From 6e55611be005b723e3f0d2ec521f2e73fce4c003 Mon Sep 17 00:00:00 2001
From: Joe Mistachkin <joe@mistachkin.com>
Date: Mon, 28 Oct 2013 21:45:52 +0000
Subject: Try resetting all the 'one time' locks as well.

---
 generic/tclInt.h    |  1 +
 unix/tclUnixNotfy.c |  8 ++++++++
 unix/tclUnixThrd.c  | 30 ++++++++++++++++++++++++++++++
 win/tclWinThrd.c    | 23 +++++++++++++++++++++++
 4 files changed, 62 insertions(+)

diff --git a/generic/tclInt.h b/generic/tclInt.h
index dc28b97..9ec4a55 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -2665,6 +2665,7 @@ MODULE_SCOPE int	TclpThreadCreate(Tcl_ThreadId *idPtr,
 MODULE_SCOPE int	TclpFindVariable(const char *name, int *lengthPtr);
 MODULE_SCOPE void	TclpInitLibraryPath(char **valuePtr,
 			    int *lengthPtr, Tcl_Encoding *encodingPtr);
+MODULE_SCOPE void	TclpResetLocks(void);
 MODULE_SCOPE void	TclpInitLock(void);
 MODULE_SCOPE void	TclpInitPlatform(void);
 MODULE_SCOPE void	TclpInitUnlock(void);
diff --git a/unix/tclUnixNotfy.c b/unix/tclUnixNotfy.c
index 4ce4840..2440b01 100644
--- a/unix/tclUnixNotfy.c
+++ b/unix/tclUnixNotfy.c
@@ -1370,6 +1370,14 @@ AtForkChildProc(void)
     notifierMutex = NULL;
 
     /*
+     * Next, forcibly reset all the "one time" locks used by the threading
+     * subsystem.  This is necessary on some (all?) variants of Unix where
+     * the pthread internal state does not survive a call to fork().
+     */
+
+    TclpResetLocks();
+
+    /*
      * Force the notifier subsystem to be initialized now.  This should
      * create the notifier thread in this process.  Subsequently, that new
      * thread will re-open the trigger pipe.
diff --git a/unix/tclUnixThrd.c b/unix/tclUnixThrd.c
index ad36242..04d736b 100644
--- a/unix/tclUnixThrd.c
+++ b/unix/tclUnixThrd.c
@@ -317,6 +317,36 @@ Tcl_GetCurrentThread(void)
 /*
  *----------------------------------------------------------------------
  *
+ * TclpResetLocks
+ *
+ *	This procedure is used to forcibly reset all the "one time" locks
+ *	used by the other platform-specific locking procedures. Currently,
+ *	this procedure is only called from the notifier to handle fork()
+ *	and must not be called from anywhere else.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclpResetLocks(void)
+{
+#ifdef TCL_THREADS
+  pthread_mutex_t dummyLock = PTHREAD_MUTEX_INITIALIZER;
+  memcpy((void *)&masterLock, (void *)&dummyLock, sizeof(pthread_mutex_t));
+  memcpy((void *)&initLock, (void *)&dummyLock, sizeof(pthread_mutex_t));
+  memcpy((void *)&allocLock, (void *)&dummyLock, sizeof(pthread_mutex_t));
+#endif
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
  * TclpInitLock
  *
  *	This procedure is used to grab a lock that serializes initialization
diff --git a/win/tclWinThrd.c b/win/tclWinThrd.c
index 2413a78..51d4d76 100644
--- a/win/tclWinThrd.c
+++ b/win/tclWinThrd.c
@@ -340,6 +340,29 @@ Tcl_GetCurrentThread(void)
 /*
  *----------------------------------------------------------------------
  *
+ * TclpResetLocks
+ *
+ *	This procedure is used to forcibly reset all the "one time" locks
+ *	used by the other platform-specific locking procedures.  Currently,
+ *	this procedure does nothing and should not be called.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclpResetLocks(void)
+{
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
  * TclpInitLock
  *
  *	This procedure is used to grab a lock that serializes initialization
-- 
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