SharedArray{T}(dims::NTuple; init=false, pids=Int[])SharedArray{T,N}(...)

Construct aSharedArray of a bits typeT and sizedims across the processes specified bypids - all of which have to be on the same host. IfN is specified by callingSharedArray{T,N}(dims), thenN must match the length ofdims.

Ifpids is left unspecified, the shared array will be mapped across all processes on the current host, including the master. But,localindices andindexpids will only refer to worker processes. This facilitates work distribution code to use workers for actual computation with the master process acting as a driver.

If aninit function of the typeinitfn(S::SharedArray) is specified, it is called on all the participating workers.

The shared array is valid as long as a reference to theSharedArray object exists on the node which created the mapping.

SharedArray{T}(filename::AbstractString, dims::NTuple, [offset=0]; mode=nothing, init=false, pids=Int[])SharedArray{T,N}(...)

Construct aSharedArray backed by the filefilename, with element typeT (must be a bits type) and sizedims, across the processes specified bypids - all of which have to be on the same host. This file is mmapped into the host memory, with the following consequences:

• The array data must be represented in binary format (e.g., an ASCII format like CSV cannot be supported)

• Any changes you make to the array values (e.g.,A[3] = 0) will also change the values on disk

Ifpids is left unspecified, the shared array will be mapped across all processes on the current host, including the master. But,localindices andindexpids will only refer to worker processes. This facilitates work distribution code to use workers for actual computation with the master process acting as a driver.

mode must be one of"r","r+","w+", or"a+", and defaults to"r+" if the file specified byfilename already exists, or"w+" if not. If aninit function of the typeinitfn(S::SharedArray) is specified, it is called on all the participating workers. You cannot specify aninit function if the file is not writable.

offset allows you to skip the specified number of bytes at the beginning of the file.

SharedVector

A one-dimensionalSharedArray.

SharedMatrix

A two-dimensionalSharedArray.

procs(S::SharedArray)

Get the vector of processes mapping the shared array.

sdata(S::SharedArray)

Return the actualArray object backingS.

indexpids(S::SharedArray)

Return the current worker's index in the list of workers mapping theSharedArray (i.e. in the same list returned byprocs(S)), or 0 if theSharedArray is not mapped locally.

localindices(S::SharedArray)

Return a range describing the "default" indices to be handled by the current process. This range should be interpreted in the sense of linear indexing, i.e., as a sub-range of1:length(S). In multi-process contexts, returns an empty range in the parent process (or any process for whichindexpids returns 0).

It's worth emphasizing thatlocalindices exists purely as a convenience, and you can partition work on the array among workers any way you wish. For aSharedArray, all indices should be equally fast for each worker process.