gc.c: rb_gc_adjust_memory_usage

nobu · nobu · commit 68aa1d81cfb2 · 2016-09-20T07:52:25.000Z
* gc.c (rb_gc_adjust_memory_usage): notify memory usage to the GC engine by extension libraries, to trigger GC. [Feature ruby#12690] git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56189 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
diff --git a/ChangeLog b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Sep 20 16:52:23 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* gc.c (rb_gc_adjust_memory_usage): notify memory usage to the GC
+	  engine by extension libraries, to trigger GC.  [Feature #12690]
+
 Mon Sep 19 17:05:22 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* numeric.c (Init_Numeric), bignum.c (Init_Bignum): deprecate
diff --git a/doc/extension.rdoc b/doc/extension.rdoc
@@ -1652,6 +1652,18 @@ int rb_remove_event_hook(rb_event_hook_func_t func) ::
 
   Removes the specified hook function.
 
+== Memory usage
+
+void rb_gc_adjust_memory_usage(ssize_t diff) ::
+
+  Adjusts the amount of registered external memory.  You can tell GC how
+  much memory is used by an external library by this function.  Calling
+  this function with positive diff means the memory usage is increased;
+  new memory block is allocated or a block is reallocated as larger
+  size.  Calling this function with negative diff means the memory usage
+  is decreased; a memory block is freed or a block is reallocated as
+  smaller size.  This function may trigger the GC.
+
 == Macros for Compatibility
 
 Some macros to check API compatibilities are available by default.
diff --git a/gc.c b/gc.c
@@ -8096,6 +8096,18 @@ gc_malloc_allocations(VALUE self)
 }
 #endif
 
+void
+rb_gc_adjust_memory_usage(ssize_t diff)
+{
+    rb_objspace_t *objspace = &rb_objspace;
+    if (diff > 0) {
+	objspace_malloc_increase(objspace, 0, diff, 0, MEMOP_TYPE_REALLOC);
+    }
+    else if (diff < 0) {
+	objspace_malloc_increase(objspace, 0, 0, -diff, MEMOP_TYPE_REALLOC);
+    }
+}
+
 /*
   ------------------------------ WeakMap ------------------------------
 */
diff --git a/include/ruby/intern.h b/include/ruby/intern.h
@@ -502,6 +502,7 @@ VALUE rb_undefine_finalizer(VALUE);
 size_t rb_gc_count(void);
 size_t rb_gc_stat(VALUE);
 VALUE rb_gc_latest_gc_info(VALUE);
+void rb_gc_adjust_memory_usage(ssize_t);
 /* hash.c */
 void st_foreach_safe(struct st_table *, int (*)(ANYARGS), st_data_t);
 VALUE rb_check_hash_type(VALUE);
