Re: [sqlite] SQLite, pthread and daemon
In the source code that I posted earlier you are correct.
But I tested that after changing that code a bit. I called 'sqlite3_close'
just after I called 'sqlite3_open'.
Then also I am not getting correct PID inside the thread.
So can I do just a 'open' and 'close' of sqlite in parent process and then I
create the child process?
On 10/4/07, John Stanton <[EMAIL PROTECTED]> wrote:
>
> You are not only accessing an Sqlite connection across threads, but also
> processes!
>
> Create the DB connection in the thread in which it is being used and you
> will obey the needs of all versions of Sqlite.
>
> One da6tabase may be used across processes provided that you create the
> connection according to the Sqlite rules and do it in the thread of
> execution.
>
> Sabyasachi Ruj wrote:
> > I read that.
> > But it prohibits to use SQLite open handles across processes.
> > It is not written that one database should not be used acoross process.
> > I am carrying any sqlite open across processes.
> >
> > Before creating the daemon:-
> > I am opening sqlite
> > doing something
> > closing sqlite.
> >
> > But then also the problem persists.
> >
> > I mean I am not getting the process id of the CHILD PROCESS inside the
> > threads
> > (which has created the threads).
> >
> > But in that CHILD process, the pid is OK(it returns its id, not of the
> > PARENT PROCESS).
> >
> >
> >
> > Thanks for your repply.
> >
> > On 10/4/07, Rich Rattanni <[EMAIL PROTECTED]> wrote:
> >
> >>Just read this today, after doing some other research. Does this help
> >>any?
> >>
> >>http://www.sqlite.org/faq.html#q6
> >>
> >>It says, in a nutshell, don't use a database across forks.
> >>
> >>On 10/3/07, John Stanton <[EMAIL PROTECTED]> wrote:
> >>
> >>>How do you know that when your process forks that you are looking at
> the
> >>>child, not the parent?
> >>>
> >>>Sabyasachi Ruj wrote:
> >>>
> Hi,
>
> I am writing an application which will continue to execute as a
> >>
> >>'daemon' in
> >>
> Linux.
> The application is multi threaded.
> And once the daemon is created, it will create few threads to perform
> >>
> >>some
> >>
> tasks.
>
> >From here, I'll refer the 'process before creating the daemon' as
> >>
> >>'PARENT
> >>
> PROCESS',
> and 'process after creating the daemon' as 'CHILD PROCESS'.
>
> So the threads are being created in CHILD PROCESS.
>
> I need to get the process id (PID) in those threads.
>
> Here is my problem!
>
> If I have called 'sqlite3_open' BEFORE creating the daemon,
> then the PID I am getting inside the thread, is the PID of the
> 'PARENT PROCESS', not the 'CHILD PROCESS'!
>
> But as after creating the daemon, the PARENT PROCESS gets killed,
> those are invalid PIDs.
>
> This happens ONLY if I am calling the 'sqlite3_open' before creating
> >>
> >>the
> >>
> daemon!
>
>
> I am not getting if this is the expected behavior or not.
>
>
> Herewith I am attaching one sample test project, that will depict the
> >>
> >>issue.
> >>
> It is having one Makefile. The executable will be named as: pidtest
>
> To execute that process as a daemon use the '-d' command line
> >>
> >>argument.
> >>
> For example:-
> ./pidtest -d
>
> This process will create one log file called 'log.txt' in the current
> directory.
> which will show the output.
>
> For limitation on size of the mail,I have removed SQLite source code('
> sqlite3.c' and 'sqlite3.h').
> I am using amalgamated code, version 3.4.0.
> Checked with the latest 3.4.2. The problem is same.
