New interface (not part of robust mutexes)

16 files changed, 260 insertions, 29 deletions

diff --git a/ChangeLog b/ChangeLog
index 7ea66ae..d143ea2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2011-03-26  Ross Johnson <ross.johnson at homemail.com.au>

+

+	* pthread_getsequence_np.c: New non-POSIX interface for compatibility

+	with some other implementations; returns a 64 bit sequence number

+	that is unique to each thread in the process.

+	* pthread.h (pthread_getsequence_np): Added.

+	* global.c: Add global sequence counter for above.

+	* implement.h: Likewise.

+

 2011-03-25  Ross Johnson <ross.johnson at homemail.com.au>

 

 	* (cancelLock): Convert to an MCS lock and rename to stateLock.

diff --git a/GNUmakefile b/GNUmakefile
index 40fd538..3491efd 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -194,6 +194,7 @@ SMALL_STATIC_OBJS	= \
 		pthread_mutexattr_setkind_np.o \
 		pthread_mutexattr_getkind_np.o \
 		pthread_getw32threadhandle_np.o \
+		pthread_getsequence_np.o \
 		pthread_delay_np.o \
 		pthread_num_processors_np.o \
 		pthread_win32_attach_detach_np.o \
@@ -353,6 +354,7 @@ NONPORTABLE_SRCS = \
 		pthread_mutexattr_setkind_np.c \
 		pthread_mutexattr_getkind_np.c \
 		pthread_getw32threadhandle_np.c \
+                pthread_getsequence_np.c \
 		pthread_delay_np.c \
 		pthread_num_processors_np.c \
 		pthread_win32_attach_detach_np.c \
diff --git a/Makefile b/Makefile
index 23ef981..f7c6dc3 100644
--- a/Makefile
+++ b/Makefile
@@ -140,6 +140,7 @@ SMALL_STATIC_OBJS	= \
 		pthread_mutexattr_setkind_np.obj \
 		pthread_mutexattr_getkind_np.obj \
 		pthread_getw32threadhandle_np.obj \
+		pthread_getsequence_np.obj \
 		pthread_delay_np.obj \
 		pthread_num_processors_np.obj \
 		pthread_win32_attach_detach_np.obj \
@@ -295,6 +296,7 @@ NONPORTABLE_SRCS = \
 		pthread_mutexattr_setkind_np.c \
 		pthread_mutexattr_getkind_np.c \
 		pthread_getw32threadhandle_np.c \
+		pthread_getsequence_np.c \
 		pthread_delay_np.c \
 		pthread_num_processors_np.c \
 		pthread_win32_attach_detach_np.c \
diff --git a/global.c b/global.c
index be6d027..874b71b 100644
--- a/global.c
+++ b/global.c
@@ -52,6 +52,11 @@ int ptw32_concurrency = 0;
 /* What features have been auto-detected */
 int ptw32_features = 0;
 
+/*
+ * Global [process wide] thread sequence Number
+ */
+unsigned long long ptw32_threadSeqNumber = 0;
+
 /* 
  * Function pointer to QueueUserAPCEx if it exists, otherwise
  * it will be set at runtime to a substitute routine which cannot unblock
diff --git a/implement.h b/implement.h
index b4c80b3..8a27fae 100644
--- a/implement.h
+++ b/implement.h
@@ -561,6 +561,8 @@ extern pthread_cond_t ptw32_cond_list_tail;
 
 extern int ptw32_mutex_default_kind;
 
+extern unsigned long long ptw32_threadSeqNumber;
+
 extern int ptw32_concurrency;
 
