[Guile-commits] 02/03: Inline freelist vectors into scm_thread

[Andy Wingo]

wingo pushed a commit to branch master
in repository guile.

commit 33aecf48b057f6f3abd65bea7c4b7a0d9aadf980
Author: Andy Wingo <address@hidden>
Date:   Thu Jun 20 13:44:47 2019 +0200

    Inline freelist vectors into scm_thread
    
    * libguile/gc-inline.h:
    * libguile/threads.h (SCM_INLINE_GC_GRANULE_WORDS)
      (SCM_INLINE_GC_GRANULE_BYTES, SCM_INLINE_GC_FREELIST_COUNT): Move
      definitions here, from gc-inline.h.
      (struct scm_thread): Inline freelist vectors.
    * libguile/threads.c (thread_mark): Update marker for pointerless
      freelists.
      (on_thread_exit): Clear individual freelist entries, instead of the
      vector as a whole.
      (guilify_self_2): No need to alloc freelist vectors.
---
 libguile/gc-inline.h | 13 +------------
 libguile/threads.c   | 32 +++++++++++---------------------
 libguile/threads.h   | 17 +++++++++++++++--
 3 files changed, 27 insertions(+), 35 deletions(-)

diff --git a/libguile/gc-inline.h b/libguile/gc-inline.h
index 62fdb9e..a1932d6 100644
--- a/libguile/gc-inline.h
+++ b/libguile/gc-inline.h
@@ -1,7 +1,7 @@
 #ifndef SCM_GC_INLINE_H
 #define SCM_GC_INLINE_H
 
-/* Copyright 1995-1996,1998-2004,2006-2014,2018
+/* Copyright 1995-1996,1998-2004,2006-2014,2018-2019
      Free Software Foundation, Inc.
 
    This file is part of Guile.
@@ -47,17 +47,6 @@
 
 
 
-#define SCM_INLINE_GC_GRANULE_WORDS 2
-#define SCM_INLINE_GC_GRANULE_BYTES \
-  (sizeof(void *) * SCM_INLINE_GC_GRANULE_WORDS)
-
-/* A freelist set contains SCM_INLINE_GC_FREELIST_COUNT pointers to
-   singly linked lists of objects of different sizes, the ith one
-   containing objects i + 1 granules in size.  This setting of
-   SCM_INLINE_GC_FREELIST_COUNT will hold freelists for allocations of
-   up to 256 bytes.  */
-#define SCM_INLINE_GC_FREELIST_COUNT (256U / SCM_INLINE_GC_GRANULE_BYTES)
-
 static inline size_t
 scm_inline_gc_bytes_to_freelist_index (size_t bytes)
 {
diff --git a/libguile/threads.c b/libguile/threads.c
index 0e01062..86ac5e8 100644
--- a/libguile/threads.c
+++ b/libguile/threads.c
@@ -1,4 +1,4 @@
-/* Copyright 1995-1998,2000-2014,2018
+/* Copyright 1995-1998,2000-2014,2018-2019
      Free Software Foundation, Inc.
 
    This file is part of Guile.
@@ -99,20 +99,16 @@ thread_mark (GC_word *addr, struct GC_ms_entry 
*mark_stack_ptr,
      but GC doesn't know to trace them (as they are pointerless), so we
      need to do that here.  See the comments at the top of libgc's
      gc_inline.h.  */
-  if (t->pointerless_freelists)
+  for (size_t n = 0; n < SCM_INLINE_GC_FREELIST_COUNT; n++)
     {
-      size_t n;
-      for (n = 0; n < SCM_INLINE_GC_FREELIST_COUNT; n++)
+      void *chain = t->pointerless_freelists[n];
+      if (chain)
         {
-          void *chain = t->pointerless_freelists[n];
-          if (chain)
-            {
-              /* The first link is already marked by the freelist vector,
-                 so we just have to mark the tail.  */
-              while ((chain = *(void **)chain))
-                mark_stack_ptr = GC_mark_and_push (chain, mark_stack_ptr,
-                                                   mark_stack_limit, NULL);
-            }
+          /* The first link is already marked by the thread itsel, so we
+             just have to mark the tail.  */
+          while ((chain = *(void **)chain))
+            mark_stack_ptr = GC_mark_and_push (chain, mark_stack_ptr,
+                                               mark_stack_limit, NULL);
         }
     }
 
@@ -443,12 +439,6 @@ guilify_self_2 (SCM dynamic_state)
   t->continuation_root = scm_cons (t->handle, SCM_EOL);
   t->continuation_base = t->base;
 
-  {
-    size_t size = SCM_INLINE_GC_FREELIST_COUNT * sizeof (void *);
-    t->freelists = scm_gc_malloc (size, "freelists");
-    t->pointerless_freelists = scm_gc_malloc (size, "atomic freelists");
-  }
-
   t->dynamic_state = scm_gc_typed_calloc (scm_t_dynamic_state);
   t->dynamic_state->thread_local_values = scm_c_make_hash_table (0);
   scm_set_current_dynamic_state (dynamic_state);
@@ -508,8 +498,8 @@ on_thread_exit (void *v)
 
   /* Although this thread has exited, the thread object might still be
      alive.  Release unused memory.  */
-  t->freelists = NULL;
-  t->pointerless_freelists = NULL;
+  for (size_t n = 0; n < SCM_INLINE_GC_FREELIST_COUNT; n++)
+    t->freelists[n] = t->pointerless_freelists[n] = NULL;
   t->dynamic_state = NULL;
   t->dynstack.base = NULL;
   t->dynstack.top = NULL;
diff --git a/libguile/threads.h b/libguile/threads.h
index d3de35b..337dc83 100644
--- a/libguile/threads.h
+++ b/libguile/threads.h
@@ -39,6 +39,19 @@
 
 
 
+#define SCM_INLINE_GC_GRANULE_WORDS 2
+#define SCM_INLINE_GC_GRANULE_BYTES \
+  (sizeof(void *) * SCM_INLINE_GC_GRANULE_WORDS)
+
+/* A freelist set contains SCM_INLINE_GC_FREELIST_COUNT pointers to
+   singly linked lists of objects of different sizes, the ith one
+   containing objects i + 1 granules in size.  This setting of
+   SCM_INLINE_GC_FREELIST_COUNT will hold freelists for allocations of
+   up to 256 bytes.  */
+#define SCM_INLINE_GC_FREELIST_COUNT (256U / SCM_INLINE_GC_GRANULE_BYTES)
+
+
+
 /* smob tags for the thread datatypes */
 SCM_API scm_t_bits scm_tc16_thread;
 SCM_API scm_t_bits scm_tc16_mutex;
@@ -60,8 +73,8 @@ struct scm_thread {
                                    not be run. */
 
   /* Thread-local freelists; see gc-inline.h.  */
-  void **freelists;
-  void **pointerless_freelists;
+  void *freelists[SCM_INLINE_GC_FREELIST_COUNT];
+  void *pointerless_freelists[SCM_INLINE_GC_FREELIST_COUNT];
 
   SCM handle;
   scm_i_pthread_t pthread;