>
>
>
>
> >>
> >>
> >>
>
>
> >>-
> >>
> To unsubscribe, send email to [EMAIL PROTECTED]
>
> >>
>
> >>-
> >>
> >>>
> >>>
>
> >>-
> >>
> >>>To unsubscribe, send email to [EMAIL PROTECTED]
> >>>
> >>
>
> >>-
> >>
> >>>
> >>
>
> >>-
> >>To unsubscribe, send email to [EMAIL PROTECTED]
> >>
>
> >>-
> >>
> >>
> >
> >
> >
>
>
>
> -
> To unsubscribe, send email to [EMAIL PROTECTED]
>
> -
>
>
--
Sabyasachi
Re: [sqlite] SQLite, pthread and daemon
You are not only accessing an Sqlite connection across threads, but also
processes!
Create the DB connection in the thread in which it is being used and you
will obey the needs of all versions of Sqlite.
One da6tabase may be used across processes provided that you create the
connection according to the Sqlite rules and do it in the thread of
execution.
Sabyasachi Ruj wrote:
I read that.
But it prohibits to use SQLite open handles across processes.
It is not written that one database should not be used acoross process.
I am carrying any sqlite open across processes.
Before creating the daemon:-
I am opening sqlite
doing something
closing sqlite.
But then also the problem persists.
I mean I am not getting the process id of the CHILD PROCESS inside the
threads
(which has created the threads).
But in that CHILD process, the pid is OK(it returns its id, not of the
PARENT PROCESS).
Thanks for your repply.
On 10/4/07, Rich Rattanni <[EMAIL PROTECTED]> wrote:
Just read this today, after doing some other research. Does this help
any?
http://www.sqlite.org/faq.html#q6
It says, in a nutshell, don't use a database across forks.
On 10/3/07, John Stanton <[EMAIL PROTECTED]> wrote:
How do you know that when your process forks that you are looking at the
child, not the parent?
Sabyasachi Ruj wrote:
Hi,
I am writing an application which will continue to execute as a
'daemon' in
Linux.
The application is multi threaded.
And once the daemon is created, it will create few threads to perform
some
tasks.
From here, I'll refer the 'process before creating the daemon' as
'PARENT
PROCESS',
and 'process after creating the daemon' as 'CHILD PROCESS'.
So the threads are being created in CHILD PROCESS.
I need to get the process id (PID) in those threads.
Here is my problem!
If I have called 'sqlite3_open' BEFORE creating the daemon,
then the PID I am getting inside the thread, is the PID of the
'PARENT PROCESS', not the 'CHILD PROCESS'!
But as after creating the daemon, the PARENT PROCESS gets killed,
those are invalid PIDs.
This happens ONLY if I am calling the 'sqlite3_open' before creating
the
daemon!
I am not getting if this is the expected behavior or not.
Herewith I am attaching one sample test project, that will depict the
issue.
It is having one Makefile. The executable will be named as: pidtest
To execute that process as a daemon use the '-d' command line
argument.
For example:-
./pidtest -d
This process will create one log file called 'log.txt' in the current
directory.
which will show the output.
For limitation on size of the mail,I have removed SQLite source code('
sqlite3.c' and 'sqlite3.h').
I am using amalgamated code, version 3.4.0.
Checked with the latest 3.4.2. The problem is same.
-
To unsubscribe, send email to [EMAIL PROTECTED]
-
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Re: [sqlite] SQLite, pthread and daemon
I read that.
But it prohibits to use SQLite open handles across processes.
It is not written that one database should not be used acoross process.
I am carrying any sqlite open across processes.
Before creating the daemon:-
I am opening sqlite
doing something
closing sqlite.
But then also the problem persists.
I mean I am not getting the process id of the CHILD PROCESS inside the
threads
(which has created the threads).
But in that CHILD process, the pid is OK(it returns its id, not of the
PARENT PROCESS).
Thanks for your repply.
On 10/4/07, Rich Rattanni <[EMAIL PROTECTED]> wrote:
>
> Just read this today, after doing some other research. Does this help
> any?
>
> http://www.sqlite.org/faq.html#q6
>
> It says, in a nutshell, don't use a database across forks.
