Remove the SQLITE_MUTEX_APPDEF compile-time option.  The SQLITE_THREADSAFE=0
option always removes all mutex code.  For application-defined mutexes only,
use SQLITE_THREADSAFE=1 with SQLITE_MUTEX_NOOP=1.  Ticket #3421. (CVS 5779)

FossilOrigin-Name: 02a12eb1cfe9307c66556105a1a99d657cc01ab5
diff --git a/src/mutex.h b/src/mutex.h
index 5f51dda..9457cb4 100644
--- a/src/mutex.h
+++ b/src/mutex.h
@@ -19,28 +19,21 @@
 ** Source files should #include the sqliteInt.h file and let that file
 ** include this one indirectly.
 **
-** $Id: mutex.h,v 1.8 2008/06/26 10:41:19 danielk1977 Exp $
+** $Id: mutex.h,v 1.9 2008/10/07 15:25:48 drh Exp $
 */
 
 
-#ifdef SQLITE_MUTEX_APPDEF
-/*
-** If SQLITE_MUTEX_APPDEF is defined, then this whole module is
-** omitted and equivalent functionality must be provided by the
-** application that links against the SQLite library.
-*/
-#else
 /*
 ** Figure out what version of the code to use.  The choices are
 **
-**   SQLITE_MUTEX_NOOP         For single-threaded applications that
-**                             do not desire error checking.
+**   SQLITE_MUTEX_OMIT         No mutex logic.  Not even stubs.  The
+**                             mutexes implemention cannot be overridden
+**                             at start-time.
 **
-**   SQLITE_MUTEX_NOOP_DEBUG   For single-threaded applications with
-**                             error checking to help verify that mutexes
-**                             are being used correctly even though they
-**                             are not needed.  Used when SQLITE_DEBUG is
-**                             defined on single-threaded builds.
+**   SQLITE_MUTEX_NOOP         For single-threaded applications.  No
+**                             mutual exclusion is provided.  But this
+**                             implementation can be overridden at
+**                             start-time.
 **
 **   SQLITE_MUTEX_PTHREADS     For multi-threaded applications on Unix.
 **
@@ -48,25 +41,22 @@
 **
 **   SQLITE_MUTEX_OS2          For multi-threaded applications on OS/2.
 */
-#define SQLITE_MUTEX_NOOP 1   /* The default */
-#if defined(SQLITE_DEBUG) && !SQLITE_THREADSAFE
-# undef SQLITE_MUTEX_NOOP
-# define SQLITE_MUTEX_NOOP_DEBUG
+#if !SQLITE_THREADSAFE
+# define SQLITE_MUTEX_OMIT
 #endif
-#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && SQLITE_OS_UNIX
-# undef SQLITE_MUTEX_NOOP
-# define SQLITE_MUTEX_PTHREADS
-#endif
-#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && SQLITE_OS_WIN
-# undef SQLITE_MUTEX_NOOP
-# define SQLITE_MUTEX_W32
-#endif
-#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && SQLITE_OS_OS2
-# undef SQLITE_MUTEX_NOOP
-# define SQLITE_MUTEX_OS2
+#if SQLITE_THREADSAFE && !defined(SQLITE_MUTEX_NOOP)
+#  if SQLITE_OS_UNIX
+#    define SQLITE_MUTEX_PTHREADS
+#  elif SQLITE_OS_WIN
+#    define SQLITE_MUTEX_W32
+#  elif SQLITE_OS_OS2
+#    define SQLITE_MUTEX_OS2
+#  else
+#    define SQLITE_MUTEX_NOOP
+#  endif
 #endif
 
-#ifdef SQLITE_MUTEX_NOOP
+#ifdef SQLITE_MUTEX_OMIT
 /*
 ** If this is a no-op implementation, implement everything as macros.
 */
@@ -80,6 +70,4 @@
 #define sqlite3MutexAlloc(X)      ((sqlite3_mutex*)8)
 #define sqlite3MutexInit()        SQLITE_OK
 #define sqlite3MutexEnd()
-#endif
-
-#endif /* SQLITE_MUTEX_APPDEF */
+#endif /* defined(SQLITE_OMIT_MUTEX) */