 extern int ptw32_features;
diff --git a/nonportable.c b/nonportable.c
index 6c2a990..82c558b 100644
--- a/nonportable.c
+++ b/nonportable.c
@@ -40,6 +40,7 @@
 #include "pthread_mutexattr_setkind_np.c"
 #include "pthread_mutexattr_getkind_np.c"
 #include "pthread_getw32threadhandle_np.c"
+#include "pthread_getsequence_np.c"
 #include "pthread_delay_np.c"
 #include "pthread_num_processors_np.c"
 #include "pthread_win32_attach_detach_np.c"
diff --git a/pthread.h b/pthread.h
index 0c0aeb8..a3506b6 100644
--- a/pthread.h
+++ b/pthread.h
@@ -1176,6 +1176,7 @@ PTW32_DLLPORT int PTW32_CDECL pthread_mutexattr_getkind_np(pthread_mutexattr_t *
  */
 PTW32_DLLPORT int PTW32_CDECL pthread_delay_np (struct timespec * interval);
 PTW32_DLLPORT int PTW32_CDECL pthread_num_processors_np(void);
+PTW32_DLLPORT unsigned long long PTW32_CDECL pthread_getsequence_np(pthread_t thread);
 
 /*
  * Useful if an application wants to statically link
diff --git a/pthread_getsequence_np.c b/pthread_getsequence_np.c
new file mode 100755
index 0000000..0e643e9
--- /dev/null
+++ b/pthread_getsequence_np.c
@@ -0,0 +1,47 @@
+/*
+ * pthread_getsequence_np.c
+ *
+ * Description:
+ * This translation unit implements non-portable thread functions.
+ *
+ * --------------------------------------------------------------------------
+ *
+ *      Pthreads-win32 - POSIX Threads Library for Win32
+ *      Copyright(C) 1998 John E. Bossom
+ *      Copyright(C) 1999,2005 Pthreads-win32 contributors
+ * 
+ *      Contact Email: rpj@callisto.canberra.edu.au
+ * 
+ *      The current list of contributors is contained
+ *      in the file CONTRIBUTORS included with the source
+ *      code distribution. The list can also be seen at the
+ *      following World Wide Web location:
+ *      http://sources.redhat.com/pthreads-win32/contributors.html
+ * 
+ *      This library is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU Lesser General Public
+ *      License as published by the Free Software Foundation; either
+ *      version 2 of the License, or (at your option) any later version.
+ * 
+ *      This library is distributed in the hope that it will be useful,
+ *      but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *      Lesser General Public License for more details.
+ * 
+ *      You should have received a copy of the GNU Lesser General Public
+ *      License along with this library in the file COPYING.LIB;
+ *      if not, write to the Free Software Foundation, Inc.,
+ *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include "pthread.h"
+#include "implement.h"
+
+/*
+ *
+ */
+unsigned long long
+pthread_getsequence_np (pthread_t thread)
+{
+  return ((ptw32_thread_t*)thread.p)->seqNumber;
+}
diff --git a/pthread_mutex_consistent.c b/pthread_mutex_consistent.c
index 5ceab0c..08572a5 100755
--- a/pthread_mutex_consistent.c
+++ b/pthread_mutex_consistent.c
@@ -83,7 +83,7 @@ ptw32_robust_mutex_inherit(pthread_mutex_t * mutex)
   switch (PTW32_INTERLOCKED_COMPARE_EXCHANGE(
             (LPLONG)&robust->stateInconsistent,
             (LONG)PTW32_ROBUST_INCONSISTENT,
-            -1L /* Terminating thread sets this */))
+            -1L /* The terminating thread sets this */))
     {
       case -1L:
           result = EOWNERDEAD;
@@ -99,6 +99,18 @@ ptw32_robust_mutex_inherit(pthread_mutex_t * mutex)
   return result;
 }
 
+/*
+ * The next two internal support functions depend on only being
+ * called by the thread that owns the robust mutex. This enables
+ * us to avoid additional locks.
+ * Any mutex currently in the thread's robust mutex list is held
+ * by the thread, again eliminating the need for locks.
+ * The forward/backward links allow the thread to unlock mutexes
+ * in any order, not necessarily the reverse locking order.
+ * This is all possible because it is an error if a thread that
+ * does not own the [robust] mutex attempts to unlock it.
+ */
+
 INLINE
 void
 ptw32_robust_mutex_add(pthread_mutex_t* mutex, pthread_t self)
@@ -131,10 +143,9 @@ ptw32_robust_mutex_remove(pthread_mutex_t* mutex, ptw32_thread_t* otp)
 {
   ptw32_robust_node_t** list;
   pthread_mutex_t mx = *mutex;
-  ptw32_thread_t* tp = mx->ownerThread.p;
   ptw32_robust_node_t* robust = mx->robustNode;
 
