From 0135b328edb1b58d1ff97cfdc35e05f02cec1c2a Mon Sep 17 00:00:00 2001 From: Subv Date: Sun, 12 Aug 2018 17:47:15 -0500 Subject: [PATCH 1/4] Kernel/Thread: Always use the threadsafe option when scheduling wakeups. WakeAfterDelay might be called from any host thread, so err on the side of caution and use the thread-safe CoreTiming::ScheduleEventThreadsafe. Note that CoreTiming is still far from thread-safe, there may be more things we have to work on for it to be up to par with what we want. --- src/core/core_timing.cpp | 2 -- src/core/hle/kernel/thread.cpp | 6 ++++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/src/core/core_timing.cpp b/src/core/core_timing.cpp index d3bb6f8188..f977d1b325 100644 --- a/src/core/core_timing.cpp +++ b/src/core/core_timing.cpp @@ -135,11 +135,9 @@ void ClearPendingEvents() { void ScheduleEvent(s64 cycles_into_future, const EventType* event_type, u64 userdata) { ASSERT(event_type != nullptr); s64 timeout = GetTicks() + cycles_into_future; - // If this event needs to be scheduled before the next advance(), force one early if (!is_global_timer_sane) ForceExceptionCheck(cycles_into_future); - event_queue.emplace_back(Event{timeout, event_fifo_id++, userdata, event_type}); std::push_heap(event_queue.begin(), event_queue.end(), std::greater<>()); } diff --git a/src/core/hle/kernel/thread.cpp b/src/core/hle/kernel/thread.cpp index b9022feae2..e308b9c7bd 100644 --- a/src/core/hle/kernel/thread.cpp +++ b/src/core/hle/kernel/thread.cpp @@ -155,8 +155,10 @@ void Thread::WakeAfterDelay(s64 nanoseconds) { if (nanoseconds == -1) return; - CoreTiming::ScheduleEvent(CoreTiming::nsToCycles(nanoseconds), ThreadWakeupEventType, - callback_handle); + // This function might be called from any thread so we have to be cautious and use the + // thread-safe version of ScheduleEvent. + CoreTiming::ScheduleEventThreadsafe(CoreTiming::nsToCycles(nanoseconds), ThreadWakeupEventType, + callback_handle); } void Thread::CancelWakeupTimer() { From 84b542c386063339c03069b8f4db8221200a27cd Mon Sep 17 00:00:00 2001 From: Subv Date: Sun, 12 Aug 2018 17:49:55 -0500 Subject: [PATCH 2/4] Kernel/Threads: Lock the HLE mutex when executing the wakeup callback. Another thread might be in the middle of a reschedule, thus altering the state of the schedulers. --- src/core/hle/kernel/thread.cpp | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/core/hle/kernel/thread.cpp b/src/core/hle/kernel/thread.cpp index e308b9c7bd..5f87ff8593 100644 --- a/src/core/hle/kernel/thread.cpp +++ b/src/core/hle/kernel/thread.cpp @@ -23,6 +23,7 @@ #include "core/hle/kernel/object.h" #include "core/hle/kernel/process.h" #include "core/hle/kernel/thread.h" +#include "core/hle/lock.h" #include "core/hle/result.h" #include "core/memory.h" @@ -104,6 +105,10 @@ void ExitCurrentThread() { */ static void ThreadWakeupCallback(u64 thread_handle, int cycles_late) { const auto proper_handle = static_cast(thread_handle); + + // Lock the global kernel mutex when we enter the kernel HLE. + std::lock_guard lock(HLE::g_hle_lock); + SharedPtr thread = wakeup_callback_handle_table.Get(proper_handle); if (thread == nullptr) { LOG_CRITICAL(Kernel, "Callback fired for invalid thread {:08X}", proper_handle); From 3a338d9286bb7c8a4e169914965e6241c466bc6a Mon Sep 17 00:00:00 2001 From: Subv Date: Sun, 12 Aug 2018 17:50:44 -0500 Subject: [PATCH 3/4] CPU/HLE: Lock the HLE mutex before performing a reschedule. Another thread might be in the middle of an SVC, thus altering the state of the schedulers. --- src/core/core_cpu.cpp | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/core/core_cpu.cpp b/src/core/core_cpu.cpp index 46a522fcd4..9b306faf6a 100644 --- a/src/core/core_cpu.cpp +++ b/src/core/core_cpu.cpp @@ -14,6 +14,7 @@ #include "core/core_timing.h" #include "core/hle/kernel/scheduler.h" #include "core/hle/kernel/thread.h" +#include "core/hle/lock.h" #include "core/settings.h" namespace Core { @@ -125,6 +126,8 @@ void Cpu::Reschedule() { } reschedule_pending = false; + // Lock the global kernel mutex when we manipulate the HLE state + std::lock_guard lock(HLE::g_hle_lock); scheduler->Reschedule(); } From 2e7802ad7d4ab80d9547c3ee44ad3a1341dea625 Mon Sep 17 00:00:00 2001 From: Subv Date: Sun, 12 Aug 2018 17:51:47 -0500 Subject: [PATCH 4/4] Core/HLE: Make the 'reschedule_pending' flag atomic. Another thread may write to this variable while the core in question is in the middle of checking for a reschedule request. --- src/core/core_cpu.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/core/core_cpu.h b/src/core/core_cpu.h index 9769529033..56cdae1947 100644 --- a/src/core/core_cpu.h +++ b/src/core/core_cpu.h @@ -79,7 +79,7 @@ private: std::shared_ptr cpu_barrier; std::shared_ptr scheduler; - bool reschedule_pending{}; + std::atomic reschedule_pending = false; size_t core_index; };