/* default method cache size: 256 */
 /* cache size needs to be power of 2 */
-# define MRB_METHOD_CACHE_SIZE (1<<7)
+# define MRB_METHOD_CACHE_SIZE (1<<8)
 #endif
 
 /**
@@ -218,7 +218,7 @@ typedef struct {
 } mrb_method_t;
 #endif
 
-#ifdef MRB_METHOD_CACHE
+#ifndef MRB_NO_METHOD_CACHE
 struct mrb_cache_entry {
   struct RClass *c, *c0;
   mrb_sym mid;
@@ -264,7 +264,7 @@ typedef struct mrb_state {
 
   mrb_gc gc;
 
-#ifdef MRB_METHOD_CACHE
+#ifndef MRB_NO_METHOD_CACHE
   struct mrb_cache_entry cache[MRB_METHOD_CACHE_SIZE];
 #endif
 
diff --git a/include/mruby/class.h b/include/mruby/class.h
index 94356d3b2..88e5915e5 100644
--- a/include/mruby/class.h
+++ b/include/mruby/class.h
@@ -92,7 +92,7 @@ void mrb_gc_mark_mt(mrb_state*, struct RClass*);
 size_t mrb_gc_mark_mt_size(mrb_state*, struct RClass*);
 void mrb_gc_free_mt(mrb_state*, struct RClass*);
 
-#ifdef MRB_METHOD_CACHE
+#ifndef MRB_NO_METHOD_CACHE
 void mrb_mc_clear_by_class(mrb_state *mrb, struct RClass* c);
 #else
 #define mrb_mc_clear_by_class(mrb,c)
diff --git a/src/class.c b/src/class.c
index c48229d8a..30f4a3e2f 100644
--- a/src/class.c
+++ b/src/class.c
@@ -292,7 +292,7 @@ mrb_define_class(mrb_state *mrb, const char *name, struct RClass *super)
 }
 
 static mrb_value mrb_bob_init(mrb_state *mrb, mrb_value);
-#ifdef MRB_METHOD_CACHE
+#ifndef MRB_NO_METHOD_CACHE
 static void mc_clear_all(mrb_state *mrb);
 static void mc_clear_by_id(mrb_state *mrb, struct RClass*, mrb_sym);
 #else
@@ -1404,7 +1404,7 @@ mrb_define_module_function(mrb_state *mrb, struct RClass *c, const char *name, m
   mrb_define_module_function_id(mrb, c, mrb_intern_cstr(mrb, name), func, aspec);
 }
 
-#ifdef MRB_METHOD_CACHE
+#ifndef MRB_NO_METHOD_CACHE
 static void
 mc_clear_all(mrb_state *mrb)
 {
@@ -1456,7 +1456,7 @@ mrb_method_search_vm(mrb_state *mrb, struct RClass **cp, mrb_sym mid)
   khiter_t k;
   mrb_method_t m;
   struct RClass *c = *cp;
-#ifdef MRB_METHOD_CACHE
+#ifndef MRB_NO_METHOD_CACHE
   struct RClass *oc = c;
   int h = kh_int_hash_func(mrb, ((intptr_t)oc) ^ mid) & (MRB_METHOD_CACHE_SIZE-1);
   struct mrb_cache_entry *mc = &mrb->cache[h];
@@ -1476,7 +1476,7 @@ mrb_method_search_vm(mrb_state *mrb, struct RClass **cp, mrb_sym mid)
         m = kh_value(h, k);
         if (MRB_METHOD_UNDEF_P(m)) break;
         *cp = c;
-#ifdef MRB_METHOD_CACHE
+#ifndef MRB_NO_METHOD_CACHE
         mc->c = oc;
         mc->c0 = c;
         mc->mid = mid;
diff --git a/target/appveyor.rb b/target/appveyor.rb
index 2336935c9..6a8dbbf4a 100644
--- a/target/appveyor.rb
+++ b/target/appveyor.rb
@@ -10,7 +10,7 @@ MRuby::Build.new('full-debug') do |conf|
 
   # include all core GEMs
   conf.gembox 'full-core'
-  conf.cc.defines += %w(MRB_GC_STRESS MRB_METHOD_CACHE MRB_ENABLE_DEBUG_HOOK)
+  conf.cc.defines += %w(MRB_GC_STRESS MRB_ENABLE_DEBUG_HOOK)
   setup_option(conf)
 
   conf.enable_test
diff --git a/target/host-gprof.rb b/target/host-gprof.rb
index c8a2f3b13..31b952920 100644
--- a/target/host-gprof.rb
+++ b/target/host-gprof.rb
@@ -5,7 +5,6 @@ MRuby::Build.new do |conf|
   # include the GEM box
   conf.gembox 'full-core'
 
-  conf.cc.defines = %w(MRB_METHOD_CACHE)
   conf.cc.flags << '-pg'
   conf.linker.flags << '-pg'
 
diff --git a/target/travis.rb b/target/travis.rb
index f4bef0a52..b8b04da18 100644
--- a/target/travis.rb
+++ b/target/travis.rb
@@ -5,7 +5,7 @@ MRuby::Build.new('full-debug') do |conf|
   # include all core GEMs
   conf.gembox 'full-core'
   conf.cc.flags += %w(-Werror=declaration-after-statement)
-  conf.cc.defines += %w(MRB_GC_STRESS MRB_METHOD_CACHE MRB_ENABLE_DEBUG_HOOK)
+  conf.cc.defines += %w(MRB_GC_STRESS MRB_ENABLE_DEBUG_HOOK)
 
   conf.enable_test
 end