// wrapper for sqlite3_prepare_v2 which retries
creating statements if the db returns SQLITE_BUSY or
SQLITE_LOCKED
int sql_prepare(sqlite3 *db, const char *sql,
sqlite3_stmt **ppStmt, int wait) {
#ifdef SQL_DEBUG
printf(sql);
printf("\n");
fflush(stdout);
#endif
int rc;
char looper[4] = {'|','/','-','\\'};
int looperc = 0;
int waited = 0;
while (1) {
rc = sqlite3_prepare_v2(db,sql,-1,ppStmt,NULL);
if (rc == SQLITE_LOCKED || rc == SQLITE_BUSY) {
if (wait != 0) {
fprintf(stdout,"Database is locked or busy.
Waiting %is ... %1c \r", ++waited,
looper[looperc]);
fflush(stdout);
wait--;
looperc = ++looperc % sizeof(looper);
sleep(1);
} else {
fprintf(stderr,"Database was locked or busy
while
creating statement. I've given up.\n");
return rc;
}
} else {
if (waited != 0) printf("\n\n");
return rc;
}
}
}
--- [EMAIL PROTECTED] schrieb:
> Hi,
>
> I am having a scenario where I have one
> reader/writer and many writer threads.
> All writers are pretty basic (single INSERT INTO;
> some sort of a logging info
> what a thread has done).
>
> I believe I will receive many BUSY return codes and
> I don't like these
> spinlock-like retries. The problem I am having with
> this design is that I would
> like to complete the thread ASAP, so that I don't
> have many threads idling and
> consuming resources of my embedded system.
>
> I was thinking to either:
>
> a. Use mutex/semaphore before writting to the
> database or
>
> b. Have a (thread safe) list of INSERT INTO strings
> that every writer thread
> populates and the main reader/writer thread later
> executes.
>
> Is this a good approach? Does anyone have a better
> design? I don't want to use
> other database, because I think Sqlite is great for
> an embedded system that I
> am using.
>
___________________________________________________________________________
> Najhitrej¹i brezplaèni klicni dostop :: Varno in
> zanesljivo po internetu
> Obi¹èite http://www.dialup386.com/
>
>
-----------------------------------------------------------------------------
> To unsubscribe, send email to
> [EMAIL PROTECTED]
>
-----------------------------------------------------------------------------
>
>
___________________________________________________________
Telefonate ohne weitere Kosten vom PC zum PC: http://messenger.yahoo.de
-----------------------------------------------------------------------------
To unsubscribe, send email to [EMAIL PROTECTED]
-----------------------------------------------------------------------------
