adds input hook for julia event loop

Author: Christopher Doris

pysrc/juliacall/__init__.py

@@ -21,6 +21,13 @@ def convert(T, x):
         _convert = PythonCall.seval("pyjlcallback((T,x)->pyjl(pyconvert(pyjlvalue(T)::Type,x)))")
     return _convert(T, x)
 
+def interactive(enable=True):
+    "Allow the Julia event loop to run in the background of the Python REPL."
+    if enable:
+        PythonCall._set_python_input_hook()
+    else:
+        PythonCall._unset_python_input_hook()
+
 class JuliaError(Exception):
     "An error arising in Julia code."
     def __init__(self, exception, backtrace=None):

src/compat/gui.jl

@@ -165,3 +165,30 @@ function event_loop_on(g::Symbol; interval::Real = 0.04, fix::Bool = false)
     callback = new_event_loop_callback(string(g), Float64(interval))
     EVENT_LOOPS[g] = Timer(t -> callback(), 0; interval = interval)
 end
+
+function _python_input_hook()
+    try
+        while true
+            yield()
+            @static if Sys.iswindows()
+                if ccall(:_kbhit, Cint, ()) != 0
+                    break
+                end
+            end
+            sleep(0.001)
+        end
+    catch
+        return Cint(1)
+    end
+    return Cint(0)
+end
+
+function _set_python_input_hook()
+    C.PyOS_SetInputHook(@cfunction(_python_input_hook, Cint, ()))
+    return
+end
+
+function _unset_python_input_hook()
+    C.PyOS_SetInputHook(C_NULL)
+    return
+end

src/cpython/extras.jl

@@ -41,8 +41,17 @@ PyBuffer_Release(_b) = begin
     return
 end
 
+function PyOS_SetInputHook(hook::Ptr{Cvoid})
+    Base.unsafe_store!(POINTERS.PyOS_InputHookPtr, hook)
+    return
+end
+
+function PyOS_GetInputHook()
+    return Base.unsafe_load(POINTERS.PyOS_InputHookPtr)
+end
+
 function PyOS_RunInputHook()
-    hook = Base.unsafe_load(Ptr{Ptr{Cvoid}}(dlsym(CTX.lib_ptr, :PyOS_InputHook)))
+    hook = PyOS_GetInputHook()
     if hook == C_NULL
         return false
     else

src/cpython/pointers.jl

@@ -273,6 +273,7 @@ const CAPI_OBJECTS = Set([
     $([:($name :: Ptr{Cvoid} = C_NULL) for name in CAPI_FUNCS]...)
     $([:($name :: PyPtr = C_NULL) for name in CAPI_EXCEPTIONS]...)
     $([:($name :: PyPtr = C_NULL) for name in CAPI_OBJECTS]...)
+    PyOS_InputHookPtr :: Ptr{Ptr{Cvoid}} = C_NULL
     PyJuliaBase_Type :: PyPtr = C_NULL
     PyExc_JuliaError :: PyPtr = C_NULL
 end
@@ -290,6 +291,7 @@ const POINTERS = CAPIPointers()
     ]...)
     $([:(p.$name = Base.unsafe_load(Ptr{PyPtr}(dlsym(lib, $(QuoteNode(name)))))) for name in CAPI_EXCEPTIONS]...)
     $([:(p.$name = dlsym(lib, $(QuoteNode(name)))) for name in CAPI_OBJECTS]...)
+    p.PyOS_InputHookPtr = dlsym(CTX.lib_ptr, :PyOS_InputHook)
 end
 
 for (name, (argtypes, rettype)) in CAPI_FUNC_SIGS