From f0bfb24c61ceb61b621ba38bcc1a1aa020a9d397 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Tue, 12 Feb 2019 22:03:48 -0500
Subject: [PATCH 1/2] threadsafe_queue: Remove NeedSize template parameter

The necessity of this parameter is dubious at best, and in 2019 probably
offers completely negligible savings as opposed to just leaving this
enabled. This removes it and simplifies the overall interface.
---
 src/common/threadsafe_queue.h | 24 +++++++++++-------------
 src/core/core_timing.cpp      |  4 ++--
 2 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/src/common/threadsafe_queue.h b/src/common/threadsafe_queue.h
index edf13bc49..2660b118a 100644
--- a/src/common/threadsafe_queue.h
+++ b/src/common/threadsafe_queue.h
@@ -14,10 +14,10 @@
 #include "common/common_types.h"
 
 namespace Common {
-template <typename T, bool NeedSize = true>
+template <typename T>
 class SPSCQueue {
 public:
-    SPSCQueue() : size(0) {
+    SPSCQueue() {
         write_ptr = read_ptr = new ElementPtr();
     }
     ~SPSCQueue() {
@@ -26,12 +26,11 @@ public:
     }
 
     u32 Size() const {
-        static_assert(NeedSize, "using Size() on FifoQueue without NeedSize");
         return size.load();
     }
 
     bool Empty() const {
-        return !read_ptr->next.load();
+        return Size() == 0;
     }
 
     T& Front() const {
@@ -47,13 +46,13 @@ public:
         ElementPtr* new_ptr = new ElementPtr();
         write_ptr->next.store(new_ptr, std::memory_order_release);
         write_ptr = new_ptr;
-        if (NeedSize)
-            size++;
+
+        ++size;
     }
 
     void Pop() {
-        if (NeedSize)
-            size--;
+        --size;
+
         ElementPtr* tmpptr = read_ptr;
         // advance the read pointer
         read_ptr = tmpptr->next.load();
@@ -66,8 +65,7 @@ public:
         if (Empty())
             return false;
 
-        if (NeedSize)
-            size--;
+        --size;
 
         ElementPtr* tmpptr = read_ptr;
         read_ptr = tmpptr->next.load(std::memory_order_acquire);
@@ -103,13 +101,13 @@ private:
 
     ElementPtr* write_ptr;
     ElementPtr* read_ptr;
-    std::atomic<u32> size;
+    std::atomic<u32> size{0};
 };
 
 // a simple thread-safe,
 // single reader, multiple writer queue
 
-template <typename T, bool NeedSize = true>
+template <typename T>
 class MPSCQueue {
 public:
     u32 Size() const {
@@ -144,7 +142,7 @@ public:
     }
 
 private:
-    SPSCQueue<T, NeedSize> spsc_queue;
+    SPSCQueue<T> spsc_queue;
     std::mutex write_lock;
 };
 } // namespace Common
diff --git a/src/core/core_timing.cpp b/src/core/core_timing.cpp
index 2b7ca9766..0308030c5 100644
--- a/src/core/core_timing.cpp
+++ b/src/core/core_timing.cpp
@@ -54,10 +54,10 @@ static std::vector<Event> event_queue;
 static u64 event_fifo_id;
 // the queue for storing the events from other threads threadsafe until they will be added
 // to the event_queue by the emu thread
-static Common::MPSCQueue<Event, false> ts_queue;
+static Common::MPSCQueue<Event> ts_queue;
 
 // the queue for unscheduling the events from other threads threadsafe
-static Common::MPSCQueue<std::pair<const EventType*, u64>, false> unschedule_queue;
+static Common::MPSCQueue<std::pair<const EventType*, u64>> unschedule_queue;
 
 constexpr int MAX_SLICE_LENGTH = 20000;
 

From 0829ef97cac6cb96c49d1401433d9f46639bfeb8 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Tue, 12 Feb 2019 22:12:23 -0500
Subject: [PATCH 2/2] threadsafe_queue: Use std::size_t for representing size

Makes it consistent with the regular standard containers in terms of
size representation. This also gets rid of dependence on our own
type aliases, removing the need for an include.
---
 src/common/threadsafe_queue.h | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/common/threadsafe_queue.h b/src/common/threadsafe_queue.h
index 2660b118a..f553efdc9 100644
--- a/src/common/threadsafe_queue.h
+++ b/src/common/threadsafe_queue.h
@@ -7,11 +7,10 @@
 // a simple lockless thread-safe,
 // single reader, single writer queue
 
-#include <algorithm>
 #include <atomic>
 #include <cstddef>
 #include <mutex>
-#include "common/common_types.h"
+#include <utility>
 
 namespace Common {
 template <typename T>
@@ -25,7 +24,7 @@ public:
         delete read_ptr;
     }
 
-    u32 Size() const {
+    std::size_t Size() const {
         return size.load();
     }
 
@@ -87,7 +86,7 @@ private:
     // and a pointer to the next ElementPtr
     class ElementPtr {
     public:
-        ElementPtr() : next(nullptr) {}
+        ElementPtr() {}
         ~ElementPtr() {
             ElementPtr* next_ptr = next.load();
 
@@ -96,12 +95,12 @@ private:
         }
 
         T current;
-        std::atomic<ElementPtr*> next;
+        std::atomic<ElementPtr*> next{nullptr};
     };
 
     ElementPtr* write_ptr;
     ElementPtr* read_ptr;
-    std::atomic<u32> size{0};
+    std::atomic_size_t size{0};
 };
 
 // a simple thread-safe,
@@ -110,7 +109,7 @@ private:
 template <typename T>
 class MPSCQueue {
 public:
-    u32 Size() const {
+    std::size_t Size() const {
         return spsc_queue.Size();
     }