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Comment:Add test/threadtest3.c, containing multi-thread tests implemented in C.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
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SHA1:aad88cf54e9e55b757d2ece9e39d436e71dcaa9f
User & Date: dan 2010-07-22 15:44:06
Context
2010-07-22
17:49
Enhance the LIKE/GLOB query optimization so that it works as long as there is an index with the appropriate collating sequence and even if the default collating sequence of the column is different. Ticket [4711020446da7d93d99]. check-in: 9f932655 user: drh tags: trunk
15:44
Add test/threadtest3.c, containing multi-thread tests implemented in C. check-in: aad88cf5 user: dan tags: trunk
12:33
Try to optimize LIKE and GLOB operators when RHS contains no wildcard. Ticket [e090183531fc274747] check-in: 613a87d6 user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Added test/threadtest3.c.



























































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































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/*
** The code in this file runs a few multi-threaded test cases using the
** SQLite library. It can be compiled to an executable on unix using the
** following command:
**
**   gcc -O2 threadtest3.c sqlite3.c -ldl -lpthread -lm
**
** Then run the compiled program. The exit status is non-zero if any tests
** failed (hopefully there is also some output to stdout to clarify what went
** wrong).
**
** There are three parts to the code in this file, in the following order:
**
**   1. Code for the SQL aggregate function md5sum() copied from 
**      tclsqlite.c in the SQLite distribution. The names of all the 
**      types and functions in this section begin with "MD5" or "md5".
**
**   2. A set of utility functions that may be used to implement
**      multi-threaded test cases. These are all called by test code
**      via macros that help with error reporting. The macros are defined
**      immediately below this comment.
**
**   3. The test code itself. And a main() routine to drive the test 
**      code.
*/

/*************************************************************************
** Start of test code/infrastructure interface macros.
**
** The following macros constitute the interface between the test
** programs and the test infrastructure. Test infrastructure code 
** does not itself use any of these macros. Test code should not
** call any of the macroname_x() functions directly.
**
** See the header comments above the corresponding macroname_x()
** function for a description of each interface.
*/

/* Database functions */
#define opendb(w,x,y,z)         (SEL(w), opendb_x(w,x,y,z))
#define closedb(y,z)            (SEL(y), closedb_x(y,z))

/* Functions to execute SQL */
#define sql_script(x,y,z)       (SEL(x), sql_script_x(x,y,z))
#define integrity_check(x,y)    (SEL(x), integrity_check_x(x,y))
#define execsql_i64(x,y,...)    (SEL(x), execsql_i64_x(x,y,__VA_ARGS__))
#define execsql_text(x,y,z,...) (SEL(x), execsql_text_x(x,y,z,__VA_ARGS__))
#define execsql(x,y,...)        (SEL(x), (void)execsql_i64_x(x,y,__VA_ARGS__))

/* Thread functions */
#define launch_thread(w,x,y,z)  (SEL(w), launch_thread_x(w,x,y,z))
#define join_all_threads(y,z)   (SEL(y), join_all_threads_x(y,z))

/* Timer functions */
#define setstoptime(y,z)        (SEL(y), setstoptime_x(y,z))
#define timetostop(z)           (SEL(z), timetostop_x(z))

/* Report/clear errors. */
#define test_error(z, ...)      test_error_x(z, sqlite3_mprintf(__VA_ARGS__))
#define clear_error(y,z)        clear_error_x(y, z)

/* File-system operations */
#define filesize(y,z)           (SEL(y), filesize_x(y,z))
#define filecopy(x,y,z)         (SEL(x), filecopy_x(x,y,z))

/*
** End of test code/infrastructure interface macros.
*************************************************************************/




#include <sqlite3.h>
#include <unistd.h>
#include <stdio.h>
#include <pthread.h>
#include <assert.h>
#include <sys/types.h> 
#include <sys/stat.h> 
#include <string.h>
#include <fcntl.h>
#include <errno.h>

/*
 * This code implements the MD5 message-digest algorithm.
 * The algorithm is due to Ron Rivest.  This code was
 * written by Colin Plumb in 1993, no copyright is claimed.
 * This code is in the public domain; do with it what you wish.
 *
 * Equivalent code is available from RSA Data Security, Inc.
 * This code has been tested against that, and is equivalent,
 * except that you don't need to include two pages of legalese
 * with every copy.
 *
 * To compute the message digest of a chunk of bytes, declare an
 * MD5Context structure, pass it to MD5Init, call MD5Update as
 * needed on buffers full of bytes, and then call MD5Final, which
 * will fill a supplied 16-byte array with the digest.
 */

/*
 * If compiled on a machine that doesn't have a 32-bit integer,
 * you just set "uint32" to the appropriate datatype for an
 * unsigned 32-bit integer.  For example:
 *
 *       cc -Duint32='unsigned long' md5.c
 *
 */
#ifndef uint32
#  define uint32 unsigned int
#endif

struct MD5Context {
  int isInit;
  uint32 buf[4];
  uint32 bits[2];
  unsigned char in[64];
};
typedef struct MD5Context MD5Context;

