> Multi-thread -- one sqlite3 object per thread is required -- no sharing of
> prepared statements or anything else.
This is not true. Sharing of prepared statements and sqlite3 object is
allowed in this mode as long as any access to them is protected by
mutex or any other synchronization mechanism so that no two threads
are accessing objects simultaneously.
So basically the only difference between multi-thread mode and
serialized mode is responsibility of access synchronization: in
serialized mode it's SQLite's responsibility, in multi-thread mode
it's developer responsibility.
Pavel
On Tue, May 29, 2012 at 9:57 AM, Black, Michael (IS)
<michael.bla...@ngc.com> wrote:
> This seems to fly in thte face of what I remember reading on here before.
> Can we get a clear explanation of what to do with the different THREADSAFE
> settings? I think it's implied...
>
>
>
> i.e. (assumign this is correct)
>
> Single-thread -- no threading allowed at all
>
> Multi-thread -- one sqlite3 object per thread is required -- no sharing of
> prepared statements or anything else.
>
> Serialized -- sqlite3 object can be shared among threads along with prepared
> statements and all other functions.
>
>
>
> Michael D. Black
>
> Senior Scientist
>
> Advanced Analytics Directorate
>
> Advanced GEOINT Solutions Operating Unit
>
> Northrop Grumman Information Systems
>
> ________________________________
> From: sqlite-users-boun...@sqlite.org [sqlite-users-boun...@sqlite.org] on
> behalf of Pavel Ivanov [paiva...@gmail.com]
> Sent: Tuesday, May 29, 2012 8:08 AM
> To: 吴 毅; General Discussion of SQLite Database
> Subject: EXT :Re: [sqlite] How to write and read the same sqlite3 DB in
> memory concurrently in two thread?
>
>> How to write and read the same sqlite3 DB in memory concurrently in two
>> thread?
>
> You need to use one connection (sqlite3 object) and not to use
> SQLITE_OPEN_NOMUTEX flag (assuming you used default SQLite compilation
> options) or protect access to sqlite3 object with your own mutex.
>
>
> Pavel
>
>
> On Fri, May 25, 2012 at 4:51 AM, 吴 毅 <wuyiy...@yahoo.com.cn> wrote:
>> Now I am writing datas to sqlite3 DB in memory(":memory:") in a thread .
>> And concurrently I want to read the datas of the same DB in memory too.
>> but While i used the same object of sqlite3 to write and read, i had got the
>> error:SQLITE_MISUSE.
>> If i use the different objects of sqlite3 to write and read
>> concurrently,these objects get the different DB in memory.This is not I want
>> to do.I want to get datas of the same database.
>> Moreover, I don't plan to write and read the database in disks too.Becase I
>> thick it's more faster to operate in memory.
>> I open the database in the way of "m_sqliteDB.open(":memory:");" now.
>>
>> How to write and read the same sqlite3 DB in memory concurrently in two
>> thread?
>>
>> That might be?
>>
>> thank you.
>> _______________________________________________
>> sqlite-users mailing list
>> sqlite-users@sqlite.org
>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
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