Index: main.mk
==================================================================
--- main.mk
+++ main.mk
@@ -7,17 +7,10 @@
 #                  "configure.in" script.
 #
 # BCC              C Compiler and options for use in building executables that
 #                  will run on the platform that is doing the build.
 #
-# USLEEP           If the target operating system supports the "usleep()" system
-#                  call, then define the HAVE_USLEEP macro for all C modules.
-#
-# THREADSAFE       If you want the SQLite library to be safe for use within a 
-#                  multi-threaded program, then define the following macro
-#                  appropriately:
-#
 # THREADLIB        Specify any extra linker options needed to make the library
 #                  thread safe
 #
 # OPTS             Extra compiler command-line options.
 #
@@ -49,11 +42,11 @@
 # build the SQLite library and testing tools.
 ################################################################################
 
 # This is how we compile
 #
-TCCX = $(TCC) $(OPTS) $(THREADSAFE) $(USLEEP) -I. -I$(TOP)/src
+TCCX = $(TCC) $(OPTS) -I. -I$(TOP)/src
 
 # Object files for the SQLite library.
 #
 LIBOBJ+= alter.o analyze.o attach.o auth.o btmutex.o btree.o build.o \
          callback.o complete.o date.o delete.o \

Index: src/btree.c
==================================================================
--- src/btree.c
+++ src/btree.c
@@ -7,11 +7,11 @@
 **    May you do good and not evil.
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.421 2007/09/03 15:19:35 drh Exp $
+** $Id: btree.c,v 1.422 2007/09/03 22:00:39 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** See the header comment on "btreeInt.h" for additional information.
 ** Including a description of file format and an overview of operation.
 */
@@ -1265,15 +1265,17 @@
     */
     if( p->sharable ){
       sqlite3_mutex *mutexShared;
       pBt->nRef = 1;
       mutexShared = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
-      pBt->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
-      if( pBt->mutex==0 ){
-        rc = SQLITE_NOMEM;
-        pSqlite->mallocFailed = 0;
-        goto btree_open_out;
+      if( SQLITE_THREADSAFE ){
+        pBt->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
+        if( pBt->mutex==0 ){
+          rc = SQLITE_NOMEM;
+          pSqlite->mallocFailed = 0;
+          goto btree_open_out;
+        }
       }
       sqlite3_mutex_enter(mutexShared);
       pBt->pNext = sqlite3SharedCacheList;
       sqlite3SharedCacheList = pBt;
       sqlite3_mutex_leave(mutexShared);
@@ -1352,11 +1354,13 @@
       }
       if( pList ){
         pList->pNext = pBt->pNext;
       }
     }
-    sqlite3_mutex_free(pBt->mutex);
+    if( SQLITE_THREADSAFE ){
+      sqlite3_mutex_free(pBt->mutex);
+    }
     removed = 1;
   }
   sqlite3_mutex_leave(pMaster);
   return removed;
 #else