Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
OK, I found the problem. The LockFile line is commented out in test.py
which causes Apache to try to create the lock in the default location in
/var/run.
http://svn.apache.org/viewcvs.cgi/httpd/mod_python/trunk/test/test.py?rev=125771r1=106619r2=125771
So the question is - can we just put it back in, or does it break
something on Win32?
Cheers
Grisha
On Tue, 13 Sep 2005, Jim Gallacher wrote:
Nicolas Lehuen wrote:
Jim, do you manage to build and test the 3.1.4 version on your setup ?
This looks like a permission problem, not something related to our current
problem.
I haven't tried 3.1.4. And I could also try the tests as root, which would
eliminate any permission problems. I have a busy day ahead of me so this will
have to wait until tonight.
Jim
Regards,
Nicolas
2005/9/13, Jim Gallacher [EMAIL PROTECTED]
mailto:[EMAIL PROTECTED]:
-1 for this patch. Actually, the patch itself is fine - it just
doesn't
fix the problem. The unit tests are still failings as per my previous
messages. ie the following is getting logged in test/logs/error_log:
[Mon Sep 12 19:49:33 2005] [emerg] (2)No such file or directory:
Couldn't create accept lock
Jim
Gregory (Grisha) Trubetskoy wrote:
Here's a patch (this is against 3.1.2b). Untested. This replaces
GIL
with with the APR lock.
--- src/mod_python.c.orig Mon Sep 12 16:42:28 2005
+++ src/mod_python.cMon Sep 12 17:32:26 2005
@@ -31,7 +31,9 @@
* (In a Python dictionary) */
static PyObject * interpreters = NULL;
+#ifdef APR_HAS_THREAD
static apr_thread_mutex_t* interpreters_lock = 0;
+#endif
apr_pool_t *child_init_pool = NULL;
@@ -127,9 +129,8 @@
if (! name)
name = MAIN_INTERPRETER;
-#ifdef WITH_THREAD
+#ifdef APR_HAS_THREAD
apr_thread_mutex_lock(interpreters_lock);
-PyEval_AcquireLock();
#endif
if (!interpreters) {
@@ -156,8 +157,7 @@
idata = (interpreterdata *)PyCObject_AsVoidPtr(p);
}
-#ifdef WITH_THREAD
-PyEval_ReleaseLock();
+#ifdef APR_HAS_THREAD
apr_thread_mutex_unlock(interpreters_lock);
#endif
@@ -513,8 +513,10 @@
/* initialze the interpreter */
Py_Initialize();
-#ifdef WITH_THREAD
+#ifdef APR_HAS_THREAD
apr_thread_mutex_create(interpreters_lock,APR_THREAD_MUTEX_UNNESTED,p);
+#endif
+#ifdef WITH_THREAD
/* create and acquire the interpreter lock */
PyEval_InitThreads();
#endif
On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote:
Yep, this is getting a little hairy, but nothing we couldn't
handle :-)
I did a little more research. Basically, this started with
Graham's
patch that addressed a problem with modules being reimported (or
something). From Graham's message:
The basic problem revolves around the Python dictionary used to
hold
the set of interpreters. The code in mod_python.c is trying to
use
the Python GIL to provide exclusive access to that dictionary
and any
subsequent creation of an interpreter.
The only catch is that in creating a new interpreter, the
Python core
is, in someway I don't understand, swapping thread states at some
point which is allowing other threads to acquire the GIL.
So what Graham's patch does is create an APR lock
(interpreters_lock)
and wrap all the access to the dictionary with calls to
apr_mutex_lock/unlock.
I think the _real_ way to address this issue is to first find
what is
the problem with using the Python GIL to serialize access to the
interpreters dictionary. Is this a Python bug, or are we not
understanding GIL and using it improperly?
BUT, given that the above question may be complicated to answer,
and
that Graham's patch resolves the issue, another thought:
If the APR lock works, what is the point of using the GIL in
addition?
Should we just use the APR-based lock alone? I.e., where we had
(after
Graham's patch):
#ifdef WITH_THREAD
apr_thread_mutex_lock(interpreters_lock);
PyEval_AcquireLock();
#endif
we would use:
#ifdef APR_HAS_THREAD
apr_thread_mutex_lock(interpreters_lock);
#endif
_without_ a call to PyEval_AcquireLock() at all.
It should compile OK, and on platforms where APR has no thread
support, like you said, it's not an issue since no separate
interpreters run in one process at the same time.
Grisha
On Mon, 12 Sep 2005, Nicolas Lehuen wrote:
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
I'd keep the patch nonetheless - I think this is how it should be.
Grisha
On Mon, 12 Sep 2005, Jim Gallacher wrote:
-1 for this patch. Actually, the patch itself is fine - it just doesn't fix
the problem. The unit tests are still failings as per my previous messages.
ie the following is getting logged in test/logs/error_log:
[Mon Sep 12 19:49:33 2005] [emerg] (2)No such file or directory: Couldn't
create accept lock
Jim
Gregory (Grisha) Trubetskoy wrote:
Here's a patch (this is against 3.1.2b). Untested. This replaces GIL with
with the APR lock.
--- src/mod_python.c.orig Mon Sep 12 16:42:28 2005
+++ src/mod_python.cMon Sep 12 17:32:26 2005
@@ -31,7 +31,9 @@
* (In a Python dictionary) */
static PyObject * interpreters = NULL;
+#ifdef APR_HAS_THREAD
static apr_thread_mutex_t* interpreters_lock = 0;
+#endif
apr_pool_t *child_init_pool = NULL;
@@ -127,9 +129,8 @@
if (! name)
name = MAIN_INTERPRETER;
-#ifdef WITH_THREAD
+#ifdef APR_HAS_THREAD
apr_thread_mutex_lock(interpreters_lock);
-PyEval_AcquireLock();
#endif
if (!interpreters) {
@@ -156,8 +157,7 @@
idata = (interpreterdata *)PyCObject_AsVoidPtr(p);
}
-#ifdef WITH_THREAD
-PyEval_ReleaseLock();
+#ifdef APR_HAS_THREAD
apr_thread_mutex_unlock(interpreters_lock);
#endif
@@ -513,8 +513,10 @@
/* initialze the interpreter */
Py_Initialize();
-#ifdef WITH_THREAD
+#ifdef APR_HAS_THREAD
apr_thread_mutex_create(interpreters_lock,APR_THREAD_MUTEX_UNNESTED,p);
+#endif
+#ifdef WITH_THREAD
/* create and acquire the interpreter lock */
PyEval_InitThreads();
#endif
On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote:
Yep, this is getting a little hairy, but nothing we couldn't handle :-)
I did a little more research. Basically, this started with Graham's
patch that addressed a problem with modules being reimported (or
something). From Graham's message:
The basic problem revolves around the Python dictionary used to hold
the set of interpreters. The code in mod_python.c is trying to use the
Python GIL to provide exclusive access to that dictionary and any
subsequent creation of an interpreter.
The only catch is that in creating a new interpreter, the Python core
is, in someway I don't understand, swapping thread states at some
point which is allowing other threads to acquire the GIL.
So what Graham's patch does is create an APR lock (interpreters_lock)
and wrap all the access to the dictionary with calls to
apr_mutex_lock/unlock.
I think the _real_ way to address this issue is to first find what is
the problem with using the Python GIL to serialize access to the
interpreters dictionary. Is this a Python bug, or are we not
understanding GIL and using it improperly?
BUT, given that the above question may be complicated to answer, and
that Graham's patch resolves the issue, another thought:
If the APR lock works, what is the point of using the GIL in addition?
Should we just use the APR-based lock alone? I.e., where we had (after
Graham's patch):
#ifdef WITH_THREAD
apr_thread_mutex_lock(interpreters_lock);
PyEval_AcquireLock();
#endif
we would use:
#ifdef APR_HAS_THREAD
apr_thread_mutex_lock(interpreters_lock);
#endif
_without_ a call to PyEval_AcquireLock() at all.
It should compile OK, and on platforms where APR has no thread support,
like you said, it's not an issue since no separate interpreters run in
one process at the same time.
Grisha
On Mon, 12 Sep 2005, Nicolas Lehuen wrote:
Duh, this is becoming difficult :)
I was thinking that if APR_HAS_THREADS was 0, then Apache was forcibly
ran
in prefork mode, so there was no need for thread safety at all, given
the
fact that mod_python would only run one interpreter thread. So if
WITH_THREAD was not defined, ORAPR_HAS_THREADS was 0, then we would
not need
any thread safety code. Hence the definition of
MOD_PYTHON_WITH_THREAD_SUPPORT.
