Atmosphere/libraries/libmesosphere/source/kern_k_synchronization_object.cpp

197 lines
6.9 KiB
C++

/*
* Copyright (c) 2018-2020 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 {
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 = this->thread_list_root; 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;
{
/* Setup the scheduling lock and sleep. */
KScopedSchedulerLockAndSleep slp(std::addressof(timer), thread, timeout);
/* Check if any of the objects are already signaled. */
for (auto i = 0; i < num_objects; ++i) {
AMS_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 the thread should terminate. */
if (thread->IsTerminationRequested()) {
slp.CancelSleep();
return svc::ResultTerminationRequested();
}
/* 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;
if (objects[i]->thread_list_tail == nullptr) {
objects[i]->thread_list_head = std::addressof(thread_nodes[i]);
} else {
objects[i]->thread_list_tail->next = std::addressof(thread_nodes[i]);
}
objects[i]->thread_list_tail = std::addressof(thread_nodes[i]);
}
/* Mark the thread as waiting. */
thread->SetCancellable();
thread->SetSyncedObject(nullptr, svc::ResultTimedOut());
thread->SetState(KThread::ThreadState_Waiting);
}
/* The lock/sleep is done, so we should be able to get our result. */
/* Thread is no longer cancellable. */
thread->ClearCancellable();
/* Cancel the timer as needed. */
if (timer != nullptr) {
timer->CancelTask(thread);
}
/* Get the wait result. */
Result wait_result;
s32 sync_index = -1;
{
KScopedSchedulerLock lk;
KSynchronizationObject *synced_obj;
wait_result = thread->GetWaitResult(std::addressof(synced_obj));
for (auto i = 0; i < num_objects; ++i) {
/* Unlink the object from the list. */
ThreadListNode *prev_ptr = reinterpret_cast<ThreadListNode *>(std::addressof(objects[i]->thread_list_head));
ThreadListNode *prev_val = nullptr;
ThreadListNode *prev, *tail_prev;
do {
prev = prev_ptr;
prev_ptr = prev_ptr->next;
tail_prev = prev_val;
prev_val = prev_ptr;
} while (prev_ptr != std::addressof(thread_nodes[i]));
if (objects[i]->thread_list_tail == std::addressof(thread_nodes[i])) {
objects[i]->thread_list_tail = tail_prev;
}
prev->next = thread_nodes[i].next;
if (objects[i] == synced_obj) {
sync_index = i;
}
}
}
/* Set output. */
*out_index = sync_index;
return wait_result;
}
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 = this->thread_list_head; cur_node != nullptr; cur_node = cur_node->next) {
KThread *thread = cur_node->thread;
if (thread->GetState() == KThread::ThreadState_Waiting) {
thread->SetSyncedObject(this, result);
thread->SetState(KThread::ThreadState_Runnable);
}
}
}
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 = this->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 (this->thread_list_head == nullptr) {
MESOSPHERE_RELEASE_LOG(" None\n");
}
}
#endif
}
}