[ruby-core:28866] Re: st.c: pool allocator for tables and entries

Eric Wong <[e-mail]> wrote:
> The only other downside is that memory used for each type of struct
> cannot be used anything else, nor released back to the OS (though some
> malloc implementations don't do this anyways).

And there was a leak in the original patch, this fixes it
since name##_head can be populated during GC when ruby_xmalloc
is called.

diff --git a/st.c b/st.c
index cbc57d8..54ebee9 100644
--- a/st.c
+++ b/st.c
@@ -57,6 +57,11 @@ static void more_##name(void) \
     long i; \
     struct name##_alloc_ptr *cur, *tmp; \
     tmp = ruby_xmalloc((size / sizeof(type)) * sizeof(type)); \
+    if (name##_head) { \
+        /* malloc called GC and released memory for us */ \
+        ruby_xfree(tmp); \
+        return; \
+    } \
     name##_head = tmp; \
     for (i = size / sizeof(type); --i >= 0; ) { \
 	cur = tmp++; \
-- 
Eric Wong