You're right in writing that a user could launch a new thread in
Python,
provided that WITH_THREAD is defined, even if APR_HAS_THREADS==0.
However,
having a look at the parts of mod_python.c where the thread safety was
put
in, I think we can safely say that those parts are only called by
mod_python
(through python_handler, python_cleanup etc who call get_interpreter).
Those
parts are therefore always called in the same thread (if
APR_HAS_THREADS==0,
that is) and there is no need for thread synchronization to be done
(no
shared data between the main thread and the other user threads, no
need to
release the GIL etc.).
BUT, I could be very, very wrong here, and your idea of reverting to a
conservative shield python threading calls with WITH_THREAD and apr
threading code with APR_HAS_THREADS is way more attractive to my
tired mind
right now. So if you want I can revert all this
MOD_PYTHON_WITH_THREAD_SUPPORT hack.
Regards,
Nicolas
2005/9/12, Gregory (Grisha) Trubetskoy
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
Done. All tests pass on my FreeBSD box. Nicolas - can you test Win32, I'm
not 100% sure if the change to test.py I made will work.
Grisha
On Tue, 13 Sep 2005, Nicolas Lehuen wrote:
Yes, now I remember I had to comment this line out because it broke
something on Win32. Go ahead, uncomment it and I'll add a test to remove it
when running the test on Win32.
Regards,
Nicolas
2005/9/13, Gregory (Grisha) Trubetskoy [EMAIL PROTECTED]:
OK, I found the problem. The LockFile line is commented out in test.py
which causes Apache to try to create the lock in the default location in
/var/run.
http://svn.apache.org/viewcvs.cgi/httpd/mod_python/trunk/test/test.py?rev=125771r1=106619r2=125771
So the question is - can we just put it back in, or does it break
something on Win32?
Cheers
Grisha
On Tue, 13 Sep 2005, Jim Gallacher wrote:
Nicolas Lehuen wrote:
Jim, do you manage to build and test the 3.1.4 version on your setup ?
This looks like a permission problem, not something related to our
current
problem.
I haven't tried 3.1.4. And I could also try the tests as root, which
would
eliminate any permission problems. I have a busy day ahead of me so this
will
have to wait until tonight.
Jim
Regards,
Nicolas
2005/9/13, Jim Gallacher [EMAIL PROTECTED]
mailto:[EMAIL PROTECTED]:
-1 for this patch. Actually, the patch itself is fine - it just
doesn't
fix the problem. The unit tests are still failings as per my previous
messages. ie the following is getting logged in test/logs/error_log:
[Mon Sep 12 19:49:33 2005] [emerg] (2)No such file or directory:
Couldn't create accept lock
Jim
Gregory (Grisha) Trubetskoy wrote:
Here's a patch (this is against 3.1.2b). Untested. This replaces
GIL
with with the APR lock.
--- src/mod_python.c.orig Mon Sep 12 16:42:28 2005
+++ src/mod_python.c Mon Sep 12 17:32:26 2005
@@ -31,7 +31,9 @@
* (In a Python dictionary) */
static PyObject * interpreters = NULL;
+#ifdef APR_HAS_THREAD
static apr_thread_mutex_t* interpreters_lock = 0;
+#endif
apr_pool_t *child_init_pool = NULL;
@@ -127,9 +129,8 @@
if (! name)
name = MAIN_INTERPRETER;
-#ifdef WITH_THREAD
+#ifdef APR_HAS_THREAD
apr_thread_mutex_lock(interpreters_lock);
- PyEval_AcquireLock();
#endif
if (!interpreters) {
@@ -156,8 +157,7 @@
idata = (interpreterdata *)PyCObject_AsVoidPtr(p);
}
-#ifdef WITH_THREAD
- PyEval_ReleaseLock();
+#ifdef APR_HAS_THREAD
apr_thread_mutex_unlock(interpreters_lock);
#endif
@@ -513,8 +513,10 @@
/* initialze the interpreter */
Py_Initialize();
-#ifdef WITH_THREAD
+#ifdef APR_HAS_THREAD
apr_thread_mutex_create(interpreters_lock,APR_THREAD_MUTEX_UNNESTED,p);
+#endif
+#ifdef WITH_THREAD
/* create and acquire the interpreter lock */
PyEval_InitThreads();
#endif
On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote:
Yep, this is getting a little hairy, but nothing we couldn't
handle :-)
I did a little more research. Basically, this started with
Graham's
patch that addressed a problem with modules being reimported (or
something). From Graham's message:
The basic problem revolves around the Python dictionary used to
hold
the set of interpreters. The code in mod_python.c is trying to
use
the Python GIL to provide exclusive access to that dictionary
and any
subsequent creation of an interpreter.
The only catch is that in creating a new interpreter, the
Python core
is, in someway I don't understand, swapping thread states at some
point which is allowing other threads to acquire the GIL.
So what Graham's patch does is create an APR lock
(interpreters_lock)
and wrap all the access to the dictionary with calls to
apr_mutex_lock/unlock.
I think the _real_ way to address this issue is to first find
what is
the problem with using the Python GIL to serialize access to the
interpreters dictionary. Is this a Python bug, or are we not
understanding GIL and using it improperly?
BUT, given that the above question may be complicated to answer,
and
that Graham's patch resolves the issue, another thought:
If the APR lock works, what is the point of using the GIL in
addition?
Should we just use the APR-based lock alone? I.e., where we had
(after
Graham's patch):
#ifdef WITH_THREAD
apr_thread_mutex_lock(interpreters_lock);
PyEval_AcquireLock();
#endif
we would use:
#ifdef APR_HAS_THREAD
apr_thread_mutex_lock(interpreters_lock);
#endif
_without_ a call to PyEval_AcquireLock() at all.
It should compile OK, and on platforms where APR has no thread
support, like you said, it's not an issue since no separate
interpreters run in one process at the same time.
Grisha
On Mon, 12 Sep 2005, Nicolas Lehuen wrote:
Duh, this is becoming difficult :)
I was thinking that if APR_HAS_THREADS was 0, then Apache was
forcibly ran
in prefork mode, so there was no need for thread safety at all,
given
the
fact that mod_python would only run one interpreter thread. So if
WITH_THREAD was not defined, ORAPR_HAS_THREADS was 0, then we
would
not need
any thread safety
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
Gregory (Grisha) Trubetskoy wrote:
Done. All tests pass on my FreeBSD box. Nicolas - can you test Win32,
I'm not 100% sure if the change to test.py I made will work.
Good news. If the changes can be checked in and Nicolas can give a +1 on
the Windows test then I'll be able to generate the next, and hopefully
last, beta tonight.
As an aside, it may be useful to have an option for test.py to preserve
a copy of the apache logs. It would make troubleshooting the unit test
failures much easier. Currently test.py deletes the logs after each unit
test.
Regards,
Jim
Grisha
On Tue, 13 Sep 2005, Nicolas Lehuen wrote:
Yes, now I remember I had to comment this line out because it broke
something on Win32. Go ahead, uncomment it and I'll add a test to
remove it
when running the test on Win32.
Regards,
Nicolas
2005/9/13, Gregory (Grisha) Trubetskoy [EMAIL PROTECTED]:
OK, I found the problem. The LockFile line is commented out in test.py
which causes Apache to try to create the lock in the default location in
/var/run.
http://svn.apache.org/viewcvs.cgi/httpd/mod_python/trunk/test/test.py?rev=125771r1=106619r2=125771
So the question is - can we just put it back in, or does it break
something on Win32?
Cheers
Grisha
On Tue, 13 Sep 2005, Jim Gallacher wrote:
Nicolas Lehuen wrote:
Jim, do you manage to build and test the 3.1.4 version on your setup ?
This looks like a permission problem, not something related to our
current
problem.
I haven't tried 3.1.4. And I could also try the tests as root, which
would
eliminate any permission problems. I have a busy day ahead of me so
this
will
have to wait until tonight.
Jim
Regards,
Nicolas
2005/9/13, Jim Gallacher [EMAIL PROTECTED]
mailto:[EMAIL PROTECTED]:
-1 for this patch. Actually, the patch itself is fine - it just
doesn't
fix the problem. The unit tests are still failings as per my previous
messages. ie the following is getting logged in test/logs/error_log:
[Mon Sep 12 19:49:33 2005] [emerg] (2)No such file or directory:
Couldn't create accept lock
Jim
Gregory (Grisha) Trubetskoy wrote:
Here's a patch (this is against 3.1.2b). Untested. This replaces
GIL
with with the APR lock.
