Hello,
I ran into an interesting problem today. It doesn't seem like Cython
respects the `nogil` statement on extern cpp functions. I am trying to use
a blocking I/O function, and am running it in secondary thread so I can use
another library function to cancel it.
I have tried it both on the `extern` line:
cdef extern from "digitalpersona/dpfp_api.h" nogil:
uint32_t DPFPGetEvent(dp_uid_t* pDevUID, dp_device_event_t**
ppEvent, uint32_t uTimeoutMsec)
and on the function itself:
cdef extern from "digitalpersona/dpfp_api.h" nogil:
uint32_t DPFPGetEvent(dp_uid_t* pDevUID, dp_device_event_t**
ppEvent, uint32_t uTimeoutMsec) nogil
Either way, this statement still blocks other threads:
res = dpfp_api.DPFPGetEvent(pIdDev, &pEvent,
dpfp_api.DP_TIMEOUT_INFINITE)
While this statement does not:
with nogil:
res = dpfp_api.DPFPGetEvent(pIdDev, &pEvent,
dpfp_api.DP_TIMEOUT_INFINITE)
All variables used (res, pIdDev, pEvent) are C variables.
Obviously this is not a huge issue, as I can bypass the GIL using `with
nogil`. But I figured it would be a good idea to report it anyway.
Ryan Pessa
AerisPOS Project Manager / Developer
Essential Elements <http://www.essential-elements.net/> |
AerisPOS<http://www.aerispos.com/>
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