Calling open_resource with a hislip address when the instrument is not available causes hang (works ok using Keysight backend)
DareDevilDenis opened this issue · comments
The code below attempts to connect to a non-existent hislip instrument "hislip999" on the local machine. The call to 'open_resource' hangs.
To Reproduce
import pyvisa
rm = pyvisa.ResourceManager("@py") # If I remove "@py" then it works i.e. the connection attempt immediately fails
my_instrument = rm.open_resource("TCPIP0::127.0.0.1::hislip999::INSTR")If I remove "@py" so that it uses my installation of Keysight IVI backend then it works as expected - we get immediate exception pyvisa.errors.VisaIOError: VI_ERROR_RSRC_NFOUND (-1073807343): Insufficient location information or the requested device or resource is not present in the system
Output of pyvisa-info
Machine Details:
Platform ID: Windows-10-10.0.19045-SP0
Processor: Intel64 Family 6 Model 141 Stepping 1, GenuineIntel
Python:
Implementation: CPython
Executable: C:\Program Files\Python312\python.exe
Version: 3.12.0
Compiler: MSC v.1935 64 bit (AMD64)
Architecture: AMD64
Build: Oct 2 2023 13:03:39 (#tags/v3.12.0:0fb18b0)
Unicode: UCS4
PyVISA Version: 1.14.1
Backends:
ivi:
Version: 1.14.1 (bundled with PyVISA)
#1: C:\Windows\system32\visa32.dll:
found by: auto
architecture:
('x86', 64)
Vendor: Keysight Technologies
Impl. Version: 1377199637
Spec. Version: 5244928
#2: C:\Windows\system32\visa64.dll:
found by: auto
architecture:
('x86', 64)
Vendor: Keysight Technologies
Impl. Version: 1377199637
Spec. Version: 5244928
py:
Version: 0.7.2
TCPIP INSTR: Available
Resource discovery:
- VXI-11: partial (psutil not installed)
- hislip: disabled (zeroconf not installed)
TCPIP SOCKET: Available
ASRL INSTR:
Please install PySerial (>=3.0) to use this resource type.
No module named 'serial'
USB INSTR:
Please install PyUSB to use this resource type.
No module named 'usb'
USB RAW:
Please install PyUSB to use this resource type.
No module named 'usb'
VICP INSTR:
Please install PyVICP to use this resource type.
GPIB INSTR:
Please install linux-gpib (Linux) or gpib-ctypes (Windows, Linux) to use this resource type. Note that installing gpib-ctypes will give you access to a broader range of functionalities.
No module named 'gpib'
GPIB INTFC:
Please install linux-gpib (Linux) or gpib-ctypes (Windows, Linux) to use this resource type. Note that installing gpib-ctypes will give you access to a broader range of functionalities.
No module named 'gpib'
Indeed hslip currently ignore the open_timeout. Please have a look at #430
Hi @MatthieuDartiailh
I don't have enough knowledge of pyvisa-py to be able to review your PR however I tried your fix by installing it as follows:
pip install git+https://github.com/pyvisa/pyvisa-py@hislip-connect-timeout
I repeated the above test, trying to connect to a non-existent hislip instrument ("hislip999") and it threw the following exception:
Traceback (most recent call last):
File "C:\temp\test_timeout.py", line 4, in <module>
my_instrument = rm.open_resource("TCPIP0::127.0.0.1::hislip999::INSTR")
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Program Files\Python312\Lib\site-packages\pyvisa\highlevel.py", line 3292, in open_resource
res.open(access_mode, open_timeout)
File "C:\Program Files\Python312\Lib\site-packages\pyvisa\resources\resource.py", line 281, in open
self.session, status = self._resource_manager.open_bare_resource(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Program Files\Python312\Lib\site-packages\pyvisa\highlevel.py", line 3217, in open_bare_resource
return self.visalib.open(self.session, resource_name, access_mode, open_timeout)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Program Files\Python312\Lib\site-packages\pyvisa_py\highlevel.py", line 168, in open
sess = cls(session, resource_name, parsed, open_timeout)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Program Files\Python312\Lib\site-packages\pyvisa_py\tcpip.py", line 86, in __new__
return newcls(resource_manager_session, resource_name, parsed, open_timeout)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Program Files\Python312\Lib\site-packages\pyvisa_py\sessions.py", line 322, in __init__
self.after_parsing()
File "C:\Program Files\Python312\Lib\site-packages\pyvisa_py\tcpip.py", line 138, in after_parsing
self.interface = hislip.Instrument(
^^^^^^^^^^^^^^^^^^
File "C:\Program Files\Python312\Lib\site-packages\pyvisa_py\protocols\hislip.py", line 386, in __init__
self._sync.connect((ip_addr, port))
BlockingIOError: [WinError 10035] A non-blocking socket operation could not be completed immediately
I initially thought that this was the expected result however when I repeated the test with an available instrument it threw the same exception.
Hi @MatthieuDartiailh, did I run it correctly?
Sorry I have been quite busy lately with little time for OSS. I will try to look into it this week.