--- src/mod_python.c.orig Mon Sep 12 16:42:28 2005
+++ src/mod_python.c Mon Sep 12 17:32:26 2005
@@ -31,7 +31,9 @@
* (In a Python dictionary) */
static PyObject * interpreters = NULL;
+#ifdef APR_HAS_THREAD
static apr_thread_mutex_t* interpreters_lock = 0;
+#endif
apr_pool_t *child_init_pool = NULL;
@@ -127,9 +129,8 @@
if (! name)
name = MAIN_INTERPRETER;
-#ifdef WITH_THREAD
+#ifdef APR_HAS_THREAD
apr_thread_mutex_lock(interpreters_lock);
- PyEval_AcquireLock();
#endif
if (!interpreters) {
@@ -156,8 +157,7 @@
idata = (interpreterdata *)PyCObject_AsVoidPtr(p);
}
-#ifdef WITH_THREAD
- PyEval_ReleaseLock();
+#ifdef APR_HAS_THREAD
apr_thread_mutex_unlock(interpreters_lock);
#endif
@@ -513,8 +513,10 @@
/* initialze the interpreter */
Py_Initialize();
-#ifdef WITH_THREAD
+#ifdef APR_HAS_THREAD
apr_thread_mutex_create(interpreters_lock,APR_THREAD_MUTEX_UNNESTED,p);
+#endif
+#ifdef WITH_THREAD
/* create and acquire the interpreter lock */
PyEval_InitThreads();
#endif
On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote:
Yep, this is getting a little hairy, but nothing we couldn't
handle :-)
I did a little more research. Basically, this started with
Graham's
patch that addressed a problem with modules being reimported (or
something). From Graham's message:
The basic problem revolves around the Python dictionary used to
hold
the set of interpreters. The code in mod_python.c is trying to
use
the Python GIL to provide exclusive access to that dictionary
and any
subsequent creation of an interpreter.
The only catch is that in creating a new interpreter, the
Python core
is, in someway I don't understand, swapping thread states at some
point which is allowing other threads to acquire the GIL.
So what Graham's patch does is create an APR lock
(interpreters_lock)
and wrap all the access to the dictionary with calls to
apr_mutex_lock/unlock.
I think the _real_ way to address this issue is to first find
what is
the problem with using the Python GIL to serialize access to the
interpreters dictionary. Is this a Python bug, or are we not
understanding GIL and using it improperly?
BUT, given that the above question may be complicated to answer,
and
that Graham's patch resolves the issue, another thought:
If the APR lock works, what is the point of using the GIL in
addition?
Should we just use the APR-based lock alone? I.e., where we had
(after
Graham's patch):
#ifdef WITH_THREAD
apr_thread_mutex_lock(interpreters_lock);
PyEval_AcquireLock();
#endif
we would use:
#ifdef APR_HAS_THREAD
apr_thread_mutex_lock(interpreters_lock);
#endif
_without_ a call to PyEval_AcquireLock() at all.
It should compile OK, and on platforms where APR has no thread
support, like you said, it's
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
Alright, cool. So I guess we're ready to roll the next tarfile now.
Grisha
On Tue, 13 Sep 2005, Nicolas Lehuen wrote:
I'm sure it is required, even after fixing the S in APR_HAS_THREADS I tried
with and without the PyEval_AcquireLock code and the latter works while the
former doesn't. I don't know why though... I'll have to review the code once
more to understand.
Regards,
Nicolas
2005/9/13, Gregory (Grisha) Trubetskoy [EMAIL PROTECTED]:
Good job - I've tested it and it works on FreeBSD. Just one last thing I
wanted to confirm - are you sure that PyEval_AcquireLock is required, or
was this a sideffect of the missing 'S'? I just want to make sure we're
not doing double locking where it's not needed.
Grisha
On Tue, 13 Sep 2005, Nicolas Lehuen wrote:
OK I fixed the problem, please check again on FreeBSD. Here is what I've
done (from the subversion comment) :
Fixed : APR_HAS_THREADS ends with an 'S'. Reintroduced the calls to
PyEval_AcquireLock and PyEval_ReleaseLock as they are required if
threading
is enabled. Removed two debugging log entries. Added the conditional
commenting of the LockFile directive in the LockFile class.
Regards,
Nicolas
2005/9/13, Nicolas Lehuen [EMAIL PROTECTED]:
Well, bad news... I have a -1 for now on Win32. I don't know why, but
when
I install and test the 20050911 version, everything is OK. When I
install
and test the latest version, the unit test behave very strangely (with
or
without the changes done by Graham). Basically, the Apache server takes
forever to stop. Weird...
I'm trying to find out what happens here.
Regards,
Nicolas
2005/9/13, Jim Gallacher [EMAIL PROTECTED]:
Gregory (Grisha) Trubetskoy wrote:
Done. All tests pass on my FreeBSD box. Nicolas - can you test Win32,
I'm not 100% sure if the change to test.py I made will work.
Good news. If the changes can be checked in and Nicolas can give a +1
on
the Windows test then I'll be able to generate the next, and hopefully
last, beta tonight.
As an aside, it may be useful to have an option for test.py to
preserve
a copy of the apache logs. It would make troubleshooting the unit test
failures much easier. Currently test.py deletes the logs after each
unit
test.
Regards,
Jim
Grisha
On Tue, 13 Sep 2005, Nicolas Lehuen wrote:
Yes, now I remember I had to comment this line out because it broke
something on Win32. Go ahead, uncomment it and I'll add a test to
remove it
when running the test on Win32.
Regards,
Nicolas
2005/9/13, Gregory (Grisha) Trubetskoy [EMAIL PROTECTED]:
OK, I found the problem. The LockFile line is commented out in
test.py
which causes Apache to try to create the lock in the default
location in
/var/run.
http://svn.apache.org/viewcvs.cgi/httpd/mod_python/trunk/test/test.py?rev=125771r1=106619r2=125771
So the question is - can we just put it back in, or does it break
something on Win32?
Cheers
Grisha
On Tue, 13 Sep 2005, Jim Gallacher wrote:
Nicolas Lehuen wrote:
Jim, do you manage to build and test the 3.1.4 version on your
setup ?
This looks like a permission problem, not something related to
our
current
problem.
I haven't tried 3.1.4. And I could also try the tests as root,
which
would
eliminate any permission problems. I have a busy day ahead of me
so
this
will
have to wait until tonight.
Jim
Regards,
Nicolas
2005/9/13, Jim Gallacher [EMAIL PROTECTED]
mailto: [EMAIL PROTECTED]:
-1 for this patch. Actually, the patch itself is fine - it just
doesn't
fix the problem. The unit tests are still failings as per my
previous
messages. ie the following is getting logged in
test/logs/error_log:
[Mon Sep 12 19:49:33 2005] [emerg] (2)No such file or directory:
Couldn't create accept lock
Jim
Gregory (Grisha) Trubetskoy wrote:
Here's a patch (this is against 3.1.2b). Untested. This replaces
GIL
with with the APR lock.
--- src/mod_python.c.orig Mon Sep 12 16:42:28 2005
+++ src/mod_python.c Mon Sep 12 17:32:26 2005
@@ -31,7 +31,9 @@
* (In a Python dictionary) */
static PyObject * interpreters = NULL;
+#ifdef APR_HAS_THREAD
static apr_thread_mutex_t* interpreters_lock = 0;
+#endif
apr_pool_t *child_init_pool = NULL;
@@ -127,9 +129,8 @@
if (! name)
name = MAIN_INTERPRETER;
-#ifdef WITH_THREAD
+#ifdef APR_HAS_THREAD
apr_thread_mutex_lock(interpreters_lock);
- PyEval_AcquireLock();
#endif
if (!interpreters) {
@@ -156,8 +157,7 @@
idata = (interpreterdata *)PyCObject_AsVoidPtr(p);
}
-#ifdef WITH_THREAD
- PyEval_ReleaseLock();
+#ifdef APR_HAS_THREAD
apr_thread_mutex_unlock(interpreters_lock);
#endif
@@ -513,8 +513,10 @@
/* initialze the interpreter */
Py_Initialize();
-#ifdef WITH_THREAD
+#ifdef APR_HAS_THREAD
apr_thread_mutex_create(interpreters_lock,APR_THREAD_MUTEX_UNNESTED,p);
+#endif
+#ifdef WITH_THREAD
/* create and acquire the interpreter lock */
PyEval_InitThreads();
#endif
On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote:
Yep, this is getting a little hairy, but
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
OK, so on a non-threaded Apache, we can suppose we will be using the
prefork MPM, so we don't need any code to support threading in
mod_python, then, right ?
