[sqlite] Is there any memory leak in the code?

[liubin liu]

Below is my code. My question is:
Is there any memory leak in the pthread2?

While pthread1 is using test.db exclusively, the sqlite3_prepare_v2() of
pthread2 still prepares the p_stmt pointer to a piece of memory malloced by
sqlite3_preapare_v2(). And then the sqlite3_finalize() can't free the memory
still because pthread1 is using test.db exclusively. Does it cause a memory
leak?


______code__________________________________________________________

#include <stdio.h>
#include <unistd.h>      // for usleep()
#include <sys/time.h>   // for gettimeofday()
#include <pthread.h>
#include <sqlite3.h>

void pthread1 (void);
void pthread2 (void);


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

    sqlite3 *g_db = NULL;
    ret = sqlite3_open ("test.db", &g_db);
    ret = sqlite3_exec (g_db, "CREATE TABLE t1 (id INTEGER PRIMARY KEY, d1
TEXT)", NULL,NULL,NULL);
    ret = sqlite3_close (g_db);

    usleep (500000);


    pthread_t pthr1, pthr2;
    ret = pthread_create (&pthr1, NULL, (void *) pthread1, NULL);
    ret = pthread_create (&pthr2, NULL, (void *) pthread2, NULL);


    ret = pthread_join (pthr1, NULL);
    printf ("thread1 end\n");
    ret = pthread_join (pthr2, NULL);
    printf ("thread2 end\n");

    return 0;
}


void pthread1 (void)
{
    int ret = -1;
    sqlite3 *db1 = NULL;
    ret = sqlite3_open ("test.db", &db1);

    char *sql_f = "INSERT OR REPLACE INTO t1 VALUES (%d,
'aaabbbcccddd1122')";
    char *sql = NULL;

    sqlite3_stmt *p_stmt = NULL;

    struct timeval tv1, tv2;
    ret = gettimeofday (&tv1, NULL);

    ret = sqlite3_prepare_v2 (db1, "BEGIN TRANSACTION", -1, &p_stmt, NULL);
    ret = sqlite3_step (p_stmt);
    ret = sqlite3_finalize (p_stmt);

    // n=1000000, test.db is 25843712 bytes, 25M;
    int i=0, n=1000000;
    for (i=0; i<n; i++)
    {
        sql = sqlite3_mprintf (sql_f, i);
        ret = sqlite3_prepare_v2 (db1, sql, -1, &p_stmt, NULL);
        ret = sqlite3_step (p_stmt);
        ret = sqlite3_finalize (p_stmt);
    }

    printf ("pthread1:   ret: %d\n", ret);
    ret = sqlite3_prepare_v2 (db1, "COMMIT TRANSACTION", -1, &p_stmt, NULL);
    ret = sqlite3_step (p_stmt);
    ret = sqlite3_finalize (p_stmt);

    ret = gettimeofday (&tv2, NULL);
    printf ("time is : %ds\n", (int) (tv2.tv_sec - tv1.tv_sec));


    ret = sqlite3_close (db1);
}



void pthread2 (void)
{
    int ret = -1;

    sqlite3 *db2 = NULL;
    ret = sqlite3_open ("test.db", &db2);

    usleep (2000000);


    sqlite3_stmt *p_stmt = NULL;
    int i=0, n=10;
    for (i=0; i<n; i++)
    {
        char *sql_f = "INSERT OR REPLACE INTO t1 VALUES (%d,
'bbbbbbbbbbbb1122')";
        char *sql = NULL;

        sql = sqlite3_mprintf (sql_f, i);
        ret = sqlite3_prepare_v2 (db2, sql, -1, &p_stmt, NULL);
        printf ("pthread2:   prepare:  %d,   p_stmt: %p, errmsg: %s\n", ret,
p_stmt, sqlite3_errmsg(db2));
        ret = sqlite3_step (p_stmt);
        printf ("pthread2:   step:     %d,   p_stmt: %p, errmsg: %s\n", ret,
p_stmt, sqlite3_errmsg(db2));
        ret = sqlite3_finalize (p_stmt);
        printf ("pthread2:   finalize: %d,   p_stmt: %p, errmsg: %s\n", ret,
p_stmt, sqlite3_errmsg(db2));
        printf ("\n");

        usleep (300000);
    }

    ret = sqlite3_close (db2);
    printf ("pthread2:   close: %d,      p_stmt: %p, errmsg: %s\n", ret,
p_stmt, sqlite3_errmsg(db2));
}

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