Atmosphere/libraries/libstratosphere/source/os/impl/os_waitable_manager_impl.cpp
2020-05-08 03:12:51 -07:00

166 lines
6 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 <stratosphere.hpp>
#include "os_waitable_manager_impl.hpp"
#include "os_waitable_object_list.hpp"
#include "os_tick_manager.hpp"
namespace ams::os::impl {
WaitableHolderBase *WaitableManagerImpl::WaitAnyImpl(bool infinite, TimeSpan timeout) {
/* Prepare for processing. */
this->signaled_holder = nullptr;
this->target_impl.SetCurrentThreadHandleForCancelWait();
WaitableHolderBase *result = this->LinkHoldersToObjectList();
/* Check if we've been signaled. */
{
std::scoped_lock lk(this->cs_wait);
if (this->signaled_holder != nullptr) {
result = this->signaled_holder;
}
}
/* Process object array. */
if (result == nullptr) {
result = this->WaitAnyHandleImpl(infinite, timeout);
}
/* Unlink holders from the current object list. */
this->UnlinkHoldersFromObjectList();
this->target_impl.ClearCurrentThreadHandleForCancelWait();
return result;
}
WaitableHolderBase *WaitableManagerImpl::WaitAnyHandleImpl(bool infinite, TimeSpan timeout) {
Handle object_handles[MaximumHandleCount];
WaitableHolderBase *objects[MaximumHandleCount];
const s32 count = this->BuildHandleArray(object_handles, objects, MaximumHandleCount);
const TimeSpan end_time = infinite ? TimeSpan::FromNanoSeconds(std::numeric_limits<s64>::max()) : GetCurrentTick().ToTimeSpan() + timeout;
while (true) {
this->current_time = GetCurrentTick().ToTimeSpan();
TimeSpan min_timeout = 0;
WaitableHolderBase *min_timeout_object = this->RecalculateNextTimeout(&min_timeout, end_time);
s32 index;
if (infinite && min_timeout_object == nullptr) {
index = this->target_impl.WaitAny(object_handles, MaximumHandleCount, count);
} else {
if (count == 0 && min_timeout == 0) {
index = WaitTimedOut;
} else {
index = this->target_impl.TimedWaitAny(object_handles, MaximumHandleCount, count, min_timeout);
AMS_ABORT_UNLESS(index != WaitInvalid);
}
}
switch (index) {
case WaitTimedOut:
if (min_timeout_object) {
this->current_time = GetCurrentTick().ToTimeSpan();
if (min_timeout_object->IsSignaled() == TriBool::True) {
std::scoped_lock lk(this->cs_wait);
this->signaled_holder = min_timeout_object;
return this->signaled_holder;
}
continue;
}
return nullptr;
case WaitCancelled:
if (this->signaled_holder) {
return this->signaled_holder;
}
continue;
default: /* 0 - 0x3F, valid. */
{
std::scoped_lock lk(this->cs_wait);
this->signaled_holder = objects[index];
return this->signaled_holder;
}
}
}
}
s32 WaitableManagerImpl::BuildHandleArray(Handle out_handles[], WaitableHolderBase *out_objects[], s32 num) {
s32 count = 0;
for (WaitableHolderBase &holder_base : this->waitable_list) {
if (Handle handle = holder_base.GetHandle(); handle != svc::InvalidHandle) {
AMS_ASSERT(count < num);
out_handles[count] = handle;
out_objects[count] = &holder_base;
count++;
}
}
return count;
}
WaitableHolderBase *WaitableManagerImpl::LinkHoldersToObjectList() {
WaitableHolderBase *signaled_holder = nullptr;
for (WaitableHolderBase &holder_base : this->waitable_list) {
TriBool is_signaled = holder_base.LinkToObjectList();
if (signaled_holder == nullptr && is_signaled == TriBool::True) {
signaled_holder = &holder_base;
}
}
return signaled_holder;
}
void WaitableManagerImpl::UnlinkHoldersFromObjectList() {
for (WaitableHolderBase &holder_base : this->waitable_list) {
holder_base.UnlinkFromObjectList();
}
}
WaitableHolderBase *WaitableManagerImpl::RecalculateNextTimeout(TimeSpan *out_min_timeout, TimeSpan end_time) {
WaitableHolderBase *min_timeout_holder = nullptr;
TimeSpan min_time = end_time;
for (WaitableHolderBase &holder_base : this->waitable_list) {
if (const TimeSpan cur_time = holder_base.GetAbsoluteWakeupTime(); cur_time < min_time) {
min_timeout_holder = &holder_base;
min_time = cur_time;
}
}
if (min_time < this->current_time) {
*out_min_timeout = 0;
} else {
*out_min_timeout = min_time - this->current_time;
}
return min_timeout_holder;
}
void WaitableManagerImpl::SignalAndWakeupThread(WaitableHolderBase *holder_base) {
std::scoped_lock lk(this->cs_wait);
if (this->signaled_holder == nullptr) {
this->signaled_holder = holder_base;
this->target_impl.CancelWait();
}
}
}