-  list = &tp->robustMxList;
+  list = &(((ptw32_thread_t*)mx->ownerThread.p)->robustMxList);
   mx->ownerThread.p = otp;
   if (robust->next != NULL)
     {
diff --git a/ptw32_new.c b/ptw32_new.c
index 881c6ac..ac836ea 100644
--- a/ptw32_new.c
+++ b/ptw32_new.c
@@ -70,6 +70,7 @@ ptw32_new (void)
     }
 
   /* Set default state. */
+  tp->seqNumber = ++ptw32_threadSeqNumber;
   tp->sched_priority = THREAD_PRIORITY_NORMAL;
   tp->detachState = PTHREAD_CREATE_JOINABLE;
   tp->cancelState = PTHREAD_CANCEL_ENABLE;
diff --git a/tests/Bmakefile b/tests/Bmakefile
index 263d127..bd8d7b7 100644
--- a/tests/Bmakefile
+++ b/tests/Bmakefile
@@ -85,7 +85,7 @@ PASSES=   loadfree.pass \
 	  mutex2r.pass  mutex2e.pass  mutex3r.pass  mutex3e.pass  \
 	  condvar1.pass  condvar1_1.pass  condvar1_2.pass  condvar2.pass  condvar2_1.pass  \
 	  exit1.pass  create1.pass  create2.pass  reuse1.pass  reuse2.pass  equal1.pass  \
-	  kill1.pass  valid1.pass  valid2.pass  \
+	  sequence1.pass  kill1.pass  valid1.pass  valid2.pass  \
 	  exit2.pass  exit3.pass  exit4.pass  exit5.pass  \
 	  join0.pass  join1.pass  detach1.pass  join2.pass join3.pass  \
 	  mutex4.pass  mutex6.pass  mutex6n.pass  mutex6e.pass  mutex6r.pass  \
@@ -311,11 +311,6 @@ mutex8.pass: mutex7.pass
 mutex8n.pass: mutex7n.pass
 mutex8e.pass: mutex7e.pass
 mutex8r.pass: mutex7r.pass
-robust1.pass: mutex8r.pass
-robust2.pass: mutex8r.pass
-robust3.pass: robust2.pass
-robust4.pass: robust3.pass
-robust5.pass: robust4.pass
 once1.pass: create1.pass
 once2.pass: once1.pass
 once3.pass: once2.pass
@@ -324,6 +319,11 @@ priority1.pass: join1.pass
 priority2.pass: priority1.pass barrier3.pass
 reuse1.pass: create2.pass
 reuse2.pass: reuse1.pass
+robust1.pass: mutex8r.pass
+robust2.pass: mutex8r.pass
+robust3.pass: robust2.pass
+robust4.pass: robust3.pass
+robust5.pass: robust4.pass
 rwlock1.pass: condvar6.pass
 rwlock2.pass: rwlock1.pass
 rwlock3.pass: rwlock2.pass
@@ -346,6 +346,7 @@ semaphore3.pass: semaphore2.pass
 semaphore4.pass: semaphore3.pass cancel1.pass
 semaphore4t.pass: semaphore4.pass
 semaphore5.pass: semaphore4.pass
+sequence1.pass: reuse2.pass
 sizes.pass:
 spin1.pass:
 spin2.pass: spin1.pass
diff --git a/tests/ChangeLog b/tests/ChangeLog
index 8d7604f..47b8253 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,7 @@
+2011-03-26  Ross Johnson <ross.johnson at homemail.com.au>
+
+	* sequence1.c: New test for new pthread_getsequence_np().
+
 2011-03-24  Ross Johnson <ross.johnson at homemail.com.au>
 