>
> On 10/3/07, John Stanton <[EMAIL PROTECTED]> wrote:
> > How do you know that when your process forks that you are looking at the
> > child, not the parent?
> >
> > Sabyasachi Ruj wrote:
> > > Hi,
> > >
> > > I am writing an application which will continue to execute as a
> 'daemon' in
> > > Linux.
> > > The application is multi threaded.
> > > And once the daemon is created, it will create few threads to perform
> some
> > > tasks.
> > >
> > >>From here, I'll refer the 'process before creating the daemon' as
> 'PARENT
> > > PROCESS',
> > > and 'process after creating the daemon' as 'CHILD PROCESS'.
> > >
> > > So the threads are being created in CHILD PROCESS.
> > >
> > > I need to get the process id (PID) in those threads.
> > >
> > > Here is my problem!
> > >
> > > If I have called 'sqlite3_open' BEFORE creating the daemon,
> > > then the PID I am getting inside the thread, is the PID of the
> > > 'PARENT PROCESS', not the 'CHILD PROCESS'!
> > >
> > > But as after creating the daemon, the PARENT PROCESS gets killed,
> > > those are invalid PIDs.
> > >
> > > This happens ONLY if I am calling the 'sqlite3_open' before creating
> the
> > > daemon!
> > >
> > >
> > > I am not getting if this is the expected behavior or not.
> > >
> > >
> > > Herewith I am attaching one sample test project, that will depict the
> issue.
> > > It is having one Makefile. The executable will be named as: pidtest
> > >
> > > To execute that process as a daemon use the '-d' command line
> argument.
> > >
> > > For example:-
> > > ./pidtest -d
> > >
> > > This process will create one log file called 'log.txt' in the current
> > > directory.
> > > which will show the output.
> > >
> > > For limitation on size of the mail,I have removed SQLite source code('
> > > sqlite3.c' and 'sqlite3.h').
> > > I am using amalgamated code, version 3.4.0.
> > > Checked with the latest 3.4.2. The problem is same.
> > >
> > >
> > >
> > >
>
> > >
> > >
> -
> > > To unsubscribe, send email to [EMAIL PROTECTED]
> > >
> -
> >
> >
> >
> -
> > To unsubscribe, send email to [EMAIL PROTECTED]
> >
> -
> >
> >
>
>
> -
> To unsubscribe, send email to [EMAIL PROTECTED]
>
> -
>
>
--
Sabyasachi
Re: [sqlite] SQLite, pthread and daemon
Just read this today, after doing some other research. Does this help any?
http://www.sqlite.org/faq.html#q6
It says, in a nutshell, don't use a database across forks.
On 10/3/07, John Stanton <[EMAIL PROTECTED]> wrote:
> How do you know that when your process forks that you are looking at the
> child, not the parent?
>
> Sabyasachi Ruj wrote:
> > Hi,
> >
> > I am writing an application which will continue to execute as a 'daemon' in
> > Linux.
> > The application is multi threaded.
> > And once the daemon is created, it will create few threads to perform some
> > tasks.
> >
> >>From here, I'll refer the 'process before creating the daemon' as 'PARENT
> > PROCESS',
> > and 'process after creating the daemon' as 'CHILD PROCESS'.
> >
> > So the threads are being created in CHILD PROCESS.
> >
> > I need to get the process id (PID) in those threads.
> >
> > Here is my problem!
> >
> > If I have called 'sqlite3_open' BEFORE creating the daemon,
> > then the PID I am getting inside the thread, is the PID of the
> > 'PARENT PROCESS', not the 'CHILD PROCESS'!
> >
> > But as after creating the daemon, the PARENT PROCESS gets killed,
> > those are invalid PIDs.
> >
> > This happens ONLY if I am calling the 'sqlite3_open' before creating the
> > daemon!
> >
> >
> > I am not getting if this is the expected behavior or not.
> >
> >
> > Herewith I am attaching one sample test project, that will depict the issue.
