svc: Implement svcLockMutex.

1 files changed, 63 insertions, 18 deletions

diff --git a/src/core/hle/kernel/mutex.cpp b/src/core/hle/kernel/mutex.cpp
index 30dade552..1b7cda740 100644
--- a/src/core/hle/kernel/mutex.cpp
+++ b/src/core/hle/kernel/mutex.cpp
@@ -7,8 +7,10 @@
 #include <boost/range/algorithm_ext/erase.hpp>
 #include "common/assert.h"
 #include "core/core.h"
+#include "core/hle/kernel/handle_table.h"
 #include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/mutex.h"
+#include "core/hle/kernel/object_address_table.h"
 #include "core/hle/kernel/thread.h"
 
 namespace Kernel {
@@ -25,17 +27,25 @@ void ReleaseThreadMutexes(Thread* thread) {
 Mutex::Mutex() {}
 Mutex::~Mutex() {}
 
-SharedPtr<Mutex> Mutex::Create(bool initial_locked, VAddr addr, std::string name) {
+SharedPtr<Mutex> Mutex::Create(SharedPtr<Kernel::Thread> holding_thread, VAddr guest_addr,
+                               std::string name) {
     SharedPtr<Mutex> mutex(new Mutex);
 
     mutex->lock_count = 0;
-    mutex->addr = addr;
+    mutex->guest_addr = guest_addr;
     mutex->name = std::move(name);
     mutex->holding_thread = nullptr;
 
-    // Acquire mutex with current thread if initialized as locked
-    if (initial_locked)
-        mutex->Acquire(GetCurrentThread());
+    // If mutex was initialized with a holding thread, acquire it by the holding thread
+    if (holding_thread) {
+        mutex->Acquire(holding_thread.get());
+    }
+
+    // Mutexes are referenced by guest address, so track this in the kernel
+    g_object_address_table.Insert(guest_addr, mutex);
+
+    // Verify that the created mutex matches the guest state for the mutex
+    mutex->VerifyGuestState();
 
     return mutex;
 }
@@ -53,38 +63,60 @@ void Mutex::Acquire(Thread* thread) {
         thread->held_mutexes.insert(this);
         holding_thread = thread;
         thread->UpdatePriority();
+        UpdateGuestState();
         Core::System::GetInstance().PrepareReschedule();
     }
 
     lock_count++;
 }
 
-void Mutex::Release() {
-    // 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);
-            holding_thread->UpdatePriority();
-            holding_thread = nullptr;
-            WakeupAllWaitingThreads();
-            Core::System::GetInstance().PrepareReschedule();
+ResultCode Mutex::Release(Thread* thread) {
+    // We can only release the mutex if it's held by the calling thread.
+    if (thread != holding_thread) {
+        if (holding_thread) {
+            LOG_ERROR(
+                Kernel,
+                "Tried to release a mutex (owned by thread id %u) from a different thread id %u",
+                holding_thread->thread_id, thread->thread_id);
         }
+        // TODO(bunnei): Use correct error code
+        return ResultCode(-1);
+    }
+
+    // Note: It should not be possible for the situation where the mutex has a holding thread with a
+    // zero lock count to occur. The real kernel still checks for this, so we do too.
+    if (lock_count <= 0) {
+        // TODO(bunnei): Use correct error code
+        return ResultCode(-1);
+    }
+
+    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);
+        holding_thread->UpdatePriority();
+        holding_thread = nullptr;
+        WakeupAllWaitingThreads();
+        UpdateGuestState();
+        Core::System::GetInstance().PrepareReschedule();
     }
+
+    return RESULT_SUCCESS;
 }
 
 void Mutex::AddWaitingThread(SharedPtr<Thread> thread) {
     WaitObject::AddWaitingThread(thread);
     thread->pending_mutexes.insert(this);
     UpdatePriority();
+    UpdateGuestState();
 }
 
 void Mutex::RemoveWaitingThread(Thread* thread) {
     WaitObject::RemoveWaitingThread(thread);
     thread->pending_mutexes.erase(this);
     UpdatePriority();
+    UpdateGuestState();
 }
 
 void Mutex::UpdatePriority() {
@@ -103,4 +135,17 @@ void Mutex::UpdatePriority() {
     }
 }
 
-} // namespace
+void Mutex::UpdateGuestState() {
+    GuestState guest_state{Memory::Read32(guest_addr)};
+    guest_state.has_waiters.Assign(!GetWaitingThreads().empty());
+    guest_state.holding_thread_handle.Assign(holding_thread ? holding_thread->guest_handle : 0);
+    Memory::Write32(guest_addr, guest_state.raw);
+}
+
+void Mutex::VerifyGuestState() {
+    GuestState guest_state{Memory::Read32(guest_addr)};
+    ASSERT(guest_state.has_waiters == !GetWaitingThreads().empty());
+    ASSERT(guest_state.holding_thread_handle == holding_thread->guest_handle);
+}
+
+} // namespace Kernel