From 0599d7de5844a2f838cdf631b9c88b05010ebe5d Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Wed, 9 Dec 2015 06:48:15 +0000
Subject: use atomic operations

* regcomp.c (onig_chain_link_add): use atomic operation instead of
  mutex.
* regint.h (ONIG_STATE_{INC,DEC}_THREAD): ditto.
* regparse.c (PopFreeNode, node_recycle): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52995 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 regparse.c | 93 +++++++++++++++++++++++++++++++-------------------------------
 1 file changed, 47 insertions(+), 46 deletions(-)

(limited to 'regparse.c')

diff --git a/regparse.c b/regparse.c
index 094332f90e..0baf02c145 100644
--- a/regparse.c
+++ b/regparse.c
@@ -1031,7 +1031,43 @@ typedef struct _FreeNode {
 } FreeNode;
 
 static FreeNode* FreeNodeList = (FreeNode* )NULL;
+
+#define PopFreeNode(n, popped) \
+  do { \
+    FreeNode* n = FreeNodeList; \
+    while (IS_NOT_NULL(n)) { \
+      FreeNode* next = n->next; \
+      FreeNode *head = ATOMIC_PTR_CAS(FreeNodeList, n, next); \
+      if (head == n) { \
+	popped; \
+	n = next; \
+      } \
+      else { \
+	n = head; /* modified, retry */ \
+      } \
+    } \
+  } while (0)
+
+#endif
+
+static void
+node_recycle(Node* node)
+{
+#ifdef USE_PARSE_TREE_NODE_RECYCLE
+  FreeNode* n = (FreeNode* )node;
+  FreeNode* list = FreeNodeList;
+  FreeNode* l;
+
+  /* THREAD_ATOMIC_START; */
+  do {
+    n->next = l = list;
+    list = ATOMIC_PTR_CAS(FreeNodeList, list, n);
+  } while (list != l);
+  /* THREAD_ATOMIC_END; */
+#else
+  xfree(node);
 #endif
+}
 
 extern void
 onig_node_free(Node* node)
@@ -1053,18 +1089,7 @@ onig_node_free(Node* node)
     {
       Node* next_node = NCDR(node);
 
-#ifdef USE_PARSE_TREE_NODE_RECYCLE
-      {
-	FreeNode* n = (FreeNode* )node;
-
-        THREAD_ATOMIC_START;
-	n->next = FreeNodeList;
-	FreeNodeList = n;
-        THREAD_ATOMIC_END;
-      }
-#else
-      xfree(node);
-#endif
+      node_recycle(node);
       node = next_node;
       goto start;
     }
@@ -1101,32 +1126,15 @@ onig_node_free(Node* node)
     break;
   }
 
-#ifdef USE_PARSE_TREE_NODE_RECYCLE
-  {
-    FreeNode* n = (FreeNode* )node;
-
-    THREAD_ATOMIC_START;
-    n->next = FreeNodeList;
-    FreeNodeList = n;
-    THREAD_ATOMIC_END;
-  }
-#else
-  xfree(node);
-#endif
+  node_recycle(node);
 }
 
 #ifdef USE_PARSE_TREE_NODE_RECYCLE
 extern int
 onig_free_node_list(void)
 {
-  FreeNode* n;
-
   /* THREAD_ATOMIC_START; */
-  while (IS_NOT_NULL(FreeNodeList)) {
-    n = FreeNodeList;
-    FreeNodeList = FreeNodeList->next;
-    xfree(n);
-  }
+  PopFreeNode(n, xfree(n));
   /* THREAD_ATOMIC_END; */
   return 0;
 }
@@ -1138,14 +1146,9 @@ node_new(void)
   Node* node;
 
 #ifdef USE_PARSE_TREE_NODE_RECYCLE
-  THREAD_ATOMIC_START;
-  if (IS_NOT_NULL(FreeNodeList)) {
-    node = (Node* )FreeNodeList;
-    FreeNodeList = FreeNodeList->next;
-    THREAD_ATOMIC_END;
-    return node;
-  }
-  THREAD_ATOMIC_END;
+  /* THREAD_ATOMIC_START; */
+  PopFreeNode(n, return (Node* )n);
+  /* THREAD_ATOMIC_END; */
 #endif
 
   node = (Node* )xmalloc(sizeof(Node));
@@ -1155,17 +1158,14 @@ node_new(void)
 
 #if defined(USE_MULTI_THREAD_SYSTEM) && \
     defined(USE_SHARED_CCLASS_TABLE) && \
-    defined(USE_PARSE_TREE_NODE_RECYCLE)
+    defined(USE_PARSE_TREE_NODE_RECYCLE) && \
+    0
 static Node*
 node_new_locked(void)
 {
   Node* node;
 
-  if (IS_NOT_NULL(FreeNodeList)) {
-    node = (Node* )FreeNodeList;
-    FreeNodeList = FreeNodeList->next;
-    return node;
-  }
+  PopFreeNode(n, return (Node* )n);
 
   node = (Node* )xmalloc(sizeof(Node));
   /* xmemset(node, 0, sizeof(Node)); */
@@ -1195,7 +1195,8 @@ node_new_cclass(void)
 
 #if defined(USE_MULTI_THREAD_SYSTEM) && \
     defined(USE_SHARED_CCLASS_TABLE) && \
-    defined(USE_PARSE_TREE_NODE_RECYCLE)
+    defined(USE_PARSE_TREE_NODE_RECYCLE) && \
+    0
 static Node*
 node_new_cclass_locked(void)
 {
-- 
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