/*

 ** 2004 January 13

 **

 ** 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.

 **

 *************************************************************************

 ** This file implements a simple standalone program used to test whether

 ** or not the SQLite library is threadsafe.

 **

 ** This file is NOT part of the standard SQLite library.  It is used for

 ** testing only.

 */

 #include <stdio.h>

 #include <unistd.h>

 #include <pthread.h>

 #include <string.h>

 #include <stdlib.h>

 #include "sqlite.h"

 /*

 ** Name of the database

 */

 #define DB_FILE "test.db"

 /* 

 ** When this variable becomes non-zero, all threads stop

 ** what they are doing.

 */

 volatile int all_stop = 0;

 /* 

 ** Callback from the integrity check.  If the result is anything other

 ** than "ok" it means the integrity check has failed.  Set the "all_stop"

 ** global variable to stop all other activity.  Print the error message

 ** or print OK if the string "ok" is seen.

 */

 int check_callback(void *pid, int argc, char **argv, char **notUsed2){

   int id = (int)pid;

   if( strcmp(argv[0],"ok") ){

     all_stop = 1;

     fprintf(stderr,"id: %s\n", id, argv[0]);

   }else{

     /* fprintf(stderr,"%d: OK\n", id); */

   }

   return 0;

 }

 /*

 ** Do an integrity check on the database.  If the first integrity check

 ** fails, try it a second time.

 */

 int integrity_check(sqlite *db, int id){

   int rc;

   if( all_stop ) return 0;

   /* fprintf(stderr,"%d: CHECK\n", id); */

   rc = sqlite3_exec(db, "pragma integrity_check", check_callback, 0, 0);

   if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){

     fprintf(stderr,"%d, Integrity check returns %d\n", id, rc);

   }

   if( all_stop ){

     sqlite3_exec(db, "pragma integrity_check", check_callback, 0, 0);

   }

   return 0;

 }

 /*

 ** This is the worker thread

 */

 void *worker(void *workerArg){

   sqlite *db;

   int id = (int)workerArg;

   int rc;

   int cnt = 0;

   fprintf(stderr, "Starting worker %d\n", id);

   while( !all_stop && cnt++<10000 ){

     if( cnt%100==0 ) printf("%d: %d\n", id, cnt);

     while( (sqlite3_open(DB_FILE, &db))!=SQLITE_OK ) sched_yield();

     sqlite3_exec(db, "PRAGMA synchronous=OFF", 0, 0, 0);

     /* integrity_check(db, id); */

     if( all_stop ){ sqlite3_close(db); break; }

     /* fprintf(stderr, "%d: BEGIN\n", id); */

     rc = sqlite3_exec(db, "INSERT INTO t1 VALUES('bogus data')", 0, 0, 0);

     /* fprintf(stderr, "%d: END rc=%d\n", id, rc); */

     sqlite3_close(db);

   }

   fprintf(stderr, "Worker %d finished\n", id);

   return 0;

 }

 /*

 ** Initialize the database and start the threads

 */

 int main(int argc, char **argv){

   sqlite *db;

   int i, rc;

   pthread_t aThread[5];

   if( strcmp(DB_FILE,":memory:") ){

     char *zJournal = sqlite3_mprintf("%s-journal", DB_FILE);

     unlink(DB_FILE);

     unlink(zJournal);

     sqlite3_free(zJournal);

   }  

   sqlite3_open(DB_FILE, &db);

   if( db==0 ){

     fprintf(stderr,"unable to initialize database\n");

     exit(1);

   }

   rc = sqlite3_exec(db, "CREATE TABLE t1(x);", 0,0,0);

   if( rc ){

     fprintf(stderr,"cannot create table t1: %d\n", rc);

     exit(1);

   }

   sqlite3_close(db);

   for(i=0; i<sizeof(aThread)/sizeof(aThread[0]); i++){

     pthread_create(&aThread[i], 0, worker, (void*)i);

   }

   for(i=0; i<sizeof(aThread)/sizeof(aThread[i]); i++){

     pthread_join(aThread[i], 0);

   }

   if( !all_stop ){

     printf("Everything seems ok.\n");

     return 0;

   }else{

     printf("We hit an error.\n");

     return 1;

   }

 }