On Fri, Dec 05, 2008 at 10:33:31PM +0100, Bram Moolenaar wrote:
>
>
> Marc Weber wrote:
>
> > > Please explain what this would do what vim.command() isn't doing.
> > > I mean the one explained below ":he python-vim".
> >
> > You can start multiple threads in python. The help didn't say tat
> > vim.command() is thread safe. However it would be nice to replace this
> > executeVimCommand hackery with a more native, non blocking thread safe
> > command. Then you could start writing nice interfaces for debuggers
> > more easily.
>
> I do think that vim.command() is thread safe. Not 100% sure, I didn't
> look at the detailed documentation for Python native interface. The
> code contains:
>
> Py_BEGIN_ALLOW_THREADS
> Python_Lock_Vim();
>
> do_cmdline_cmd((char_u *)cmd);
> update_screen(VALID);
>
> Python_Release_Vim();
> Py_END_ALLOW_THREADS
>
> Looks like a lock is used to guarantee only one command is done at a
> time. And that's required, since the Vim core is defenitely not
> thread-safe.
Hi Bram,
Could you try running the testcase at the end of the file?
it starts 200 threads each running a loop
200 times running vim.cmd.
It segfaults here.
Have you actually had a look at the code. The implementation is empty
(stripped :)
static void Python_Lock_Vim(void) { }
static void Python_Release_Vim(void) { }
:-)
no actions (current SVN HEAD)
I've also searched for Py_BEGIN_ALLOW_THREADS. All occurences are within
if_pyhton.c
Even if the a lock had been aquired there it wouldn't have been
enough unless vim does so itself:
Imagine this: vim is running the vimscript garbage collector. Then a
pyhton thread runs vim.cmd().. It will acquire its lock.. and both, the
gc and the the python thread will start reading / writing the same
memory! So this requires kind of global lock anyway. But you know the
code much better than me. I guess you can just tell me wether such a
global lock does exist?
It could be fixed easily.. Just acquire the lock when any action is
triggerd. Sources which can trigger actions: Keyboard/ mouse input and
script threads such as the python one. Don't know about (perl, ruby,
...)
Sincerly
Marc Weber
" ==== test case segfaulting here ======================
" thread safe testcase
fun! Test()
py << EOF
from subprocess import Popen, PIPE
import threading
import os
import vim
print "python start"
from time import sleep
class MyThread ( threading.Thread ):
def __init__(self, start, command):
vim.command(start)
threading.Thread.__init__(self)
self.command=command
def run ( self ):
sleep(3)
for i in range(1,200):
vim.command(self.command)
vim.command("let g:started=0")
for i in range(1,200):
thread=MyThread("let g:start=1 | echo \"starting\"", "let g:done=1|
echo \"succ\"")
thread.start()
vim.command("let g:started = g:started+1")
print "python thread started"
EOF
endfun
call Test()
--~--~---------~--~----~------------~-------~--~----~
You received this message from the "vim_dev" maillist.
For more information, visit http://www.vim.org/maillist.php
-~----------~----~----~----~------~----~------~--~---
