os: implement SdkRecursiveMutex

libraries/libstratosphere/source/os/os_sdk_condition_variable.cpp

@@ -45,4 +45,58 @@ namespace ams::os {
         return status == ConditionVariableStatus::Success;
     }
 
+    void SdkConditionVariableType::Wait(SdkRecursiveMutexType &mutex) {
+        /* Check preconditions. */
+        AMS_ABORT_UNLESS(os::IsSdkRecursiveMutexLockedByCurrentThread(std::addressof(mutex)));
+        AMS_ABORT_UNLESS(mutex.recursive_count == 1);
+
+        /* Decrement the mutex's recursive count. */
+        --mutex.recursive_count;
+
+        /* Wait on the mutex. */
+        GetReference(this->_storage).Wait(GetPointer(mutex._storage));
+
+        /* Increment the mutex's recursive count. */
+        ++mutex.recursive_count;
+
+        /* Check that the mutex's recursive count is valid. */
+        AMS_ABORT_UNLESS(mutex.recursive_count != 0);
+    }
+
+    bool SdkConditionVariableType::TimedWait(SdkRecursiveMutexType &mutex, TimeSpan timeout) {
+        /* Check preconditions. */
+        AMS_ASSERT(timeout.GetNanoSeconds() >= 0);
+        AMS_ABORT_UNLESS(os::IsSdkRecursiveMutexLockedByCurrentThread(std::addressof(mutex)));
+
+        /* Handle zero timeout by unlocking and re-locking. */
+        if (timeout == TimeSpan(0)) {
+            /* NOTE: Nintendo doesn't check recursive_count here...seems really suspicious? */
+            /*       Not sure that this is correct, or if they just forgot to check. */
+            GetReference(mutex._storage).Leave();
+            GetReference(mutex._storage).Enter();
+            return false;
+        }
+
+        /* Check that the mutex is held exactly once. */
+        AMS_ABORT_UNLESS(mutex.recursive_count == 1);
+
+        /* Decrement the mutex's recursive count. */
+        --mutex.recursive_count;
+
+        /* Create timeout helper. */
+        impl::TimeoutHelper timeout_helper(timeout);
+
+        /* Perform timed wait. */
+        auto status = GetReference(this->_storage).TimedWait(GetPointer(mutex._storage), timeout_helper);
+
+        /* Increment the mutex's recursive count. */
+        ++mutex.recursive_count;
+
+        /* Check that the mutex's recursive count is valid. */
+        AMS_ABORT_UNLESS(mutex.recursive_count != 0);
+
+        /* Return whether we succeeded. */
+        return status == ConditionVariableStatus::Success;
+    }
+
 }

libraries/libstratosphere/source/os/os_sdk_mutex.cpp

@@ -18,25 +18,36 @@
 namespace ams::os {
 
     void InitializeSdkMutex(SdkMutexType *mutex) {
+        /* Initialize the critical section. */
         GetReference(mutex->_storage).Initialize();
     }
 
     bool IsSdkMutexLockedByCurrentThread(const SdkMutexType *mutex) {
+        /* Check whether the critical section is held. */
         return GetReference(mutex->_storage).IsLockedByCurrentThread();
     }
 
     void LockSdkMutex(SdkMutexType *mutex) {
+        /* Check pre-conditions. */
         AMS_ABORT_UNLESS(!IsSdkMutexLockedByCurrentThread(mutex));
+
+        /* Enter the critical section. */
         return GetReference(mutex->_storage).Enter();
     }
 
     bool TryLockSdkMutex(SdkMutexType *mutex) {
+        /* Check pre-conditions. */
         AMS_ABORT_UNLESS(!IsSdkMutexLockedByCurrentThread(mutex));
+
+        /* Try to enter the critical section. */
         return GetReference(mutex->_storage).TryEnter();
     }
 
     void UnlockSdkMutex(SdkMutexType *mutex) {
+        /* Check pre-conditions. */
         AMS_ABORT_UNLESS(IsSdkMutexLockedByCurrentThread(mutex));
+
+        /* Leave the critical section. */
         return GetReference(mutex->_storage).Leave();
     }
 

libraries/libstratosphere/source/os/os_sdk_recursive_mutex.cpp

@@ -0,0 +1,69 @@
+/*
+ * 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>
+
+namespace ams::os {
+
+    void InitializeSdkRecursiveMutex(SdkRecursiveMutexType *rmutex) {
+        /* Initialize the critical section. */
+        GetReference(rmutex->_storage).Initialize();
+
+        /* Set recursive count. */
+        rmutex->recursive_count = 0;
+    }
+
+    bool IsSdkRecursiveMutexLockedByCurrentThread(const SdkRecursiveMutexType *rmutex) {
+        /* Check whether the critical section is held. */
+        return GetReference(rmutex->_storage).IsLockedByCurrentThread();
+    }
+
+    void LockSdkRecursiveMutex(SdkRecursiveMutexType *rmutex) {
+        /* If we don't hold the mutex, enter the critical section. */
+        if (!IsSdkRecursiveMutexLockedByCurrentThread(rmutex)) {
+            GetReference(rmutex->_storage).Enter();
+        }
+
+        /* Increment (and check) recursive count. */
+        ++rmutex->recursive_count;
+        AMS_ABORT_UNLESS(rmutex->recursive_count != 0);
+    }
+
+    bool TryLockSdkRecursiveMutex(SdkRecursiveMutexType *rmutex) {
+        /* If we don't hold the mutex, try to enter the critical section. */
+        if (!IsSdkRecursiveMutexLockedByCurrentThread(rmutex)) {
+            if (!GetReference(rmutex->_storage).TryEnter()) {
+                return false;
+            }
+        }
+
+        /* Increment (and check) recursive count. */
+        ++rmutex->recursive_count;
+        AMS_ABORT_UNLESS(rmutex->recursive_count != 0);
+
+        return true;
+    }
+
+    void UnlockSdkRecursiveMutex(SdkRecursiveMutexType *rmutex) {
+        /* Check pre-conditions. */
+        AMS_ABORT_UNLESS(IsSdkRecursiveMutexLockedByCurrentThread(rmutex));
+
+        /* Decrement recursive count, and leave critical section if we no longer hold the mutex. */
+        if ((--rmutex->recursive_count) == 0) {
+            GetReference(rmutex->_storage).Leave();
+        }
+    }
+
+}