Upgrade our sqlite to 3.6.1, with the local changes made by Gears. I'm

checking in the full sqlite tree to make upstream merges easier.  This means
we'll have generated sources split out from the originals.

One important change this makes is that "BEGIN" now defaults to "BEGIN
IMMEDIATE" rather than "BEGIN DEFERRED".  This doesn't affect us because we
don't use unqualified BEGIN statements.

The full CL is too big for Rietveld.  I'm splitting it into 2.  This one is
reviewable.  The other CL is just a fresh drop of:
//depot/googleclient/gears/opensource/third_party/sqlite_google
Review URL: http://codereview.chromium.org/15067

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@7623 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 723 insertions, 0 deletions

diff --git a/third_party/sqlite/src/test7.c b/third_party/sqlite/src/test7.c
new file mode 100755
index 0000000..78754bf
--- /dev/null
+++ b/third_party/sqlite/src/test7.c
@@ -0,0 +1,723 @@
+/*
+** 2006 January 09
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    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.
+**
+*************************************************************************
+** Code for testing the client/server version of the SQLite library.
+** Derived from test4.c.
+**
+** $Id: test7.c,v 1.12 2008/07/28 19:34:54 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "tcl.h"
+
+/*
+** This test only works on UNIX with a SQLITE_THREADSAFE build that includes
+** the SQLITE_SERVER option.
+*/
+#if defined(SQLITE_SERVER) && !defined(SQLITE_OMIT_SHARED_CACHE) && \
+    defined(SQLITE_OS_UNIX) && OS_UNIX && SQLITE_THREADSAFE
+
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <sched.h>
+#include <ctype.h>
+
+/*
+** Interfaces defined in server.c
+*/
+int sqlite3_client_open(const char*, sqlite3**);
+int sqlite3_client_prepare(sqlite3*,const char*,int,
+                           sqlite3_stmt**,const char**);
+int sqlite3_client_step(sqlite3_stmt*);
+int sqlite3_client_reset(sqlite3_stmt*);
+int sqlite3_client_finalize(sqlite3_stmt*);
+int sqlite3_client_close(sqlite3*);
+int sqlite3_server_start(void);
+int sqlite3_server_stop(void);
+
+/*
+** Each thread is controlled by an instance of the following
+** structure.
+*/
+typedef struct Thread Thread;
+struct Thread {
+  /* The first group of fields are writable by the supervisor thread
+  ** and read-only to the client threads
+  */
+  char *zFilename;         /* Name of database file */
+  void (*xOp)(Thread*);    /* next operation to do */
+  char *zArg;              /* argument usable by xOp */
+  volatile int opnum;      /* Operation number */
+  volatile int busy;       /* True if this thread is in use */
+
+  /* The next group of fields are writable by the client threads 
+  ** but read-only to the superviser thread.
+  */
+  volatile int completed;  /* Number of operations completed */
+  sqlite3 *db;             /* Open database */
+  sqlite3_stmt *pStmt;     /* Pending operation */
+  char *zErr;              /* operation error */
+  char *zStaticErr;        /* Static error message */
+  int rc;                  /* operation return code */
+  int argc;                /* number of columns in result */
+  const char *argv[100];   /* result columns */
+  const char *colv[100];   /* result column names */
+};
+
+/*
+** There can be as many as 26 threads running at once.  Each is named
+** by a capital letter: A, B, C, ..., Y, Z.
+*/
+#define N_THREAD 26
+static Thread threadset[N_THREAD];
+
+/*
+** The main loop for a thread.  Threads use busy waiting. 
+*/
+static void *client_main(void *pArg){
+  Thread *p = (Thread*)pArg;
+  if( p->db ){
+    sqlite3_client_close(p->db);
+  }
+  sqlite3_client_open(p->zFilename, &p->db);
+  if( SQLITE_OK!=sqlite3_errcode(p->db) ){
+    p->zErr = strdup(sqlite3_errmsg(p->db));
+    sqlite3_client_close(p->db);
+    p->db = 0;
+  }
+  p->pStmt = 0;
+  p->completed = 1;
+  while( p->opnum<=p->completed ) sched_yield();
+  while( p->xOp ){
+    if( p->zErr && p->zErr!=p->zStaticErr ){
+      sqlite3_free(p->zErr);
+      p->zErr = 0;
+    }
+    (*p->xOp)(p);
+    p->completed++;
+    while( p->opnum<=p->completed ) sched_yield();
+  }
+  if( p->pStmt ){
+    sqlite3_client_finalize(p->pStmt);
+    p->pStmt = 0;
+  }
+  if( p->db ){
+    sqlite3_client_close(p->db);
+    p->db = 0;
+  }
+  if( p->zErr && p->zErr!=p->zStaticErr ){
+    sqlite3_free(p->zErr);
+    p->zErr = 0;
+  }
+  p->completed++;
+  sqlite3_thread_cleanup();
+  return 0;
+}
+
+/*
+** Get a thread ID which is an upper case letter.  Return the index.
