1 files changed, 259 insertions, 0 deletions
diff --git a/src/kmk/alloccache.c b/src/kmk/alloccache.c
new file mode 100644
index 0000000..54c28d5
--- /dev/null
+++ b/src/kmk/alloccache.c
@@ -0,0 +1,259 @@
+/* $Id: alloccache.c 3141 2018-03-14 21:58:32Z bird $ */
+/** @file
+ * alloccache - Fixed sized allocation cache.
+ *
+ * The rational for using an allocation cache, is that it is way faster
+ * than malloc+free on most systems.  It may be more efficient as well,
+ * depending on the way the heap implementes small allocations.  Also,
+ * with the incdep.c code being threaded, all heaps (except for MSC)
+ * ran into severe lock contention issues since both the main thread
+ * and the incdep worker thread was allocating a crazy amount of tiny
+ * allocations (struct dep, struct nameseq, ++).
+ *
+ * Darwin also showed a significant amount of time spent just executing
+ * free(), which is kind of silly.  The alloccache helps a bit here too.
+ */
+
+/*
+ * Copyright (c) 2008-2010 knut st. osmundsen <bird-kBuild-spamx@anduin.net>
+ *
+ * This file is part of kBuild.
+ *
+ * kBuild is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * kBuild is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with kBuild.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+/*******************************************************************************
+*   Header Files                                                               *
+*******************************************************************************/
+#include "makeint.h"
+#include "filedef.h"
+#include "dep.h"
+#include "debug.h"
+#include <assert.h>
+
+
+#ifdef CONFIG_WITH_ALLOC_CACHES
+
+/* Free am item.
+   This was not inlined because of aliasing issues arrising with GCC.
+   It is also in a separate file for this reason (it used to be in misc.c
+   but since free_dep_chain() was using it there, we ran the risk of it
+   being inlined and gcc screwing up).  */
+void
+alloccache_free (struct alloccache *cache, void *item)
+{
+#ifndef CONFIG_WITH_ALLOCCACHE_DEBUG
+  struct alloccache_free_ent *f = (struct alloccache_free_ent *)item;
+# if 0 /*ndef NDEBUG*/
+  struct alloccache_free_ent *c;
+  unsigned int i = 0;
+  for (c = cache->free_head; c != NULL; c = c->next, i++)
+    MY_ASSERT_MSG (c != f && i < 0x10000000,
+                   ("i=%u total_count=%u\n", i, cache->total_count));
+# endif
+
+  f->next = cache->free_head;
+  cache->free_head = f;
+  MAKE_STATS(cache->free_count++;);
+#else  /* CONFIG_WITH_ALLOCCACHE_DEBUG */
+
+  struct alloccache **ppcache = (struct alloccache **)item - 1;
+  MY_ASSERT_MSG (*ppcache == cache, ("*ppcache=%p cache=%p item=%p\n", *ppcache, cache, item));
+  *ppcache = NULL;
+  free(ppcache);
+#endif /* CONFIG_WITH_ALLOCCACHE_DEBUG */
+}
+
+/* Default allocator. */
+static void *
+alloccache_default_grow_alloc(void *ignore, unsigned int size)
+{
+  return xmalloc (size);
+}
+
+/* Worker for growing the cache. */
+struct alloccache_free_ent *
+alloccache_alloc_grow (struct alloccache *cache)
+{
+#ifndef CONFIG_WITH_ALLOCCACHE_DEBUG
+  void *item;
+  unsigned int items = (64*1024 - 32) / cache->size;
+  cache->free_start  = cache->grow_alloc (cache->grow_arg, items * cache->size);
+  cache->free_end    = cache->free_start + items * cache->size;
+  cache->total_count+= items;
+
+# ifndef NDEBUG /* skip the first item so the heap can detect free(). */
+  cache->total_count--;
+  cache->free_start += cache->size;
+# endif
+
+  item = cache->free_start;
+  cache->free_start += cache->size;
+  /* caller counts */
+  return (struct alloccache_free_ent *)item;
+#else  /* CONFIG_WITH_ALLOCCACHE_DEBUG */
+
+  /* Prefix the allocation with a cache pointer so alloccahce_free can better
+     catch incorrect calls. */
+  struct alloccache **ppcache = (struct alloccache **)xmalloc(sizeof(*ppcache) + cache->size);
+  *ppcache = cache;
+  return (struct alloccache_free_ent *)(ppcache + 1);
+#endif /* CONFIG_WITH_ALLOCCACHE_DEBUG */
+}
+
+/* List of alloc caches, for printing. */
+static struct alloccache *alloccache_head = NULL;
+
+/* Initializes an alloc cache */
+void
