Fix a deadlock introduced by 5c2e3bf7 by using a separate low level lock to procect...

diff --git a/mono/io-layer/handles.c b/mono/io-layer/handles.c
index 23ef0f4a2aa33a7f1f1fb2ecdf0601e44ff9a8c0..0dbc5ed2e6d0170e8ec2363b66d26fed35a4231f 100644 (file)
--- a/mono/io-layer/handles.c
+++ b/mono/io-layer/handles.c
@@ -124,6 +124,10 @@ struct _WapiFileShareLayout *_wapi_fileshare_layout = NULL;
  * 4MB array.
  */
 static GHashTable *file_share_hash;
+static CRITICAL_SECTION file_share_hash_mutex;
+
+#define file_share_hash_lock() EnterCriticalSection (&file_share_hash_mutex)
+#define file_share_hash_unlock() LeaveCriticalSection (&file_share_hash_mutex)
 
 guint32 _wapi_fd_reserve;
 
@@ -220,8 +224,10 @@ static void handle_cleanup (void)
        _wapi_shm_detach (WAPI_SHM_DATA);
        _wapi_shm_detach (WAPI_SHM_FILESHARE);
 
-       if (file_share_hash)
+       if (file_share_hash) {
                g_hash_table_destroy (file_share_hash);
+               DeleteCriticalSection (&file_share_hash_mutex);
+       }
 
        for (i = 0; i < _WAPI_PRIVATE_MAX_SLOTS; ++i)
                g_free (_wapi_private_handles [i]);
@@ -1643,9 +1649,9 @@ void
 _wapi_free_share_info (_WapiFileShare *share_info)
 {
        if (!_wapi_shm_enabled ()) {
-               _wapi_handle_lock_shared_handles ();
+               file_share_hash_lock ();
                g_hash_table_remove (file_share_hash, share_info);
-               _wapi_handle_unlock_shared_handles ();
+               file_share_hash_unlock ();
        } else {
                memset (share_info, '\0', sizeof(struct _WapiFileShare));
        }
@@ -1697,11 +1703,16 @@ gboolean _wapi_handle_get_or_set_share (dev_t device, ino_t inode,
                 * info. This is needed even if SHM is disabled, to track sharing inside
                 * the current process.
                 */
-               if (!file_share_hash)
+               if (!file_share_hash) {
                        file_share_hash = g_hash_table_new_full (wapi_share_info_hash, wapi_share_info_equal, NULL, g_free);
+                       InitializeCriticalSection (&file_share_hash_mutex);
+               }
+                       
                tmp.device = device;
                tmp.inode = inode;
 
+               file_share_hash_lock ();
+
                file_share = g_hash_table_lookup (file_share_hash, &tmp);
                if (file_share) {
                        *old_sharemode = file_share->sharemode;
@@ -1723,6 +1734,8 @@ gboolean _wapi_handle_get_or_set_share (dev_t device, ino_t inode,
 
                        g_hash_table_insert (file_share_hash, file_share, file_share);
                }
+
+               file_share_hash_unlock ();
        } else {
                /* If a linear scan gets too slow we'll have to fit a hash
                 * table onto the shared mem backing store