folly::coro::AsyncScope

Synopsis

Declared in <folly/coro/AsyncScope.h>

class AsyncScope;

Description

The AsyncScope class is used to allow you to start a dynamic, unbounded number of tasks, which can all run concurrently, and then later wait for completion of all of the tasks.

Tasks added to an AsyncScope must have a void or folly::Unit result-type and must handle any errors prior to completing.

Example:


folly::coro::Task<void> process(Event event) {
  try {
    co_await do_processing(event.data);
  } catch (...) {
    LOG(ERROR) << "Processing event failed";
  }
}

folly::coro::AsyncScope scope;
scope.add(co_withExecutor(folly::getGlobalCPUExecutor(), process(ev1)));
scope.add(co_withExecutor(folly::getGlobalCPUExecutor(), process(ev2)));
scope.add(co_withExecutor(folly::getGlobalCPUExecutor(), process(ev3)));
co_await scope.joinAsync();

refcode folly/docs/examples/folly/coro/AsyncScope.cpp

Member Functions

Name	Description
`AsyncScope` [constructor]	Constructs an empty scope with no started tasks.
`~AsyncScope` [destructor]	Destroy the AsyncScope object.
`add`	Start the specified task/awaitable by co_awaiting it.
`addWithSourceLoc`	Like add(), but records the call-site source location for diagnostics.
`cleanup`	Asynchronously cleanup all started tasks.
`joinAsync`	Asynchronously wait for all started tasks to complete.
`remaining`	Query the number of tasks added to the scope that have not yet completed.

Non-Member Functions

Name	Description
`makeUnorderedAsyncGenerator`	Yield the results of a vector of awaitables in order of completion.
`makeUnorderedAsyncGenerator`	Yield the results of a range of awaitables in order of completion.
`makeUnorderedTryAsyncGenerator`	Yield Try results of a vector of awaitables in order of completion.
`makeUnorderedTryAsyncGenerator`	Yield Try results of a range of awaitables in order of completion.