sqlite:多线程操作数据库“database is locked”解决方法

1. 使sqlite支持多线程(不确定是否非加不可,暂且加上,以备后患)

可以在编译时/启动时/运行时选择线程模式,参考:http://www.cnblogs.com/liaj/p/4015219.html

我的修改:

1)添加编译选项:

-DSQLITE_THREADSAFE=2

2)打开数据库文件使用sqlite3_open_v2替代sqlite3_open

sqlite3_open_v2(strDbName,sqlite_p, SQLITE_OPEN_READWRITE| SQLITE_OPEN_CREATE | SQLITE_OPEN_NOMUTEX, NULL);

 

2. 使用sqlite3_busy_handler对SQLITE_BUSY状态进行处理(必须)

参考:

https://www.sqlite.org/c3ref/busy_handler.html

http://iihero.iteye.com/blog/1222539

http://blog.csdn.net/guofu8241260/article/details/36378291

我的修改:

static int callback_in_busy(void *ptr, int count)
{
    int timeout = *((int *)ptr);
    
    usleep(timeout);
    return 1;
}

static void SqlGetLock(sqlite3 *sqlite_p, int ms)
{
    if (ms > 0)
    {
        sqlite3_busy_handler(sqlite_p, callback_in_busy, (void*)&ms);
    }
    else
    {
        sqlite3_busy_handler(sqlite_p, 0, 0);
    }
}

int SqlExec(sqlite3 *sqlite_p, const char *strSql)
{
    char *pErrMsg = NULL;
    int rc = SQLITE_OK;
    int ret = -1;
    
    SqlGetLock(sqlite_p, 200);    
    rc = sqlite3_exec(sqlite_p, strSql, NULL, NULL, &pErrMsg);
    
    if (rc != SQLITE_OK)
    {
        printf("%s %d sqlite3_exec error:%s, strSql = [%s].\n", 
            __func__, __LINE__, sqlite3_errmsg(sqlite_p), strSql);
        if (pErrMsg != NULL)
        {
            printf("%s %d sqlite3_exec error:%s\n", __func__, __LINE__, pErrMsg);
            sqlite3_free(pErrMsg);
        }
        ret = -1;
    }
    else
    {
        ret = 0;
    }

    return ret;
}

 

    原文作者:sqlite
    原文地址: https://www.cnblogs.com/tanghuimin0713/p/4025114.html
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