async: context: allow many exceptions
Allow many spawned tasks to throw exceptions and queue them up,
re-throwing them one-by-one from `context::run` calls. Similarly
enhance `context::scope` so that many `context::empty` completions
can complete with error.
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I8744e0a3b8b0663ebd5ca26db0f5943688afe62a
diff --git a/src/async/context.cpp b/src/async/context.cpp
index b16cf3e..6d50301 100644
--- a/src/async/context.cpp
+++ b/src/async/context.cpp
@@ -142,10 +142,10 @@
wait_for_wait_process_stopped();
// Wait for all the internal tasks to complete.
- std::this_thread::sync_wait(internal_tasks.empty() |
- execution::upon_error([&](auto&& e) {
- pending_exception = std::move(e);
- }));
+ std::this_thread::sync_wait(
+ internal_tasks.empty() | execution::upon_error([&](auto&& e) {
+ pending_exceptions.emplace_back(std::move(e));
+ }));
// Finish up the loop and join the thread.
// (There shouldn't be anything going on by this point anyhow.)
@@ -177,7 +177,7 @@
if (e)
{
- pending_exception = std::move(e);
+ pending_exceptions.emplace_back(std::move(e));
}
}
@@ -225,7 +225,7 @@
// we get an exception.
auto keep_running = [this]() {
std::lock_guard l{lock};
- return !final_stop.stop_requested() && !pending_exception;
+ return !final_stop.stop_requested() && pending_exceptions.empty();
};
// If we are suppose to keep running, start the run loop.
@@ -284,9 +284,11 @@
{
{
std::lock_guard l{lock};
- if (pending_exception)
+ if (!pending_exceptions.empty())
{
- std::rethrow_exception(std::exchange(pending_exception, {}));
+ auto e = pending_exceptions.front();
+ pending_exceptions.pop_front();
+ std::rethrow_exception(std::move(e));
}
}
}
@@ -338,7 +340,7 @@
ctx.caller_wait.wait(lock, [&] {
return (ctx.pending != nullptr) || (ctx.staged != nullptr) ||
ctx.final_stop.stop_requested() ||
- (ctx.pending_exception != nullptr);
+ !ctx.pending_exceptions.empty();
});
// Save the waiter as pending.