Threads: Use a dummy idle thread when no other are ready.

This thread will not actually execute instructions, it will only advance the timing/events and try to yield immediately to the next ready thread, if there aren't any ready threads then it will be rescheduled and start its job again.
This commit is contained in:
Subv 2015-01-07 10:10:58 -05:00
parent b659cac2dc
commit 60a373a786
4 changed files with 47 additions and 2 deletions

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@ -5,6 +5,7 @@
#include "common/common_types.h" #include "common/common_types.h"
#include "core/core.h" #include "core/core.h"
#include "core/core_timing.h"
#include "core/settings.h" #include "core/settings.h"
#include "core/arm/disassembler/arm_disasm.h" #include "core/arm/disassembler/arm_disasm.h"
@ -23,7 +24,17 @@ ARM_Interface* g_sys_core = nullptr; ///< ARM11 system (OS) core
/// Run the core CPU loop /// Run the core CPU loop
void RunLoop(int tight_loop) { void RunLoop(int tight_loop) {
// If the current thread is an idle thread, then don't execute instructions,
// instead advance to the next event and try to yield to the next thread
if (Kernel::IsIdleThread(Kernel::GetCurrentThreadHandle())) {
LOG_TRACE(Core_ARM11, "Idling");
CoreTiming::Idle();
CoreTiming::Advance();
HLE::Reschedule(__func__);
} else {
g_app_core->Run(tight_loop); g_app_core->Run(tight_loop);
}
HW::Update(); HW::Update();
if (HLE::g_reschedule) { if (HLE::g_reschedule) {
Kernel::Reschedule(); Kernel::Reschedule();

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@ -124,6 +124,8 @@ bool LoadExec(u32 entry_point) {
// 0x30 is the typical main thread priority I've seen used so far // 0x30 is the typical main thread priority I've seen used so far
g_main_thread = Kernel::SetupMainThread(0x30); g_main_thread = Kernel::SetupMainThread(0x30);
// Setup the idle thread
Kernel::SetupIdleThread();
return true; return true;
} }

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@ -11,6 +11,7 @@
#include "common/thread_queue_list.h" #include "common/thread_queue_list.h"
#include "core/core.h" #include "core/core.h"
#include "core/core_timing.h"
#include "core/hle/hle.h" #include "core/hle/hle.h"
#include "core/hle/kernel/kernel.h" #include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/thread.h" #include "core/hle/kernel/thread.h"
@ -34,6 +35,7 @@ public:
inline bool IsReady() const { return (status & THREADSTATUS_READY) != 0; } inline bool IsReady() const { return (status & THREADSTATUS_READY) != 0; }
inline bool IsWaiting() const { return (status & THREADSTATUS_WAIT) != 0; } inline bool IsWaiting() const { return (status & THREADSTATUS_WAIT) != 0; }
inline bool IsSuspended() const { return (status & THREADSTATUS_SUSPEND) != 0; } inline bool IsSuspended() const { return (status & THREADSTATUS_SUSPEND) != 0; }
inline bool IsIdle() const { return idle; }
ResultVal<bool> WaitSynchronization() override { ResultVal<bool> WaitSynchronization() override {
const bool wait = status != THREADSTATUS_DORMANT; const bool wait = status != THREADSTATUS_DORMANT;
@ -69,6 +71,9 @@ public:
std::vector<Handle> waiting_threads; std::vector<Handle> waiting_threads;
std::string name; std::string name;
/// Whether this thread is intended to never actually be executed, i.e. always idle
bool idle = false;
}; };
// Lists all thread ids that aren't deleted/etc. // Lists all thread ids that aren't deleted/etc.
@ -444,7 +449,14 @@ ResultCode SetThreadPriority(Handle handle, s32 priority) {
return RESULT_SUCCESS; return RESULT_SUCCESS;
} }
/// Sets up the primary application thread Handle SetupIdleThread() {
Handle handle;
Thread* thread = CreateThread(handle, "idle", 0, THREADPRIO_LOWEST, THREADPROCESSORID_0, 0, 0);
thread->idle = true;
CallThread(thread);
return handle;
}
Handle SetupMainThread(s32 priority, int stack_size) { Handle SetupMainThread(s32 priority, int stack_size) {
Handle handle; Handle handle;
@ -497,6 +509,15 @@ void Reschedule() {
ResumeThreadFromWait(prev->GetHandle()); ResumeThreadFromWait(prev->GetHandle());
} }
bool IsIdleThread(Handle handle) {
Thread* thread = g_handle_table.Get<Thread>(handle);
if (!thread) {
LOG_ERROR(Kernel, "Thread not found %u", handle);
return false;
}
return thread->IsIdle();
}
ResultCode GetThreadId(u32* thread_id, Handle handle) { ResultCode GetThreadId(u32* thread_id, Handle handle) {
Thread* thread = g_handle_table.Get<Thread>(handle); Thread* thread = g_handle_table.Get<Thread>(handle);
if (thread == nullptr) if (thread == nullptr)

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@ -104,6 +104,17 @@ ResultVal<u32> GetThreadPriority(const Handle handle);
/// Set the priority of the thread specified by handle /// Set the priority of the thread specified by handle
ResultCode SetThreadPriority(Handle handle, s32 priority); ResultCode SetThreadPriority(Handle handle, s32 priority);
/**
* 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.
* @returns The handle of the idle thread
*/
Handle SetupIdleThread();
/// Whether the current thread is an idle thread
bool IsIdleThread(Handle thread);
/// Initialize threading /// Initialize threading
void ThreadingInit(); void ThreadingInit();