fix async deadlock

This commit is contained in:
tqcq
2024-03-28 22:19:28 +08:00
parent fd46ca62ae
commit 181823d4fe
6 changed files with 126 additions and 88 deletions

View File

@ -19,7 +19,7 @@
// THE SOFTWARE.
#ifndef ASYNCXX_H_
# error "Do not include this header directly, include <async++.h> instead."
#error "Do not include this header directly, include <async++.h> instead."
#endif
namespace async {
@ -37,20 +37,22 @@ namespace detail {
// Detect whether an object is a scheduler
template<typename T, typename = decltype(std::declval<T>().schedule(std::declval<task_run_handle>()))>
two& is_scheduler_helper(int);
two &is_scheduler_helper(int);
template<typename T>
one& is_scheduler_helper(...);
one &is_scheduler_helper(...);
template<typename T>
struct is_scheduler: public std::integral_constant<bool, sizeof(is_scheduler_helper<T>(0)) - 1> {};
struct is_scheduler : public std::integral_constant<bool, sizeof(is_scheduler_helper<T>(0)) - 1> {};
// Singleton scheduler classes
class thread_scheduler_impl {
public:
LIBASYNC_EXPORT static void schedule(task_run_handle t);
LIBASYNC_EXPORT static void schedule(task_run_handle t);
};
class inline_scheduler_impl {
public:
static void schedule(task_run_handle t);
static void schedule(task_run_handle t);
};
// Reference counted pointer to task data
@ -59,93 +61,98 @@ typedef ref_count_ptr<task_base> task_ptr;
// Helper function to schedule a task using a scheduler
template<typename Sched>
void schedule_task(Sched& sched, task_ptr t);
void schedule_task(Sched &sched, task_ptr t);
// Wait for the given task to finish. This will call the wait handler currently
// active for this thread, which causes the thread to sleep by default.
LIBASYNC_EXPORT void wait_for_task(task_base* wait_task);
#ifndef LIBASYNC_CUSTOM_WAIT_FOR_TASK
LIBASYNC_EXPORT void wait_for_task(task_base *wait_task);
#endif
// Forward-declaration for data used by threadpool_scheduler
struct threadpool_data;
} // namespace detail
}// namespace detail
// Run a task in the current thread as soon as it is scheduled
inline detail::inline_scheduler_impl& inline_scheduler()
inline detail::inline_scheduler_impl &
inline_scheduler()
{
static detail::inline_scheduler_impl instance;
return instance;
static detail::inline_scheduler_impl instance;
return instance;
}
// Run a task in a separate thread. Note that this scheduler does not wait for
// threads to finish at process exit. You must ensure that all threads finish
// before ending the process.
inline detail::thread_scheduler_impl& thread_scheduler()
inline detail::thread_scheduler_impl &
thread_scheduler()
{
static detail::thread_scheduler_impl instance;
return instance;
static detail::thread_scheduler_impl instance;
return instance;
}
// Built-in thread pool scheduler with a size that is configurable from the
// LIBASYNC_NUM_THREADS environment variable. If that variable does not exist
// then the number of CPUs in the system is used instead.
LIBASYNC_EXPORT threadpool_scheduler& default_threadpool_scheduler();
LIBASYNC_EXPORT threadpool_scheduler &default_threadpool_scheduler();
// Default scheduler that is used when one isn't specified. This defaults to
// default_threadpool_scheduler(), but can be overriden by defining
// LIBASYNC_CUSTOM_DEFAULT_SCHEDULER before including async++.h. Keep in mind
// that in that case async::default_scheduler should be declared before
// including async++.h.
#ifndef LIBASYNC_CUSTOM_DEFAULT_SCHEDULER
inline threadpool_scheduler& default_scheduler()
inline threadpool_scheduler &
default_scheduler()
{
return default_threadpool_scheduler();
return default_threadpool_scheduler();
}
#endif
// Scheduler that holds a list of tasks which can then be explicitly executed
// by a thread. Both adding and running tasks are thread-safe operations.
class fifo_scheduler {
struct internal_data;
std::unique_ptr<internal_data> impl;
struct internal_data;
std::unique_ptr<internal_data> impl;
public:
LIBASYNC_EXPORT fifo_scheduler();
LIBASYNC_EXPORT ~fifo_scheduler();
LIBASYNC_EXPORT fifo_scheduler();
LIBASYNC_EXPORT ~fifo_scheduler();
// Add a task to the queue
LIBASYNC_EXPORT void schedule(task_run_handle t);
// Add a task to the queue
LIBASYNC_EXPORT void schedule(task_run_handle t);
// Try running one task from the queue. Returns false if the queue was empty.
LIBASYNC_EXPORT bool try_run_one_task();
// Try running one task from the queue. Returns false if the queue was empty.
LIBASYNC_EXPORT bool try_run_one_task();
// Run all tasks in the queue
LIBASYNC_EXPORT void run_all_tasks();
// Run all tasks in the queue
LIBASYNC_EXPORT void run_all_tasks();
};
// Scheduler that runs tasks in a work-stealing thread pool of the given size.
// Note that destroying the thread pool before all tasks have completed may
// result in some tasks not being executed.
class threadpool_scheduler {
std::unique_ptr<detail::threadpool_data> impl;
std::unique_ptr<detail::threadpool_data> impl;
public:
LIBASYNC_EXPORT threadpool_scheduler(threadpool_scheduler&& other);
LIBASYNC_EXPORT threadpool_scheduler(threadpool_scheduler &&other);
// Create a thread pool with the given number of threads
LIBASYNC_EXPORT threadpool_scheduler(std::size_t num_threads);
// Create a thread pool with the given number of threads
LIBASYNC_EXPORT threadpool_scheduler(std::size_t num_threads);
// Create a thread pool with the given number of threads. Call `prerun`
// Create a thread pool with the given number of threads. Call `prerun`
// function before execution loop and `postrun` after.
LIBASYNC_EXPORT threadpool_scheduler(std::size_t num_threads,
std::function<void()>&& prerun_,
std::function<void()>&& postrun_);
LIBASYNC_EXPORT
threadpool_scheduler(std::size_t num_threads, std::function<void()> &&prerun_, std::function<void()> &&postrun_);
// Destroy the thread pool, tasks that haven't been started are dropped
LIBASYNC_EXPORT ~threadpool_scheduler();
// Destroy the thread pool, tasks that haven't been started are dropped
LIBASYNC_EXPORT ~threadpool_scheduler();
// Schedule a task to be run in the thread pool
LIBASYNC_EXPORT void schedule(task_run_handle t);
// Schedule a task to be run in the thread pool
LIBASYNC_EXPORT void schedule(task_run_handle t);
};
namespace detail {
@ -153,5 +160,5 @@ namespace detail {
// Work-around for Intel compiler handling decltype poorly in function returns
typedef std::remove_reference<decltype(::async::default_scheduler())>::type default_scheduler_type;
} // namespace detail
} // namespace async
}// namespace detail
}// namespace async