Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Programming > Python > embedded python and interpreter threads

Reply
Thread Tools

embedded python and interpreter threads

 
 
Charlie DeTar
Guest
Posts: n/a
 
      12-07-2004
So, I have an amazing, functioning foobar class that embeds python.
Only trouble is, I want to be able to have multiple foobar objects at
once, each with their own interpreters, stdouts, and stderrs.

My initialization of the python interpreter in the class "x" is as follows:
[snip]
if (!Py_IsInitialized()) {
PyEval_InitThreads();
Py_Initialize();
}

// Start and switch to a new interpreter thread.
x->thread = Py_NewInterpreter();

// initialize the module 'logMethods', defined elsewhere,
// which contains my stdout and stderr definitions
Py_InitModule("log", logMethods);

// overwrite Python's stdout and stderr
PyRun_SimpleString(
"import log\n"
"import sys\n"
"class StdoutCatcher:\n"
"\tdef write(self, str):\n"
"\t\t.CaptureStdout(str)\n"
"class StderrCatcher:\n"
"\tdef write(self, str):\n"
"\t\t.CaptureStderr(str)\n"
"sys.stdout = StdoutCatcher()\n"
"sys.stderr = StderrCatcher()\n");

PyEval_ReleaseThread(x->thread);
[snip]

Everything seems to work as expected - each object seems to have its own
interpreter (if I evaluate "tree = 'a larch'" in one of them, 'tree' is
not thusly defined in the others). Since I store the threadstate as a
property of the object, I can easily juggle the interpreter lock between
objects when evaluating python code. However, the last foobar object to
be instantiated collects the stdout and stderr of all the other objects
(as though the stdout and stderr definitions were shared over all the
objects). This seems strange, as the docs say that if I start a
"Py_NewInterpreter()" I get new copies of all the modules, particuarly
'sys', and explicitly 'stdout' and 'stderr'.

I thought of the possibility that the 'logMethods' structure which
includes my versions of stdout and stderr might be behaving statically.
But I didn't define it as static... I am new to C, so there might be
something basic I am missing. Any suggestions or ideas?

Thanks,
Charlie DeTar
 
Reply With Quote
 
 
 
 
Charlie DeTar
Guest
Posts: n/a
 
      12-07-2004
Quick correction, sorry - the command should read like this (I had
omitted the "log" before 'CaptureStdout' and 'CaptureStderr'). Same
problems exist.

PyRun_SimpleString(
"import log\n"
"import sys\n"
"class StdoutCatcher:\n"
"\tdef write(self, str):\n"
"\t\tlog.CaptureStdout(str)\n"
"class StderrCatcher:\n"
"\tdef write(self, str):\n"
"\t\tlog.CaptureStderr(str)\n"
"sys.stdout = StdoutCatcher()\n"
"sys.stderr = StderrCatcher()\n");

=Charlie

Charlie DeTar wrote:
> So, I have an amazing, functioning foobar class that embeds python. Only
> trouble is, I want to be able to have multiple foobar objects at once,
> each with their own interpreters, stdouts, and stderrs.
>
> My initialization of the python interpreter in the class "x" is as follows:
> [snip]
> if (!Py_IsInitialized()) {
> PyEval_InitThreads();
> Py_Initialize();
> }
>
> // Start and switch to a new interpreter thread.
> x->thread = Py_NewInterpreter();
>
> // initialize the module 'logMethods', defined elsewhere,
> // which contains my stdout and stderr definitions
> Py_InitModule("log", logMethods);
>
> // overwrite Python's stdout and stderr
> PyRun_SimpleString(
> "import log\n"
> "import sys\n"
> "class StdoutCatcher:\n"
> "\tdef write(self, str):\n"
> "\t\t.CaptureStdout(str)\n"
> "class StderrCatcher:\n"
> "\tdef write(self, str):\n"
> "\t\t.CaptureStderr(str)\n"
> "sys.stdout = StdoutCatcher()\n"
> "sys.stderr = StderrCatcher()\n");

 
Reply With Quote
 
 
 
 
Charlie DeTar
Guest
Posts: n/a
 
      12-07-2004
Woohoo, fixed my problem. It had to do with the way I was handling the
methods which overwrote stderr and stdout. Yeehaw!

=Charlie


Charlie DeTar wrote:
> Quick correction, sorry - the command should read like this (I had
> omitted the "log" before 'CaptureStdout' and 'CaptureStderr'). Same
> problems exist.
>
> PyRun_SimpleString(
> "import log\n"
> "import sys\n"
> "class StdoutCatcher:\n"
> "\tdef write(self, str):\n"
> "\t\tlog.CaptureStdout(str)\n"
> "class StderrCatcher:\n"
> "\tdef write(self, str):\n"
> "\t\tlog.CaptureStderr(str)\n"
> "sys.stdout = StdoutCatcher()\n"
> "sys.stderr = StderrCatcher()\n");
>
> =Charlie
>
> Charlie DeTar wrote:
>
>> So, I have an amazing, functioning foobar class that embeds python.
>> Only trouble is, I want to be able to have multiple foobar objects at
>> once, each with their own interpreters, stdouts, and stderrs.
>>
>> My initialization of the python interpreter in the class "x" is as
>> follows:
>> [snip]
>> if (!Py_IsInitialized()) {
>> PyEval_InitThreads();
>> Py_Initialize();
>> } // Start and switch to a new interpreter thread.
>> x->thread = Py_NewInterpreter();
>>
>> // initialize the module 'logMethods', defined elsewhere,
>> // which contains my stdout and stderr definitions
>> Py_InitModule("log", logMethods);
>> // overwrite Python's stdout and stderr
>> PyRun_SimpleString(
>> "import log\n"
>> "import sys\n"
>> "class StdoutCatcher:\n"
>> "\tdef write(self, str):\n"
>> "\t\t.CaptureStdout(str)\n"
>> "class StderrCatcher:\n"
>> "\tdef write(self, str):\n"
>> "\t\t.CaptureStderr(str)\n"
>> "sys.stdout = StdoutCatcher()\n"
>> "sys.stderr = StderrCatcher()\n");

 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Python embedded interpreter: how to initialize the interpreter ? ycollet@freesurf.fr Python 3 01-03-2007 01:00 AM
Debugging of Python code in embedded interpreter TK Python 1 11-30-2005 04:05 PM
Embedded Python interpreter and sockets wahn@acm.org Python 4 11-23-2005 01:15 AM
Embedded Python interpreter, runtime libs, and crashing Peter Newman Python 1 10-26-2005 03:38 AM
Threads in embedded interpreter doesn't run devrim.erdem@gmail.com Python 3 10-21-2004 07:27 PM



Advertisments