/*

** 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;

}