+** If the argument is not a valid thread ID put an error message in
+** the interpreter and return -1.
+*/
+static int parse_client_id(Tcl_Interp *interp, const char *zArg){
+  if( zArg==0 || zArg[0]==0 || zArg[1]!=0 || !isupper((unsigned char)zArg[0]) ){
+    Tcl_AppendResult(interp, "thread ID must be an upper case letter", 0);
+    return -1;
+  }
+  return zArg[0] - 'A';
+}
+
+/*
+** Usage:    client_create NAME  FILENAME
+**
+** NAME should be an upper case letter.  Start the thread running with
+** an open connection to the given database.
+*/
+static int tcl_client_create(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  pthread_t x;
+  int rc;
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID FILENAME", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( threadset[i].busy ){
+    Tcl_AppendResult(interp, "thread ", argv[1], " is already running", 0);
+    return TCL_ERROR;
+  }
+  threadset[i].busy = 1;
+  sqlite3_free(threadset[i].zFilename);
+  threadset[i].zFilename = sqlite3DbStrDup(0, argv[2]);
+  threadset[i].opnum = 1;
+  threadset[i].completed = 0;
+  rc = pthread_create(&x, 0, client_main, &threadset[i]);
+  if( rc ){
+    Tcl_AppendResult(interp, "failed to create the thread", 0);
+    sqlite3_free(threadset[i].zFilename);
+    threadset[i].busy = 0;
+    return TCL_ERROR;
+  }
+  pthread_detach(x);
+  sqlite3_server_start();
+  return TCL_OK;
+}
+
+/*
+** Wait for a thread to reach its idle state.
+*/
+static void client_wait(Thread *p){
+  while( p->opnum>p->completed ) sched_yield();
+}
+
+/*
+** Usage:  client_wait ID
+**
+** Wait on thread ID to reach its idle state.
+*/
+static int tcl_client_wait(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  return TCL_OK;
+}
+
+/*
+** Stop a thread.
+*/
+static void stop_thread(Thread *p){
+  client_wait(p);
+  p->xOp = 0;
+  p->opnum++;
+  client_wait(p);
+  sqlite3_free(p->zArg);
+  p->zArg = 0;
+  sqlite3_free(p->zFilename);
+  p->zFilename = 0;
+  p->busy = 0;
+}
+
+/*
+** Usage:  client_halt ID
+**
+** Cause a client thread to shut itself down.  Wait for the shutdown to be
+** completed.  If ID is "*" then stop all client threads.
+*/
+static int tcl_client_halt(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  if( argv[1][0]=='*' && argv[1][1]==0 ){
+    for(i=0; i<N_THREAD; i++){
+      if( threadset[i].busy ){
+        stop_thread(&threadset[i]);
+      }
+    }
+  }else{
+    i = parse_client_id(interp, argv[1]);
+    if( i<0 ) return TCL_ERROR;
+    if( !threadset[i].busy ){
+      Tcl_AppendResult(interp, "no such thread", 0);
+      return TCL_ERROR;
+    }
+    stop_thread(&threadset[i]);
+  }
+
+  /* If no client threads are still running, also stop the server */
+  for(i=0; i<N_THREAD && threadset[i].busy==0; i++){}
+  if( i>=N_THREAD ){
+    sqlite3_server_stop();
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage: client_argc  ID
+**
+** Wait on the most recent client_step to complete, then return the
+** number of columns in the result set.
+*/
+static int tcl_client_argc(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  char zBuf[100];
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  sprintf(zBuf, "%d", threadset[i].argc);
+  Tcl_AppendResult(interp, zBuf, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: client_argv  ID   N
+**
+** Wait on the most recent client_step to complete, then return the
+** value of the N-th columns in the result set.
+*/
+static int tcl_client_argv(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  int n;
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID N", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetInt(interp, argv[2], &n) ) return TCL_ERROR;
+  client_wait(&threadset[i]);
+  if( n<0 || n>=threadset[i].argc ){
+    Tcl_AppendResult(interp, "column number out of range", 0);
+    return TCL_ERROR;
+  }
+  Tcl_AppendResult(interp, threadset[i].argv[n], 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: client_colname  ID   N
+**
+** Wait on the most recent client_step to complete, then return the
+** name of the N-th columns in the result set.
