discourse/spec/components/distributed_mutex_spec.rb
Sam 5302709343 FIX: in redis readonly raise an exception from DistributedMutex
If we detect redis is in readonly we can not correctly get a mutex
raise an exception to notify caller

When getting optimized images avoid the distributed mutex unless
for some reason it is the first call and we need to generate a thumb

In redis readonly no thumbnails will be generated
2018-09-19 15:50:58 +10:00

74 lines
1.4 KiB
Ruby

require 'rails_helper'
require_dependency 'distributed_mutex'
describe DistributedMutex do
it "allows only one mutex object to have the lock at a time" do
mutexes = (1..10).map do
DistributedMutex.new("test_mutex_key")
end
x = 0
mutexes.map do |m|
Thread.new do
m.synchronize do
y = x
sleep 0.001
x = y + 1
end
end
end.map(&:join)
expect(x).to eq(10)
end
it "handles auto cleanup correctly" do
m = DistributedMutex.new("test_mutex_key")
$redis.setnx "test_mutex_key", Time.now.to_i - 1
start = Time.now.to_i
m.synchronize do
"nop"
end
# no longer than a second
expect(Time.now.to_i).to be <= start + 1
end
it "maintains mutex semantics" do
m = DistributedMutex.new("test_mutex_key")
expect {
m.synchronize do
m.synchronize {}
end
}.to raise_error(ThreadError)
end
context "readonly redis" do
before do
$redis.slaveof "127.0.0.1", "99991"
end
after do
$redis.slaveof "no", "one"
end
it "works even if redis is in readonly" do
m = DistributedMutex.new("test_readonly")
start = Time.now
done = false
expect {
m.synchronize do
done = true
end
}.to raise_error(Discourse::ReadOnly)
expect(done).to eq(false)
expect(Time.now - start).to be < (1.second)
end
end
end