/*
 * Note: this code is harmless on little-endian machines.
 */
static void byteReverse (unsigned char *buf, unsigned longs){
  uint32 t;
  do {
    t = (uint32)((unsigned)buf[3]<<8 | buf[2]) << 16 |
          ((unsigned)buf[1]<<8 | buf[0]);
    *(uint32 *)buf = t;
    buf += 4;
  } while (--longs);
}
/* The four core functions - F1 is optimized somewhat */

/* #define F1(x, y, z) (x & y | ~x & z) */
#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))

/* This is the central step in the MD5 algorithm. */
#define MD5STEP(f, w, x, y, z, data, s) \
  ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )

/*
 * The core of the MD5 algorithm, this alters an existing MD5 hash to
 * reflect the addition of 16 longwords of new data.  MD5Update blocks
 * the data and converts bytes into longwords for this routine.
 */
static void MD5Transform(uint32 buf[4], const uint32 in[16]){
  register uint32 a, b, c, d;

  a = buf[0];
  b = buf[1];
  c = buf[2];
  d = buf[3];

  MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478,  7);
  MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
  MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
  MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
  MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf,  7);
  MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
  MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
  MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
  MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8,  7);
  MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
  MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
  MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
  MD5STEP(F1, a, b, c, d, in[12]+0x6b901122,  7);
  MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
  MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
  MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);

  MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562,  5);
  MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340,  9);
  MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
  MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
  MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d,  5);
  MD5STEP(F2, d, a, b, c, in[10]+0x02441453,  9);
  MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
  MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
  MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6,  5);
  MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6,  9);
  MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
  MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
  MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905,  5);
  MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8,  9);
  MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
  MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);

  MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942,  4);
  MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
  MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
  MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
  MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44,  4);
  MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
  MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
  MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
  MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6,  4);
  MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
  MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
  MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
  MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039,  4);
  MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
  MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
  MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);

  MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244,  6);
  MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
  MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
  MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
  MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3,  6);
  MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
  MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
  MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
  MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f,  6);
  MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
  MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
  MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
  MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82,  6);
  MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
  MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
  MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);

  buf[0] += a;
  buf[1] += b;
  buf[2] += c;
  buf[3] += d;
}

/*
 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */
static void MD5Init(MD5Context *ctx){
  ctx->isInit = 1;
  ctx->buf[0] = 0x67452301;
  ctx->buf[1] = 0xefcdab89;
  ctx->buf[2] = 0x98badcfe;
  ctx->buf[3] = 0x10325476;
  ctx->bits[0] = 0;
  ctx->bits[1] = 0;
}

/*
 * Update context to reflect the concatenation of another buffer full
 * of bytes.
 */
static 
void MD5Update(MD5Context *ctx, const unsigned char *buf, unsigned int len){
  uint32 t;

  /* Update bitcount */

  t = ctx->bits[0];
  if ((ctx->bits[0] = t + ((uint32)len << 3)) < t)
    ctx->bits[1]++; /* Carry from low to high */
  ctx->bits[1] += len >> 29;

  t = (t >> 3) & 0x3f;    /* Bytes already in shsInfo->data */

  /* Handle any leading odd-sized chunks */

  if ( t ) {
    unsigned char *p = (unsigned char *)ctx->in + t;

    t = 64-t;
    if (len < t) {
      memcpy(p, buf, len);
      return;
    }
    memcpy(p, buf, t);
    byteReverse(ctx->in, 16);
    MD5Transform(ctx->buf, (uint32 *)ctx->in);
    buf += t;
    len -= t;
  }

  /* Process data in 64-byte chunks */

  while (len >= 64) {
    memcpy(ctx->in, buf, 64);
    byteReverse(ctx->in, 16);
    MD5Transform(ctx->buf, (uint32 *)ctx->in);
    buf += 64;
    len -= 64;
  }

  /* Handle any remaining bytes of data. */

  memcpy(ctx->in, buf, len);
}

/*
 * Final wrapup - pad to 64-byte boundary with the bit pattern 
 * 1 0* (64-bit count of bits processed, MSB-first)
 */
static void MD5Final(unsigned char digest[16], MD5Context *ctx){
  unsigned count;
  unsigned char *p;

  /* Compute number of bytes mod 64 */
  count = (ctx->bits[0] >> 3) & 0x3F;

  /* Set the first char of padding to 0x80.  This is safe since there is
     always at least one byte free */
  p = ctx->in + count;
  *p++ = 0x80;

  /* Bytes of padding needed to make 64 bytes */
  count = 64 - 1 - count;