In this case instead of testing for WITH_THREAD in mod_python.c :
#ifdef WITH_THREAD
maybe we could test for WITH_THREAD and APR_HAS_THREADS :
#if APR_HAS_THREADS defined(WITH_THREAD)
Right ? This would remove all threading-related code from mod_python
when only prefork is available or when Python isn't compiled to support
threads (I which case I wonder how it works in a threaded Apache...).
I have given up using QEMU for now, minotaur is sufficient to make sure
mod_python builds on FreeBSD. Granted, it won't allow me to give any +1
since I cannot run the unit tests (or can I ?)...
Regards,
Nicolas
2005/9/11, Jim Gallacher [EMAIL PROTECTED]:
FYI, I found the following note in the INSTALL file in the apache source: * If you are building on FreeBSD, be aware that threads will be disabled and the prefork MPM will be used by default, as threads do not work well with Apache on FreeBSD.If
you wish to try a threaded Apache on FreeBSD anyway, use ./configure --enable-threads.I'm also setting up FreeBSD under QEMU... so far so good, but installinganything using ports is really slow. QEMU's performance here is just
killing me. I guess I should have read the manual first and used thebinary packages for the software I wanted to install. :-(Regards,JimJim Gallacher wrote: Nicolas Lehuen wrote:
OK, I've checked in a version that compiles both on at least Win32 and FreeBSD. I'm just testing if APR_HAS_THREAD is defined and only include the apr_thread_mutex_lock and unlock calls if it is defined.
Compiles a passes unit tests on Linux Debian sid with mpm-prefork. Now, on minotaur, APR_HAS_THREAD is defined as 0. Does this mean that Apache is not configured for threading ? Can we assume that we are in
the prefork model if APR_HAS_THREAD==0, so that we can skip all the locking code ? Because that's what we do right now. On Debian sid with apache2.0.54 mpm-prefork, APR_HAS_THREAD == 1.
Jim Regards, Nicolas 2005/9/11, Nicolas Lehuen [EMAIL PROTECTED] mailto:
[EMAIL PROTECTED]: Yes, this new code is something I commited on the 29/12/2004 (I used the blame function of TortoiseSVN for that). It was a patch by
Graham to fix MODPYTHON-2 http://issues.apache.org/jira/browse/MODPYTHON-2. The problem is not in the patch, but rather in the fact that APR
seems configured without the thread support while Python is configured with thread support. mod_python.c assumes that is WITH_THREAD is defined, then the APR mutex functions are available,
which is wrong. Maybe we should test for APR_HAS_THREADS instead ? In that case, won't this cause any problems on threaded platforms ? I don't know if this is a problem specific to minotaur or to all
version of FreeBSD. I'm currently downloading the ISOs of FreeBSD and I'll try using QEMU to run a FreeBSD setup on my computer, but that will be long and troublesome. If someone has more clue on this
issue, feel free to tell us :). Regards, Nicolas 2005/9/10, Jim Gallacher [EMAIL PROTECTED]
mailto:[EMAIL PROTECTED]:I'm stubling around in the dark here, but maybe this will create a spark
of an idea. I took a diff of mod_python.c from 3.1.4 and 3.2.1b andisolated the lines which correspond to the compilation error.Compiler messages
-mod_python.c:34: error: syntax error before '*' tokenmod_python.c:34: warning: type defaults to `int' in declaration of`interpreters_lock'
mod_python.c:34: warning: data definition has no type or storage classmod_python.c: In function `get_interpreter':mod_python.c:131: warning: implicit declaration of function
`apr_thread_mutex_lock'mod_python.c:161: warning: implicit declaration of function`apr_thread_mutex_unlock'mod_python.c: In function `python_init':
mod_python.c:517: warning: implicit declaration of function`apr_thread_mutex_create'mod_python.c:517: error: `APR_THREAD_MUTEX_UNNESTED' undeclared (firstuse in this function)
Diff output---I've only copied the diff chunks which correspond to the complier errors
mentioned above.--- mod_python-3.1.4/src/mod_python.c Sat Jan 29 13:25:28 2005+++ mod_python-3.2.1b/src/mod_python.cTue Sep6 17:11:03 2005@@ -31,6 +31,8 @@
* (In a Python dictionary) */ static PyObject * interpreters = NULL;+static apr_thread_mutex_t* interpreters_lock = 0;+ apr_pool_t *child_init_pool = NULL;
... snip ...@@ -124,11 +128,15 @@ name = MAIN_INTERPRETER; #ifdef WITH_THREAD+apr_thread_mutex_lock(interpreters_lock);
PyEval_AcquireLock(); #endif... snip ...@@ -149,6 +158,7 @@ #ifdef WITH_THREAD
PyEval_ReleaseLock();+apr_thread_mutex_unlock(interpreters_lock); #endif... snip ...@@ -490,13 +506,15 @@
} /* initialize global Python interpreter if necessary */-if (! Py_IsInitialized())+if (initialized == 0 || !Py_IsInitialized())
{-+initialized = 1;+ /* initialze the interpreter */ Py_Initialize();
#ifdef WITH_THREAD+
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
Nicolas Lehuen wrote: OK, so on a non-threaded Apache, we can suppose we will be using the prefork MPM, so we don't need any code to support threading in mod_python, then, right ? Makes sense to me. In this case instead of testing for WITH_THREAD in mod_python.c : #ifdef WITH_THREAD maybe we could test for WITH_THREAD and APR_HAS_THREADS : #if APR_HAS_THREADS defined(WITH_THREAD) Right ? This would remove all threading-related code from mod_python when only prefork is available or when Python isn't compiled to support threads (I which case I wonder how it works in a threaded Apache...). Seems reasonable. It compiles and passes the unit tests on debian. I have given up using QEMU for now, minotaur is sufficient to make sure mod_python builds on FreeBSD. Granted, it won't allow me to give any +1 since I cannot run the unit tests (or can I ?)... I got FreeBSD running under QEMU, and the results are the same as on minotaur. With the #if APR_HAS_THREADS defined(WITH_THREAD) code change, mod_python compiles but the final link step generates a warning on both minotaur and qemu: /usr/local/share/apache2/build/libtool --silent --mode=link cc -o mod_python.la -rpath /usr/local/libexec/apache2 -module -avoid-version hlistobject.lo hlist.lo filterobject.lo connobject.lo serverobject.lo util.lo tableobject.lo requestobject.lo _apachemodule.lo mod_python.lo -Wl,--export-dynamic -pthread -lm /usr/local/lib/python2.4/config/libpython2.4.a -lutil -lm *** Warning: Linking the shared library mod_python.la against the *** static library /usr/local/lib/python2.4/config/libpython2.4.a is not portable! Likewise, the unit tests on both QEMU and minotaur fail. On minotaur: Syntax error on line 44 of /home/jgallacher/tmp/mod_python/test/conf/test.conf: Cannot load /home/jgallacher/tmp/mod_python/src/mod_python.so into server: /home/jgallacher/tmp/mod_python/src/mod_python.so: Undefined symbol btowc On qemu: Syntax error on line 44 of /usr/home/jim/tmp/mod_python/test/conf/test.conf: Cannot load /usr/home/jim/tmp/mod_python/src/mod_python.so into server: /usr/home/jim/tmp/mod_python/src/mod_python.so: Undefined symbol pthread_attr_init It is quite possible I don't have things configured correctly on the QEMU version and hence the different undefined symbol but it doesn't really matter since it fails either way. I don't have time to investigate further right now. I'll revisit this tonight. Regards, Jim Regards, Nicolas #if APR_HAS_THREADS defined(WITH_THREAD) 2005/9/11, Jim Gallacher [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]: FYI, I found the following note in the INSTALL file in the apache source: * If you are building on FreeBSD, be aware that threads will be disabled and the prefork MPM will be used by default, as threads do not work well with Apache on FreeBSD. If you wish to try a threaded Apache on FreeBSD anyway, use ./configure --enable-threads. I'm also setting up FreeBSD under QEMU... so far so good, but installing anything using ports is really slow. QEMU's performance here is just killing me. I guess I should have read the manual first and used the binary packages for the software I wanted to install. :-( Regards, Jim Jim Gallacher wrote: Nicolas Lehuen wrote: OK, I've checked in a version that compiles both on at least Win32 and FreeBSD. I'm just testing if APR_HAS_THREAD is defined and only include the apr_thread_mutex_lock and unlock calls if it is defined. Compiles a passes unit tests on Linux Debian sid with mpm-prefork. Now, on minotaur, APR_HAS_THREAD is defined as 0. Does this mean that Apache is not configured for threading ? Can we assume that we are in the prefork model if APR_HAS_THREAD==0, so that we can skip all the locking code ? Because that's what we do right now. On Debian sid with apache2.0.54 mpm-prefork, APR_HAS_THREAD == 1. Jim Regards, Nicolas 2005/9/11, Nicolas Lehuen [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto: [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]: Yes, this new code is something I commited on the 29/12/2004 (I used the blame function of TortoiseSVN for that). It was a patch by Graham to fix MODPYTHON-2 http://issues.apache.org/jira/browse/MODPYTHON-2. The problem is not in the patch, but rather in the fact that APR seems configured without the thread support while Python is configured with thread support. mod_python.c assumes that is WITH_THREAD is defined, then the APR mutex functions are available, which is wrong. Maybe we should test for APR_HAS_THREADS instead ? In that case, won't this cause any problems on threaded platforms ?
