1 files changed, 67 insertions, 30 deletions

diff --git a/fitz/base_hash.c b/fitz/base_hash.c
index 630f6b6a..0fda86cd 100644
--- a/fitz/base_hash.c
+++ b/fitz/base_hash.c
@@ -22,6 +22,7 @@ struct fz_hash_table_s
 	int keylen;
 	int size;
 	int load;
+	int lock; /* -1 or the lock used to protect this hash table */
 	fz_hash_entry *ents;
 };
 
@@ -42,7 +43,7 @@ static unsigned hash(unsigned char *s, int len)
 }
 
 fz_hash_table *
-fz_new_hash_table(fz_context *ctx, int initialsize, int keylen)
+fz_new_hash_table(fz_context *ctx, int initialsize, int keylen, int lock)
 {
 	fz_hash_table *table;
 
@@ -52,6 +53,7 @@ fz_new_hash_table(fz_context *ctx, int initialsize, int keylen)
 	table->keylen = keylen;
 	table->size = initialsize;
 	table->load = 0;
+	table->lock = lock;
 	fz_try(ctx)
 	{
 		table->ents = fz_malloc_array(ctx, table->size, sizeof(fz_hash_entry));
@@ -98,10 +100,45 @@ fz_free_hash(fz_context *ctx, fz_hash_table *table)
 	fz_free(ctx, table);
 }
 
+static void *
+do_hash_insert(fz_context *ctx, fz_hash_table *table, void *key, void *val)
+{
+	fz_hash_entry *ents;
+	unsigned size;
+	unsigned pos;
+
+	ents = table->ents;
+	size = table->size;
+	pos = hash(key, table->keylen) % size;
+
+	if (table->lock >= 0)
+		fz_assert_lock_held(ctx, table->lock);
+
+	while (1)
+	{
+		if (!ents[pos].val)
+		{
+			memcpy(ents[pos].key, key, table->keylen);
+			ents[pos].val = val;
+			table->load ++;
+			return NULL;
+		}
+
+		if (memcmp(key, ents[pos].key, table->keylen) == 0)
+		{
+			fz_warn(ctx, "assert: overwrite hash slot");
+			return ents[pos].val = val;
+		}
+
+		pos = (pos + 1) % size;
+	}
+}
+
 static void
 fz_resize_hash(fz_context *ctx, fz_hash_table *table, int newsize)
 {
 	fz_hash_entry *oldents = table->ents;
+	fz_hash_entry *newents = table->ents;
 	int oldsize = table->size;
 	int oldload = table->load;
 	int i;
@@ -112,7 +149,22 @@ fz_resize_hash(fz_context *ctx, fz_hash_table *table, int newsize)
 		return;
 	}
 
-	table->ents = fz_malloc_array(ctx, newsize, sizeof(fz_hash_entry));
+	if (table->lock == FZ_LOCK_ALLOC)
+		fz_unlock(ctx, FZ_LOCK_ALLOC);
+	newents = fz_malloc_array(ctx, newsize, sizeof(fz_hash_entry));
+	if (table->lock == FZ_LOCK_ALLOC)
+		fz_lock(ctx, FZ_LOCK_ALLOC);
+	if (table->lock >= 0)
+	{
+		if (table->size >= newsize)
+		{
+			/* Someone else fixed it before we could lock! */
+			fz_unlock(ctx, table->lock);
+			fz_free(ctx, newents);
+			return;
+		}
+	}
+	table->ents = newents;
 	memset(table->ents, 0, sizeof(fz_hash_entry) * newsize);
 	table->size = newsize;
 	table->load = 0;
@@ -121,11 +173,15 @@ fz_resize_hash(fz_context *ctx, fz_hash_table *table, int newsize)
 	{
 		if (oldents[i].val)
 		{
-			fz_hash_insert(ctx, table, oldents[i].key, oldents[i].val);
+			do_hash_insert(ctx, table, oldents[i].key, oldents[i].val);
 		}
 	}
 
+	if (table->lock == FZ_LOCK_ALLOC)
+		fz_unlock(ctx, FZ_LOCK_ALLOC);
 	fz_free(ctx, oldents);
+	if (table->lock == FZ_LOCK_ALLOC)
+		fz_lock(ctx, FZ_LOCK_ALLOC);
 }
 
 void *
@@ -135,6 +191,9 @@ fz_hash_find(fz_context *ctx, fz_hash_table *table, void *key)
 	unsigned size = table->size;
 	unsigned pos = hash(key, table->keylen) % size;
 
+	if (table->lock >= 0)
+		fz_assert_lock_held(ctx, table->lock);
+
 	while (1)
 	{
 		if (!ents[pos].val)
@@ -150,37 +209,12 @@ fz_hash_find(fz_context *ctx, fz_hash_table *table, void *key)
 void *
 fz_hash_insert(fz_context *ctx, fz_hash_table *table, void *key, void *val)
 {
-	fz_hash_entry *ents;
-	unsigned size;
-	unsigned pos;
-
 	if (table->load > table->size * 8 / 10)
 	{
 		fz_resize_hash(ctx, table, table->size * 2);
 	}
 
-	ents = table->ents;
-	size = table->size;
-	pos = hash(key, table->keylen) % size;
-
-	while (1)
-	{
-		if (!ents[pos].val)
-		{
-			memcpy(ents[pos].key, key, table->keylen);
-			ents[pos].val = val;
-			table->load ++;
-			return NULL;
-		}
-
-		if (memcmp(key, ents[pos].key, table->keylen) == 0)
-		{
-			fz_warn(ctx, "assert: overwrite hash slot");
-			return ents[pos].val;
-		}
-
-		pos = (pos + 1) % size;
-	}
+	return do_hash_insert(ctx, table, key, val);
 }
 
 void
@@ -191,11 +225,14 @@ fz_hash_remove(fz_context *ctx, fz_hash_table *table, void *key)
 	unsigned pos = hash(key, table->keylen) % size;
 	unsigned hole, look, code;
 
+	if (table->lock >= 0)
+		fz_assert_lock_held(ctx, table->lock);
+
 	while (1)
 	{
 		if (!ents[pos].val)
 		{
-			fz_warn(ctx, "assert: remove inexistent hash entry");
+			fz_warn(ctx, "assert: remove non-existent hash entry");
 			return;
 		}