re-add interrupts as option

examples/interruptions.m

@@ -1,15 +1,9 @@
-function interruption_test()
+function interruptions()
 
-jleval println("Hit Ctrl-C to stop me!")
-
-% this one causes crashes (sometimes?)
-jleval 'global x = 0; while(true); global x += 1; if x%10000 == 0; println(x); end; yield(); end'
-
-% this one doesn't cause any problems
+% this one requires the ENABLE_INTERRUPTS flag to be set to `true`
 % jleval 'global x = 0; while(true); global x += 1; yield(); end'
 
 % this one isn't interruptable, as it never yields
 % jleval 'global x = 0; while(true); global x += 1; end'
 
-
 end

src/Mex.jl

@@ -15,6 +15,9 @@ const mex_call_matlab_with_trap = Ref{Ptr{Cvoid}}()
 const libut = Ref{Ptr{Cvoid}}()
 const ut_is_interrupt_pending = Ref{Ptr{Cvoid}}()
 
+# Flag for turning on/off interrupts
+const ENABLE_INTERRUPTS = false
+
 function __init__()
 
     result = Libdl.dlopen(joinpath(MATLAB.matlab_libpath, "libmex"), Libdl.RTLD_GLOBAL; throw_error=false)

src/exceptions.jl

@@ -1,3 +1,13 @@
+# --- Interrupt Handling --- #
+
+is_interrupt_pending() = ccall(ut_is_interrupt_pending[], Cuchar, ()) != 0
+
+function check_for_interrupt()
+    if is_interrupt_pending()
+        throw(InterruptException())
+    end
+end
+
 # --- Exception Handling --- #
 
 # MatlabException is basically identical to MxArray, but is an exception

src/matlabtojulia.jl

@@ -1,8 +1,40 @@
 # --- Calling Embedded Julia from MATLAB --- #
 
+const catching_interrupts = Ref(false)
+
 # entry point for MATLAB calling Julia
-jl_mex(plhs::Vector{Ptr{Cvoid}}, prhs::Vector{Ptr{Cvoid}}) = jl_mex_inner(plhs, prhs)
+function jl_mex(plhs::Vector{Ptr{Cvoid}}, prhs::Vector{Ptr{Cvoid}})
+    if ENABLE_INTERRUPTS && !catching_interrupts[]
+        try 
+            catching_interrupts[] = true
+            jl_mex_outer(plhs, prhs)
+        finally
+            catching_interrupts[] = false
+        end
+    else
+        jl_mex_inner(plhs, prhs)
+    end
+end
+
+# enables interrupt processing
+function jl_mex_outer(plhs::Vector{Ptr{Cvoid}}, prhs::Vector{Ptr{Cvoid}})
+    # do the desired computation
+    main_task = @async jl_mex_inner(plhs, prhs)
 
+    # check for interrupt
+    interrupt_handler = @async begin
+        while !Base.istaskdone(main_task)
+            if is_interrupt_pending()
+                Base.throwto(main_task, InterruptException())
+            end
+            yield()
+        end
+    end
+
+    # wait for main task to finish
+    wait(main_task)
+end
+
 # runs julia function with mex function inputs, catching errors if they occur
 function jl_mex_inner(plhs::Vector{Ptr{Cvoid}}, prhs::Vector{Ptr{Cvoid}})