Common: Add helper for thread-safe localtime()

And use it with fmt instead of fmt::localtime.

src/common/CMakeLists.txt

@@ -56,6 +56,7 @@ add_library(common
   small_string.h
   string_util.cpp
   string_util.h
+  time_helpers.h
   thirdparty/SmallVector.cpp
   thirdparty/SmallVector.h
   thirdparty/aes.cpp

src/common/common.vcxproj

@@ -23,6 +23,7 @@
     <ClInclude Include="heap_array.h" />
     <ClInclude Include="intrin.h" />
     <ClInclude Include="layered_settings_interface.h" />
+    <ClInclude Include="time_helpers.h" />
     <ClInclude Include="log.h" />
     <ClInclude Include="log_channels.h" />
     <ClInclude Include="lru_cache.h" />
@@ -105,6 +106,9 @@
   <ItemGroup>
     <None Include="thirdparty\usb_key_code_data.inl" />
   </ItemGroup>
+  <ItemGroup>
+    <Text Include="CMakeLists.txt" />
+  </ItemGroup>
   <ImportGroup Label="ExtensionTargets">
     <Import Project="$(VCTargetsPath)\BuildCustomizations\marmasm.targets" />
     <Import Project="$(VCTargetsPath)\BuildCustomizations\masm.targets" />

src/common/common.vcxproj.filters

@@ -57,6 +57,7 @@
     <ClInclude Include="thirdparty\usb_key_code_data.h">
       <Filter>thirdparty</Filter>
     </ClInclude>
+    <ClInclude Include="time_helpers.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="small_string.cpp" />
@@ -112,4 +113,7 @@
       <Filter>thirdparty</Filter>
     </None>
   </ItemGroup>
+  <ItemGroup>
+    <Text Include="CMakeLists.txt" />
+  </ItemGroup>
 </Project>

src/common/time_helpers.h

@@ -0,0 +1,21 @@
+// SPDX-FileCopyrightText: 2019-2024 Connor McLaughlin <stenzek@gmail.com>
+// SPDX-License-Identifier: CC-BY-NC-ND-4.0
+
+#pragma once
+
+#include <ctime>
+
+namespace Common {
+
+inline std::tm LocalTime(std::time_t tvalue)
+{
+  std::tm ttime;
+#ifdef _MSC_VER
+  localtime_s(&ttime, &tvalue);
+#else
+  localtime_r(&tvalue, &ttime);
+#endif
+  return ttime;
+}
+
+} // namespace Common

src/core/game_list.cpp

@@ -27,6 +27,7 @@
 #include "common/progress_callback.h"
 #include "common/string_util.h"
 #include "common/thirdparty/SmallVector.h"
+#include "common/time_helpers.h"
 #include "common/timer.h"
 
 #include "fmt/format.h"
@@ -1592,17 +1593,8 @@ std::string GameList::FormatTimestamp(std::time_t timestamp)
   }
   else
   {
-    struct tm ctime = {};
+    const std::tm ctime = Common::LocalTime(std::time(nullptr));
-    struct tm ttime = {};
+    const std::tm ttime = Common::LocalTime(timestamp);
-    const std::time_t ctimestamp = std::time(nullptr);
-#ifdef _MSC_VER
-    localtime_s(&ctime, &ctimestamp);
-    localtime_s(&ttime, &timestamp);
-#else
-    localtime_r(&ctimestamp, &ctime);
-    localtime_r(&timestamp, &ttime);
-#endif
-
     if (ctime.tm_year == ttime.tm_year && ctime.tm_yday == ttime.tm_yday)
     {
       ret = TRANSLATE_STR("GameList", "Today");

src/core/imgui_overlays.cpp

@@ -34,6 +34,7 @@
 #include "common/path.h"
 #include "common/string_util.h"
 #include "common/thirdparty/SmallVector.h"
+#include "common/time_helpers.h"
 #include "common/timer.h"
 
 #include "IconsEmoji.h"
@@ -44,7 +45,6 @@
 
 #include <array>
 #include <atomic>
-#include <chrono>
 #include <cmath>
 #include <deque>
 #include <mutex>
@@ -1157,7 +1157,8 @@ void SaveStateSelectorUI::InitializeListEntry(ListEntry* li, ExtendedSaveStateIn
   if (global)
     li->game_details = fmt::format(TRANSLATE_FS("SaveStateSelectorUI", "{} ({})"), ssi->title, ssi->serial);
 
