/*

 ** This program tests the ability of SQLite database to recover from a crash.

 ** This program runs under Unix only, but the results are applicable to all

 ** systems.

 **

 ** The main process first constructs a test database, then starts creating

 ** subprocesses that write to that database.  Each subprocess is killed off,

 ** without a chance to clean up its database connection, after a random

 ** delay.  This killing of the subprocesses simulates a crash or power

 ** failure.  The next subprocess to open the database should rollback

 ** whatever operation was in process at the time of the simulated crash.

 **

 ** If any problems are encountered, an error is reported and the test stops.

 ** If no problems are seen after a large number of tests, we assume that

 ** the rollback mechanism is working.

 */

 #include <stdio.h>

 #include <unistd.h>

 #include <sys/types.h>

 #include <sys/wait.h>

 #include <signal.h>

 #include <stdlib.h>

 #include <string.h>

 #include <sched.h>

 #include "sqlite.h"

 static void do_some_sql(int parent){

   char *zErr;

   int rc = SQLITE_OK;

   sqlite *db;

   int cnt = 0;

   static char zBig[] = 

     "-abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

     "-abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

   if( access("./test.db-journal",0)==0 ){

     /*printf("pid %d: journal exists.  rollback will be required\n",getpid());*/    unlink("test.db-saved");

     system("cp test.db test.db-saved");

     unlink("test.db-journal-saved");

     system("cp test.db-journal test.db-journal-saved");

   }

   db = sqlite_open("./test.db", 0, &zErr);

   if( db==0 ){

     printf("ERROR: %s\n", zErr);

     if( strcmp(zErr,"database disk image is malformed")==0 ){

       kill(parent, SIGKILL);

     }

     exit(1);

   }

   srand(getpid());

   while( rc==SQLITE_OK ){

     cnt++;

     rc = sqlite_exec_printf(db, 

        "INSERT INTO t1 VALUES(%d,'%d%s')", 0, 0, &zErr,

        rand(), rand(), zBig);

   }

   if( rc!=SQLITE_OK ){

     printf("ERROR #%d: %s\n", rc, zErr);

     if( rc==SQLITE_CORRUPT ){

       kill(parent, SIGKILL);

     }

   }

   printf("pid %d: cnt=%d\n", getpid(), cnt);

 }

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

   int i;

   sqlite *db;

   char *zErr;

   int status;

   int parent = getpid();

   unlink("test.db");

   unlink("test.db-journal");

   db = sqlite_open("test.db", 0, &zErr);

   if( db==0 ){

     printf("Cannot initialize: %s\n", zErr);

     return 1;

   }

   sqlite_exec(db, "CREATE TABLE t1(a,b)", 0, 0, 0);

   sqlite_close(db);

   for(i=0; i<10000; i++){

     int pid = fork();

     if( pid==0 ){

       sched_yield();

       do_some_sql(parent);

       return 0;

     }

     printf("test %d, pid=%d\n", i, pid);

     usleep(rand()%10000 + 1000);

     kill(pid, SIGKILL);

     waitpid(pid, &status, 0);

   }

   return 0;

 }