1 files changed, 122 insertions, 0 deletions

diff --git a/src/core/hle/kernel/mutex.cpp b/src/core/hle/kernel/mutex.cpp
new file mode 100644
index 000000000..2b2cff4ea
--- /dev/null
+++ b/src/core/hle/kernel/mutex.cpp
@@ -0,0 +1,122 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.  
+
+#include <map>
+#include <vector>
+
+#include "common/common.h"
+
+#include "core/hle/kernel/kernel.h"
+#include "core/hle/kernel/thread.h"
+
+namespace Kernel {
+
+class Mutex : public Object {
+public:
+    const char* GetTypeName() { return "Mutex"; }
+
+    static Kernel::HandleType GetStaticHandleType() {  return Kernel::HandleType::Mutex; }
+    Kernel::HandleType GetHandleType() const { return Kernel::HandleType::Mutex; }
+
+    bool initial_locked;                        ///< Initial lock state when mutex was created
+    bool locked;                                ///< Current locked state
+    Handle lock_thread;                         ///< Handle to thread that currently has mutex
+    std::vector<Handle> waiting_threads;        ///< Threads that are waiting for the mutex
+};
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+typedef std::multimap<Handle, Handle> MutexMap;
+static MutexMap g_mutex_held_locks;
+
+void __MutexAcquireLock(Mutex* mutex, Handle thread) {
+    g_mutex_held_locks.insert(std::make_pair(thread, mutex->GetHandle()));
+    mutex->lock_thread = thread;
+}
+
+void __MutexAcquireLock(Mutex* mutex) {
+    Handle thread = GetCurrentThread();
+    __MutexAcquireLock(mutex, thread);
+}
+
+void __MutexEraseLock(Mutex* mutex) {
+    Handle handle = mutex->GetHandle();
+    auto locked = g_mutex_held_locks.equal_range(mutex->lock_thread);
+    for (MutexMap::iterator iter = locked.first; iter != locked.second; ++iter) {
+        if ((*iter).second == handle) {
+            g_mutex_held_locks.erase(iter);
+            break;
+        }
+    }
+    mutex->lock_thread = -1;
+}
+
+bool __LockMutex(Mutex* mutex) {
+    // Mutex alread locked?
+    if (mutex->locked) {
+        return false;
+    }
+    __MutexAcquireLock(mutex);
+    return true;
+}
+
+bool __ReleaseMutexForThread(Mutex* mutex, Handle thread) {
+    __MutexAcquireLock(mutex, thread);
+    Kernel::ResumeThreadFromWait(thread);
+    return true;
+}
+
+bool __ReleaseMutex(Mutex* mutex) {
+    __MutexEraseLock(mutex);
+    bool woke_threads = false;
+    auto iter = mutex->waiting_threads.begin();
+
+    // Find the next waiting thread for the mutex...
+    while (!woke_threads && !mutex->waiting_threads.empty()) {
+        woke_threads |= __ReleaseMutexForThread(mutex, *iter);
+        mutex->waiting_threads.erase(iter);
+    }
+    // Reset mutex lock thread handle, nothing is waiting
+    if (!woke_threads) {
+        mutex->locked = false;
+        mutex->lock_thread = -1;
+    }
+    return woke_threads;
+}
+
+/**
+ * Releases a mutex
+ * @param handle Handle to mutex to release
+ */
+Result ReleaseMutex(Handle handle) {
+    Mutex* mutex = Kernel::g_object_pool.GetFast<Mutex>(handle);
+    if (!__ReleaseMutex(mutex)) {
+        return -1;
+    }
+    return 0;
+}
+
+/**
+ * Creates a mutex
+ * @param handle Reference to handle for the newly created mutex
+ * @param initial_locked Specifies if the mutex should be locked initially
+ */
+Result CreateMutex(Handle& handle, bool initial_locked) {
+    Mutex* mutex = new Mutex;
+    handle = Kernel::g_object_pool.Create(mutex);
+
+    mutex->locked = mutex->initial_locked = initial_locked;
+
+    // Acquire mutex with current thread if initialized as locked...
+    if (mutex->locked) {
+        __MutexAcquireLock(mutex);
+
+    // Otherwise, reset lock thread handle
+    } else {
+        mutex->lock_thread = -1;
+    }
+    return 0;
+}
+
+} // namespace