  /* Pad out to 56 mod 64 */
  if (count < 8) {
    /* Two lots of padding:  Pad the first block to 64 bytes */
    memset(p, 0, count);
    byteReverse(ctx->in, 16);
    MD5Transform(ctx->buf, (uint32 *)ctx->in);

    /* Now fill the next block with 56 bytes */
    memset(ctx->in, 0, 56);
  } else {
    /* Pad block to 56 bytes */
    memset(p, 0, count-8);
  }
  byteReverse(ctx->in, 14);

  /* Append length in bits and transform */
  ((uint32 *)ctx->in)[ 14 ] = ctx->bits[0];
  ((uint32 *)ctx->in)[ 15 ] = ctx->bits[1];

  MD5Transform(ctx->buf, (uint32 *)ctx->in);
  byteReverse((unsigned char *)ctx->buf, 4);
  memcpy(digest, ctx->buf, 16);
  memset(ctx, 0, sizeof(ctx));    /* In case it is sensitive */
}

/*
** Convert a 128-bit MD5 digest into a 32-digit base-16 number.
*/
static void MD5DigestToBase16(unsigned char *digest, char *zBuf){
  static char const zEncode[] = "0123456789abcdef";
  int i, j;

  for(j=i=0; i<16; i++){
    int a = digest[i];
    zBuf[j++] = zEncode[(a>>4)&0xf];
    zBuf[j++] = zEncode[a & 0xf];
  }
  zBuf[j] = 0;
}

/*
** During testing, the special md5sum() aggregate function is available.
** inside SQLite.  The following routines implement that function.
*/
static void md5step(sqlite3_context *context, int argc, sqlite3_value **argv){
  MD5Context *p;
  int i;
  if( argc<1 ) return;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( p==0 ) return;
  if( !p->isInit ){
    MD5Init(p);
  }
  for(i=0; i<argc; i++){
    const char *zData = (char*)sqlite3_value_text(argv[i]);
    if( zData ){
      MD5Update(p, (unsigned char*)zData, strlen(zData));
    }
  }
}
static void md5finalize(sqlite3_context *context){
  MD5Context *p;
  unsigned char digest[16];
  char zBuf[33];
  p = sqlite3_aggregate_context(context, sizeof(*p));
  MD5Final(digest,p);
  MD5DigestToBase16(digest, zBuf);
  sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
}

/*************************************************************************
** End of copied md5sum() code.
*/

typedef sqlite3_int64 i64;

typedef struct Error Error;
typedef struct Sqlite Sqlite;
typedef struct Statement Statement;

typedef struct Threadset Threadset;
typedef struct Thread Thread;

/* Total number of errors in this process so far. */
static int nGlobalErr = 0;

/* Set to true to run in "process" instead of "thread" mode. */
static int bProcessMode = 0;

struct Error {
  int rc;
  int iLine;
  char *zErr;
};

struct Sqlite {
  sqlite3 *db;                    /* Database handle */
  Statement *pCache;              /* Linked list of cached statements */
  int nText;                      /* Size of array at aText[] */
  char **aText;                   /* Stored text results */
};

struct Statement {
  sqlite3_stmt *pStmt;            /* Pre-compiled statement handle */
  Statement *pNext;               /* Next statement in linked-list */
};

struct Thread {
  int iTid;                       /* Thread number within test */
  int iArg;                       /* Integer argument passed by caller */

  pthread_t tid;                  /* Thread id */
  char *(*xProc)(int, int);       /* Thread main proc */
  Thread *pNext;                  /* Next in this list of threads */
};

struct Threadset {
  int iMaxTid;                    /* Largest iTid value allocated so far */
  Thread *pThread;                /* Linked list of threads */
};

static void free_err(Error *p){
  sqlite3_free(p->zErr);
  p->zErr = 0;
  p->rc = 0;
}

static void print_err(Error *p){
  if( p->rc!=SQLITE_OK ){
    printf("Error: (%d) \"%s\" at line %d\n", p->rc, p->zErr, p->iLine);
    nGlobalErr++;
  }
}

static void print_and_free_err(Error *p){
  print_err(p);
  free_err(p);
}

static void system_error(Error *pErr, int iSys){
  pErr->rc = iSys;
  pErr->zErr = (char *)sqlite3_malloc(512);
  strerror_r(iSys, pErr->zErr, 512);
  pErr->zErr[511] = '\0';
}

static void sqlite_error(
  Error *pErr, 
  Sqlite *pDb, 
  const char *zFunc
){
  pErr->rc = sqlite3_errcode(pDb->db);
  pErr->zErr = sqlite3_mprintf(
      "sqlite3_%s() - %s (%d)", zFunc, sqlite3_errmsg(pDb->db),
      sqlite3_extended_errcode(pDb->db)
  );
}

static void test_error_x(
  Error *pErr,
  char *zErr
){
  if( pErr->rc==SQLITE_OK ){
    pErr->rc = 1;
    pErr->zErr = zErr;
  }else{
    sqlite3_free(zErr);
  }
}

