Fix incompatibility of callback notify func with precompilation

src/RobotOS.jl

@@ -14,6 +14,7 @@ function __init__()
     copy!(_py_sys, pyimport("sys"))
     _py_sys["argv"] = ARGS
 
+    #Fill in empty PyObjects
     if ! (dirname(@__FILE__) in _py_sys["path"])
         unshift!(_py_sys["path"], dirname(@__FILE__))
     end
@@ -29,6 +30,9 @@ function __init__()
             rethrow(ex)
         end
     end
+
+    #Compile the callback notify function, see callbacks.jl
+    CB_NOTIFY_PTR[] = cfunction(_callback_notify, Cint, Tuple{Ptr{Void}})
 end
 
 include("debug.jl")

src/callbacks.jl

@@ -4,7 +4,9 @@ function _callback_notify(handle::Ptr{Void})
     ccall(:uv_async_send, Cint, (Ptr{Void},), handle)
 end
 
-const CB_NOTIFY_PTR = cfunction(_callback_notify, Cint, Tuple{Ptr{Void}})
+#The pointer to the compiled notify function. This can't be precompiled so it gets initialized in
+#the module __init__ function.
+const CB_NOTIFY_PTR = Ref{Ptr{Void}}()
 
 function _callback_async_loop(rosobj, cond)
     @debug("Spinning up callback loop...")

src/pubsub.jl

@@ -52,7 +52,7 @@ mutable struct Subscriber{MsgType<:AbstractMsg}
         rospycls = _get_rospy_class(MT)
 
         cond = Base.AsyncCondition()
-        mqueue = _py_ros_callbacks["MessageQueue"](CB_NOTIFY_PTR, cond.handle)
+        mqueue = _py_ros_callbacks["MessageQueue"](CB_NOTIFY_PTR[], cond.handle)
         subobj = __rospy__[:Subscriber](ascii(topic), rospycls, mqueue["storemsg"]; kwargs...)
 
         rosobj = new{MT}(cb, cb_args, subobj, mqueue)

src/services.jl

@@ -51,7 +51,7 @@ mutable struct Service{SrvType <: AbstractService}
         rospycls = _get_rospy_class(ST)
 
         cond = Base.AsyncCondition()
-        pysrv = _py_ros_callbacks["ServiceCallback"](CB_NOTIFY_PTR, cond.handle)
+        pysrv = _py_ros_callbacks["ServiceCallback"](CB_NOTIFY_PTR[], cond.handle)
 
         srvobj = try
             __rospy__[:Service](ascii(name), rospycls, pysrv["srv_cb"]; kwargs...)