Questions tagged [c-api]
154 questions
2
votes
2 answers
Cannot connect to postgreSQL server using libpq
I'm a complete novice trying to learn PostgreSQL. I'm trying to connect to my postgres server throught a C program using libpq.
Here is the server status:
home/planb/postgresql-9.2.4/Project status -o "-p 5555"
pg_ctl: server is running (PID:…
kensw
- 33
- 1
- 6
2
votes
0 answers
Python C_API: how to define nested classes?
I'm currently writing a C extension module for python using the "raw" C-API. I would like to be able to define "nested classes" like in the following python code
class A:
class B:
def __init__(self):
self.i = 2
def…
Serge Weinstock
- 1,235
- 3
- 12
- 20
2
votes
2 answers
Why is PyObject_Print crashing?
I've been playing with the Python 3.3 C-API to see if I could possibly use it in a planned upcoming project, and almost immediately ran into problems.
Even code this simple crashes with 0xc0000005 as the return:
#include
#include…
Conscious Code
- 53
- 2
- 8
2
votes
1 answer
Berkeley DB: stuck at futex_wait because of previous abnormal quit during c api call
I'm programming in C, using berkeley db 4.3 (/usr/lib64/libdb-4.3.so) on RHEL5.6 with kernel 2.6.18-238_xen_AMD64.
In my tests (writing 1,000,000 key/value pairs), if one process quitted abnormally (ctrl + c, kill, or assert fails) while an…
felix021
- 1,936
- 3
- 16
- 20
1
vote
2 answers
Get a File Pointer from a Tcl_Channel using the Tcl C API
I want to operate on a file from C using the tcl C API.
From within tcl, this is what I would do:
% set file [open "my_file"]
file3
% myfunc::load $file
where myfunc::load is from a C extension:
#include
#include
#include…
Lukas
- 13
- 3
1
vote
0 answers
How to free ruby object allocated through rb_marshal_load through C api?
I have this code which takes bytes from stdin and then tries to unmarshal (basically deserialize) that data through the rubys c api rb_marshal_load function:
#include
#include "ruby/re.h"
#define MAX_INPUT_SIZE 120
VALUE…
1
vote
1 answer
C API: Error allocating / deallocating memory for array
I'm in the process of implementing an API for C. The code base itself is purely written in C++ and I only plan to offer said interface for any consumer using C. The interface is defined in a .h file, whereas the implementation itself is written in…
Xershy
- 177
- 11
1
vote
2 answers
Sharing Python multiprocessing shared Value with C extension
I have two processes in python that share a single boolean flag:
from multiprocessing import Process, Value
class MyProcess(Process):
def __init__(self):
self.flag = Value('B',false)
# [...]
def run(self):
while…
Buzz
- 1,102
- 1
- 9
- 24
1
vote
1 answer
C-API register a ufunc loop against builtin ufunc
I am looking to build a numpy extension module which declares a new structured dtype and provides the necessary inner ufunc loops to allow built-in math operations to be performed on it.
Following the guide on creating your own ufunc, I have been…
garryod
- 21
- 3
1
vote
0 answers
Python C API - catch call to non-existent function
I need to do some processing in the C backend during runtime. So what I want to do is,
to define a C callback that'd get called each time there's a call to a non-existent python function.
For example:
// C code
PyObject* callback_func(PyObject*…
Insane
- 31
- 4
1
vote
1 answer
How do I read OpenVINO IR models from memory with the OpenVINO C API
I am having trouble reading OpenVINO IR networks (XML and bin) from memory using ie_core_read_network_from_memory() in the OpenVINO 2021.4 C API ie_c_api.h.
I suspect that I am creating the network weight blob wrong, but I cannot find any…
mags
- 489
- 2
- 11
1
vote
1 answer
Running several tests with single initialization/destruction of objects to test
TL;DR: is it possible with pytest to create an instance of an object and then run a battery of tests on the same instance ?
I have a custom C API, that uses posix threads and does operations on serial ports. My API is an implementation of a…
ZimLeTux
- 13
- 2
1
vote
1 answer
Tensorflow c_api decision forest savedModel loaded but status is not TF_OK
I am using tensorflow decision forests. I trained my model using Python and saved the model with SavedModel format. Then for inference I am trying to load the model in C using tensorflow C_API. I found that for this task I need to load the decision…
hpirlo
- 133
- 1
- 12
1
vote
0 answers
Returning an error instead of raising it from python C API
Whether or not it is a good idea (and it probably is considered bad practice), I sometimes return an Error in python instead of raising it.
def fnA( some_param ):
# use some_param in complicated thing
if some_param is None:
return…
ghlecl
- 3,127
- 1
- 16
- 15
1
vote
1 answer
why does python import causes an error with PyImport_ImportModule but not with python interpreter
I have a python module mymodule that contains an import psutil statement. I can run it using python interpreter without any errors.
However, I fail to load it with
PyImport_ImportModule("mymodule") (from python C API), due to an undefined symbol in…
jsofri
- 227
- 1
- 10