static void clear_error_x(
  Error *pErr,
  int rc
){
  if( pErr->rc==rc ){
    pErr->rc = SQLITE_OK;
    sqlite3_free(pErr->zErr);
    pErr->zErr = 0;
  }
}

static int busyhandler(void *pArg, int n){
  usleep(10*1000);
  return 1;
}

static void opendb_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb,                    /* OUT: Database handle */
  const char *zFile,              /* Database file name */
  int bDelete                     /* True to delete db file before opening */
){
  if( pErr->rc==SQLITE_OK ){
    int rc;
    if( bDelete ) unlink(zFile);
    rc = sqlite3_open(zFile, &pDb->db);
    if( rc ){
      sqlite_error(pErr, pDb, "open");
      sqlite3_close(pDb->db);
      pDb->db = 0;
    }else{
      sqlite3_create_function(
          pDb->db, "md5sum", -1, SQLITE_UTF8, 0, 0, md5step, md5finalize
      );
      sqlite3_busy_handler(pDb->db, busyhandler, 0);
    }
  }
}

static void closedb_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb                     /* OUT: Database handle */
){
  int rc;
  int i;
  Statement *pIter;
  Statement *pNext;
  for(pIter=pDb->pCache; pIter; pIter=pNext){
    pNext = pIter->pNext;
    sqlite3_finalize(pIter->pStmt);
    sqlite3_free(pIter);
  }
  for(i=0; i<pDb->nText; i++){
    sqlite3_free(pDb->aText[i]);
  }
  sqlite3_free(pDb->aText);
  rc = sqlite3_close(pDb->db);
  if( rc && pErr->rc==SQLITE_OK ){
    pErr->zErr = sqlite3_mprintf("%s", sqlite3_errmsg(pDb->db));
  }
  memset(pDb, 0, sizeof(Sqlite));
}

static void sql_script_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb,                    /* Database handle */
  const char *zSql                /* SQL script to execute */
){
  if( pErr->rc==SQLITE_OK ){
    pErr->rc = sqlite3_exec(pDb->db, zSql, 0, 0, &pErr->zErr);
  }
}

static Statement *getSqlStatement(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb,                    /* Database handle */
  const char *zSql                /* SQL statement */
){
  Statement *pRet;
  int rc;

  for(pRet=pDb->pCache; pRet; pRet=pRet->pNext){
    if( 0==strcmp(sqlite3_sql(pRet->pStmt), zSql) ){
      return pRet;
    }
  }

  pRet = sqlite3_malloc(sizeof(Statement));
  rc = sqlite3_prepare_v2(pDb->db, zSql, -1, &pRet->pStmt, 0);
  if( rc!=SQLITE_OK ){
    sqlite_error(pErr, pDb, "prepare_v2");
    return 0;
  }
  assert( 0==strcmp(sqlite3_sql(pRet->pStmt), zSql) );

  pRet->pNext = pDb->pCache;
  pDb->pCache = pRet;
  return pRet;
}

static sqlite3_stmt *getAndBindSqlStatement(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb,                    /* Database handle */
  va_list ap                      /* SQL followed by parameters */
){
  Statement *pStatement;          /* The SQLite statement wrapper */
  sqlite3_stmt *pStmt;            /* The SQLite statement to return */
  int i;                          /* Used to iterate through parameters */

  pStatement = getSqlStatement(pErr, pDb, va_arg(ap, const char *));
  if( !pStatement ) return 0;
  pStmt = pStatement->pStmt;
  for(i=1; i<=sqlite3_bind_parameter_count(pStmt); i++){
    const char *zName = sqlite3_bind_parameter_name(pStmt, i);
    void * pArg = va_arg(ap, void*);

    switch( zName[1] ){
      case 'i':
        sqlite3_bind_int64(pStmt, i, *(i64 *)pArg);
        break;

      default:
        pErr->rc = 1;
        pErr->zErr = sqlite3_mprintf("Cannot discern type: \"%s\"", zName);
        pStmt = 0;
        break;
    }
  }

  return pStmt;
}

static i64 execsql_i64_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb,                    /* Database handle */
  ...                             /* SQL and pointers to parameter values */
){
  i64 iRet = 0;
  if( pErr->rc==SQLITE_OK ){
    sqlite3_stmt *pStmt;          /* SQL statement to execute */
    va_list ap;                   /* ... arguments */
    int i;                        /* Used to iterate through parameters */
    va_start(ap, pDb);
    pStmt = getAndBindSqlStatement(pErr, pDb, ap);
    if( pStmt ){
      int rc;
      int first = 1;
      while( SQLITE_ROW==sqlite3_step(pStmt) ){
        if( first && sqlite3_column_count(pStmt)>0 ){
          iRet = sqlite3_column_int64(pStmt, 0);
        }
        first = 0;
      }
      if( SQLITE_OK!=sqlite3_reset(pStmt) ){
        sqlite_error(pErr, pDb, "reset");
      }
    }
    va_end(ap);
  }
  return iRet;
}

