3 files changed, 62 insertions, 30 deletions

diff --git a/src/core/hle/kernel/svc.cpp b/src/core/hle/kernel/svc.cpp
index 6b2995fe2..7b41c9cfd 100644
--- a/src/core/hle/kernel/svc.cpp
+++ b/src/core/hle/kernel/svc.cpp
@@ -650,12 +650,27 @@ static ResultCode SignalProcessWideKey(VAddr condition_variable_addr, s32 target
 
         ASSERT(thread->condvar_wait_address == condition_variable_addr);
 
-        // If the mutex is not yet acquired, acquire it.
-        u32 mutex_val = Memory::Read32(thread->mutex_wait_address);
+        size_t current_core = Core::System::GetInstance().CurrentCoreIndex();
+
+        auto& monitor = Core::System::GetInstance().Monitor();
+
+        // Atomically read the value of the mutex.
+        u32 mutex_val = 0;
+        do {
+            monitor.SetExclusive(current_core, thread->mutex_wait_address);
+
+            // If the mutex is not yet acquired, acquire it.
+            mutex_val = Memory::Read32(thread->mutex_wait_address);
+
+            if (mutex_val != 0) {
+                monitor.ClearExclusive();
+                break;
+            }
+        } while (!monitor.ExclusiveWrite32(current_core, thread->mutex_wait_address,
+                                           thread->wait_handle));
 
         if (mutex_val == 0) {
             // We were able to acquire the mutex, resume this thread.
-            Memory::Write32(thread->mutex_wait_address, thread->wait_handle);
             ASSERT(thread->status == ThreadStatus::WaitMutex);
             thread->ResumeFromWait();
 
@@ -668,7 +683,19 @@ static ResultCode SignalProcessWideKey(VAddr condition_variable_addr, s32 target
             thread->condvar_wait_address = 0;
             thread->wait_handle = 0;
         } else {
-            // Couldn't acquire the mutex, block the thread.
+            // Atomically signal that the mutex now has a waiting thread.
+            do {
+                monitor.SetExclusive(current_core, thread->mutex_wait_address);
+
+                // Ensure that the mutex value is still what we expect.
+                u32 value = Memory::Read32(thread->mutex_wait_address);
+                // TODO(Subv): When this happens, the kernel just clears the exclusive state and
+                // retries the initial read for this thread.
+                ASSERT_MSG(mutex_val == value, "Unhandled synchronization primitive case");
+            } while (!monitor.ExclusiveWrite32(current_core, thread->mutex_wait_address,
+                                               mutex_val | Mutex::MutexHasWaitersFlag));
+
+            // The mutex is already owned by some other thread, make this thread wait on it.
             Handle owner_handle = static_cast<Handle>(mutex_val & Mutex::MutexOwnerMask);
             auto owner = g_handle_table.Get<Thread>(owner_handle);
             ASSERT(owner);
@@ -676,9 +703,6 @@ static ResultCode SignalProcessWideKey(VAddr condition_variable_addr, s32 target
             thread->status = ThreadStatus::WaitMutex;
             thread->wakeup_callback = nullptr;
 
-            // Signal that the mutex now has a waiting thread.
-            Memory::Write32(thread->mutex_wait_address, mutex_val | Mutex::MutexHasWaitersFlag);
-
             owner->AddMutexWaiter(thread);
 
             Core::System::GetInstance().CpuCore(thread->processor_id).PrepareReschedule();
diff --git a/src/core/hle/service/set/set.cpp b/src/core/hle/service/set/set.cpp
index 886133b74..4195c9067 100644
--- a/src/core/hle/service/set/set.cpp
+++ b/src/core/hle/service/set/set.cpp
@@ -11,44 +11,51 @@
 
 namespace Service::Set {
 
+constexpr std::array<LanguageCode, 17> available_language_codes = {{
+    LanguageCode::JA,
+    LanguageCode::EN_US,
+    LanguageCode::FR,
+    LanguageCode::DE,
+    LanguageCode::IT,
+    LanguageCode::ES,
+    LanguageCode::ZH_CN,
+    LanguageCode::KO,
+    LanguageCode::NL,
+    LanguageCode::PT,
+    LanguageCode::RU,
+    LanguageCode::ZH_TW,
+    LanguageCode::EN_GB,
+    LanguageCode::FR_CA,
+    LanguageCode::ES_419,
+    LanguageCode::ZH_HANS,
+    LanguageCode::ZH_HANT,
+}};
+
 void SET::GetAvailableLanguageCodes(Kernel::HLERequestContext& ctx) {
-    static constexpr std::array<LanguageCode, 17> available_language_codes = {{
-        LanguageCode::JA,
-        LanguageCode::EN_US,
-        LanguageCode::FR,
-        LanguageCode::DE,
-        LanguageCode::IT,
-        LanguageCode::ES,
-        LanguageCode::ZH_CN,
-        LanguageCode::KO,
-        LanguageCode::NL,
-        LanguageCode::PT,
-        LanguageCode::RU,
-        LanguageCode::ZH_TW,
-        LanguageCode::EN_GB,
-        LanguageCode::FR_CA,
-        LanguageCode::ES_419,
-        LanguageCode::ZH_HANS,
-        LanguageCode::ZH_HANT,
-    }};
     ctx.WriteBuffer(available_language_codes);
 
-    IPC::ResponseBuilder rb{ctx, 4};
+    IPC::ResponseBuilder rb{ctx, 3};
     rb.Push(RESULT_SUCCESS);
-    rb.Push(static_cast<u64>(available_language_codes.size()));
+    rb.Push(static_cast<u32>(available_language_codes.size()));
 
     LOG_DEBUG(Service_SET, "called");
 }
 
+void SET::GetAvailableLanguageCodeCount(Kernel::HLERequestContext& ctx) {
+    IPC::ResponseBuilder rb{ctx, 3};
+    rb.Push(RESULT_SUCCESS);
+    rb.Push(static_cast<u32>(available_language_codes.size()));
+}
+
 SET::SET() : ServiceFramework("set") {
     static const FunctionInfo functions[] = {
         {0, nullptr, "GetLanguageCode"},
         {1, &SET::GetAvailableLanguageCodes, "GetAvailableLanguageCodes"},
         {2, nullptr, "MakeLanguageCode"},
-        {3, nullptr, "GetAvailableLanguageCodeCount"},
+        {3, &SET::GetAvailableLanguageCodeCount, "GetAvailableLanguageCodeCount"},
         {4, nullptr, "GetRegionCode"},
         {5, &SET::GetAvailableLanguageCodes, "GetAvailableLanguageCodes2"},
-        {6, nullptr, "GetAvailableLanguageCodeCount2"},
+        {6, &SET::GetAvailableLanguageCodeCount, "GetAvailableLanguageCodeCount2"},
         {7, nullptr, "GetKeyCodeMap"},
         {8, nullptr, "GetQuestFlag"},
     };
diff --git a/src/core/hle/service/set/set.h b/src/core/hle/service/set/set.h
index ec0df0152..a2472ec4c 100644
--- a/src/core/hle/service/set/set.h
+++ b/src/core/hle/service/set/set.h
@@ -36,6 +36,7 @@ public:
 
 private:
     void GetAvailableLanguageCodes(Kernel::HLERequestContext& ctx);
+    void GetAvailableLanguageCodeCount(Kernel::HLERequestContext& ctx);
 };
 
 } // namespace Service::Set