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
Gregory (Grisha) Trubetskoy wrote: Shouldn't that be PYTHON_WITH_THREAD rather than MOD_PYTHON_WITH_THREAD? I understand it to mean that we want the thread handling code compiled into mod_python. Compiling and testing right now. Jim On Mon, 12 Sep 2005, Nicolas Lehuen wrote: I've checked in a changeset wherein I define MOD_PYTHON_WITH_THREAD_SUPPORT and use it everywhere WITH_THREAD was previously used. This should do the trick ! Now if someone (like Jim) can give us his +1, that would be great. Regards, Nicolas 2005/9/12, Gregory (Grisha) Trubetskoy [EMAIL PROTECTED]: Just wanted to add to this message that if Jim's version runs and tests with the trick below (envvars is executed prior to apache start, but I don't think the tests use it, so you'll probably just have to set this var in the shell in which the tests are run), then this would be a solution for all FreeBSD issues and we could roll a beta 3 which will have a great change of being publicly released. Grisha On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote: OK, found it. This should work on FreeBSD where Python is threaded and Apache is not. [snip] And, if you built apache without thread support, you may need to add the following lines to $PREFIX/sbin/envvars: LD_PRELOAD=/usr/lib/libc_r.so export LD_PRELOAD [snip] On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote: On Mon, 12 Sep 2005, Jim Gallacher wrote: *** Warning: Linking the shared library mod_python.la against the *** static library /usr/local/lib/python2.4/config/libpython2.4.a is not portable! I think this was always there and its pretty harmless. On qemu: Syntax error on line 44 of /usr/home/jim/tmp/mod_python/test/conf/test.conf: Cannot load /usr/home/jim/tmp/mod_python/src/mod_python.so into server: /usr/home/jim/tmp/mod_python/src/mod_python.so: Undefined symbol pthread_attr_init This is because FreeBSD's libc comes in two versions - threaded and non-threaded. If Python is linked against the threaded ones and Apache against the non-thrreaded, then you get this problem. There is a simple fix for this - you just cause Apache to start with threaded libs, but I can't find any references to it right now and have to run off to a meeting. Grisha It is quite possible I don't have things configured correctly on the QEMU version and hence the different undefined symbol but it doesn't really matter since it fails either way. I don't have time to investigate further right now. I'll revisit this tonight. Regards, Jim Regards, Nicolas #if APR_HAS_THREADS defined(WITH_THREAD) 2005/9/11, Jim Gallacher [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]: FYI, I found the following note in the INSTALL file in the apache source: * If you are building on FreeBSD, be aware that threads will be disabled and the prefork MPM will be used by default, as threads do not work well with Apache on FreeBSD. If you wish to try a threaded Apache on FreeBSD anyway, use ./configure --enable-threads. I'm also setting up FreeBSD under QEMU... so far so good, but installing anything using ports is really slow. QEMU's performance here is just killing me. I guess I should have read the manual first and used the binary packages for the software I wanted to install. :-( Regards, Jim Jim Gallacher wrote: Nicolas Lehuen wrote: OK, I've checked in a version that compiles both on at least Win32 and FreeBSD. I'm just testing if APR_HAS_THREAD is defined and only include the apr_thread_mutex_lock and unlock calls if it is defined. Compiles a passes unit tests on Linux Debian sid with mpm-prefork. Now, on minotaur, APR_HAS_THREAD is defined as 0. Does this mean that Apache is not configured for threading ? Can we assume that we are in the prefork model if APR_HAS_THREAD==0, so that we can skip all the locking code ? Because that's what we do right now. On Debian sid with apache2.0.54 mpm-prefork, APR_HAS_THREAD == 1. Jim Regards, Nicolas 2005/9/11, Nicolas Lehuen [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto: [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]: Yes, this new code is something I commited on the 29/12/2004 (I used the blame function of TortoiseSVN for that). It was a patch by Graham to fix MODPYTHON-2 http://issues.apache.org/jira/browse/MODPYTHON-2. The problem is not in the patch, but rather in the fact that APR seems configured without the thread support while Python is configured with thread support. mod_python.c assumes that is WITH_THREAD is defined, then the APR mutex functions are available, which is wrong. Maybe we should test for APR_HAS_THREADS instead ? In that case, won't this cause any problems on threaded platforms ? I don't know if this is a problem specific to minotaur or to all version of FreeBSD. I'm currently downloading the ISOs of FreeBSD and I'll try using QEMU to run a FreeBSD setup on my computer, but that will
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
Well, it depends : #if(defined(WITH_THREAD) APR_HAS_THREADS) #define MOD_PYTHON_WITH_THREAD_SUPPORT 1 #else #define MOD_PYTHON_WITH_THREAD_SUPPORT 0 #endif It's not only a matter of Python supporting threads, we must also have a thread-enabled APR. So that's the reason for the weird name I chose. But I don't mind changing it ! Regards, Nicolas2005/9/12, Gregory (Grisha) Trubetskoy [EMAIL PROTECTED]: Shouldn't that be PYTHON_WITH_THREAD rather than MOD_PYTHON_WITH_THREAD?GrishaOn Mon, 12 Sep 2005, Nicolas Lehuen wrote: I've checked in a changeset wherein I define MOD_PYTHON_WITH_THREAD_SUPPORT and use it everywhere WITH_THREAD was previously used. This should do the trick ! Now if someone (like Jim) can give us his +1, that would be great. Regards, Nicolas 2005/9/12, Gregory (Grisha) Trubetskoy [EMAIL PROTECTED]: Just wanted to add to this message that if Jim's version runs and tests with the trick below (envvars is executed prior to apache start, but I don't think the tests use it, so you'll probably just have to set this var in the shell in which the tests are run), then this would be a solution for all FreeBSD issues and we could roll a beta 3 which will have a great change of being publicly released. Grisha On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote: OK, found it. This should work on FreeBSD where Python is threaded and Apache is not. [snip] And, if you built apache without thread support, you may need to add the following lines to $PREFIX/sbin/envvars: LD_PRELOAD=/usr/lib/libc_r.so export LD_PRELOAD [snip] On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote: On Mon, 12 Sep 2005, Jim Gallacher wrote: *** Warning: Linking the shared library mod_python.la against the *** static library /usr/local/lib/python2.4/config/libpython2.4.a is not portable! I think this was always there and its pretty harmless. On qemu: Syntax error on line 44 of /usr/home/jim/tmp/mod_python/test/conf/test.conf: Cannot load /usr/home/jim/tmp/mod_python/src/mod_python.so into server: /usr/home/jim/tmp/mod_python/src/mod_python.so: Undefined symbol pthread_attr_init This is because FreeBSD's libc comes in two versions - threaded and non-threaded. If Python is linked against the threaded ones and Apache against the non-thrreaded, then you get this problem. There is a simple fix for this - you just cause Apache to start with threaded libs, but I can't find any references to it right now and have to run off to a meeting. Grisha It is quite possible I don't have things configured correctly on the QEMU version and hence the different undefined symbol but it doesn't really matter since it fails either way. I don't have time to investigate further right now. I'll revisit this tonight. Regards, Jim Regards, Nicolas #if APR_HAS_THREADS defined(WITH_THREAD) 2005/9/11, Jim Gallacher [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] : FYI, I found the following note in the INSTALL file in the apache source: * If you are building on FreeBSD, be aware that threads will be disabled and the prefork MPM will be used by default, as threads do not work well with Apache on FreeBSD. If you wish to try a threaded Apache on FreeBSD anyway, use ./configure --enable-threads. I'm also setting up FreeBSD under QEMU... so far so good, but installing anything using ports is really slow. QEMU's performance here is just killing me. I guess I should have read the manual first and used the binary packages for the software I wanted to