Merge pull request #2238 from lioncash/thread

kernel/thread: Amend conditional test and assignment within UpdatePriority()
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bunnei 2019-03-17 22:27:33 -04:00 committed by GitHub
commit 30f228a8c9
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2 changed files with 40 additions and 20 deletions

View file

@ -7,8 +7,6 @@
#include <optional>
#include <vector>
#include <boost/range/algorithm_ext/erase.hpp>
#include "common/assert.h"
#include "common/common_types.h"
#include "common/logging/log.h"
@ -258,8 +256,8 @@ void Thread::AddMutexWaiter(SharedPtr<Thread> thread) {
if (thread->lock_owner == this) {
// If the thread is already waiting for this thread to release the mutex, ensure that the
// waiters list is consistent and return without doing anything.
auto itr = std::find(wait_mutex_threads.begin(), wait_mutex_threads.end(), thread);
ASSERT(itr != wait_mutex_threads.end());
const auto iter = std::find(wait_mutex_threads.begin(), wait_mutex_threads.end(), thread);
ASSERT(iter != wait_mutex_threads.end());
return;
}
@ -267,11 +265,16 @@ void Thread::AddMutexWaiter(SharedPtr<Thread> thread) {
ASSERT(thread->lock_owner == nullptr);
// Ensure that the thread is not already in the list of mutex waiters
auto itr = std::find(wait_mutex_threads.begin(), wait_mutex_threads.end(), thread);
ASSERT(itr == wait_mutex_threads.end());
const auto iter = std::find(wait_mutex_threads.begin(), wait_mutex_threads.end(), thread);
ASSERT(iter == wait_mutex_threads.end());
// Keep the list in an ordered fashion
const auto insertion_point = std::find_if(
wait_mutex_threads.begin(), wait_mutex_threads.end(),
[&thread](const auto& entry) { return entry->GetPriority() > thread->GetPriority(); });
wait_mutex_threads.insert(insertion_point, thread);
thread->lock_owner = this;
wait_mutex_threads.emplace_back(std::move(thread));
UpdatePriority();
}
@ -279,31 +282,42 @@ void Thread::RemoveMutexWaiter(SharedPtr<Thread> thread) {
ASSERT(thread->lock_owner == this);
// Ensure that the thread is in the list of mutex waiters
auto itr = std::find(wait_mutex_threads.begin(), wait_mutex_threads.end(), thread);
ASSERT(itr != wait_mutex_threads.end());
const auto iter = std::find(wait_mutex_threads.begin(), wait_mutex_threads.end(), thread);
ASSERT(iter != wait_mutex_threads.end());
wait_mutex_threads.erase(iter);
boost::remove_erase(wait_mutex_threads, thread);
thread->lock_owner = nullptr;
UpdatePriority();
}
void Thread::UpdatePriority() {
// Find the highest priority among all the threads that are waiting for this thread's lock
// If any of the threads waiting on the mutex have a higher priority
// (taking into account priority inheritance), then this thread inherits
// that thread's priority.
u32 new_priority = nominal_priority;
for (const auto& thread : wait_mutex_threads) {
if (thread->nominal_priority < new_priority)
new_priority = thread->nominal_priority;
if (!wait_mutex_threads.empty()) {
if (wait_mutex_threads.front()->current_priority < new_priority) {
new_priority = wait_mutex_threads.front()->current_priority;
}
}
if (new_priority == current_priority)
if (new_priority == current_priority) {
return;
}
scheduler->SetThreadPriority(this, new_priority);
current_priority = new_priority;
if (!lock_owner) {
return;
}
// Ensure that the thread is within the correct location in the waiting list.
lock_owner->RemoveMutexWaiter(this);
lock_owner->AddMutexWaiter(this);
// Recursively update the priority of the thread that depends on the priority of this one.
if (lock_owner)
lock_owner->UpdatePriority();
}

View file

@ -401,8 +401,14 @@ private:
VAddr entry_point = 0;
VAddr stack_top = 0;
u32 nominal_priority = 0; ///< Nominal thread priority, as set by the emulated application
u32 current_priority = 0; ///< Current thread priority, can be temporarily changed
/// Nominal thread priority, as set by the emulated application.
/// The nominal priority is the thread priority without priority
/// inheritance taken into account.
u32 nominal_priority = 0;
/// Current thread priority. This may change over the course of the
/// thread's lifetime in order to facilitate priority inheritance.
u32 current_priority = 0;
u64 total_cpu_time_ticks = 0; ///< Total CPU running ticks.
u64 last_running_ticks = 0; ///< CPU tick when thread was last running