Thread/Thread: replacement library for GThread

src/thread/Thread.cxx

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+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "Thread.hxx"
+#include "util/Error.hxx"
+
+bool
+Thread::Start(void (*_f)(void *ctx), void *_ctx, Error &error)
+{
+	assert(!IsDefined());
+
+	f = _f;
+	ctx = _ctx;
+
+#ifdef WIN32
+	handle = ::CreateThread(nullptr, 0, ThreadProc, this, 0, &id);
+	if (handle == nullptr) {
+		error.SetLastError("Failed to create thread");
+		return false;
+	}
+#else
+#ifndef NDEBUG
+	creating = true;
+#endif
+
+	int e = pthread_create(&handle, nullptr, ThreadProc, this);
+
+	if (e != 0) {
+#ifndef NDEBUG
+		creating = false;
+#endif
+		error.SetErrno(e, "Failed to create thread");
+		return false;
+	}
+
+	defined = true;
+#ifndef NDEBUG
+	creating = false;
+#endif
+#endif
+
+	return true;
+}
+
+void
+Thread::Join()
+{
+	assert(IsDefined());
+	assert(!IsInside());
+
+#ifdef WIN32
+	::WaitForSingleObject(handle, INFINITE);
+	::CloseHandle(handle);
+	handle = nullptr;
+#else
+	pthread_join(handle, nullptr);
+	defined = false;
+#endif
+}
+
+#ifdef WIN32
+
+DWORD WINAPI
+Thread::ThreadProc(LPVOID ctx)
+{
+	Thread &thread = *(Thread *)ctx;
+
+	thread.f(thread.ctx);
+	return 0;
+}
+
+#else
+
+void *
+Thread::ThreadProc(void *ctx)
+{
+	Thread &thread = *(Thread *)ctx;
+
+#ifndef NDEBUG
+	/* this works around a race condition that causes an assertion
+	   failure due to IsInside() spuriously returning false right
+	   after the thread has been created, and the calling thread
+	   hasn't initialised "defined" yet */
+	thread.defined = true;
+#endif
+
+	thread.f(thread.ctx);
+	return nullptr;
+}
+
+#endif

src/thread/Thread.hxx

@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_THREAD_HXX
+#define MPD_THREAD_HXX
+
+#include "check.h"
+#include "Compiler.h"
+
+#ifdef WIN32
+#include <windows.h>
+#else
+#include <pthread.h>
+#endif
+
+#include <assert.h>
+
+class Error;
+
+class Thread {
+#ifdef WIN32
+	HANDLE handle;
+	DWORD id;
+#else
+	pthread_t handle;
+	bool defined;
+
+#ifndef NDEBUG
+	/**
+	 * The thread is currently being created.  This is a workaround for
+	 * IsInside(), which may return false until pthread_create() has
+	 * initialised the #handle.
+	 */
+	bool creating;
+#endif
+#endif
+
+	void (*f)(void *ctx);
+	void *ctx;
+
+public:
+#ifdef WIN32
+	Thread():handle(nullptr) {}
+#else
+	Thread():defined(false) {
+#ifndef NDEBUG
+		creating = false;
+#endif
+	}
+#endif
+
+	Thread(const Thread &) = delete;
+
+#ifndef NDEBUG
+	virtual ~Thread() {
+		/* all Thread objects must be destructed manually by calling
+		   Join(), to clean up */
+		assert(!IsDefined());
+	}
+#endif
+
+	bool IsDefined() const {
+#ifdef WIN32
+		return handle != nullptr;
+#else
+		return defined;
+#endif
+  }
+
+	/**
+	 * Check if this thread is the current thread.
+	 */
+	gcc_pure
+	bool IsInside() const {
+#ifdef WIN32
+		return GetCurrentThreadId() == id;
+#else
+#ifdef NDEBUG
+		constexpr bool creating = false;
+#endif
+		return IsDefined() && (creating ||
+				       pthread_equal(pthread_self(), handle));
+#endif
+	}
+
+	bool Start(void (*f)(void *ctx), void *ctx, Error &error);
+	void Join();
+
+private:
+#ifdef WIN32
+	static DWORD WINAPI ThreadProc(LPVOID ctx);
+#else
+	static void *ThreadProc(void *ctx);
+#endif
+
+};
+
+#endif