+*/
+static int tcl_client_colname(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  int n;
+
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID N", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetInt(interp, argv[2], &n) ) return TCL_ERROR;
+  client_wait(&threadset[i]);
+  if( n<0 || n>=threadset[i].argc ){
+    Tcl_AppendResult(interp, "column number out of range", 0);
+    return TCL_ERROR;
+  }
+  Tcl_AppendResult(interp, threadset[i].colv[n], 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: client_result  ID
+**
+** Wait on the most recent operation to complete, then return the
+** result code from that operation.
+*/
+static int tcl_client_result(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  const char *zName;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  switch( threadset[i].rc ){
+    case SQLITE_OK:         zName = "SQLITE_OK";          break;
+    case SQLITE_ERROR:      zName = "SQLITE_ERROR";       break;
+    case SQLITE_PERM:       zName = "SQLITE_PERM";        break;
+    case SQLITE_ABORT:      zName = "SQLITE_ABORT";       break;
+    case SQLITE_BUSY:       zName = "SQLITE_BUSY";        break;
+    case SQLITE_LOCKED:     zName = "SQLITE_LOCKED";      break;
+    case SQLITE_NOMEM:      zName = "SQLITE_NOMEM";       break;
+    case SQLITE_READONLY:   zName = "SQLITE_READONLY";    break;
+    case SQLITE_INTERRUPT:  zName = "SQLITE_INTERRUPT";   break;
+    case SQLITE_IOERR:      zName = "SQLITE_IOERR";       break;
+    case SQLITE_CORRUPT:    zName = "SQLITE_CORRUPT";     break;
+    case SQLITE_FULL:       zName = "SQLITE_FULL";        break;
+    case SQLITE_CANTOPEN:   zName = "SQLITE_CANTOPEN";    break;
+    case SQLITE_PROTOCOL:   zName = "SQLITE_PROTOCOL";    break;
+    case SQLITE_EMPTY:      zName = "SQLITE_EMPTY";       break;
+    case SQLITE_SCHEMA:     zName = "SQLITE_SCHEMA";      break;
+    case SQLITE_CONSTRAINT: zName = "SQLITE_CONSTRAINT";  break;
+    case SQLITE_MISMATCH:   zName = "SQLITE_MISMATCH";    break;
+    case SQLITE_MISUSE:     zName = "SQLITE_MISUSE";      break;
+    case SQLITE_NOLFS:      zName = "SQLITE_NOLFS";       break;
+    case SQLITE_AUTH:       zName = "SQLITE_AUTH";        break;
+    case SQLITE_FORMAT:     zName = "SQLITE_FORMAT";      break;
+    case SQLITE_RANGE:      zName = "SQLITE_RANGE";       break;
+    case SQLITE_ROW:        zName = "SQLITE_ROW";         break;
+    case SQLITE_DONE:       zName = "SQLITE_DONE";        break;
+    default:                zName = "SQLITE_Unknown";     break;
+  }
+  Tcl_AppendResult(interp, zName, 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: client_error  ID
+**
+** Wait on the most recent operation to complete, then return the
+** error string.
+*/
+static int tcl_client_error(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  Tcl_AppendResult(interp, threadset[i].zErr, 0);
+  return TCL_OK;
+}
+
+/*
+** This procedure runs in the thread to compile an SQL statement.
+*/
+static void do_compile(Thread *p){
+  if( p->db==0 ){
+    p->zErr = p->zStaticErr = "no database is open";
+    p->rc = SQLITE_ERROR;
+    return;
+  }
+  if( p->pStmt ){
+    sqlite3_client_finalize(p->pStmt);
+    p->pStmt = 0;
+  }
+  p->rc = sqlite3_client_prepare(p->db, p->zArg, -1, &p->pStmt, 0);
+}
+
+/*
+** Usage: client_compile ID SQL
+**
+** Compile a new virtual machine.
+*/
+static int tcl_client_compile(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID SQL", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  threadset[i].xOp = do_compile;
+  sqlite3_free(threadset[i].zArg);
+  threadset[i].zArg = sqlite3DbStrDup(0, argv[2]);
+  threadset[i].opnum++;
+  return TCL_OK;
+}
+
+/*
+** This procedure runs in the thread to step the virtual machine.
