Julia wrapper for the CUDA driver API.


Build status (Linux x86-64):

Julia 0.5 Julia 0.6
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This package wraps the CUDA driver API. It is meant for users who need low-level access to the CUDA toolkit or the underlying GPU. For a wrapper of the higher-level runtime API, see CUDArt.



  • Julia 0.5 or higher (use v0.1.0 of this package for compatibility with Julia 0.4)
  • NVIDIA driver, providing (the full CUDA toolkit is not necessary)
  • CUDA hardware


In general, this wrapper tries to stay close to the abstraction level of the CUDA driver API. However, there are some additional features:

Automatic memory management

Except for the encapsulating context, destroy or unload calls are never needed. Objects are registered with the Julia garbage collector, and are automatically finalized when they go out of scope.

However, many CUDA API functions implicitly depend on global state, such as the current active context. The wrapper needs to model those dependencies in order for objects not to get destroyed before any dependent object is. If we fail to model these dependency relations, API calls might randomly fail, eg. in the case of a missing context dependency with a INVALID_CONTEXT or CONTEXT_IS_DESTROYED error message.

If this seems to be the case, re-run with TRACE=1 and file a bug report.


You can enable verbose logging using two environment variables:

  • DEBUG: if set, enable additional (possibly costly) run-time checks, and some more verbose output
  • TRACE: if set, the DEBUG level will be activated, in addition with a trace of every call to the underlying library

In order to avoid run-time cost for checking the log level, these flags are implemented by means of global constants. As a result, you need to run Julia with precompilation disabled if you want to modify these flags:

$ TRACE=1 julia --compilecache=no examples/vadd.jl
TRACE: CUDAdrv.jl is running in trace mode, this will generate a lot of additional output

Enabling colors with --color=yes is also recommended as it color-codes the output.

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