From 4e33b4b42f404ff6250df15f1a48ed96ce839b77 Mon Sep 17 00:00:00 2001
From: bunnei <bunneidev@gmail.com>
Date: Sun, 7 Jan 2018 16:52:23 -0500
Subject: [PATCH] semaphore: More changes for Switch.

---
 src/core/hle/kernel/semaphore.cpp | 20 +++++++++++++-------
 src/core/hle/kernel/semaphore.h   |  8 ++++----
 2 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/src/core/hle/kernel/semaphore.cpp b/src/core/hle/kernel/semaphore.cpp
index 3f364661b..9c58aa42f 100644
--- a/src/core/hle/kernel/semaphore.cpp
+++ b/src/core/hle/kernel/semaphore.cpp
@@ -14,7 +14,8 @@ namespace Kernel {
 Semaphore::Semaphore() {}
 Semaphore::~Semaphore() {}
 
-ResultVal<SharedPtr<Semaphore>> Semaphore::Create(VAddr guest_addr, VAddr mutex_addr, std::string name) {
+ResultVal<SharedPtr<Semaphore>> Semaphore::Create(VAddr guest_addr, VAddr mutex_addr,
+                                                  std::string name) {
     SharedPtr<Semaphore> semaphore(new Semaphore);
 
     // When the semaphore is created, some slots are reserved for other threads,
@@ -37,23 +38,28 @@ bool Semaphore::ShouldWait(Thread* thread) const {
 void Semaphore::Acquire(Thread* thread) {
     if (available_count <= 0)
         return;
+
     --available_count;
     UpdateGuestState();
 }
 
-ResultVal<s32> Semaphore::Release(s32 release_count) {
-    s32 previous_count = available_count;
-    available_count += release_count;
+ResultCode Semaphore::Release(s32 target) {
+    ++available_count;
     UpdateGuestState();
 
-    WakeupAllWaitingThreads();
+    if (target == -1) {
+        // When -1, wake up all waiting threads
+        WakeupAllWaitingThreads();
+    } else {
+        // Otherwise, wake up just a single thread
+        WakeupWaitingThread(GetHighestPriorityReadyThread());
+    }
 
-    return MakeResult<s32>(previous_count);
+    return RESULT_SUCCESS;
 }
 
 void Semaphore::UpdateGuestState() {
     Memory::Write32(guest_addr, available_count);
 }
 
-
 } // namespace Kernel
diff --git a/src/core/hle/kernel/semaphore.h b/src/core/hle/kernel/semaphore.h
index 9cad4450a..e80230cac 100644
--- a/src/core/hle/kernel/semaphore.h
+++ b/src/core/hle/kernel/semaphore.h
@@ -50,11 +50,11 @@ public:
     void Acquire(Thread* thread) override;
 
     /**
-     * Releases a certain number of slots from a semaphore.
-     * @param release_count The number of slots to release
-     * @return The number of free slots the semaphore had before this call
+     * Releases a slot from a semaphore.
+     * @param target The number of threads to wakeup, -1 is all.
+     * @return ResultCode indicating if the operation succeeded.
      */
-    ResultVal<s32> Release(s32 release_count);
+    ResultCode Release(s32 target);
 
 private:
     Semaphore();