-  li->summary = fmt::format(TRANSLATE_FS("SaveStateSelectorUI", DATE_TIME_FORMAT), fmt::localtime(ssi->timestamp));
+  li->summary = fmt::format(TRANSLATE_FS("SaveStateSelectorUI", DATE_TIME_FORMAT),
+                            Common::LocalTime(static_cast<std::time_t>(ssi->timestamp)));
   li->filename = Path::GetFileName(path);
   li->slot = slot;
   li->global = global;
@@ -1440,7 +1441,7 @@ void SaveStateSelectorUI::ShowSlotOSDMessage()
   FILESYSTEM_STAT_DATA sd;
   std::string date;
   if (!path.empty() && FileSystem::StatFile(path.c_str(), &sd))
-    date = fmt::format(TRANSLATE_FS("SaveStateSelectorUI", DATE_TIME_FORMAT), fmt::localtime(sd.ModificationTime));
+    date = fmt::format(TRANSLATE_FS("SaveStateSelectorUI", DATE_TIME_FORMAT), Common::LocalTime(sd.ModificationTime));
   else
     date = TRANSLATE_STR("SaveStateSelectorUI", "no save yet");
 

src/core/system.cpp

@@ -67,6 +67,7 @@
 #include "common/ryml_helpers.h"
 #include "common/string_util.h"
 #include "common/task_queue.h"
+#include "common/time_helpers.h"
 #include "common/timer.h"
 
 #include "IconsEmoji.h"
@@ -80,6 +81,7 @@
 #include "xxhash.h"
 
 #include <cctype>
+#include <chrono>
 #include <cinttypes>
 #include <cmath>
 #include <cstdio>
@@ -351,7 +353,7 @@ static StateVars s_state;
 
 static TinyString GetTimestampStringForFileName()
 {
-  return TinyString::from_format("{:%Y-%m-%d-%H-%M-%S}", fmt::localtime(std::time(nullptr)));
+  return TinyString::from_format("{:%Y-%m-%d-%H-%M-%S}", Common::LocalTime(std::time(nullptr)));
 }
 
 bool System::PerformEarlyHardwareChecks(Error* error)

src/duckstation-mini/mini_host.cpp

@@ -37,6 +37,7 @@
 #include "common/path.h"
 #include "common/string_util.h"
 #include "common/threading.h"
+#include "common/time_helpers.h"
 
 #include "IconsEmoji.h"
 #include "fmt/format.h"
@@ -1415,15 +1416,8 @@ std::string Host::FormatNumber(NumberFormatType type, s64 value)
         DefaultCaseIsUnreachable();
     }
 
-    struct tm ttime = {};
-    const std::time_t tvalue = static_cast<std::time_t>(value);
-#ifdef _MSC_VER
-    localtime_s(&ttime, &tvalue);
-#else
-    localtime_r(&tvalue, &ttime);
-#endif
-
     char buf[128];
+    const std::tm ttime = Common::LocalTime(static_cast<std::time_t>(value));
     std::strftime(buf, std::size(buf), format, &ttime);
     ret.assign(buf);
   }

src/duckstation-regtest/regtest_host.cpp

@@ -34,6 +34,7 @@
 #include "common/sha256_digest.h"
 #include "common/string_util.h"
 #include "common/threading.h"
+#include "common/time_helpers.h"
 #include "common/timer.h"
 
 #include "fmt/format.h"
@@ -604,15 +605,8 @@ std::string Host::FormatNumber(NumberFormatType type, s64 value)
         DefaultCaseIsUnreachable();
     }
 
-    struct tm ttime = {};
-    const std::time_t tvalue = static_cast<std::time_t>(value);
-#ifdef _MSC_VER
-    localtime_s(&ttime, &tvalue);
-#else
-    localtime_r(&tvalue, &ttime);
-#endif
-
     char buf[128];
+    const std::tm ttime = Common::LocalTime(static_cast<std::time_t>(value));
     std::strftime(buf, std::size(buf), format, &ttime);
     ret.assign(buf);
   }

src/util/iso_reader.cpp

@@ -10,6 +10,7 @@
 #include "common/file_system.h"
 #include "common/progress_callback.h"
 #include "common/string_util.h"
+#include "common/time_helpers.h"
 
 #include "fmt/format.h"
 
@@ -572,14 +573,8 @@ std::string IsoReader::ISODirectoryEntryDateTime::GetFormattedTime() const
   const s32 uts_offset = static_cast<s32>(gmt_offset) * 3600;
   const time_t uts = std::mktime(&utime) + uts_offset;
 
-  struct tm ltime;
-#ifdef _MSC_VER
-  localtime_s(&ltime, &uts);
-#else
-  localtime_r(&uts, &ltime);
-#endif
-
   char buf[128];
+  const std::tm ltime = Common::LocalTime(uts);
   const size_t len = std::strftime(buf, std::size(buf), "%c", &ltime);
   return std::string(buf, len);
 }