Atmosphere/libraries/libmesosphere/source/kern_k_synchronization_object.cpp

204 lines
7.5 KiB
C++

/*
* Copyright (c) Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <mesosphere.hpp>
namespace ams::kern {
namespace {
class ThreadQueueImplForKSynchronizationObjectWait final : public KThreadQueueWithoutEndWait {
private:
using ThreadListNode = KSynchronizationObject::ThreadListNode;
private:
KSynchronizationObject **m_objects;
ThreadListNode *m_nodes;
s32 m_count;
public:
constexpr ThreadQueueImplForKSynchronizationObjectWait(KSynchronizationObject **o, ThreadListNode *n, s32 c) : m_objects(o), m_nodes(n), m_count(c) { /* ... */ }
virtual void NotifyAvailable(KThread *waiting_thread, KSynchronizationObject *signaled_object, Result wait_result) override {
/* Determine the sync index, and unlink all nodes. */
s32 sync_index = -1;
for (auto i = 0; i < m_count; ++i) {
/* Check if this is the signaled object. */
if (m_objects[i] == signaled_object && sync_index == -1) {
sync_index = i;
}
/* Unlink the current node from the current object. */
m_objects[i]->UnlinkNode(std::addressof(m_nodes[i]));
}
/* Set the waiting thread's sync index. */
waiting_thread->SetSyncedIndex(sync_index);
/* Set the waiting thread as not cancellable. */
waiting_thread->ClearCancellable();
/* Invoke the base end wait handler. */
KThreadQueue::EndWait(waiting_thread, wait_result);
}
virtual void CancelWait(KThread *waiting_thread, Result wait_result, bool cancel_timer_task) override {
/* Remove all nodes from our list. */
for (auto i = 0; i < m_count; ++i) {
m_objects[i]->UnlinkNode(std::addressof(m_nodes[i]));
}
/* Set the waiting thread as not cancellable. */
waiting_thread->ClearCancellable();
/* Invoke the base cancel wait handler. */
KThreadQueue::CancelWait(waiting_thread, wait_result, cancel_timer_task);
}
};
}
void KSynchronizationObject::Finalize() {
MESOSPHERE_ASSERT_THIS();
/* If auditing, ensure that the object has no waiters. */
#if defined(MESOSPHERE_BUILD_FOR_AUDITING)
{
KScopedSchedulerLock sl;
for (auto *cur_node = m_thread_list_head; cur_node != nullptr; cur_node = cur_node->next) {
KThread *thread = cur_node->thread;
MESOSPHERE_LOG("KSynchronizationObject::Finalize(%p) with %p (id=%ld) waiting.\n", this, thread, thread->GetId());
}
}
#endif
this->OnFinalizeSynchronizationObject();
KAutoObject::Finalize();
}
Result KSynchronizationObject::Wait(s32 *out_index, KSynchronizationObject **objects, const s32 num_objects, s64 timeout) {
/* Allocate space on stack for thread nodes. */
ThreadListNode *thread_nodes = static_cast<ThreadListNode *>(__builtin_alloca(sizeof(ThreadListNode) * num_objects));
/* Prepare for wait. */
KThread *thread = GetCurrentThreadPointer();
KHardwareTimer *timer;
ThreadQueueImplForKSynchronizationObjectWait wait_queue(objects, thread_nodes, num_objects);
{
/* Setup the scheduling lock and sleep. */
KScopedSchedulerLockAndSleep slp(std::addressof(timer), thread, timeout);
/* Check if the thread should terminate. */
if (thread->IsTerminationRequested()) {
slp.CancelSleep();
return svc::ResultTerminationRequested();
}
/* Check if any of the objects are already signaled. */
for (auto i = 0; i < num_objects; ++i) {
MESOSPHERE_ASSERT(objects[i] != nullptr);
if (objects[i]->IsSignaled()) {
*out_index = i;
slp.CancelSleep();
return ResultSuccess();
}
}
/* Check if the timeout is zero. */
if (timeout == 0) {
slp.CancelSleep();
return svc::ResultTimedOut();
}
/* Check if waiting was canceled. */
if (thread->IsWaitCancelled()) {
slp.CancelSleep();
thread->ClearWaitCancelled();
return svc::ResultCancelled();
}
/* Add the waiters. */
for (auto i = 0; i < num_objects; ++i) {
thread_nodes[i].thread = thread;
thread_nodes[i].next = nullptr;
objects[i]->LinkNode(std::addressof(thread_nodes[i]));
}
/* Mark the thread as cancellable. */
thread->SetCancellable();
/* Clear the thread's synced index. */
thread->SetSyncedIndex(-1);
/* Wait for an object to be signaled. */
wait_queue.SetHardwareTimer(timer);
thread->BeginWait(std::addressof(wait_queue));
}
/* Set the output index. */
*out_index = thread->GetSyncedIndex();
/* Get the wait result. */
return thread->GetWaitResult();
}
void KSynchronizationObject::NotifyAvailable(Result result) {
MESOSPHERE_ASSERT_THIS();
KScopedSchedulerLock sl;
/* If we're not signaled, we've nothing to notify. */
if (!this->IsSignaled()) {
return;
}
/* Iterate over each thread. */
for (auto *cur_node = m_thread_list_head; cur_node != nullptr; cur_node = cur_node->next) {
cur_node->thread->NotifyAvailable(this, result);
}
}
void KSynchronizationObject::DumpWaiters() {
MESOSPHERE_ASSERT_THIS();
/* If debugging, dump the list of waiters. */
#if defined(MESOSPHERE_BUILD_FOR_DEBUGGING)
{
KScopedSchedulerLock sl;
MESOSPHERE_RELEASE_LOG("Threads waiting on %p:\n", this);
for (auto *cur_node = m_thread_list_head; cur_node != nullptr; cur_node = cur_node->next) {
KThread *thread = cur_node->thread;
if (KProcess *process = thread->GetOwnerProcess(); process != nullptr) {
MESOSPHERE_RELEASE_LOG(" %p tid=%ld pid=%ld (%s)\n", thread, thread->GetId(), process->GetId(), process->GetName());
} else {
MESOSPHERE_RELEASE_LOG(" %p tid=%ld (Kernel)\n", thread, thread->GetId());
}
}
/* If we didn't have any waiters, print so. */
if (m_thread_list_head == nullptr) {
MESOSPHERE_RELEASE_LOG(" None\n");
}
}
#endif
}
}