Fix reproject with threads + add Windows and Mac CI (#292)

* Run CI on mac and windows on julia v1 at least

this way we don't get hammered

* Use proj_context_destroy not proj_destroy

That was causing the segfault it seems.

* Clean up the code and remove allocations from broadcasting

TODO: is it "safe" to use ntuple here?  is nthreads a compile time constant?  Not sure, we can leave that for later, but this is a nice note

* add arch on Win

Author: asinghvi17

.github/workflows/CI.yml

@@ -25,6 +25,13 @@ jobs:
           - ubuntu-latest
         arch:
           - x64
+        include:
+          - os: windows-latest
+            version: '1'
+            arch: x64
+          - os: macos-latest
+            version: '1'
+            arch: arm64
     steps:
       - uses: actions/checkout@v2
       - uses: julia-actions/cache@v1

ext/GeometryOpsProjExt/reproject.jl

@@ -52,12 +52,16 @@ function reproject(geom, transform::Proj.Transformation;
     if istrue(threaded)
         tasks_per_thread = 2
         ntasks = Threads.nthreads() * tasks_per_thread
+        # Clone the transformation once for each task.  
+        # Currently, these transformations live in the same context, but we will soon
+        # assign them to per-task contexts.
+        proj_transforms = [Proj.Transformation(Proj.proj_clone(transform.pj)) for _ in 1:ntasks]
+
         # Construct one context per planned task
         contexts = [Proj.proj_context_clone(context) for _ in 1:ntasks]
-        # Clone the transformation for each context
-        proj_transforms = [Proj.Transformation(Proj.proj_clone(transform.pj)) for context in contexts]
-        # Assign the context to the transformation
-        Proj.proj_assign_context.(getproperty.(proj_transforms, :pj), contexts)
+        # Assign the context to the transformation.  We use `foreach` here 
+        # to avoid generating output where we don't have to.
+        foreach(Proj.proj_assign_context, getproperty.(proj_transforms, :pj), contexts)
 
         results = if _is3d(geom)
             functors = TaskFunctors(WithXYZ.(proj_transforms))
@@ -67,7 +71,7 @@ function reproject(geom, transform::Proj.Transformation;
             apply(functors, GI.PointTrait(), geom; kw1...)
         end
         # Destroy the temporary threading contexts that we created
-        Proj.proj_destroy.(contexts)
+        foreach(Proj.proj_context_destroy, contexts)
         # Return the results
         return results
     else