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Progress the simulator clock even when there are messages to deliver

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This commit is contained in:
Tyler Neely 2022-11-18 09:04:29 +00:00
parent f6017697d6
commit 923325b8fa
2 changed files with 24 additions and 28 deletions
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50
src/io/simulator/simulator_handle.cpp
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@ -75,6 +75,8 @@ bool SimulatorHandle::MaybeTickSimulator() {
return false;
}
// We allow the simulator to progress the state of the system only
// after all servers are blocked on receive.
spdlog::info("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ simulator tick ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
stats_.simulator_ticks++;
@ -88,37 +90,31 @@ bool SimulatorHandle::MaybeTickSimulator() {
cv_.notify_all();
}
const Duration clock_advance = std::chrono::microseconds{time_distrib_(rng_)};
cluster_wide_time_microseconds_ += clock_advance;
if (!fired_cv) {
spdlog::info("simulator progressing: clock advanced by {}", clock_advance.count());
cv_.notify_all();
blocked_on_receive_.clear();
fired_cv = true;
}
if (cluster_wide_time_microseconds_ >= config_.abort_time) {
if (should_shut_down_) {
return true;
}
spdlog::error(
"Cluster has executed beyond its configured abort_time, and something may be failing to make progress "
"in an expected amount of time.");
throw utils::BasicException{"Cluster has executed beyond its configured abort_time"};
}
if (in_flight_.empty()) {
// return early here because there are no messages to schedule
// We tick the clock forward when all servers are blocked but
// there are no in-flight messages to schedule delivery of.
const Duration clock_advance = std::chrono::microseconds{time_distrib_(rng_)};
cluster_wide_time_microseconds_ += clock_advance;
if (!fired_cv) {
spdlog::info("simulator progressing: clock advanced by {}", clock_advance.count());
cv_.notify_all();
blocked_on_receive_.clear();
fired_cv = true;
}
if (cluster_wide_time_microseconds_ >= config_.abort_time) {
if (should_shut_down_) {
return true;
}
spdlog::error(
"Cluster has executed beyond its configured abort_time, and something may be failing to make progress "
"in an expected amount of time.");
throw utils::BasicException{"Cluster has executed beyond its configured abort_time"};
}
// if the clock is advanced, no messages should be delivered also.
// do that in a future tick.
return true;
}
if (config_.scramble_messages) {
if (config_.scramble_messages && in_flight_.size() > 1) {
// scramble messages
std::uniform_int_distribution<size_t> swap_distrib(0, in_flight_.size() - 1);
const size_t swap_index = swap_distrib(rng_);

2
src/io/simulator/simulator_handle.hpp
View File

@ -52,7 +52,7 @@ class SimulatorHandle {
std::set<Address> blocked_on_receive_;
std::set<Address> server_addresses_;
std::mt19937 rng_;
std::uniform_int_distribution<int> time_distrib_{5, 50};
std::uniform_int_distribution<int> time_distrib_{0, 50};
std::uniform_int_distribution<int> drop_distrib_{0, 99};
SimulatorConfig config_;
MessageHistogramCollector histograms_;