channels.jl
# This file is a part of Julia. License is MIT: https://julialang.org/license
# Test various constructors
let c = Channel(1)
@test eltype(c) == Any
@test put!(c, 1) == 1
@test isready(c) == true
@test take!(c) == 1
@test isready(c) == false
end
@test eltype(Channel(1.0)) == Any
let c = Channel{Int}(1)
@test eltype(c) == Int
@test_throws MethodError put!(c, "Hello")
end
let c = Channel{Int}(Inf)
@test eltype(c) == Int
pvals = map(i->put!(c,i), 1:10^6)
tvals = Int[take!(c) for i in 1:10^6]
@test pvals == tvals
end
# Uncomment line below once deprecation support has been removed.
# @test_throws MethodError Channel()
@test_throws ArgumentError Channel(-1)
@test_throws InexactError Channel(1.5)
# Test multiple concurrent put!/take! on a channel for different sizes
function testcpt(sz)
c = Channel{Int}(sz)
size = 0
inc() = size += 1
dec() = size -= 1
@sync for i = 1:10^4
@async (sleep(rand()); put!(c, i); inc())
@async (sleep(rand()); take!(c); dec())
end
@test size == 0
end
testcpt(0)
testcpt(1)
testcpt(32)
testcpt(Inf)
# Test multiple "for" loops waiting on the same channel which
# is closed after adding a few elements.
let c = Channel(32),
results = []
@sync begin
for i in 1:20
@async for ii in c
push!(results, ii)
end
end
sleep(1.0)
for i in 1:5
put!(c,i)
end
close(c)
end
@test sum(results) == 15
end
# Test channel iterator with done() being called multiple times
# This needs to be explicitly tested since `take!` is called
# in `done()` and not `next()`
let s, c = Channel(32)
foreach(i -> put!(c, i), 1:10)
close(c)
s = start(c)
@test done(c, s) == false
res = Int[]
while !done(c, s)
local v
@test done(c,s) == false
v, s = next(c, s)
push!(res, v)
end
@test res == Int[1:10...]
end
# Tests for channels bound to tasks.
using Distributed
for N in [0,10]
# Normal exit of task
c=Channel(N)
bind(c, @schedule (yield();nothing))
@test_throws InvalidStateException take!(c)
@test !isopen(c)
# Error exception in task
c=Channel(N)
bind(c, @schedule (yield();error("foo")))
@test_throws ErrorException take!(c)
@test !isopen(c)
# Multiple channels closed by the same bound task
cs = [Channel(N) for i in 1:5]
tf2 = () -> begin
if N > 0
foreach(c->assert(take!(c)==2), cs)
end
yield()
error("foo")
end
task = Task(tf2)
foreach(c->bind(c, task), cs)
schedule(task)
if N > 0
for i in 1:5
@test put!(cs[i], 2) == 2
end
end
for i in 1:5
while (isopen(cs[i])); yield(); end
@test_throws ErrorException wait(cs[i])
@test_throws ErrorException take!(cs[i])
@test_throws ErrorException put!(cs[i], 1)
@test_throws ErrorException fetch(cs[i])
end
# Multiple tasks, first one to terminate closes the channel
nth = rand(1:5)
ref = Ref(0)
cond = Condition()
tf3(i) = begin
if i == nth
ref[] = i
else
sleep(2.0)
end
end
tasks = [Task(()->tf3(i)) for i in 1:5]
c = Channel(N)
foreach(t->bind(c,t), tasks)
foreach(schedule, tasks)
@test_throws InvalidStateException wait(c)
@test !isopen(c)
@test ref[] == nth
# channeled_tasks
for T in [Any, Int]
chnls, tasks = Base.channeled_tasks(2, (c1,c2)->(assert(take!(c1)==1); put!(c2,2)); ctypes=[T,T], csizes=[N,N])
put!(chnls[1], 1)
@test take!(chnls[2]) == 2
@test_throws InvalidStateException wait(chnls[1])
@test_throws InvalidStateException wait(chnls[2])
@test istaskdone(tasks[1])
@test !isopen(chnls[1])
@test !isopen(chnls[2])
f=Future()
tf4 = (c1,c2) -> begin
assert(take!(c1)==1)
wait(f)
end
tf5 = (c1,c2) -> begin
put!(c2,2)
wait(f)
end
chnls, tasks = Base.channeled_tasks(2, tf4, tf5; ctypes=[T,T], csizes=[N,N])
put!(chnls[1], 1)
@test take!(chnls[2]) == 2
yield()
put!(f, 1)
@test_throws InvalidStateException wait(chnls[1])
@test_throws InvalidStateException wait(chnls[2])
@test istaskdone(tasks[1])
@test istaskdone(tasks[2])
@test !isopen(chnls[1])
@test !isopen(chnls[2])
end
# channel
tf6 = c -> begin
assert(take!(c)==2)
error("foo")
end
for T in [Any, Int]
taskref = Ref{Task}()
chnl = Channel(tf6, ctype=T, csize=N, taskref=taskref)
put!(chnl, 2)
yield()
@test_throws ErrorException wait(chnl)
@test istaskdone(taskref[])
@test !isopen(chnl)
