Common: Add some utilities to a new UnixUtil header.

Source/Core/Common/CMakeLists.txt

@@ -97,6 +97,7 @@ add_library(common
   JsonUtil.cpp
   Lazy.h
   LinearDiskCache.h
+  UnixUtil.h
   Logging/ConsoleListener.h
   Logging/Log.h
   Logging/LogManager.cpp

Source/Core/Common/UnixUtil.h

@@ -0,0 +1,62 @@
+// Copyright 2025 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <pthread.h>
+#include <sys/eventfd.h>
+
+#include "Common/CommonFuncs.h"
+#include "Common/Logging/Log.h"
+
+namespace UnixUtil
+{
+inline int CreateEventFD(unsigned int count, int flags)
+{
+  const int result = eventfd(count, flags);
+  if (result == -1)
+  {
+    ERROR_LOG_FMT(COMMON, "eventfd failed: {}", Common::LastStrerrorString());
+    std::abort();
+  }
+  return result;
+}
+
+// Repeatedly call a function that can erroneously produce EINTR.
+auto RetryOnEINTR(auto func, auto... args)
+{
+  while (true)
+  {
+    const int result = func(args...);
+    if (result >= 0 || errno != EINTR)
+      return result;
+  }
+}
+
+// This is a very low-effort wrapper for pthread.
+// It allows creating a pthread from any callable (e.g. a lambda).
+// The wrapper object must exist for the lifetime of the thread.
+template <typename Func>
+struct PThreadWrapper
+{
+  Func func;
+  pthread_t handle{};
+
+  explicit PThreadWrapper(Func&& f) : func(std::move(f))
+  {
+    if (int result = pthread_create(
+            &handle, nullptr,
+            [](void* arg) -> void* {
+              static_cast<PThreadWrapper*>(arg)->func();
+              return nullptr;
+            },
+            this);
+        result != 0)
+    {
+      ERROR_LOG_FMT(COMMON, "pthread_create: {}", Common::StrerrorString(result));
+      std::abort();
+    }
+  }
+};
+
+}  // namespace UnixUtil