NVIDIA's OpenCL driver is not thread-safe

[t11]

I use diplay driver 195.62 at gtx260.
The program was hang with exception error, when clEnqueueWriteImage was accessed from multi threads with the same sommand_queue at the same time.(of course, different cl_mem object)

OpenCL specification says
“OpenCL API calls that are thread-safe allow an application to call these functions in multiple host threads without having to implement mutual exclusion across these host threads.”

Is it driver’s bug??

[jcornwall]

The important word there is that in “OpenCL API calls that are thread-safe”. It does not define which calls are thread-safe.

From A.2:

The OpenCL implementation is thread-safe for API calls that create, retain and release objects

such as a context, command-queue, program, kernel and memory objects. OpenCL API calls

that queue commands to a command-queue or change the state of OpenCL objects such as

command-queue objects, memory objects, program and kernel objects are not thread-safe.

[t11]

jcornwall, thanks for your reply.

The important word there is that in “OpenCL API calls that are thread-safe”. It does not define which calls are thread-safe.

From A.2:

woops… my poor english reading skill…

clEnqueueNDRangeKernel is not asynchronous function (is asynchronous in the future??), so I just think multi thread execution.

thanks a lot.