From 1b091b5a26edec2486957eea0aeb5167c0dd6dbc Mon Sep 17 00:00:00 2001
From: Slava Pestov <slava@slava-pestovs-macbook-pro.local>
Date: Fri, 21 Nov 2008 23:13:14 -0600
Subject: [PATCH] Reuse F_CONTEXT instances used for FFI callbacks: 60x speed
improvement on benchmark.fib6
---
vm/run.c | 36 ++++++++++++++++++++++++++++--------
vm/run.h | 2 ++
2 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/vm/run.c b/vm/run.c
index c7d93d29c8..79792d79f3 100755
--- a/vm/run.c
+++ b/vm/run.c
@@ -29,10 +29,35 @@ void save_stacks(void)
}
}
+F_CONTEXT *alloc_context(void)
+{
+ F_CONTEXT *context;
+
+ if(unused_contexts)
+ {
+ context = unused_contexts;
+ unused_contexts = unused_contexts->next;
+ }
+ else
+ {
+ context = safe_malloc(sizeof(F_CONTEXT));
+ context->datastack_region = alloc_segment(ds_size);
+ context->retainstack_region = alloc_segment(rs_size);
+ }
+
+ return context;
+}
+
+void dealloc_context(F_CONTEXT *context)
+{
+ context->next = unused_contexts;
+ unused_contexts = context;
+}
+
/* called on entry into a compiled callback */
void nest_stacks(void)
{
- F_CONTEXT *new_stacks = safe_malloc(sizeof(F_CONTEXT));
+ F_CONTEXT *new_stacks = alloc_context();
new_stacks->callstack_bottom = (F_STACK_FRAME *)-1;
new_stacks->callstack_top = (F_STACK_FRAME *)-1;
@@ -54,9 +79,6 @@ void nest_stacks(void)
new_stacks->current_callback_save = userenv[CURRENT_CALLBACK_ENV];
new_stacks->catchstack_save = userenv[CATCHSTACK_ENV];
- new_stacks->datastack_region = alloc_segment(ds_size);
- new_stacks->retainstack_region = alloc_segment(rs_size);
-
new_stacks->next = stack_chain;
stack_chain = new_stacks;
@@ -67,9 +89,6 @@ void nest_stacks(void)
/* called when leaving a compiled callback */
void unnest_stacks(void)
{
- dealloc_segment(stack_chain->datastack_region);
- dealloc_segment(stack_chain->retainstack_region);
-
ds = stack_chain->datastack_save;
rs = stack_chain->retainstack_save;
@@ -79,7 +98,7 @@ void unnest_stacks(void)
F_CONTEXT *old_stacks = stack_chain;
stack_chain = old_stacks->next;
- free(old_stacks);
+ dealloc_context(old_stacks);
}
/* called on startup */
@@ -88,6 +107,7 @@ void init_stacks(CELL ds_size_, CELL rs_size_)
ds_size = ds_size_;
rs_size = rs_size_;
stack_chain = NULL;
+ unused_contexts = NULL;
}
bool stack_to_array(CELL bottom, CELL top)
diff --git a/vm/run.h b/vm/run.h
index 2dbbcc8c06..be133b7eca 100755
--- a/vm/run.h
+++ b/vm/run.h
@@ -211,6 +211,8 @@ typedef struct _F_CONTEXT {
DLLEXPORT F_CONTEXT *stack_chain;
+F_CONTEXT *unused_contexts;
+
CELL ds_size, rs_size;
#define ds_bot (stack_chain->datastack_region->start)