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

[liubin liu]

Is there any memory leak in the code?

Below is the code. 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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