static char * execsql_text_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb,                    /* Database handle */
  int iSlot,                      /* Db handle slot to store text in */
  ...                             /* SQL and pointers to parameter values */
){
  char *zRet = 0;

  if( iSlot>=pDb->nText ){
    int nByte = sizeof(char *)*(iSlot+1);
    pDb->aText = (char **)sqlite3_realloc(pDb->aText, nByte);
    memset(&pDb->aText[pDb->nText], 0, sizeof(char*)*(iSlot+1-pDb->nText));
    pDb->nText = iSlot+1;
  }

  if( pErr->rc==SQLITE_OK ){
    sqlite3_stmt *pStmt;          /* SQL statement to execute */
    va_list ap;                   /* ... arguments */
    int i;                        /* Used to iterate through parameters */
    va_start(ap, iSlot);
    pStmt = getAndBindSqlStatement(pErr, pDb, ap);
    if( pStmt ){
      int rc;
      int first = 1;
      while( SQLITE_ROW==sqlite3_step(pStmt) ){
        if( first && sqlite3_column_count(pStmt)>0 ){
          zRet = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 0));
          sqlite3_free(pDb->aText[iSlot]);
          pDb->aText[iSlot] = zRet;
        }
        first = 0;
      }
      if( SQLITE_OK!=sqlite3_reset(pStmt) ){
        sqlite_error(pErr, pDb, "reset");
      }
    }
    va_end(ap);
  }

  return zRet;
}

static void integrity_check_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb                     /* Database handle */
){
  if( pErr->rc==SQLITE_OK ){
    Statement *pStatement;        /* Statement to execute */
    int rc;                       /* Return code */
    char *zErr = 0;               /* Integrity check error */

    pStatement = getSqlStatement(pErr, pDb, "PRAGMA integrity_check");
    if( pStatement ){
      sqlite3_stmt *pStmt = pStatement->pStmt;
      while( SQLITE_ROW==sqlite3_step(pStmt) ){
        const char *z = sqlite3_column_text(pStmt, 0);
        if( strcmp(z, "ok") ){
          if( zErr==0 ){
            zErr = sqlite3_mprintf("%s", z);
          }else{
            zErr = sqlite3_mprintf("%z\n%s", zErr, z);
          }
        }
      }
      sqlite3_reset(pStmt);

      if( zErr ){
        pErr->zErr = zErr;
        pErr->rc = 1;
      }
    }
  }
}

static void *launch_thread_main(void *pArg){
  Thread *p = (Thread *)pArg;
  return (void *)p->xProc(p->iTid, p->iArg);
}

static void launch_thread_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Threadset *pThreads,            /* Thread set */
  char *(*xProc)(int, int),       /* Proc to run */
  int iArg                        /* Argument passed to thread proc */
){
  if( pErr->rc==SQLITE_OK ){
    int iTid = ++pThreads->iMaxTid;
    Thread *p;
    int rc;

    p = (Thread *)sqlite3_malloc(sizeof(Thread));
    memset(p, 0, sizeof(Thread));
    p->iTid = iTid;
    p->iArg = iArg;
    p->xProc = xProc;

    rc = pthread_create(&p->tid, NULL, launch_thread_main, (void *)p);
    if( rc!=0 ){
      system_error(pErr, rc);
      sqlite3_free(p);
    }else{
      p->pNext = pThreads->pThread;
      pThreads->pThread = p;
    }
  }
}

static void join_all_threads_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Threadset *pThreads             /* Thread set */
){
  Thread *p;
  Thread *pNext;
  for(p=pThreads->pThread; p; p=pNext){
    void *ret;
    pNext = p->pNext;
    int rc;
    rc = pthread_join(p->tid, &ret);
    if( rc!=0 ){
      if( pErr->rc==SQLITE_OK ) system_error(pErr, rc);
    }else{
      printf("Thread %d says: %s\n", p->iTid, (ret==0 ? "..." : (char *)ret));
    }
    sqlite3_free(p);
  }
  pThreads->pThread = 0;
}

static i64 filesize_x(
  Error *pErr,
  const char *zFile
){
  i64 iRet = 0;
  if( pErr->rc==SQLITE_OK ){
    struct stat sStat;
    if( stat(zFile, &sStat) ){
      iRet = -1;
    }else{
      iRet = sStat.st_size;
    }
  }
  return iRet;
}

static void filecopy_x(
  Error *pErr,
  const char *zFrom,
  const char *zTo
){
  if( pErr->rc==SQLITE_OK ){
    i64 nByte = filesize_x(pErr, zFrom);
    if( nByte<0 ){
      test_error_x(pErr, sqlite3_mprintf("no such file: %s", zFrom));
    }else{
      i64 iOff;
      char aBuf[1024];
      int fd1;
      int fd2;
      unlink(zTo);