> > It is having one Makefile. The executable will be named as: pidtest
> >
> > To execute that process as a daemon use the '-d' command line argument.
> >
> > For example:-
> > ./pidtest -d
> >
> > This process will create one log file called 'log.txt' in the current
> > directory.
> > which will show the output.
> >
> > For limitation on size of the mail,I have removed SQLite source code('
> > sqlite3.c' and 'sqlite3.h').
> > I am using amalgamated code, version 3.4.0.
> > Checked with the latest 3.4.2. The problem is same.
> >
> >
> >
> >
> >
> > -
> > To unsubscribe, send email to [EMAIL PROTECTED]
> > -
>
>
> -
> To unsubscribe, send email to [EMAIL PROTECTED]
> -
>
>
-
To unsubscribe, send email to [EMAIL PROTECTED]
-
Re: [sqlite] SQLite, pthread and daemon
How do you know that when your process forks that you are looking at the
child, not the parent?
Sabyasachi Ruj wrote:
Hi,
I am writing an application which will continue to execute as a 'daemon' in
Linux.
The application is multi threaded.
And once the daemon is created, it will create few threads to perform some
tasks.
From here, I'll refer the 'process before creating the daemon' as 'PARENT
PROCESS',
and 'process after creating the daemon' as 'CHILD PROCESS'.
So the threads are being created in CHILD PROCESS.
I need to get the process id (PID) in those threads.
Here is my problem!
If I have called 'sqlite3_open' BEFORE creating the daemon,
then the PID I am getting inside the thread, is the PID of the
'PARENT PROCESS', not the 'CHILD PROCESS'!
But as after creating the daemon, the PARENT PROCESS gets killed,
those are invalid PIDs.
This happens ONLY if I am calling the 'sqlite3_open' before creating the
daemon!
I am not getting if this is the expected behavior or not.
Herewith I am attaching one sample test project, that will depict the issue.
It is having one Makefile. The executable will be named as: pidtest
To execute that process as a daemon use the '-d' command line argument.
For example:-
./pidtest -d
This process will create one log file called 'log.txt' in the current
directory.
which will show the output.
For limitation on size of the mail,I have removed SQLite source code('
sqlite3.c' and 'sqlite3.h').
I am using amalgamated code, version 3.4.0.
Checked with the latest 3.4.2. The problem is same.
-
To unsubscribe, send email to [EMAIL PROTECTED]
-
-
To unsubscribe, send email to [EMAIL PROTECTED]
-
[sqlite] SQLite, pthread and daemon
Hi,
I am writing an application which will continue to execute as a 'daemon' in
Linux.
The application is multi threaded.
And once the daemon is created, it will create few threads to perform some
tasks.
>From here, I'll refer the 'process before creating the daemon' as 'PARENT
PROCESS',
and 'process after creating the daemon' as 'CHILD PROCESS'.
So the threads are being created in CHILD PROCESS.
I need to get the process id (PID) in those threads.
Here is my problem!
If I have called 'sqlite3_open' BEFORE creating the daemon,
then the PID I am getting inside the thread, is the PID of the
'PARENT PROCESS', not the 'CHILD PROCESS'!
But as after creating the daemon, the PARENT PROCESS gets killed,
those are invalid PIDs.
This happens ONLY if I am calling the 'sqlite3_open' before creating the
daemon!
I am not getting if this is the expected behavior or not.
Herewith I am attaching one sample test project, that will depict the issue.
It is having one Makefile. The executable will be named as: pidtest
To execute that process as a daemon use the '-d' command line argument.
For example:-
./pidtest -d
This process will create one log file called 'log.txt' in the current
directory.
which will show the output.
For limitation on size of the mail,I have removed SQLite source code('
sqlite3.c' and 'sqlite3.h').
I am using amalgamated code, version 3.4.0.
Checked with the latest 3.4.2. The problem is same.
--
Sabyasachi
pidtest_pthread.tar.gz
Description: GNU Zip compressed data
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