Merge pull request #103 from JuliaLang/kms/timer-compat

RFC: Added compat bindings for new Timer code in v0.4

README.md

@@ -46,6 +46,8 @@ Currently, the `@compat` macro supports the following syntaxes:
 
 * `@compat chol(A, Val{:U})` - Julia 0.4 type-stable cholesky factorizations (will not be type-stable on 0.3)
 
+* `@compat f(t::Timer)` - mimic the Julia 0.4 Timer class
+
 ## Type Aliases
 
 * `typealias AbstractString String` - `String` has been renamed to `AbstractString` [#8872](https://github.com/JuliaLang/julia/pull/8872)
@@ -69,6 +71,8 @@ Currently, the `@compat` macro supports the following syntaxes:
 
 * `fma(x,y,z)` and `muladd(x,y,z)` can be used in Julia 0.3 for `x*y+z`.
 
+* `Timer(timeout::Real, repeat::Real=0.0)` and `Timer(cb::Function, timeout::Real, repeat::Real=0.0)` allow julia 0.4-style Timers to be constructed and used.
+
 ## Renamed functions
 
 * `itrunc`, `iround`, `iceil`, `ifloor` are now accessed via `trunc(T, x)`, etc. [#9133](https://github.com/JuliaLang/julia/pull/9133)

src/Compat.jl

@@ -301,6 +301,11 @@ function _compat(ex::Expr)
                 ex = Expr(:stagedfunction, f.args...)
             end
         end
+    elseif VERSION < v"0.4.0-dev+5322" && ex.head == :(::) && isa(ex.args[end], Symbol)
+        # Replace Base.Timer with Compat.Timer2 in type declarations
+        if ex.args[end] == :Timer || ex.args[end] == :(Base.Timer)
+            ex.args[end] = :(Compat.Timer2)
+        end
     end
     return Expr(ex.head, map(_compat, ex.args)...)
 end
@@ -450,4 +455,8 @@ if VERSION < v"0.4.0-dev+4939"
     export isvalid
 end
 
+if VERSION < v"0.4.0-dev+5322"
+    include("timer.jl")
+end
+
 end # module

src/timer.jl

@@ -0,0 +1,79 @@
+# This file is a part of Julia. License is MIT: http://julialang.org/license
+
+##########################################
+# Timer2
+##########################################
+#
+# This is a backported replacement for the new Timer code introduced in v0.4
+#
+
+type Timer2
+    handle::Ptr{Void}
+    cond::Condition
+    isopen::Bool
+
+    function Timer2(timeout::Real, repeat::Real=0.0)
+        timeout ≥ 0 || throw(ArgumentError("timer cannot have negative timeout of $timeout seconds"))
+        repeat ≥ 0 || throw(ArgumentError("timer cannot repeat $repeat times"))
+
+        this = new(Libc.malloc(Base._sizeof_uv_timer), Condition(), true)
+        err = ccall(:uv_timer_init,Cint,(Ptr{Void},Ptr{Void}),Base.eventloop(),this.handle)
+        if err != 0
+            #TODO: this codepath is currently not tested
+            Libc.free(this.handle)
+            this.handle = C_NULL
+            throw(UVError("uv_make_timer",err))
+        end
+
+        Base.associate_julia_struct(this.handle, this)
+        Base.preserve_handle(this)
+
+        ccall(:uv_update_time, Void, (Ptr{Void},), Base.eventloop())
+        @compat ccall(:uv_timer_start, Cint, (Ptr{Void},Ptr{Void},UInt64,UInt64),
+              this.handle, Base.uv_jl_asynccb::Ptr{Void},
+              UInt64(round(timeout*1000))+1, UInt64(round(repeat*1000)))
+        this
+    end
+end
+
+Base.wait(t::Timer2) = wait(t.cond)
+
+Base.isopen(t::Timer2) = t.isopen
+
+function Base.close(t::Timer2)
+    if t.handle != C_NULL
+        t.isopen = false
+        ccall(:uv_timer_stop, Cint, (Ptr{Void},), t.handle)
+        ccall(:jl_close_uv, Void, (Ptr{Void},), t.handle)
+    end
+end
+
+function Base._uv_hook_close(t::Timer2)
+    Base.unpreserve_handle(t)
+    Base.disassociate_julia_struct(t)
+    t.handle = C_NULL
+    nothing
+end
+
+function Base._uv_hook_asynccb(t::Timer2)
+    @compat if ccall(:uv_timer_get_repeat, UInt64, (Ptr{Void},), t.handle) == 0
+        # timer is stopped now
+        close(t)
+    end
+    notify(t.cond)
+    nothing
+end
+
+# timer with repeated callback
+function Base.Timer(cb::Function, timeout::Real, repeat::Real=0.0)
+    t = Timer2(timeout, repeat)
+    @schedule begin
+        while isopen(t)
+            wait(t)
+            cb(t)
+        end
+    end
+    t
+end
+
+Base.Timer(timeout::Real, repeat::Real=0.0) = Timer2(timeout, repeat)

test/runtests.jl

@@ -342,3 +342,18 @@ if VERSION > v"0.3.99"
         @test foo(5) == Int
     end
 end
+
+# Timer
+let c = 0, f, t
+    @compat f(t::Timer) = (c += 1)
+    t = Timer(f, 0.0, 0.05)
+    sleep(0.05)
+    @test c >= 1
+    sleep(0.1)
+    @test c >= 3
+    close(t)
+    sleep(0.1)
+    val = c
+    sleep(0.1)
+    @test val == c
+end