+*/
+static void do_step(Thread *p){
+  int i;
+  if( p->pStmt==0 ){
+    p->zErr = p->zStaticErr = "no virtual machine available";
+    p->rc = SQLITE_ERROR;
+    return;
+  }
+  p->rc = sqlite3_client_step(p->pStmt);
+  if( p->rc==SQLITE_ROW ){
+    p->argc = sqlite3_column_count(p->pStmt);
+    for(i=0; i<sqlite3_data_count(p->pStmt); i++){
+      p->argv[i] = (char*)sqlite3_column_text(p->pStmt, i);
+    }
+    for(i=0; i<p->argc; i++){
+      p->colv[i] = sqlite3_column_name(p->pStmt, i);
+    }
+  }
+}
+
+/*
+** Usage: client_step ID
+**
+** Advance the virtual machine by one step
+*/
+static int tcl_client_step(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " IDL", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  threadset[i].xOp = do_step;
+  threadset[i].opnum++;
+  return TCL_OK;
+}
+
+/*
+** This procedure runs in the thread to finalize a virtual machine.
+*/
+static void do_finalize(Thread *p){
+  if( p->pStmt==0 ){
+    p->zErr = p->zStaticErr = "no virtual machine available";
+    p->rc = SQLITE_ERROR;
+    return;
+  }
+  p->rc = sqlite3_client_finalize(p->pStmt);
+  p->pStmt = 0;
+}
+
+/*
+** Usage: client_finalize ID
+**
+** Finalize the virtual machine.
+*/
+static int tcl_client_finalize(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " IDL", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  threadset[i].xOp = do_finalize;
+  sqlite3_free(threadset[i].zArg);
+  threadset[i].zArg = 0;
+  threadset[i].opnum++;
+  return TCL_OK;
+}
+
+/*
+** This procedure runs in the thread to reset a virtual machine.
+*/
+static void do_reset(Thread *p){
+  if( p->pStmt==0 ){
+    p->zErr = p->zStaticErr = "no virtual machine available";
+    p->rc = SQLITE_ERROR;
+    return;
+  }
+  p->rc = sqlite3_client_reset(p->pStmt);
+  p->pStmt = 0;
+}
+
+/*
+** Usage: client_reset ID
+**
+** Finalize the virtual machine.
+*/
+static int tcl_client_reset(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i;
+  if( argc!=2 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " IDL", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  threadset[i].xOp = do_reset;
+  sqlite3_free(threadset[i].zArg);
+  threadset[i].zArg = 0;
+  threadset[i].opnum++;
+  return TCL_OK;
+}
+
+/*
+** Usage: client_swap ID ID
+**
+** Interchange the sqlite* pointer between two threads.
+*/
+static int tcl_client_swap(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  const char **argv      /* Text of each argument */
+){
+  int i, j;
+  sqlite3 *temp;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " ID1 ID2", 0);
+    return TCL_ERROR;
+  }
+  i = parse_client_id(interp, argv[1]);
+  if( i<0 ) return TCL_ERROR;
+  if( !threadset[i].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[i]);
+  j = parse_client_id(interp, argv[2]);
+  if( j<0 ) return TCL_ERROR;
+  if( !threadset[j].busy ){
+    Tcl_AppendResult(interp, "no such thread", 0);
+    return TCL_ERROR;
+  }
+  client_wait(&threadset[j]);
+  temp = threadset[i].db;
+  threadset[i].db = threadset[j].db;
+  threadset[j].db = temp;
+  return TCL_OK;
+}
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetest7_Init(Tcl_Interp *interp){
+  static struct {
+     char *zName;
+     Tcl_CmdProc *xProc;
+  } aCmd[] = {
+     { "client_create",     (Tcl_CmdProc*)tcl_client_create     },
+     { "client_wait",       (Tcl_CmdProc*)tcl_client_wait       },
+     { "client_halt",       (Tcl_CmdProc*)tcl_client_halt       },
+     { "client_argc",       (Tcl_CmdProc*)tcl_client_argc       },
+     { "client_argv",       (Tcl_CmdProc*)tcl_client_argv       },
+     { "client_colname",    (Tcl_CmdProc*)tcl_client_colname    },
+     { "client_result",     (Tcl_CmdProc*)tcl_client_result     },
+     { "client_error",      (Tcl_CmdProc*)tcl_client_error      },
+     { "client_compile",    (Tcl_CmdProc*)tcl_client_compile    },
+     { "client_step",       (Tcl_CmdProc*)tcl_client_step       },
+     { "client_reset",      (Tcl_CmdProc*)tcl_client_reset      },
+     { "client_finalize",   (Tcl_CmdProc*)tcl_client_finalize   },
+     { "client_swap",       (Tcl_CmdProc*)tcl_client_swap       },
+  };
+  int i;
+
+  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
+    Tcl_CreateCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
+  }
+  return TCL_OK;
+}
+#else
+int Sqlitetest7_Init(Tcl_Interp *interp){ return TCL_OK; }
+#endif /* SQLITE_OS_UNIX */