X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=isl_blk.c;h=29844d5c6d39ffcdc3c9e24e314aec9c8d158a8b;hb=de51a9bc4da5dd3f1f9f57c2362da6f9752c44e0;hp=d581f2d8623f8a9070517cccfa85deb7d79001e9;hpb=0dcb90aef1a2934609fdce9d8cf527af8b558d43;p=platform%2Fupstream%2Fisl.git

diff --git a/isl_blk.c b/isl_blk.c
index d581f2d..29844d5 100644
--- a/isl_blk.c
+++ b/isl_blk.c
@@ -1,7 +1,7 @@
 /*
  * Copyright 2008-2009 Katholieke Universiteit Leuven
  *
- * Use of this software is governed by the GNU LGPLv2.1 license
+ * Use of this software is governed by the MIT license
  *
  * Written by Sven Verdoolaege, K.U.Leuven, Departement
  * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
@@ -10,6 +10,9 @@
 #include <isl/blk.h>
 #include <isl_ctx_private.h>
 
+/* The maximal number of cache misses before first element is evicted */
+#define ISL_BLK_MAX_MISS	100
+
 struct isl_blk isl_blk_empty()
 {
 	struct isl_blk block;
@@ -36,31 +39,7 @@ int isl_blk_is_error(struct isl_blk block)
 	return block.size == -1 && block.data == NULL;
 }
 
-struct isl_blk isl_blk_alloc(struct isl_ctx *ctx, size_t n)
-{
-	int i;
-	struct isl_blk block;
-
-	if (ctx->n_cached) {
-		int best = 0;
-		for (i = 1; ctx->cache[best].size != n && i < ctx->n_cached; ++i) {
-			if (ctx->cache[best].size < n) {
-				if (ctx->cache[i].size > ctx->cache[best].size)
-					best = i;
-			} else if (ctx->cache[i].size >= n &&
-				   ctx->cache[i].size < ctx->cache[best].size)
-					best = i;
-		}
-		block = ctx->cache[best];
-		if (--ctx->n_cached != best)
-			ctx->cache[best] = ctx->cache[ctx->n_cached];
-	} else
-		block = isl_blk_empty();
-
-	return isl_blk_extend(ctx, block, n);
-}
-
-struct isl_blk isl_blk_extend(struct isl_ctx *ctx, struct isl_blk block,
+static struct isl_blk extend(struct isl_ctx *ctx, struct isl_blk block,
 				size_t new_n)
 {
 	int i;
@@ -92,6 +71,48 @@ static void isl_blk_free_force(struct isl_ctx *ctx, struct isl_blk block)
 	free(block.data);
 }
 
+struct isl_blk isl_blk_alloc(struct isl_ctx *ctx, size_t n)
+{
+	int i;
+	struct isl_blk block;
+
+	block = isl_blk_empty();
+	if (n && ctx->n_cached) {
+		int best = 0;
+		for (i = 1; ctx->cache[best].size != n && i < ctx->n_cached; ++i) {
+			if (ctx->cache[best].size < n) {
+				if (ctx->cache[i].size > ctx->cache[best].size)
+					best = i;
+			} else if (ctx->cache[i].size >= n &&
+				   ctx->cache[i].size < ctx->cache[best].size)
+					best = i;
+		}
+		if (ctx->cache[best].size < 2 * n + 100) {
+			block = ctx->cache[best];
+			if (--ctx->n_cached != best)
+				ctx->cache[best] = ctx->cache[ctx->n_cached];
+			if (best == 0)
+				ctx->n_miss = 0;
+		} else if (ctx->n_miss++ >= ISL_BLK_MAX_MISS) {
+			isl_blk_free_force(ctx, ctx->cache[0]);
+			if (--ctx->n_cached != 0)
+				ctx->cache[0] = ctx->cache[ctx->n_cached];
+			ctx->n_miss = 0;
+		}
+	}
+
+	return extend(ctx, block, n);
+}
+
+struct isl_blk isl_blk_extend(struct isl_ctx *ctx, struct isl_blk block,
+				size_t new_n)
+{
+	if (isl_blk_is_empty(block))
+		return isl_blk_alloc(ctx, new_n);
+
+	return extend(ctx, block, new_n);
+}
+
 void isl_blk_free(struct isl_ctx *ctx, struct isl_blk block)
 {
 	if (isl_blk_is_empty(block) || isl_blk_is_error(block))