142 lines
3.2 KiB
Ruby
142 lines
3.2 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
RSpec.describe DistributedMutex do
|
|
before do
|
|
DistributedMutex.any_instance.stubs(:sleep)
|
|
end
|
|
|
|
let(:key) { "test_mutex_key" }
|
|
|
|
after do
|
|
Discourse.redis.del(key)
|
|
end
|
|
|
|
it "allows only one mutex object to have the lock at a time" do
|
|
mutexes = (1..10).map do
|
|
DistributedMutex.new(key, redis: DiscourseRedis.new)
|
|
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(key)
|
|
|
|
Discourse.redis.setnx key, Time.now.to_i - 1
|
|
|
|
start = Time.now
|
|
m.synchronize do
|
|
"nop"
|
|
end
|
|
|
|
# no longer than a second
|
|
expect(Time.now).to be <= start + 1
|
|
end
|
|
|
|
it "allows the validity of the lock to be configured" do
|
|
mutex = DistributedMutex.new(key, validity: 2)
|
|
|
|
mutex.synchronize do
|
|
expect(Discourse.redis.ttl(key)).to be <= 3
|
|
expect(Discourse.redis.get(key).to_i).to be_within(1.second).of(Time.now.to_i + 2)
|
|
end
|
|
|
|
mutex = DistributedMutex.new(key)
|
|
|
|
mutex.synchronize do
|
|
expect(Discourse.redis.ttl(key)).to be <= DistributedMutex::DEFAULT_VALIDITY + 1
|
|
expect(Discourse.redis.get(key).to_i).to be_within(1.second).of(Time.now.to_i + DistributedMutex::DEFAULT_VALIDITY)
|
|
end
|
|
end
|
|
|
|
it "maintains mutex semantics" do
|
|
m = DistributedMutex.new(key)
|
|
|
|
expect {
|
|
m.synchronize do
|
|
m.synchronize {}
|
|
end
|
|
}.to raise_error(ThreadError)
|
|
end
|
|
|
|
describe "readonly redis" do
|
|
before do
|
|
Discourse.redis.slaveof "127.0.0.1", "65534"
|
|
end
|
|
|
|
after do
|
|
Discourse.redis.slaveof "no", "one"
|
|
end
|
|
|
|
it "works even if redis is in readonly" do
|
|
m = DistributedMutex.new(key)
|
|
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).to be <= start + 1
|
|
end
|
|
end
|
|
|
|
describe "executions" do
|
|
it "should not allow critical sections to overlap" do
|
|
connections = 3.times.map { DiscourseRedis.new }
|
|
|
|
scenario =
|
|
Concurrency::Scenario.new do |execution|
|
|
locked = false
|
|
|
|
Discourse.redis.del('mutex_key')
|
|
|
|
connections.each do |connection|
|
|
connection.unwatch
|
|
end
|
|
|
|
3.times do |i|
|
|
execution.spawn do
|
|
begin
|
|
redis =
|
|
Concurrency::RedisWrapper.new(
|
|
connections[i],
|
|
execution
|
|
)
|
|
|
|
2.times do
|
|
DistributedMutex.synchronize('mutex_key', redis: redis) do
|
|
raise "already locked #{execution.path}" if locked
|
|
locked = true
|
|
|
|
execution.yield
|
|
|
|
raise "already unlocked #{execution.path}" unless locked
|
|
locked = false
|
|
end
|
|
end
|
|
rescue Redis::ConnectionError
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|
|
scenario.run(runs: 10)
|
|
end
|
|
end
|
|
end
|