install. :-( Regards, Jim Jim Gallacher wrote: Nicolas Lehuen wrote: OK, I've checked in a version that compiles both on at least Win32 and FreeBSD. I'm just testing if APR_HAS_THREAD is defined and only include the apr_thread_mutex_lock and unlock calls if it is defined. Compiles a passes unit tests on Linux Debian sid with mpm-prefork. Now, on minotaur, APR_HAS_THREAD is defined as 0. Does this mean that Apache is not configured for threading ? Can we assume that we are in the prefork model if APR_HAS_THREAD==0, so that we can skip all the locking code ? Because that's what we do right now. On Debian sid with apache2.0.54 mpm-prefork, APR_HAS_THREAD == 1. Jim Regards, Nicolas 2005/9/11, Nicolas Lehuen [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto: [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]: Yes, this new code is something I commited on the 29/12/2004 (I used the blame function of TortoiseSVN for that). It was a patch by Graham to fix MODPYTHON-2 http://issues.apache.org/jira/browse/MODPYTHON-2 . The problem is not in the patch, but rather in the fact that APR seems configured without the thread support while Python is configured with thread support. mod_python.c assumes that is WITH_THREAD is defined, then the APR mutex functions are available, which is wrong. Maybe we should test for APR_HAS_THREADS instead ? In that case, won't this cause any problems on threaded platforms ? I don't know if this is a problem specific to minotaur or to all version of FreeBSD. I'm
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
I'm not sure I understand this, perhaps someone could write a message to the list explaining what we're doing here so there is a record. Sorry if I'm being slow-headed here. To me it seems that when you use thread-related calls from Python, you wrap those in Python defines (WITH_THREAD) and when you use thread-related calls from APR, you wrap those in APR defines (APR_HAS_THREAD), and that's all? In other words - what does MOD_PYTHON_WITH_THREAD_SUPPORT accomplish that the above does not. Also, given: #if(defined(WITH_THREAD) APR_HAS_THREADS) #define MOD_PYTHON_WITH_THREAD_SUPPORT 1 #else #define MOD_PYTHON_WITH_THREAD_SUPPORT 0 #endif Does this mean that if Python is compiled with thread support and APR is not, MOD_PYTHON_WITH_THREAD_SUPPORT is 0 which means that the thread safety code isn't there, but you still _can_ create threads because Python will let you - isn't this asking for a segfault/deadlock/whatever? Grisha On Mon, 12 Sep 2005, Jim Gallacher wrote: Gregory (Grisha) Trubetskoy wrote: Shouldn't that be PYTHON_WITH_THREAD rather than MOD_PYTHON_WITH_THREAD? I understand it to mean that we want the thread handling code compiled into mod_python. Compiling and testing right now. Jim On Mon, 12 Sep 2005, Nicolas Lehuen wrote: I've checked in a changeset wherein I define MOD_PYTHON_WITH_THREAD_SUPPORT and use it everywhere WITH_THREAD was previously used. This should do the trick ! Now if someone (like Jim) can give us his +1, that would be great. Regards, Nicolas 2005/9/12, Gregory (Grisha) Trubetskoy [EMAIL PROTECTED]: Just wanted to add to this message that if Jim's version runs and tests with the trick below (envvars is executed prior to apache start, but I don't think the tests use it, so you'll probably just have to set this var in the shell in which the tests are run), then this would be a solution for all FreeBSD issues and we could roll a beta 3 which will have a great change of being publicly released. Grisha On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote: OK, found it. This should work on FreeBSD where Python is threaded and Apache is not. [snip] And, if you built apache without thread support, you may need to add the following lines to $PREFIX/sbin/envvars: LD_PRELOAD=/usr/lib/libc_r.so export LD_PRELOAD [snip] On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote: On Mon, 12 Sep 2005, Jim Gallacher wrote: *** Warning: Linking the shared library mod_python.la against the *** static library /usr/local/lib/python2.4/config/libpython2.4.a is not portable! I think this was always there and its pretty harmless. On qemu: Syntax error on line 44 of /usr/home/jim/tmp/mod_python/test/conf/test.conf: Cannot load /usr/home/jim/tmp/mod_python/src/mod_python.so into server: /usr/home/jim/tmp/mod_python/src/mod_python.so: Undefined symbol pthread_attr_init This is because FreeBSD's libc comes in two versions - threaded and non-threaded. If Python is linked against the threaded ones and Apache against the non-thrreaded, then you get this problem. There is a simple fix for this - you just cause Apache to start with threaded libs, but I can't find any references to it right now and have to run off to a meeting. Grisha It is quite possible I don't have things configured correctly on the QEMU version and hence the different undefined symbol but it doesn't really matter since it fails either way. I don't have time to investigate further right now. I'll revisit this tonight. Regards, Jim Regards, Nicolas #if APR_HAS_THREADS defined(WITH_THREAD) 2005/9/11, Jim Gallacher [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]: FYI, I found the following note in the INSTALL file in the apache source: * If you are building on FreeBSD, be aware that threads will be disabled and the prefork MPM will be used by default, as threads do not work well with Apache on FreeBSD. If you wish to try a threaded Apache on FreeBSD anyway, use ./configure --enable-threads. I'm also setting up FreeBSD under QEMU... so far so good, but installing anything using ports is really slow. QEMU's performance here is just killing me. I guess I should have read the manual first and used the binary packages for the software I wanted to install. :-( Regards, Jim Jim Gallacher wrote: Nicolas Lehuen wrote: OK, I've checked in a version that compiles both on at least Win32 and FreeBSD. I'm just testing if APR_HAS_THREAD is defined and only include the apr_thread_mutex_lock and unlock calls if it is defined. Compiles a passes unit tests on Linux Debian sid with mpm-prefork. Now, on minotaur, APR_HAS_THREAD is defined as 0. Does this mean that Apache is not configured for threading ? Can we assume that we are in the prefork model if APR_HAS_THREAD==0, so that we can skip all the locking code ? Because that's what we do right now. On Debian sid with apache2.0.54 mpm-prefork,
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
Duh, this is becoming difficult :) I was thinking that if APR_HAS_THREADS was 0, then Apache was forcibly ran in prefork mode, so there was no need for thread safety at all, given the fact that mod_python would only run one interpreter thread. So if WITH_THREAD was not defined, ORAPR_HAS_THREADS was 0, then we would not need any thread safety code. Hence the definition of MOD_PYTHON_WITH_THREAD_SUPPORT. You're right in writing that a user could launch a new thread in Python, provided that WITH_THREAD is defined, even if APR_HAS_THREADS==0. However, having a look at the parts of mod_python.c where the thread safety was put in, I think we can safely say that those parts are only called by mod_python (through python_handler, python_cleanup etc who call get_interpreter). Those parts are therefore always called in the same thread (if APR_HAS_THREADS==0, that is) and there is no need for thread synchronization to be done (no shared data between the main thread and the other user threads, no need to release the GIL etc.). BUT, I could be very, very wrong here, and your idea of reverting to a conservative shield python threading calls with WITH_THREAD and apr threading code with APR_HAS_THREADS is way more attractive to my tired mind right now. So if you want I can revert all this MOD_PYTHON_WITH_THREAD_SUPPORT hack. Regards, Nicolas2005/9/12, Gregory (Grisha) Trubetskoy [EMAIL PROTECTED]: I'm not sure I understand this, perhaps someone could write a message tothe list explaining what we're doing here so there is a record. Sorry ifI'm being slow-headed here.To me it seems that when you use thread-related calls from Python, you wrap those in Python defines (WITH_THREAD) and when you use thread-relatedcalls from APR, you wrap those in APR defines (APR_HAS_THREAD), and that'sall?In other words - what does MOD_PYTHON_WITH_THREAD_SUPPORT accomplish that the above does not.Also, given:#if(defined(WITH_THREAD) APR_HAS_THREADS) #define