+alloccache_init (struct alloccache *cache, unsigned int size, const char *name,
+                 void *(*grow_alloc)(void *grow_arg, unsigned int size), void *grow_arg)
+{
+  unsigned act_size;
+
+  /* ensure OK alignment and min sizeof (struct alloccache_free_ent). */
+  if (size <= sizeof (struct alloccache_free_ent))
+    act_size = sizeof (struct alloccache_free_ent);
+  else if (size <= 32)
+    {
+      act_size = 4;
+      while (act_size < size)
+        act_size <<= 1;
+    }
+  else
+    act_size = (size + 31U) & ~(size_t)31;
+
+  /* align the structure. */
+  cache->free_start  = NULL;
+  cache->free_end    = NULL;
+  cache->free_head   = NULL;
+  cache->size        = act_size;
+  cache->total_count = 0;
+  cache->alloc_count = 0;
+  cache->free_count  = 0;
+  cache->name        = name;
+  cache->grow_arg    = grow_arg;
+  cache->grow_alloc  = grow_alloc ? grow_alloc : alloccache_default_grow_alloc;
+
+  /* link it. */
+  cache->next        = alloccache_head;
+  alloccache_head    = cache;
+}
+
+/* Terminate an alloc cache, free all the memory it contains. */
+void
+alloccache_term (struct alloccache *cache,
+                 void (*term_free)(void *term_arg, void *ptr, unsigned int size), void *term_arg)
+{
+    /*cache->size = 0;*/
+    (void)cache;
+    (void)term_free;
+    (void)term_arg;
+    /* FIXME: Implement memory segment tracking and cleanup. */
+}
+
+/* Joins to caches, unlinking the 2nd one. */
+void
+alloccache_join (struct alloccache *cache, struct alloccache *eat)
+{
+  assert (cache->size == eat->size);
+
+#if 0 /* probably a waste of time */ /* FIXME: Optimize joining, avoid all list walking. */
+  /* add the free list... */
+  if (eat->free_head)
+    {
+     unsigned int eat_in_use = eat->alloc_count - eat->free_count;
+     unsigned int dst_in_use = cache->alloc_count - cache->free_count;
+     if (!cache->free_head)
+       cache->free_head = eat->free_head;
+     else if (eat->total_count - eat_in_use < cache->total_count - dst_ins_use)
+       {
+         struct alloccache_free_ent *last = eat->free_head;
+         while (last->next)
+           last = last->next;
+         last->next = cache->free_head;
+         cache->free_head = eat->free_head;
+       }
+     else
+       {
+         struct alloccache_free_ent *last = cache->free_head;
+         while (last->next)
+           last = last->next;
+         last->next = eat->free_head;
+       }
+    }
+
+  /* ... and the free space. */
+  while (eat->free_start != eat->free_end)
+    {
+      struct alloccache_free_ent *f = (struct alloccache_free_ent *)eat->free_start;
+      eat->free_start += eat->size;
+      f->next = cache->free_head;
+      cache->free_head = f;
+    }
+
+  /* and statistics */
+  cache->alloc_count += eat->alloc_count;
+  cache->free_count  += eat->free_count;
+#else
+  /* and statistics */
+  cache->alloc_count += eat->alloc_count;
+  cache->free_count  += eat->free_count;
+#endif
+  cache->total_count += eat->total_count;
+
+  /* unlink and disable the eat cache */
+  if (alloccache_head == eat)
+    alloccache_head = eat->next;
+  else
+    {
+      struct alloccache *cur = alloccache_head;
+      while (cur->next != eat)
+        cur = cur->next;
+      assert (cur && cur->next == eat);
+      cur->next = eat->next;
+    }
+
+  eat->size = 0;
+  eat->free_end = eat->free_start = NULL;
+  eat->free_head = NULL;
+}
+
+/* Print one alloc cache. */
+void
+alloccache_print (struct alloccache *cache)
+{
+  printf (_("\n# Alloc Cache: %s\n"
+              "#  Items: size = %-3u  total = %-6u"),
+          cache->name, cache->size, cache->total_count);
+  MAKE_STATS(printf (_("  in-use = %-6lu"),
+                     cache->alloc_count - cache->free_count););
+  MAKE_STATS(printf (_("\n#         alloc calls = %-7lu  free calls = %-7lu"),
+                     cache->alloc_count, cache->free_count););
+  printf ("\n");
+}
+
+/* Print all alloc caches. */
+void
+alloccache_print_all (void)
+{
+  struct alloccache *cur;
+  puts ("");
+  for (cur = alloccache_head; cur; cur = cur->next)
+    alloccache_print (cur);
+}
+
+#endif /* CONFIG_WITH_ALLOC_CACHES */
+