[sqlite] is the sqlite3's C-api used in thread-safety mode ? or non-reentrant?

[liubin liu]

does it mean that the sqlite3's C-api isn't reentrant or thread-safety?


____________________________________________________________


#include <stdio.h>      // for printf()
#include <signal.h>     // for signal()
#include <unistd.h>     // for alarm()
#include <stdlib.h>     // for system()
#include <pthread.h>    // for pthread_create()
#include <sqlite3.h>    // for sqlite3_***



sqlite3 *db = NULL;

int timer_handle_mark1 = 0;
int timer_handle_mark2 = 9;



pthread_t trd1;

void trd1_task ( void );



int sqlite3_helper_create_db (void);

int sqlite3_helper_insert_data (void);

// psf - prepare, step, finalize
int sqlite3_helper_get_data_psf_from_tb1 ( int id );

void timer_handler()
{
    int ret = -1;
    int i = 9;

    char *query_format2 = "SELECT * FROM ts2 WHERE id=%d;";
    char *query_string = NULL;


    sqlite3_stmt *p_stmt = NULL;

    timer_handle_mark2 = 0;
    query_string = sqlite3_mprintf ( query_format2, i%500 );
    timer_handle_mark1++;

    timer_handle_mark2 = 1;
    ret = sqlite3_prepare_v2 ( db, query_string, -1, &p_stmt, NULL );
    timer_handle_mark1++;

    timer_handle_mark2 = 2;
    ret = sqlite3_step ( p_stmt );
    timer_handle_mark1++;

    //if ( SQLITE_ROW == ret )
    //    printf ( "# IN timer_handler(), id: %d, length: %d\n", 
sqlite3_column_int( p_stmt, 0 ), sqlite3_column_int( p_stmt, 1 ) );

    timer_handle_mark2 = 3;
    sqlite3_finalize ( p_stmt );
    timer_handle_mark1++;


    alarm(1);
}

int inittimer()
{
    signal ( SIGALRM, timer_handler );
    alarm(1);
    return 0;
}

void trd1_task ( void )
{
    sleep (30);
    printf ( "# IN thread 1, after 30 seconds, timer_handle_mark1: %d,
timer_handle_mark2: %d\n", timer_handle_mark1, timer_handle_mark2 );
    sleep (50);
    printf ( "# IN thread 1, after 50 seconds, timer_handle_mark1: %d,
timer_handle_mark2: %d\n", timer_handle_mark1, timer_handle_mark2 );
}



int main ( void )
{
    int ret = -1;
    int i = 0;

    ret = pthread_create ( &trd1, 0, (void *)trd1_task, 0 );

    ret = sqlite3_open ( "testsignal.db", &db );

    sqlite3_helper_create_db ();

    sqlite3_helper_insert_data ();

    ret = inittimer();

    for ( i=0; ; i++ )
        ret = sqlite3_helper_get_data_psf_from_tb1 ( i );

    ret = sqlite3_close ( db );

    system ( "sqlite3 testsignal.db \"SELECT COUNT(*) FROM ts1;\"" );

    return 0;
}


int sqlite3_helper_create_db (void)
{
    int ret = -1;
    char *cr_tb1 = "CREATE TABLE ts1 (id INTEGER PRIMARY KEY, length
INTEGER, data CHAR(50));";
    char *cr_tb2 = "CREATE TABLE ts2 (id INTEGER PRIMARY KEY, length
INTEGER, data CHAR(50));";

    ret = sqlite3_exec ( db, cr_tb1, NULL, NULL, NULL );
    //printf ( "ret: %d\n", ret );
    ret = sqlite3_exec ( db, cr_tb2, NULL, NULL, NULL );
    //printf ( "ret: %d\n", ret );
    if ( SQLITE_OK == ret )
        printf ( "# IN main(), create db file, SUCCESS!\n" );


    return 0;
}


int sqlite3_helper_insert_data (void)
{
    int ret = -1;
    int i = 0;

    sqlite3_stmt *p_stmt = NULL;


    char *sql_format1 = "INSERT OR REPLACE INTO ts1 (id, length, data)
VALUES (%d, %d, %Q);";
    char *sql_format2 = "INSERT OR REPLACE INTO ts2 (id, length, data)
VALUES (%d, %d, %Q);";
    char *sql = NULL;


    ret = sqlite3_exec ( db, "BEGIN", NULL, NULL, NULL );
    for ( i=0; i<500; i++ )
    {
        sql = sqlite3_mprintf ( sql_format1, i, i%10,
"datadatadatadatadatadatadatadatadatadatadata" );
        ret = sqlite3_prepare_v2 ( db, sql, -1, &p_stmt, NULL );
        ret = sqlite3_step ( p_stmt );
        sqlite3_free ( sql );
        ret = sqlite3_finalize ( p_stmt );

        sql = sqlite3_mprintf ( sql_format2, i, i%10,
"datadatadatadatadatadatadatadatadatadatadata" );
        ret = sqlite3_prepare_v2 ( db, sql, -1, &p_stmt, NULL );
        ret = sqlite3_step ( p_stmt );
        sqlite3_free ( sql );
        ret = sqlite3_finalize ( p_stmt );
    }
    ret = sqlite3_exec ( db, "COMMIT", NULL, NULL, NULL );
    if ( SQLITE_OK == ret )
        printf ( "# IN main(), insert data, SUCCESS!\n" );

    return 0;
}


int sqlite3_helper_get_data_gt_from_tb1 ( int id )
{
    int ret = -1;


    char *query_format1 = "SELECT * FROM ts1 WHERE id=%d;";
    char *query_string = NULL;

    char **resultp = NULL;
    int row = 0;
    int column = 0;
    char *errmsg = NULL;
    char **tmp_str = NULL;

    query_string = sqlite3_mprintf ( query_format1, id%500 );
    ret = sqlite3_get_table ( db, query_string, &resultp, &row, &column,
&errmsg );
    if ( SQLITE_OK == ret )
    {
        //printf ( "sqlite3_get_table() success!\n" );
        tmp_str = resultp + column;
        printf ( "# IN main(), id: %d, length: %d\n", atoi(tmp_str[0]),
atoi(tmp_str[1]) );
    }
    sqlite3_free ( query_string );
    sqlite3_free_table ( resultp );

    return 0;
}


int sqlite3_helper_get_data_psf_from_tb1 ( int id )
{
    int ret = -1;

    sqlite3_stmt *p_stmt = NULL;


    char *query_format1 = "SELECT * FROM ts1 WHERE id=%d;";
    char *query_string = NULL;

    query_string = sqlite3_mprintf ( query_format1, id%500 );
    ret = sqlite3_prepare_v2 ( db, query_string, -1, &p_stmt, NULL );
    ret = sqlite3_step ( p_stmt );
    //if ( SQLITE_ROW == ret )
    //    printf ( "# IN main(), id: %d, length: %d;   timer_handle_mark1:
%d\n", sqlite3_column_int( p_stmt, 0 ), sqlite3_column_int( p_stmt, 1 ),
timer_handle_mark1 );
    sqlite3_finalize ( p_stmt );

    return 0;
}


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