From 4f7a055081dff4299ee049a03c7a6f1659406942 Mon Sep 17 00:00:00 2001 From: Yuri Kunde Schlesner Date: Mon, 11 May 2015 16:09:10 -0300 Subject: Thread: Remove the idle thread Instead just use nullptr to represent no thread is active. --- src/core/core.cpp | 4 ++-- src/core/hle/kernel/thread.cpp | 46 +++++++++++++++++------------------------- src/core/hle/kernel/thread.h | 17 ---------------- 3 files changed, 21 insertions(+), 46 deletions(-) diff --git a/src/core/core.cpp b/src/core/core.cpp index b5c25823..53aae8c2 100644 --- a/src/core/core.cpp +++ b/src/core/core.cpp @@ -24,9 +24,9 @@ ARM_Interface* g_sys_core = nullptr; ///< ARM11 system (OS) core /// Run the core CPU loop void RunLoop(int tight_loop) { - // If the current thread is an idle thread, then don't execute instructions, + // If we don't have a currently active thread then don't execute instructions, // instead advance to the next event and try to yield to the next thread - if (Kernel::GetCurrentThread()->IsIdle()) { + if (Kernel::GetCurrentThread() == nullptr) { LOG_TRACE(Core_ARM11, "Idling"); CoreTiming::Idle(); CoreTiming::Advance(); diff --git a/src/core/hle/kernel/thread.cpp b/src/core/hle/kernel/thread.cpp index 957cbdfe..b962da8f 100644 --- a/src/core/hle/kernel/thread.cpp +++ b/src/core/hle/kernel/thread.cpp @@ -157,7 +157,7 @@ static void PriorityBoostStarvedThreads() { u64 delta = current_ticks - thread->last_running_ticks; - if (thread->status == THREADSTATUS_READY && delta > boost_timeout && !thread->idle) { + if (thread->status == THREADSTATUS_READY && delta > boost_timeout) { const s32 priority = std::max(ready_queue.get_first()->current_priority - 1, 0); thread->BoostPriority(priority); } @@ -169,8 +169,6 @@ static void PriorityBoostStarvedThreads() { * @param new_thread The thread to switch to */ static void SwitchContext(Thread* new_thread) { - DEBUG_ASSERT_MSG(new_thread->status == THREADSTATUS_READY, "Thread must be ready to become running."); - Thread* previous_thread = GetCurrentThread(); // Save context for previous thread @@ -188,6 +186,8 @@ static void SwitchContext(Thread* new_thread) { // Load context of new thread if (new_thread) { + DEBUG_ASSERT_MSG(new_thread->status == THREADSTATUS_READY, "Thread must be ready to become running."); + current_thread = new_thread; ready_queue.remove(new_thread->current_priority, new_thread); @@ -215,6 +215,10 @@ static Thread* PopNextReadyThread() { // We have to do better than the current thread. // This call returns null when that's not possible. next = ready_queue.pop_first_better(thread->current_priority); + if (!next) { + // Otherwise just keep going with the current thread + next = thread; + } } else { next = ready_queue.pop_first(); } @@ -448,16 +452,6 @@ void Thread::BoostPriority(s32 priority) { current_priority = priority; } -SharedPtr SetupIdleThread() { - // We need to pass a few valid values to get around parameter checking in Thread::Create. - // TODO(yuriks): Figure out a way to avoid passing the bogus VAddr parameter - auto thread = Thread::Create("idle", Memory::TLS_AREA_VADDR, THREADPRIO_LOWEST, 0, - THREADPROCESSORID_0, 0).MoveFrom(); - - thread->idle = true; - return thread; -} - SharedPtr SetupMainThread(u32 entry_point, s32 priority) { DEBUG_ASSERT(!GetCurrentThread()); @@ -474,24 +468,25 @@ SharedPtr SetupMainThread(u32 entry_point, s32 priority) { } void Reschedule() { - Thread* prev = GetCurrentThread(); - PriorityBoostStarvedThreads(); + Thread* cur = GetCurrentThread(); Thread* next = PopNextReadyThread(); HLE::g_reschedule = false; - if (next != nullptr) { - LOG_TRACE(Kernel, "context switch %u -> %u", prev->GetObjectId(), next->GetObjectId()); - SwitchContext(next); - } else { - LOG_TRACE(Kernel, "cannot context switch from %u, no higher priority thread!", prev->GetObjectId()); + // Don't bother switching to the same thread + if (next == cur) + return; - for (auto& thread : thread_list) { - LOG_TRACE(Kernel, "\tid=%u prio=0x%02X, status=0x%08X", thread->GetObjectId(), - thread->current_priority, thread->status); - } + if (cur && next) { + LOG_TRACE(Kernel, "context switch %u -> %u", cur->GetObjectId(), next->GetObjectId()); + } else if (cur) { + LOG_TRACE(Kernel, "context switch %u -> idle", cur->GetObjectId()); + } else { + LOG_TRACE(Kernel, "context switch idle -> %u", next->GetObjectId()); } + + SwitchContext(next); } void Thread::SetWaitSynchronizationResult(ResultCode result) { @@ -516,9 +511,6 @@ void ThreadingInit() { thread_list.clear(); ready_queue.clear(); - - // Setup the idle thread - SetupIdleThread(); } void ThreadingShutdown() { diff --git a/src/core/hle/kernel/thread.h b/src/core/hle/kernel/thread.h index afdaf851..2ee63d27 100644 --- a/src/core/hle/kernel/thread.h +++ b/src/core/hle/kernel/thread.h @@ -71,12 +71,6 @@ public: bool ShouldWait() override; void Acquire() override; - /** - * Checks if the thread is an idle (stub) thread - * @return True if the thread is an idle (stub) thread, false otherwise - */ - inline bool IsIdle() const { return idle; } - /** * Gets the thread's current priority * @return The current thread's priority @@ -168,9 +162,6 @@ public: std::string name; - /// Whether this thread is intended to never actually be executed, i.e. always idle - bool idle = false; - private: Thread(); ~Thread() override; @@ -228,14 +219,6 @@ void WaitCurrentThread_WaitSynchronization(std::vector> wa */ void WaitCurrentThread_ArbitrateAddress(VAddr wait_address); -/** - * Sets up the idle thread, this is a thread that is intended to never execute instructions, - * only to advance the timing. It is scheduled when there are no other ready threads in the thread queue - * and will try to yield on every call. - * @return The handle of the idle thread - */ -SharedPtr SetupIdleThread(); - /** * Initialize threading */ -- cgit v1.2.3