1 files changed, 28 insertions, 36 deletions

diff --git a/src/core/hle/kernel/mutex.cpp b/src/core/hle/kernel/mutex.cpp
index acf484659..a811db392 100644
--- a/src/core/hle/kernel/mutex.cpp
+++ b/src/core/hle/kernel/mutex.cpp
@@ -5,6 +5,8 @@
 #include <map>
 #include <vector>
 
+#include <boost/range/algorithm_ext/erase.hpp>
+
 #include "common/common.h"
 
 #include "core/hle/kernel/kernel.h"
@@ -13,16 +15,13 @@
 
 namespace Kernel {
 
-typedef std::multimap<SharedPtr<Thread>, SharedPtr<Mutex>> MutexMap;
-static MutexMap g_mutex_held_locks;
-
 /**
  * Resumes a thread waiting for the specified mutex
  * @param mutex The mutex that some thread is waiting on
  */
 static void ResumeWaitingThread(Mutex* mutex) {
     // Reset mutex lock thread handle, nothing is waiting
-    mutex->locked = false;
+    mutex->lock_count = 0;
     mutex->holding_thread = nullptr;
 
     // Find the next waiting thread for the mutex...
@@ -33,24 +32,19 @@ static void ResumeWaitingThread(Mutex* mutex) {
 }
 
 void ReleaseThreadMutexes(Thread* thread) {
-    auto locked_range = g_mutex_held_locks.equal_range(thread);
-    
-    // Release every mutex that the thread holds, and resume execution on the waiting threads
-    for (auto iter = locked_range.first; iter != locked_range.second; ++iter) {
-        ResumeWaitingThread(iter->second.get());
+    for (auto& mtx : thread->held_mutexes) {
+        ResumeWaitingThread(mtx.get());
     }
-
-    // Erase all the locks that this thread holds
-    g_mutex_held_locks.erase(thread);
+    thread->held_mutexes.clear();
 }
 
-ResultVal<SharedPtr<Mutex>> Mutex::Create(bool initial_locked, std::string name) {
+Mutex::Mutex() {}
+Mutex::~Mutex() {}
+
+SharedPtr<Mutex> Mutex::Create(bool initial_locked, std::string name) {
     SharedPtr<Mutex> mutex(new Mutex);
-    // TOOD(yuriks): Don't create Handle (see Thread::Create())
-    CASCADE_RESULT(auto unused, Kernel::g_handle_table.Create(mutex));
 
-    mutex->initial_locked = initial_locked;
-    mutex->locked = false;
+    mutex->lock_count = 0;
     mutex->name = std::move(name);
     mutex->holding_thread = nullptr;
 
@@ -58,42 +52,40 @@ ResultVal<SharedPtr<Mutex>> Mutex::Create(bool initial_locked, std::string name)
     if (initial_locked)
         mutex->Acquire();
 
-    return MakeResult<SharedPtr<Mutex>>(mutex);
+    return mutex;
 }
 
 bool Mutex::ShouldWait() {
-    return locked && holding_thread != GetCurrentThread();
+    return lock_count > 0 && holding_thread != GetCurrentThread();;
 }
 
 void Mutex::Acquire() {
     Acquire(GetCurrentThread());
 }
 
-void Mutex::Acquire(Thread* thread) {
+void Mutex::Acquire(SharedPtr<Thread> thread) {
     _assert_msg_(Kernel, !ShouldWait(), "object unavailable!");
-    if (locked)
-        return;
 
-    locked = true;
+    // Actually "acquire" the mutex only if we don't already have it...
+    if (lock_count == 0) {
+        thread->held_mutexes.insert(this);
+        holding_thread = std::move(thread);
+    }
 
-    g_mutex_held_locks.insert(std::make_pair(thread, this));
-    holding_thread = thread;
+    lock_count++;
 }
 
 void Mutex::Release() {
-    if (!locked)
-        return;
-
-    auto locked_range = g_mutex_held_locks.equal_range(holding_thread);
-
-    for (MutexMap::iterator iter = locked_range.first; iter != locked_range.second; ++iter) {
-        if (iter->second == this) {
-            g_mutex_held_locks.erase(iter);
-            break;
+    // Only release if the mutex is held...
+    if (lock_count > 0) {
+        lock_count--;
+
+        // Yield to the next thread only if we've fully released the mutex...
+        if (lock_count == 0) {
+            holding_thread->held_mutexes.erase(this);
+            ResumeWaitingThread(this);
         }
     }
-
-    ResumeWaitingThread(this);
 }
 
 } // namespace