MOD_PYTHON_WITH_THREAD_SUPPORT 1#else #define MOD_PYTHON_WITH_THREAD_SUPPORT 0#endif Does this mean that if Python is compiled with thread support and APR isnot, MOD_PYTHON_WITH_THREAD_SUPPORT is 0 which means that the threadsafety code isn't there, but you still _can_ create threads because Python will let you - isn't this asking for a segfault/deadlock/whatever?GrishaOn Mon, 12 Sep 2005, Jim Gallacher wrote: Gregory (Grisha) Trubetskoy wrote: Shouldn't that be PYTHON_WITH_THREAD rather than MOD_PYTHON_WITH_THREAD? I understand it to mean that we want the thread handling code compiled into mod_python. Compiling and testing right now. Jim On Mon, 12 Sep 2005, Nicolas Lehuen wrote: I've checked in a changeset wherein I define MOD_PYTHON_WITH_THREAD_SUPPORT and use it everywhere WITH_THREAD was previously used. This should do the trick ! Now if someone (like Jim) can give us his +1, that would be great. Regards, Nicolas 2005/9/12, Gregory (Grisha) Trubetskoy [EMAIL PROTECTED]: Just wanted to add to this message that if Jim's version runs and tests with the trick below (envvars is executed prior to apache start, but I don't think the tests use it, so you'll probably just have to set this var in the shell in which the tests are run), then this would be a solution for all FreeBSD issues and we could roll a beta 3 which will have a great change of being publicly released. Grisha On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote: OK, found it. This should work on FreeBSD where Python is threaded and Apache is not. [snip] And, if you built apache without thread support, you may need to add the following lines to $PREFIX/sbin/envvars: LD_PRELOAD=/usr/lib/libc_r.so export LD_PRELOAD [snip] On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote: On Mon, 12 Sep 2005, Jim Gallacher wrote: *** Warning: Linking the shared library mod_python.la against the *** static library /usr/local/lib/python2.4/config/libpython2.4.a is not portable! I think this was always there and its pretty harmless. On qemu: Syntax error on line 44 of /usr/home/jim/tmp/mod_python/test/conf/test.conf: Cannot load /usr/home/jim/tmp/mod_python/src/mod_python.so into server: /usr/home/jim/tmp/mod_python/src/mod_python.so: Undefined symbol pthread_attr_init This is because FreeBSD's libc comes in two versions - threaded and non-threaded. If Python is linked against the threaded ones and Apache against the non-thrreaded, then you get this problem. There is a simple fix for this - you just cause Apache to start with threaded libs, but I can't find any references to it right now and have to run off to a meeting. Grisha It is quite possible I don't have things configured correctly on the QEMU version and hence the different undefined symbol but it doesn't really matter since it fails either way. I don't have time to investigate further right now. I'll revisit this tonight. Regards, Jim Regards, Nicolas #if APR_HAS_THREADS defined(WITH_THREAD) 2005/9/11, Jim Gallacher [EMAIL PROTECTED] mailto:[EMAIL
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
-1 for this patch. Actually, the patch itself is fine - it just doesn't
fix the problem. The unit tests are still failings as per my previous
messages. ie the following is getting logged in test/logs/error_log:
[Mon Sep 12 19:49:33 2005] [emerg] (2)No such file or directory:
Couldn't create accept lock
Jim
Gregory (Grisha) Trubetskoy wrote:
Here's a patch (this is against 3.1.2b). Untested. This replaces GIL
with with the APR lock.
--- src/mod_python.c.orig Mon Sep 12 16:42:28 2005
+++ src/mod_python.cMon Sep 12 17:32:26 2005
@@ -31,7 +31,9 @@
* (In a Python dictionary) */
static PyObject * interpreters = NULL;
+#ifdef APR_HAS_THREAD
static apr_thread_mutex_t* interpreters_lock = 0;
+#endif
apr_pool_t *child_init_pool = NULL;
@@ -127,9 +129,8 @@
if (! name)
name = MAIN_INTERPRETER;
-#ifdef WITH_THREAD
+#ifdef APR_HAS_THREAD
apr_thread_mutex_lock(interpreters_lock);
-PyEval_AcquireLock();
#endif
if (!interpreters) {
@@ -156,8 +157,7 @@
idata = (interpreterdata *)PyCObject_AsVoidPtr(p);
}
-#ifdef WITH_THREAD
-PyEval_ReleaseLock();
+#ifdef APR_HAS_THREAD
apr_thread_mutex_unlock(interpreters_lock);
#endif
@@ -513,8 +513,10 @@
/* initialze the interpreter */
Py_Initialize();
-#ifdef WITH_THREAD
+#ifdef APR_HAS_THREAD
apr_thread_mutex_create(interpreters_lock,APR_THREAD_MUTEX_UNNESTED,p);
+#endif
+#ifdef WITH_THREAD
/* create and acquire the interpreter lock */
PyEval_InitThreads();
#endif
On Mon, 12 Sep 2005, Gregory (Grisha) Trubetskoy wrote:
Yep, this is getting a little hairy, but nothing we couldn't handle :-)
I did a little more research. Basically, this started with Graham's
patch that addressed a problem with modules being reimported (or
something). From Graham's message:
The basic problem revolves around the Python dictionary used to hold
the set of interpreters. The code in mod_python.c is trying to use
the Python GIL to provide exclusive access to that dictionary and any
subsequent creation of an interpreter.
The only catch is that in creating a new interpreter, the Python core
is, in someway I don't understand, swapping thread states at some
point which is allowing other threads to acquire the GIL.
So what Graham's patch does is create an APR lock (interpreters_lock)
and wrap all the access to the dictionary with calls to
apr_mutex_lock/unlock.
I think the _real_ way to address this issue is to first find what is
the problem with using the Python GIL to serialize access to the
interpreters dictionary. Is this a Python bug, or are we not
understanding GIL and using it improperly?
BUT, given that the above question may be complicated to answer, and
that Graham's patch resolves the issue, another thought:
If the APR lock works, what is the point of using the GIL in addition?
Should we just use the APR-based lock alone? I.e., where we had (after
Graham's patch):
#ifdef WITH_THREAD
apr_thread_mutex_lock(interpreters_lock);
PyEval_AcquireLock();
#endif
we would use:
#ifdef APR_HAS_THREAD
apr_thread_mutex_lock(interpreters_lock);
#endif
_without_ a call to PyEval_AcquireLock() at all.
It should compile OK, and on platforms where APR has no thread
support, like you said, it's not an issue since no separate
interpreters run in one process at the same time.
Grisha
On Mon, 12 Sep 2005, Nicolas Lehuen wrote:
Duh, this is becoming difficult :)
I was thinking that if APR_HAS_THREADS was 0, then Apache was
forcibly ran
in prefork mode, so there was no need for thread safety at all, given
the
fact that mod_python would only run one interpreter thread. So if
WITH_THREAD was not defined, ORAPR_HAS_THREADS was 0, then we would
not need
any thread safety code. Hence the definition of
MOD_PYTHON_WITH_THREAD_SUPPORT.
You're right in writing that a user could launch a new thread in Python,
provided that WITH_THREAD is defined, even if APR_HAS_THREADS==0.
However,
having a look at the parts of mod_python.c where the thread safety
was put
in, I think we can safely say that those parts are only called by
mod_python
(through python_handler, python_cleanup etc who call
get_interpreter). Those
parts are therefore always called in the same thread (if
APR_HAS_THREADS==0,
that is) and there is no need for thread synchronization to be done (no
shared data between the main thread and the other user threads, no
need to
release the GIL etc.).
BUT, I could be very, very wrong here, and your idea of reverting to a
conservative shield python threading calls with WITH_THREAD and apr
threading code with APR_HAS_THREADS is way more attractive to my
tired mind
right now. So if you want I can revert all this
MOD_PYTHON_WITH_THREAD_SUPPORT hack.
Regards,
Nicolas
2005/9/12, Gregory (Grisha) Trubetskoy [EMAIL PROTECTED]:
I'm not sure I understand this, perhaps someone could write a
message to
the list explaining what
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
Yes, this new code is something I commited on the 29/12/2004 (I used
the blame function of TortoiseSVN for that). It was a patch by Graham
to fix MODPYTHON-2.
The problem is not in the patch, but rather in the fact that APR seems
configured without the thread support while Python is configured with
thread support. mod_python.c assumes that is WITH_THREAD is defined,
then the APR mutex functions are available, which is wrong. Maybe we
should test for APR_HAS_THREADS instead ? In that case, won't this
cause any problems on threaded platforms ?