      fd1 = open(zFrom, O_RDONLY);
      if( fd1<0 ){
        system_error(pErr, errno);
        return;
      }
      fd2 = open(zTo, O_RDWR|O_CREAT|O_EXCL, 0644);
      if( fd2<0 ){
        system_error(pErr, errno);
        close(fd1);
        return;
      }

      iOff = 0;
      while( iOff<nByte ){
        int nCopy = sizeof(aBuf);
        if( nCopy+iOff>nByte ){
          nCopy = nByte - iOff;
        }
        if( nCopy!=read(fd1, aBuf, nCopy) ){
          system_error(pErr, errno);
          break;
        }
        if( nCopy!=write(fd2, aBuf, nCopy) ){
          system_error(pErr, errno);
          break;
        }
        iOff += nCopy;
      }

      close(fd1);
      close(fd2);
    }
  }
}

/* 
** Used by setstoptime() and timetostop().
*/
static double timelimit = 0.0;
static sqlite3_vfs *pTimelimitVfs = 0;

static void setstoptime_x(
  Error *pErr,                    /* IN/OUT: Error code */
  int nMs                         /* Milliseconds until "stop time" */
){
  if( pErr->rc==SQLITE_OK ){
    double t;
    int rc;
    pTimelimitVfs = sqlite3_vfs_find(0);
    rc = pTimelimitVfs->xCurrentTime(pTimelimitVfs, &t);
    if( rc!=SQLITE_OK ){
      pErr->rc = rc;
    }else{
      timelimit = t + ((double)nMs)/(1000.0*60.0*60.0*24.0);
    }
  }
}

static int timetostop_x(
  Error *pErr                     /* IN/OUT: Error code */
){
  int ret = 1;
  if( pErr->rc==SQLITE_OK ){
    double t;
    int rc;
    rc = pTimelimitVfs->xCurrentTime(pTimelimitVfs, &t);
    if( rc!=SQLITE_OK ){
      pErr->rc = rc;
    }else{
      ret = (t >= timelimit);
    }
  }
  return ret;
}

/* 
** The "Set Error Line" macro.
*/
#define SEL(e) ((e)->iLine = ((e)->rc ? (e)->iLine : __LINE__))


/*************************************************************************
**************************************************************************
**************************************************************************
** End infrastructure. Begin tests.
*/

#define WALTHREAD1_NTHREAD  10
#define WALTHREAD3_NTHREAD  6

static char *walthread1_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int nIter = 0;                  /* Iterations so far */

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    const char *azSql[] = {
      "SELECT md5sum(x) FROM t1 WHERE rowid != (SELECT max(rowid) FROM t1)",
      "SELECT x FROM t1 WHERE rowid = (SELECT max(rowid) FROM t1)",
    };
    char *z1, *z2, *z3;

    execsql(&err, &db, "BEGIN");
    integrity_check(&err, &db);
    z1 = execsql_text(&err, &db, 1, azSql[0]);
    z2 = execsql_text(&err, &db, 2, azSql[1]);
    z3 = execsql_text(&err, &db, 3, azSql[0]);
    execsql(&err, &db, "COMMIT");

    if( strcmp(z1, z2) || strcmp(z1, z3) ){
      test_error(&err, "Failed read: %s %s %s", z1, z2, z3);
    }

    sql_script(&err, &db,
        "BEGIN;"
          "INSERT INTO t1 VALUES(randomblob(100));"
          "INSERT INTO t1 VALUES(randomblob(100));"
          "INSERT INTO t1 SELECT md5sum(x) FROM t1;"
        "COMMIT;"
    );
    nIter++;
  }
  closedb(&err, &db);

  print_and_free_err(&err);
  return sqlite3_mprintf("%d iterations", nIter);
}

static char *walthread1_ckpt_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int nCkpt = 0;                  /* Checkpoints so far */

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    usleep(500*1000);
    execsql(&err, &db, "PRAGMA wal_checkpoint");
    if( err.rc==SQLITE_OK ) nCkpt++;
    clear_error(&err, SQLITE_BUSY);
  }
  closedb(&err, &db);

  print_and_free_err(&err);
  return sqlite3_mprintf("%d checkpoints", nCkpt);
}

static void walthread1(int nMs){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  Threadset threads = {0};        /* Test threads */
  int i;                          /* Iterator variable */

  opendb(&err, &db, "test.db", 1);
  sql_script(&err, &db,
      "PRAGMA journal_mode = WAL;"
      "CREATE TABLE t1(x PRIMARY KEY);"
      "INSERT INTO t1 VALUES(randomblob(100));"
      "INSERT INTO t1 VALUES(randomblob(100));"
      "INSERT INTO t1 SELECT md5sum(x) FROM t1;"
  );

