From 73e37d1ba2e8052ebc10a5552b74cfaa41f536e1 Mon Sep 17 00:00:00 2001
From: Kevoot <kevinholmes88@gmail.com>
Date: Tue, 26 Jun 2018 20:15:33 -0400
Subject: [PATCH] Readded changes from code review for code style and doxygen
 comments

---
 nx/include/switch/kernel/semaphore.h | 38 +++++++++++++++++++------
 nx/source/kernel/semaphore.c         | 42 +++++++++++++++-------------
 2 files changed, 52 insertions(+), 28 deletions(-)

diff --git a/nx/include/switch/kernel/semaphore.h b/nx/include/switch/kernel/semaphore.h
index f7d27302..17bbc4c1 100644
--- a/nx/include/switch/kernel/semaphore.h
+++ b/nx/include/switch/kernel/semaphore.h
@@ -1,7 +1,7 @@
 /**
  * @file semaphore.h
  * @brief Thread synchronization based on Mutex.
- * @author Kevoot
+ * @author SciresM & Kevoot
  * @copyright libnx Authors
  */
 #pragma once
@@ -9,14 +9,36 @@
 #include "mutex.h"
 #include "condvar.h"
 
+/// Semaphore structure.
 typedef struct Semaphore
 {
-    CondVar condvar;
-    Mutex mutex;
-    u64 count;
+    CondVar condvar; ///< Conditional Variable Object.
+    Mutex   mutex;   ///< Mutex Object.
+    u64     count;   ///< Internal Counter.
 } Semaphore;
 
-void semaphoreInit(Semaphore *, u64);
-void semaphoreSignal(Semaphore *);
-void semaphoreWait(Semaphore *);
-bool semaphoreTryWait(Semaphore *);
+/**
+ * @brief Initializes a semaphore and its internal counter.
+ * @param s Semaphore object.
+ * @param initial_count initial value for internal counter (typically the # of free resources).
+ */
+void semaphoreInit(Semaphore * s, u64 initial_count);
+
+/**
+ * @brief Increments the Semaphore to allow other threads to continue.
+ * @param s Semaphore object.
+ */
+void semaphoreSignal(Semaphore * s);
+
+/**
+ * @brief Decrements Semaphore and waits if 0.
+ * @param s Semaphore object.
+ */
+void semaphoreWait(Semaphore * s);
+
+/**
+ * @brief Attempts to get lock without waiting.
+ * @param s Semaphore object.
+ * @return 1 if no wait is needed for lock, 0 otherwise.
+ */
+bool semaphoreTryWait(Semaphore * s);
diff --git a/nx/source/kernel/semaphore.c b/nx/source/kernel/semaphore.c
index 86bfbeaa..328e8414 100644
--- a/nx/source/kernel/semaphore.c
+++ b/nx/source/kernel/semaphore.c
@@ -2,34 +2,36 @@
 #include "kernel/semaphore.h"
 #include "kernel/svc.h"
 
-void semaphoreInit(Semaphore *sem, u64 c) {
-    sem->count = c;
-    mutexInit(&sem->mutex);
-    condvarInit(&sem->condvar, &sem->mutex);
+void semaphoreInit(Semaphore *s, u64 initial_count) {
+    s->count = initial_count;
+    mutexInit(&s->mutex);
+    condvarInit(&s->condvar, &s->mutex);
 }
 
-void semaphoreSignal(Semaphore *sem) {
-    mutexLock(&sem->mutex);
-    sem->count++;
-    condvarWakeOne(&sem->condvar);
-    mutexUnlock(&sem->mutex);
+void semaphoreSignal(Semaphore *s) {
+    mutexLock(&s->mutex);
+    s->count++;
+    condvarWakeOne(&s->condvar);
+    mutexUnlock(&s->mutex);
 }
 
-void semaphoreWait(Semaphore *sem) {
-    mutexLock(&sem->mutex);
-    while(!(&sem->count)) {
-        condvarWait(&sem->condvar);
+void semaphoreWait(Semaphore *s) {
+    mutexLock(&s->mutex);
+    // Wait until signalled.
+    while (!s->count) {
+        condvarWait(&s->condvar);
     }
-    sem->count--;
-    mutexUnlock(&sem->mutex);
+    s->count--;
+    mutexUnlock(&s->mutex);
 }
 
-bool semaphoreTryWait(Semaphore *sem) {
-    mutexLock(&sem->mutex);
+bool semaphoreTryWait(Semaphore *s) {
+    mutexLock(&s->mutex);
     bool success = false;
-    if(sem->count) {
-        (sem->count)--;
+    // Check and immediately return success.
+    if (s->count) {
+        s->count--;
         success = true;
     }
     return success;
-}
\ No newline at end of file
+}