 	* mutex*.c: Include tests for robust mutexes wherever
diff --git a/tests/GNUmakefile b/tests/GNUmakefile
index 98342cc..9a46b2c 100644
--- a/tests/GNUmakefile
+++ b/tests/GNUmakefile
@@ -92,7 +92,7 @@ TESTS	= \
 	  semaphore1 semaphore2 semaphore3 \
 	  condvar1 condvar1_1 condvar1_2 condvar2 condvar2_1 exit1 \
 	  create1 create2 reuse1 reuse2 equal1 \
-	  kill1 valid1 valid2 \
+	  sequence1 kill1 valid1 valid2 \
 	  exit2 exit3 exit4 exit5 \
 	  join0 join1 detach1 join2 join3 \
 	  mutex2 mutex2r mutex2e mutex3 mutex3r mutex3e \
@@ -131,7 +131,7 @@ STATICTESTS = \
 	  semaphore1 semaphore2 semaphore3 \
 	  condvar1 condvar1_1 condvar1_2 condvar2 condvar2_1 exit1 \
 	  create1 create2 reuse1 reuse2 equal1 \
-	  kill1 valid1 valid2 \
+	  sequence1 kill1 valid1 valid2 \
 	  exit2 exit3 exit4 exit5 \
 	  join0 join1 detach1 join2 join3 \
 	  mutex2 mutex2r mutex2e mutex3 mutex3r mutex3e \
@@ -329,11 +329,6 @@ mutex8.pass: mutex7.pass
 mutex8n.pass: mutex7n.pass
 mutex8e.pass: mutex7e.pass
 mutex8r.pass: mutex7r.pass
-robust1.pass: mutex8r.pass
-robust2.pass: mutex8r.pass
-robust3.pass: robust2.pass
-robust4.pass: robust3.pass
-robust5.pass: robust4.pass
 once1.pass: create1.pass
 once2.pass: once1.pass
 once3.pass: once2.pass
@@ -343,6 +338,11 @@ priority1.pass: join1.pass
 priority2.pass: priority1.pass barrier3.pass
 reuse1.pass: create2.pass
 reuse2.pass: reuse1.pass
+robust1.pass: mutex8r.pass
+robust2.pass: mutex8r.pass
+robust3.pass: robust2.pass
+robust4.pass: robust3.pass
+robust5.pass: robust4.pass
 rwlock1.pass: condvar6.pass
 rwlock2.pass: rwlock1.pass
 rwlock3.pass: rwlock2.pass
@@ -365,6 +365,7 @@ semaphore3.pass: semaphore2.pass
 semaphore4.pass: semaphore3.pass cancel1.pass
 semaphore4t.pass: semaphore4.pass
 semaphore5.pass: semaphore4.pass
+sequence1.pass: reuse2.pass
 sizes.pass:
 spin1.pass:
 spin2.pass: spin1.pass
diff --git a/tests/Makefile b/tests/Makefile
index 5439ee1..4164e1e 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -89,7 +89,7 @@ PASSES= sizes.pass  loadfree.pass \
 	  mutex2r.pass  mutex2e.pass  mutex3r.pass  mutex3e.pass  \
 	  condvar1.pass  condvar1_1.pass  condvar1_2.pass  condvar2.pass  condvar2_1.pass  \
 	  exit1.pass  create1.pass  create2.pass  reuse1.pass  reuse2.pass  equal1.pass  \
-	  kill1.pass  valid1.pass  valid2.pass  \
+	  sequence1.pass  kill1.pass  valid1.pass  valid2.pass  \
 	  exit2.pass  exit3.pass  exit4.pass  exit5.pass  \
 	  join0.pass  join1.pass  detach1.pass  join2.pass join3.pass  \
 	  mutex4.pass  mutex6.pass  mutex6n.pass  mutex6e.pass  mutex6r.pass  \
@@ -135,7 +135,7 @@ STATICRESULTS = \
 	  mutex2r.pass  mutex2e.pass  mutex3r.pass  mutex3e.pass  \
 	  condvar1.pass  condvar1_1.pass  condvar1_2.pass  condvar2.pass  condvar2_1.pass  \
 	  exit1.pass  create1.pass  create2.pass  reuse1.pass  reuse2.pass  equal1.pass  \
-	  kill1.pass  valid1.pass  valid2.pass  \
+	  sequence1.pass  kill1.pass  valid1.pass  valid2.pass  \
 	  exit2.pass  exit3.pass  exit4.pass  exit5.pass  \
 	  join0.pass  join1.pass  detach1.pass  join2.pass join3.pass  \
 	  mutex4.pass  mutex6.pass  mutex6n.pass  mutex6e.pass  mutex6r.pass  \
