diff --git a/legacy/eina/src/include/eina_inline_lock_posix.x b/legacy/eina/src/include/eina_inline_lock_posix.x
index 51733c340d..a003c4bdba 100644
--- a/legacy/eina/src/include/eina_inline_lock_posix.x
+++ b/legacy/eina/src/include/eina_inline_lock_posix.x
@@ -19,6 +19,7 @@
 #ifndef EINA_INLINE_LOCK_POSIX_X_
 #define EINA_INLINE_LOCK_POSIX_X_
 
+#include <errno.h>
 #ifndef __USE_UNIX98
 # define __USE_UNIX98
 # include <pthread.h>
@@ -27,7 +28,28 @@
 # include <pthread.h>
 #endif
 
-typedef pthread_mutex_t Eina_Lock;
+/*
+#define EINA_LOCK_DEBUG 1
+*/
+
+#ifdef EINA_LOCK_DEBUG
+#include <execinfo.h>
+#define EINA_LOCK_DEBUG_BT_NUM 64
+typedef void (*Eina_Lock_Bt_Func) ();
+#endif
+
+typedef struct _Eina_Lock Eina_Lock;
+
+struct _Eina_Lock
+{
+   pthread_mutex_t  mutex;
+#ifdef EINA_LOCK_DEBUG   
+   pthread_t         lock_thread_id;
+   Eina_Lock_Bt_Func lock_bt[EINA_LOCK_DEBUG_BT_NUM];
+   int               lock_bt_num;
+   Eina_Bool         locked : 1;
+#endif   
+};
 
 EAPI extern Eina_Bool _eina_threads_activated;
 
@@ -44,11 +66,18 @@ eina_lock_new(Eina_Lock *mutex)
 
    if (pthread_mutexattr_init(&attr) != 0)
      return EINA_FALSE;
+/* use errorcheck locks. detect deadlocks.   
 #ifdef PTHREAD_MUTEX_RECURSIVE
    if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) != 0)
      return EINA_FALSE;
 #endif
-   if (pthread_mutex_init(mutex, &attr) != 0)
+ */
+   if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK) != 0)
+     return EINA_FALSE;
+#ifdef EINA_LOCK_DEBUG
+   memset(mutex, 0, sizeof(Eina_Lock));
+#endif   
+   if (pthread_mutex_init(&(mutex->mutex), &attr) != 0)
      return EINA_FALSE;
 
    pthread_mutexattr_destroy(&attr);
@@ -59,53 +88,95 @@ eina_lock_new(Eina_Lock *mutex)
 static inline void
 eina_lock_free(Eina_Lock *mutex)
 {
-   pthread_mutex_destroy(mutex);
+   pthread_mutex_destroy(&(mutex->mutex));
+#ifdef EINA_LOCK_DEBUG
+   memset(mutex, 0, sizeof(Eina_Lock));
+#endif   
 }
 
 static inline Eina_Bool
 eina_lock_take(Eina_Lock *mutex)
 {
-   if (_eina_threads_activated)
-      {
+   Eina_Bool ret;
 #ifdef EINA_HAVE_DEBUG_THREADS
-         if (_eina_threads_debug)
-           {
-              struct timeval t0, t1;
-              int dt;
-
-              gettimeofday(&t0, NULL);
-              pthread_mutex_lock(&(x));
-              gettimeofday(&t1, NULL);
-
-              dt = (t1.tv_sec - t0.tv_sec) * 1000000;
-              if (t1.tv_usec > t0.tv_usec)
-                dt += (t1.tv_usec - t0.tv_usec);
-              else
-                dt -= t0.tv_usec - t1.tv_usec;
-              dt /= 1000;
-
-              if (dt > _eina_threads_debug) abort();
-           }
+   if (_eina_threads_debug)
+     {
+        struct timeval t0, t1;
+        int dt;
+        
+        gettimeofday(&t0, NULL);
+        pthread_mutex_lock(&(x));
+        gettimeofday(&t1, NULL);
+        
+        dt = (t1.tv_sec - t0.tv_sec) * 1000000;
+        if (t1.tv_usec > t0.tv_usec)
+           dt += (t1.tv_usec - t0.tv_usec);
+        else
+           dt -= t0.tv_usec - t1.tv_usec;
+        dt /= 1000;
+        
+        if (dt > _eina_threads_debug) abort();
+     }
 #endif
-         return (pthread_mutex_lock(mutex) == 0) ? EINA_TRUE : EINA_FALSE;
-      }
-   return EINA_FALSE;
+   ret = (pthread_mutex_lock(&(mutex->mutex)) == 0) ? 
+      EINA_TRUE : EINA_FALSE;
+#ifdef EINA_LOCK_DEBUG
+   mutex->locked = 1;
+   mutex->lock_thread_id = pthread_self();
+   mutex->lock_bt_num = backtrace((void **)(mutex->lock_bt), EINA_LOCK_DEBUG_BT_NUM);
+#endif         
+   return ret;
 }
 
 static inline Eina_Bool
 eina_lock_take_try(Eina_Lock *mutex)
 {
-   if (_eina_threads_activated)
-     return (pthread_mutex_trylock(mutex) == 0) ? EINA_TRUE : EINA_FALSE;
-   return EINA_FALSE;
+   Eina_Bool ret = EINA_FALSE;
+   int ok;
+   
+   ok = pthread_mutex_trylock(&(mutex->mutex));
+   if (ok == 0) ret = EINA_TRUE;
+   else if (ok == EDEADLK)
+     {
+        printf("ERROR ERROR: DEADLOCK on lock %p\n", mutex);
+        ret = 2; // magic
+     }
+#ifdef EINA_LOCK_DEBUG
+   if (ret == EINA_TRUE)
+     {
+        mutex->locked = 1;
+        mutex->lock_thread_id = pthread_self();
+        mutex->lock_bt_num = backtrace((void **)(mutex->lock_bt), EINA_LOCK_DEBUG_BT_NUM);
+     }
+#endif         
+   return ret;
 }
 
 static inline Eina_Bool
 eina_lock_release(Eina_Lock *mutex)
 {
-   if (_eina_threads_activated)
-     return (pthread_mutex_unlock(mutex) == 0) ? EINA_TRUE : EINA_FALSE;
-   return EINA_FALSE;
+   Eina_Bool ret;
+#ifdef EINA_LOCK_DEBUG
+   mutex->locked = 0;
+   mutex->lock_thread_id = 0;
+   memset(mutex->lock_bt, 0, EINA_LOCK_DEBUG_BT_NUM * sizeof(Eina_Lock_Bt_Func));
+   mutex->lock_bt_num = 0;
+#endif         
+   ret = (pthread_mutex_unlock(&(mutex->mutex)) == 0) ? 
+      EINA_TRUE : EINA_FALSE;
+   return ret;
+}
+
+static inline void
+eina_lock_debug(Eina_Lock *mutex)
+{
+#ifdef EINA_LOCK_DEBUG
+   printf("lock %p, locked: %i, by %i\n", 
+          mutex, (int)mutex->locked, (int)mutex->lock_thread_id);
+   backtrace_symbols_fd((void **)mutex->lock_bt, mutex->lock_bt_num, 1);
+#else
+   mutex = 0;
+#endif
 }
 
 #endif