I don't know if this is a problem specific to minotaur or to all
version of FreeBSD. I'm currently downloading the ISOs of FreeBSD and
I'll try using QEMU to run a FreeBSD setup on my computer, but that
will be long and troublesome. If someone has more clue on this issue,
feel free to tell us :).
Regards,
Nicolas2005/9/10, Jim Gallacher [EMAIL PROTECTED]: I'm stubling around in the dark here, but maybe this will create a spark of an idea. I took a diff of mod_python.c from
3.1.4 and 3.2.1b and isolated the lines which correspond to the compilation error. Compiler messages - mod_python.c:34: error: syntax error before '*' token
mod_python.c:34: warning: type defaults to `int' in declaration of `interpreters_lock' mod_python.c:34: warning: data definition has no type or storage class mod_python.c: In function `get_interpreter':
mod_python.c:131: warning: implicit declaration of function `apr_thread_mutex_lock' mod_python.c:161: warning: implicit declaration of function `apr_thread_mutex_unlock' mod_python.c: In function `python_init':
mod_python.c:517: warning: implicit declaration of function `apr_thread_mutex_create' mod_python.c:517: error: `APR_THREAD_MUTEX_UNNESTED' undeclared (first use in this function)
Diff output --- I've only copied the diff chunks which correspond to the complier errors mentioned above. --- mod_python-3.1.4/src/mod_python.c Sat Jan 29 13:25:28 2005
+++ mod_python-3.2.1b/src/mod_python.cTue Sep6 17:11:03 2005 @@ -31,6 +31,8 @@* (In a Python dictionary) */ static PyObject * interpreters = NULL; +static apr_thread_mutex_t* interpreters_lock = 0;
+ apr_pool_t *child_init_pool = NULL; ... snip ... @@ -124,11 +128,15 @@ name = MAIN_INTERPRETER; #ifdef WITH_THREAD +apr_thread_mutex_lock(interpreters_lock);
PyEval_AcquireLock(); #endif ... snip ... @@ -149,6 +158,7 @@ #ifdef WITH_THREAD PyEval_ReleaseLock(); +apr_thread_mutex_unlock(interpreters_lock);
#endif ... snip ... @@ -490,13 +506,15 @@ } /* initialize global Python interpreter if necessary */ -if (! Py_IsInitialized())
+if (initialized == 0 || !Py_IsInitialized()) { - +initialized = 1; + /* initialze the interpreter */ Py_Initialize();
#ifdef WITH_THREAD + apr_thread_mutex_create(interpreters_lock,APR_THREAD_MUTEX_UNNESTED,p); /* create and acquire the interpreter lock */ PyEval_InitThreads();
#endif So it would seem that the code causing the compile problems is new for 3.2. I also notice that in apr_arch_thread_mutex.h the typedef for apr_thread_mutex_t is wrapped by #if APR_HAS_THREADS / #endif.
Looking at the apache source in srclib/apr/locks/unix/thread_mutex.c, everything is also enclosed by #if APR_HAS_THREADS / #endif. eg, apr_thread_mutex_create, apr_thread_mutex_lock and
apr_thread_mutex_unlock. Hopefully this will give someone a clue as to what may be going on here with FreeBSD. Regards, Jim
Re: FreeBSD compile problem (was Getting ready for 3.2 beta 2)
FYI, I found the following note in the INSTALL file in the apache source:
* If you are building on FreeBSD, be aware that threads will
be disabled and the prefork MPM will be used by default,
as threads do not work well with Apache on FreeBSD. If
you wish to try a threaded Apache on FreeBSD anyway, use
./configure --enable-threads.
I'm also setting up FreeBSD under QEMU... so far so good, but installing
anything using ports is really slow. QEMU's performance here is just
killing me. I guess I should have read the manual first and used the
binary packages for the software I wanted to install. :-(
Regards,
Jim
Jim Gallacher wrote:
Nicolas Lehuen wrote:
OK, I've checked in a version that compiles both on at least Win32 and
FreeBSD. I'm just testing if APR_HAS_THREAD is defined and only
include the apr_thread_mutex_lock and unlock calls if it is defined.
Compiles a passes unit tests on Linux Debian sid with mpm-prefork.
Now, on minotaur, APR_HAS_THREAD is defined as 0. Does this mean that
Apache is not configured for threading ? Can we assume that we are in
the prefork model if APR_HAS_THREAD==0, so that we can skip all the
locking code ? Because that's what we do right now.
On Debian sid with apache2.0.54 mpm-prefork, APR_HAS_THREAD == 1.
Jim
Regards,
Nicolas
2005/9/11, Nicolas Lehuen [EMAIL PROTECTED]
mailto:[EMAIL PROTECTED]:
Yes, this new code is something I commited on the 29/12/2004 (I used
the blame function of TortoiseSVN for that). It was a patch by
Graham to fix MODPYTHON-2
http://issues.apache.org/jira/browse/MODPYTHON-2.
The problem is not in the patch, but rather in the fact that APR
seems configured without the thread support while Python is
configured with thread support. mod_python.c assumes that is
WITH_THREAD is defined, then the APR mutex functions are available,
which is wrong. Maybe we should test for APR_HAS_THREADS instead ?
In that case, won't this cause any problems on threaded platforms ?
I don't know if this is a problem specific to minotaur or to all
version of FreeBSD. I'm currently downloading the ISOs of FreeBSD
and I'll try using QEMU to run a FreeBSD setup on my computer, but
that will be long and troublesome. If someone has more clue on this
issue, feel free to tell us :).
Regards,
Nicolas
2005/9/10, Jim Gallacher [EMAIL PROTECTED]
mailto:[EMAIL PROTECTED]:
I'm stubling around in the dark here, but maybe this will create a
spark
of an idea. I took a diff of mod_python.c from 3.1.4 and 3.2.1b and
isolated the lines which correspond to the compilation error.
Compiler messages
-
mod_python.c:34: error: syntax error before '*' token
mod_python.c:34: warning: type defaults to `int' in declaration of
`interpreters_lock'
mod_python.c:34: warning: data definition has no type or storage class
mod_python.c: In function `get_interpreter':
mod_python.c:131: warning: implicit declaration of function
`apr_thread_mutex_lock'
mod_python.c:161: warning: implicit declaration of function
`apr_thread_mutex_unlock'
mod_python.c: In function `python_init':
mod_python.c:517: warning: implicit declaration of function
`apr_thread_mutex_create'
mod_python.c:517: error: `APR_THREAD_MUTEX_UNNESTED' undeclared (first
use in this function)
Diff output
---
I've only copied the diff chunks which correspond to the complier
errors
mentioned above.
--- mod_python-3.1.4/src/mod_python.c Sat Jan 29 13:25:28 2005
+++ mod_python-3.2.1b/src/mod_python.c Tue Sep 6 17:11:03 2005
@@ -31,6 +31,8 @@
* (In a Python dictionary) */
static PyObject * interpreters = NULL;
+static apr_thread_mutex_t* interpreters_lock = 0;
+
apr_pool_t *child_init_pool = NULL;
... snip ...
@@ -124,11 +128,15 @@
name = MAIN_INTERPRETER;
#ifdef WITH_THREAD
+apr_thread_mutex_lock(interpreters_lock);
PyEval_AcquireLock();
#endif
... snip ...
@@ -149,6 +158,7 @@
#ifdef WITH_THREAD
PyEval_ReleaseLock();
+apr_thread_mutex_unlock(interpreters_lock);
#endif
... snip ...
@@ -490,13 +506,15 @@
}
/* initialize global Python interpreter if necessary */
-if (! Py_IsInitialized())
+if (initialized == 0 || !Py_IsInitialized())
{
-
+initialized = 1;
+
/* initialze the interpreter */
Py_Initialize();
#ifdef WITH_THREAD
+
apr_thread_mutex_create(interpreters_lock,APR_THREAD_MUTEX_UNNESTED,p);
/* create and acquire the interpreter lock */
PyEval_InitThreads();
#endif
So it would seem that the code causing the compile problems is new
for 3.2.
I also notice that in apr_arch_thread_mutex.h the typedef for
apr_thread_mutex_t is wrapped by #if APR_HAS_THREADS / #endif.
Looking at the apache source in srclib/apr/locks/unix/thread_mutex.c,
everything is also enclosed by #if APR_HAS_THREADS /