  setstoptime(&err, nMs);
  for(i=0; i<WALTHREAD1_NTHREAD; i++){
    launch_thread(&err, &threads, walthread1_thread, 0);
  }
  launch_thread(&err, &threads, walthread1_ckpt_thread, 0);
  join_all_threads(&err, &threads);

  print_and_free_err(&err);
}

static char *walthread2_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int anTrans[2] = {0, 0};        /* Number of WAL and Rollback transactions */

  const char *zJournal = "PRAGMA journal_mode = WAL";
  if( iArg ){ zJournal = "PRAGMA journal_mode = DELETE"; }

  while( !timetostop(&err) ){
    int journal_exists = 0;
    int wal_exists = 0;

    opendb(&err, &db, "test.db", 0);

    sql_script(&err, &db, zJournal);
    clear_error(&err, SQLITE_BUSY);
    sql_script(&err, &db, "BEGIN");
    sql_script(&err, &db, "INSERT INTO t1 VALUES(NULL, randomblob(100))");

    journal_exists = (filesize(&err, "test.db-journal") >= 0);
    wal_exists = (filesize(&err, "test.db-wal") >= 0);
    if( (journal_exists+wal_exists)!=1 ){
      test_error(&err, "File system looks incorrect (%d, %d)", 
          journal_exists, wal_exists
      );
    }
    anTrans[journal_exists]++;

    sql_script(&err, &db, "COMMIT");
    integrity_check(&err, &db);
    closedb(&err, &db);
  }

  print_and_free_err(&err);
  return sqlite3_mprintf("W %d R %d", anTrans[0], anTrans[1]);
}

static void walthread2(int nMs){
  Error err = {0};
  Sqlite db = {0};
  Threadset threads = {0};

  opendb(&err, &db, "test.db", 1);
  sql_script(&err, &db, "CREATE TABLE t1(x INTEGER PRIMARY KEY, y UNIQUE)");
  closedb(&err, &db);

  setstoptime(&err, nMs);
  launch_thread(&err, &threads, walthread2_thread, 0);
  launch_thread(&err, &threads, walthread2_thread, 0);
  launch_thread(&err, &threads, walthread2_thread, 1);
  launch_thread(&err, &threads, walthread2_thread, 1);
  join_all_threads(&err, &threads);

  print_and_free_err(&err);
}

static char *walthread3_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  i64 iNextWrite;                 /* Next value this thread will write */

  opendb(&err, &db, "test.db", 0);
  sql_script(&err, &db, "PRAGMA wal_autocheckpoint = 10");

  iNextWrite = iArg+1;
  while( 1 ){
    i64 sum1;
    i64 sum2;
    int stop = 0;                 /* True to stop executing (test timed out) */

    while( 0==(stop = timetostop(&err)) ){
      i64 iMax = execsql_i64(&err, &db, "SELECT max(cnt) FROM t1");
      if( iMax+1==iNextWrite ) break;
    }
    if( stop ) break;

    sum1 = execsql_i64(&err, &db, "SELECT sum(cnt) FROM t1");
    sum2 = execsql_i64(&err, &db, "SELECT sum(sum1) FROM t1");
    execsql_i64(&err, &db, 
        "INSERT INTO t1 VALUES(:iNextWrite, :iSum1, :iSum2)",
        &iNextWrite, &sum1, &sum2
    );
    integrity_check(&err, &db);

    iNextWrite += WALTHREAD3_NTHREAD;
  }

  closedb(&err, &db);
  print_and_free_err(&err);
  return 0;
}

static void walthread3(int nMs){
  Error err = {0};
  Sqlite db = {0};
  Threadset threads = {0};
  int i;

  opendb(&err, &db, "test.db", 1);
  sql_script(&err, &db, 
      "PRAGMA journal_mode = WAL;"
      "CREATE TABLE t1(cnt PRIMARY KEY, sum1, sum2);"
      "CREATE INDEX i1 ON t1(sum1);"
      "CREATE INDEX i2 ON t1(sum2);"
      "INSERT INTO t1 VALUES(0, 0, 0);"
  );
  closedb(&err, &db);

  setstoptime(&err, nMs);
  for(i=0; i<WALTHREAD3_NTHREAD; i++){
    launch_thread(&err, &threads, walthread3_thread, i);
  }
  join_all_threads(&err, &threads);

  print_and_free_err(&err);
}

static char *walthread4_reader_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    integrity_check(&err, &db);
  }
  closedb(&err, &db);

  print_and_free_err(&err);
  return 0;
}

static char *walthread4_writer_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  i64 iRow = 1;

  opendb(&err, &db, "test.db", 0);
  sql_script(&err, &db, "PRAGMA wal_autocheckpoint = 15;");
  while( !timetostop(&err) ){
    execsql_i64(
        &err, &db, "REPLACE INTO t1 VALUES(:iRow, randomblob(300))", &iRow
    );
    iRow++;
    if( iRow==10 ) iRow = 0;
  }
  closedb(&err, &db);