@@ -400,11 +400,6 @@ mutex8.pass: mutex7.pass
 mutex8n.pass: mutex7n.pass
 mutex8e.pass: mutex7e.pass
 mutex8r.pass: mutex7r.pass
-robust1.pass: mutex8r.pass
-robust2.pass: mutex8r.pass
-robust3.pass: robust2.pass
-robust4.pass: robust3.pass
-robust5.pass: robust4.pass
 once1.pass: create1.pass
 once2.pass: once1.pass
 once3.pass: once2.pass
@@ -413,6 +408,11 @@ priority1.pass: join1.pass
 priority2.pass: priority1.pass barrier3.pass
 reuse1.pass: create2.pass
 reuse2.pass: reuse1.pass
+robust1.pass: mutex8r.pass
+robust2.pass: mutex8r.pass
+robust3.pass: robust2.pass
+robust4.pass: robust3.pass
+robust5.pass: robust4.pass
 rwlock1.pass: condvar6.pass
 rwlock2.pass: rwlock1.pass
 rwlock3.pass: rwlock2.pass
@@ -435,6 +435,7 @@ semaphore3.pass: semaphore2.pass
 semaphore4.pass: semaphore3.pass cancel1.pass
 semaphore4t.pass: semaphore4.pass
 semaphore5.pass: semaphore4.pass
+sequence1.pass: reuse2.pass
 sizes.pass:
 spin1.pass:
 spin2.pass: spin1.pass
diff --git a/tests/Wmakefile b/tests/Wmakefile
index c7e97fb..0fcbd43 100644
--- a/tests/Wmakefile
+++ b/tests/Wmakefile
@@ -87,7 +87,7 @@ PASSES	= sizes.pass  loadfree.pass &
 	  mutex2r.pass  mutex2e.pass  mutex3r.pass  mutex3e.pass  &
 	  condvar1.pass  condvar1_1.pass  condvar1_2.pass  condvar2.pass  condvar2_1.pass  &
 	  exit1.pass  create1.pass  create2.pass  reuse1.pass  reuse2.pass  equal1.pass  &
-	  kill1.pass  valid1.pass  valid2.pass  &
+	  sequence1.pass  kill1.pass  valid1.pass  valid2.pass  &
 	  exit2.pass  exit3.pass  exit4  exit5  &
 	  join0.pass  join1.pass  detach1.pass  join2.pass join3.pass  &
 	  mutex4.pass  mutex6.pass  mutex6n.pass  mutex6e.pass  mutex6r.pass  &
@@ -309,11 +309,6 @@ mutex8.pass: mutex7.pass
 mutex8n.pass: mutex7n.pass
 mutex8e.pass: mutex7e.pass
 mutex8r.pass: mutex7r.pass
-robust1.pass: mutex8r.pass
-robust2.pass: mutex8r.pass
-robust3.pass: robust2.pass
-robust4.pass: robust3.pass
-robust5.pass: robust4.pass
 once1.pass: create1.pass
 once2.pass: once1.pass
 once3.pass: once2.pass
@@ -322,6 +317,11 @@ priority1.pass: join1.pass
 priority2.pass: priority1.pass barrier3.pass
 reuse1.pass: create2.pass
 reuse2.pass: reuse1.pass
+robust1.pass: mutex8r.pass
+robust2.pass: mutex8r.pass
+robust3.pass: robust2.pass
+robust4.pass: robust3.pass
+robust5.pass: robust4.pass
 rwlock1.pass: condvar6.pass
 rwlock2.pass: rwlock1.pass
 rwlock3.pass: rwlock2.pass
@@ -343,6 +343,7 @@ semaphore3.pass: semaphore2.pass
 semaphore4.pass: semaphore3.pass cancel1.pass
 semaphore4t.pass: semaphore4.pass
 semaphore5.pass: semaphore4.pass
+sequence1.pass: reuse2.pass
 sizes.pass:
 spin1.pass:
 spin2.pass: spin1.pass
diff --git a/tests/sequence1.c b/tests/sequence1.c
new file mode 100755
index 0000000..d7c6e0b
--- /dev/null
+++ b/tests/sequence1.c
@@ -0,0 +1,142 @@
+/*
+ * File: sequence1.c
+ *
+ *
+ * --------------------------------------------------------------------------
+ *
+ *      Pthreads-win32 - POSIX Threads Library for Win32
+ *      Copyright(C) 1998 John E. Bossom
+ *      Copyright(C) 1999,2005 Pthreads-win32 contributors
+ * 
+ *      Contact Email: rpj@callisto.canberra.edu.au
