From 9036b9d8e80aa72daf4d7258ba64aac0aa04733c Mon Sep 17 00:00:00 2001
From: EmptyChaos <EmptyChaos@users.noreply.github.com>
Date: Wed, 6 Jul 2016 10:37:59 +0000
Subject: [PATCH] SectorReader: Fix cache line bias

Minor bug where SectorReader::GetEmptyCacheLine was biased towards
the first hit.
---
 Source/Core/DiscIO/Blob.cpp      | 15 +++++++++------
 Source/Core/DiscIO/DriveBlob.cpp |  4 ++--
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/Source/Core/DiscIO/Blob.cpp b/Source/Core/DiscIO/Blob.cpp
index 32c559b6eb..a3d9d8deb8 100644
--- a/Source/Core/DiscIO/Blob.cpp
+++ b/Source/Core/DiscIO/Blob.cpp
@@ -57,12 +57,15 @@ SectorReader::Cache* SectorReader::GetEmptyCacheLine()
 {
   Cache* oldest = &m_cache[0];
   // Find the Least Recently Used cache line to replace.
-  for (auto& cache_entry : m_cache)
-  {
-    if (cache_entry.IsLessRecentlyUsedThan(*oldest))
-      oldest = &cache_entry;
-    cache_entry.ShiftLRU();
-  }
+  std::for_each(m_cache.begin() + 1, m_cache.end(), [&](Cache& line) {
+    if (line.IsLessRecentlyUsedThan(*oldest))
+    {
+      oldest->ShiftLRU();
+      oldest = &line;
+      return;
+    }
+    line.ShiftLRU();
+  });
   oldest->Reset();
   return oldest;
 }
diff --git a/Source/Core/DiscIO/DriveBlob.cpp b/Source/Core/DiscIO/DriveBlob.cpp
index f522923f33..5a4c5aa2f1 100644
--- a/Source/Core/DiscIO/DriveBlob.cpp
+++ b/Source/Core/DiscIO/DriveBlob.cpp
@@ -138,9 +138,9 @@ bool DriveReader::ReadMultipleAlignedBlocks(u64 block_num, u64 num_blocks, u8* o
 #ifdef _WIN32
   LARGE_INTEGER offset;
   offset.QuadPart = GetSectorSize() * block_num;
-  SetFilePointerEx(m_disc_handle, offset, nullptr, FILE_BEGIN);
   DWORD bytes_read;
-  if (!ReadFile(m_disc_handle, out_ptr, static_cast<DWORD>(GetSectorSize() * num_blocks),
+  if (!SetFilePointerEx(m_disc_handle, offset, nullptr, FILE_BEGIN) ||
+      !ReadFile(m_disc_handle, out_ptr, static_cast<DWORD>(GetSectorSize() * num_blocks),
                 &bytes_read, nullptr))
   {
     PanicAlertT("Disc Read Error");