  print_and_free_err(&err);
  return 0;
}

static void walthread4(int nMs){
  Error err = {0};
  Sqlite db = {0};
  Threadset threads = {0};

  opendb(&err, &db, "test.db", 1);
  sql_script(&err, &db, 
      "PRAGMA journal_mode = WAL;"
      "CREATE TABLE t1(a INTEGER PRIMARY KEY, b UNIQUE);"
  );
  closedb(&err, &db);

  setstoptime(&err, nMs);
  launch_thread(&err, &threads, walthread4_reader_thread, 0);
  launch_thread(&err, &threads, walthread4_writer_thread, 0);
  join_all_threads(&err, &threads);

  print_and_free_err(&err);
}

static char *walthread5_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  i64 nRow;

  opendb(&err, &db, "test.db", 0);
  nRow = execsql_i64(&err, &db, "SELECT count(*) FROM t1");
  closedb(&err, &db);

  if( nRow!=65536 ) test_error(&err, "Bad row count: %d", (int)nRow);
  print_and_free_err(&err);
  return 0;
}
static void walthread5(int nMs){
  Error err = {0};
  Sqlite db = {0};
  Threadset threads = {0};

  opendb(&err, &db, "test.db", 1);
  sql_script(&err, &db, 
      "PRAGMA wal_autocheckpoint = 0;"
      "PRAGMA page_size = 1024;"
      "PRAGMA journal_mode = WAL;"
      "CREATE TABLE t1(x);"
      "BEGIN;"
      "INSERT INTO t1 VALUES(randomblob(900));"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*     2 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*     4 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*     8 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*    16 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*    32 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*    64 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*   128 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*   256 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*   512 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*  1024 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*  2048 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*  4096 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /*  8192 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /* 16384 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /* 32768 */"
      "INSERT INTO t1 SELECT randomblob(900) FROM t1;      /* 65536 */"
      "COMMIT;"
  );
  filecopy(&err, "test.db", "test_sv.db");
  filecopy(&err, "test.db-wal", "test_sv.db-wal");
  closedb(&err, &db);

  filecopy(&err, "test_sv.db", "test.db");
  filecopy(&err, "test_sv.db-wal", "test.db-wal");

  if( err.rc==SQLITE_OK ){
    printf("  WAL file is %d bytes,", (int)filesize(&err,"test.db-wal"));
    printf(" DB file is %d.\n", (int)filesize(&err,"test.db"));
  }

  setstoptime(&err, nMs);
  launch_thread(&err, &threads, walthread5_thread, 0);
  launch_thread(&err, &threads, walthread5_thread, 0);
  launch_thread(&err, &threads, walthread5_thread, 0);
  launch_thread(&err, &threads, walthread5_thread, 0);
  launch_thread(&err, &threads, walthread5_thread, 0);
  join_all_threads(&err, &threads);

  if( err.rc==SQLITE_OK ){
    printf("  WAL file is %d bytes,", (int)filesize(&err,"test.db-wal"));
    printf(" DB file is %d.\n", (int)filesize(&err,"test.db"));
  }

  print_and_free_err(&err);
}

int main(int argc, char **argv){
  struct ThreadTest {
    void (*xTest)(int);
    const char *zTest;
    int nMs;
  } aTest[] = {
    { walthread1, "walthread1", 20000 },
    { walthread2, "walthread2", 20000 },
    { walthread3, "walthread3", 20000 },
    { walthread4, "walthread4", 20000 },
    { walthread5, "walthread5",  1000 },
  };

  int i;
  char *zTest = 0;
  int nTest = 0;
  int bTestfound = 0;
  int bPrefix = 0;

  if( argc>2 ) goto usage;
  if( argc==2 ){
    zTest = argv[1];
    nTest = strlen(zTest);
    if( zTest[nTest-1]=='*' ){
      nTest--;
      bPrefix = 1;
    }
  }

  sqlite3_config(SQLITE_CONFIG_MULTITHREAD);

  for(i=0; i<sizeof(aTest)/sizeof(aTest[0]); i++){
    char const *z = aTest[i].zTest;
    int n = strlen(z);
    if( !zTest || ((bPrefix || n==nTest) && 0==strncmp(zTest, z, nTest)) ){
      printf("Running %s for %d seconds...\n", z, aTest[i].nMs/1000);
      aTest[i].xTest(aTest[i].nMs);
      bTestfound++;
    }
  }
  if( bTestfound==0 ) goto usage;

  printf("Total of %d errors across all tests\n", nGlobalErr);
  return (nGlobalErr>0 ? 255 : 0);

 usage:
  printf("Usage: %s [testname|testprefix*]\n", argv[0]);
  printf("Available tests are:\n");
  for(i=0; i<sizeof(aTest)/sizeof(aTest[0]); i++){
    printf("   %s\n", aTest[i].zTest);
  }

  return 254;
}