+ * 
+ *      The current list of contributors is contained
+ *      in the file CONTRIBUTORS included with the source
+ *      code distribution. The list can also be seen at the
+ *      following World Wide Web location:
+ *      http://sources.redhat.com/pthreads-win32/contributors.html
+ * 
+ *      This library is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU Lesser General Public
+ *      License as published by the Free Software Foundation; either
+ *      version 2 of the License, or (at your option) any later version.
+ * 
+ *      This library is distributed in the hope that it will be useful,
+ *      but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *      Lesser General Public License for more details.
+ * 
+ *      You should have received a copy of the GNU Lesser General Public
+ *      License along with this library in the file COPYING.LIB;
+ *      if not, write to the Free Software Foundation, Inc.,
+ *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * --------------------------------------------------------------------------
+ *
+ * Test Synopsis:
+ * - that unique thread sequence numbers are generated.
+ * - Analyse thread struct reuse.
+ *
+ * Test Method (Validation or Falsification):
+ * -
+ *
+ * Requirements Tested:
+ * -
+ *
+ * Features Tested:
+ * -
+ *
+ * Cases Tested:
+ * -
+ *
+ * Description:
+ * -
+ *
+ * Environment:
+ * - This test is implementation specific
+ * because it uses knowledge of internals that should be
+ * opaque to an application.
+ *
+ * Input:
+ * - None.
+ *
+ * Output:
+ * - File name, Line number, and failed expression on failure.
+ * - analysis output on success.
+ *
+ * Assumptions:
+ * -
+ *
+ * Pass Criteria:
+ * - unique sequence numbers are generated for every new thread.
+ *
+ * Fail Criteria:
+ * - 
+ */
+
+#include "test.h"
+
+/*
+ */
+
+enum {
+	NUMTHREADS = 10000
+};
+
+
+static long done = 0;
+/*
+ * seqmap should have 1 in every element except [0]
+ * Thread sequence numbers start at 1 and we will also
+ * include this main thread so we need NUMTHREADS+2
+ * elements. 
+ */
+static UINT64 seqmap[NUMTHREADS+2];
+
+void * func(void * arg)
+{
+  sched_yield();
+  seqmap[(int)pthread_getsequence_np(pthread_self())] = 1;
+  InterlockedIncrement(&done);
+
+  return (void *) 0; 
+}
+ 
+int
+main()
+{
+  pthread_t t[NUMTHREADS];
+  pthread_attr_t attr;
+  int i;
+
+  assert(pthread_attr_init(&attr) == 0);
+  assert(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) == 0);
+
+  for (i = 0; i <= NUMTHREADS+2; i++)
+    {
+      seqmap[i] = 0;
+    }
+
+  for (i = 0; i < NUMTHREADS; i++)
+    {
+      if (NUMTHREADS/2 == i)
+        {
+          /* Include this main thread, which will be an implicit pthread_t */
+          seqmap[(int)pthread_getsequence_np(pthread_self())] = 1;
+        }
+      assert(pthread_create(&t[i], &attr, func, NULL) == 0);
+    }
+
+  while (NUMTHREADS > InterlockedExchangeAdd((LPLONG)&done, 0L))
+    Sleep(100);
+
+  Sleep(100);
+
+  assert(seqmap[0] == 0);
+  for (i = 1; i < NUMTHREADS+2; i++)
+    {
+      assert(seqmap[i] == 1);
+    }
+
+  return 0;
+}