@test_throws ErrorException take!(chnl)
end
end
# Testing timedwait on multiple channels
using Dates
@sync begin
rr1 = Channel(1)
rr2 = Channel(1)
rr3 = Channel(1)
callback() = all(map(isready, [rr1, rr2, rr3]))
# precompile functions which will be tested for execution time
@test !callback()
@test timedwait(callback, 0.0) === :timed_out
@async begin sleep(0.5); put!(rr1, :ok) end
@async begin sleep(1.0); put!(rr2, :ok) end
@async begin sleep(2.0); put!(rr3, :ok) end
et = @elapsed timedwait(callback, Dates.Second(1))
# assuming that 0.5 seconds is a good enough buffer on a typical modern CPU
try
@assert (et >= 1.0) && (et <= 1.5)
@assert !isready(rr3)
catch
@warn "`timedwait` tests delayed. et=$et, isready(rr3)=$(isready(rr3))"
end
@test isready(rr1)
end
# test for yield/wait/event failures
@noinline garbage_finalizer(f) = finalizer(f, "gar" * "bage")
let t, run = Ref(0)
gc_enable(false)
# test for finalizers trying to yield leading to failed attempts to context switch
garbage_finalizer((x) -> (run[] += 1; sleep(1)))
garbage_finalizer((x) -> (run[] += 1; yield()))
garbage_finalizer((x) -> (run[] += 1; yieldto(@task () -> ())))
t = @task begin
gc_enable(true)
gc()
end
oldstderr = STDERR
local newstderr, errstream
try
newstderr = redirect_stderr()
errstream = @async read(newstderr[1], String)
yield(t)
finally
redirect_stderr(oldstderr)
close(newstderr[2])
end
wait(t)
@test run[] == 3
@test wait(errstream) == """
error in running finalizer: ErrorException("task switch not allowed from inside gc finalizer")
error in running finalizer: ErrorException("task switch not allowed from inside gc finalizer")
error in running finalizer: ErrorException("task switch not allowed from inside gc finalizer")
"""
# test for invalid state in Workqueue during yield
t = @schedule nothing
t.state = :invalid
try
newstderr = redirect_stderr()
errstream = @async read(newstderr[1], String)
yield()
finally
redirect_stderr(oldstderr)
close(newstderr[2])
end
@test wait(errstream) == "\nWARNING: Workqueue inconsistency detected: popfirst!(Workqueue).state != :queued\n"
end
# schedule_and_wait tests
let t = @schedule(nothing),
ct = current_task(),
testobject = "testobject"
@test length(Base.Workqueue) == 1
@test Base.schedule_and_wait(ct, 8) == 8
@test isempty(Base.Workqueue)
@test Base.schedule_and_wait(ct, testobject) === testobject
end
# throwto tests
let t = @task(nothing),
ct = current_task(),
testerr = ErrorException("expected")
@async Base.throwto(t, testerr)
@test try
wait(t)
false
catch ex
ex
end === testerr
end
# Timer / AsyncCondition triggering and race #12719
let tc = Ref(0),
t = Timer(0) do t
tc[] += 1
end
@test isopen(t)
Base.process_events(false)
@test !isopen(t)
@test tc[] == 0
yield()
@test tc[] == 1
end
let tc = Ref(0),
t = Timer(0) do t
tc[] += 1
end
@test isopen(t)
close(t)
@test !isopen(t)
sleep(0.1)
@test tc[] == 0
end
let tc = Ref(0),
async = Base.AsyncCondition() do async
tc[] += 1
end
@test isopen(async)
ccall(:uv_async_send, Cvoid, (Ptr{Cvoid},), async)
Base.process_events(false) # schedule event
ccall(:uv_async_send, Cvoid, (Ptr{Cvoid},), async)
Sys.iswindows() && Base.process_events(false) # schedule event (windows?)
@test tc[] == 0
yield() # consume event
@test tc[] == 1
sleep(0.1) # no further events
@test tc[] == 1
ccall(:uv_async_send, Cvoid, (Ptr{Cvoid},), async)
ccall(:uv_async_send, Cvoid, (Ptr{Cvoid},), async)
close(async)
@test !isopen(async)
@test tc[] == 1
Base.process_events(false) # schedule event & then close
Sys.iswindows() && Base.process_events(false) # schedule event (windows?)
yield() # consume event & then close
@test tc[] == 2
sleep(0.1) # no further events
@test tc[] == 2
end
let tc = Ref(0),
async = Base.AsyncCondition() do async
tc[] += 1
end
@test isopen(async)
ccall(:uv_async_send, Cvoid, (Ptr{Cvoid},), async)
close(async)
@test !isopen(async)
Base.process_events(false) # schedule event & then close
Sys.iswindows() && Base.process_events(false) # schedule event (windows)
@test tc[] == 0
yield() # consume event & then close
@test tc[] == 1
sleep(0.1)
@test tc[] == 1
end