If you use the database mechanism to lock the table during the
transaction, then the second simultaneous invocation of your PHP program
will wait (a tiny fraction of a second) until the first one is done.
miguel
On Wed, 29 May 2002, r wrote:
> since only my one program was accessing the table the database was safe,
> My question stands at what happens if 2 or more people access
> "enterdetails.php", click on the submit button to enter info into the same
> table at the same time?
> since I will be returning a valid ID no for each of them.......Its basically
> the old chopsticks puzzle and would like to know how does PHP handle it?
> -Ryan.
>
> ----- Original Message -----
> From: "Miguel Cruz" <[EMAIL PROTECTED]>
> To: "r" <[EMAIL PROTECTED]>
> Sent: Tuesday, May 28, 2002 12:52 PM
> Subject: Re: [PHP] Thread safe
>
>
> > Well, that's not a thread safety issue if you're trying to lock a record
> > in a database. If it was handled entirely within Java, then there was no
> > guarantee of database referential integrity. Only the database can do
> > that.
> >
> > miguel
> >
> > On Wed, 29 May 2002, r wrote:
> > > Nope its not more like a database issue as this was clearly addressed in
> > > java and so the "synchronised" keyword was made and you have to
> implement a
> > > "synchronised block" of code to make it thread safe.....
> > > is this possible in PHP or does PHP itself take care to make all scripts
> > > thread safe?
> > >
> > > Cheers,
> > > -Ryan.
> > >
> > > ----- Original Message -----
> > > From: "Miguel Cruz" <[EMAIL PROTECTED]>
> > > To: <[EMAIL PROTECTED]>
> > > Sent: Tuesday, May 28, 2002 11:44 AM
> > > Subject: Re: [PHP] Thread safe
> > >
> > >
> > > > On Mon, 27 May 2002, r wrote:
> > > > > In java servlets I used to use a "synchronised" block of code to
> make
> > > sure
> > > > > it was thread safe...how do i do this in PHP?
> > > > >
> > > > > Heres what should be thread safe
> > > > >
> > > > > {
> > > > > $r=select max(cno)+1 from MyTable;
> > > > > (then i insert into the table the new cno plus my name)
> > > > > insert into mytable ($r,'myname');
> > > > > }
> > > > > How to do this and make sure its thread safe?
> > > >
> > > > More of a database issue. "select ... for update" is a good starting
> point
> > > > as you search the manual of your particular database platform.
> > > >
> > > > miguel
> > > >
> > > >
> > > > --
> > > > PHP General Mailing List (http://www.php.net/)
> > > > To unsubscribe, visit: http://www.php.net/unsub.php
> > > >
> > >
> > >
> >
>
>
>
--
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php
