C++11 patchset 5: use std::threads and remove old compat layer (#5928)

* C++11 patchset 5: use std::threads and remove old compat layer

* use pragma once in modified headers
* use C++11 function delete for object copy

3 files changed, 12 insertions, 195 deletions

diff --git a/src/threading/thread.cpp b/src/threading/thread.cpp
index 1909da61d..e566824f7 100644
--- a/src/threading/thread.cpp
+++ b/src/threading/thread.cpp
@@ -28,31 +28,6 @@ DEALINGS IN THE SOFTWARE.
 #include "log.h"
 #include "porting.h"
 
-#define UNUSED(expr) do { (void)(expr); } while (0)
-
-#if USE_CPP11_THREADS
-	#include <chrono>
-	#include <system_error>
-#elif USE_WIN_THREADS
-	#ifndef _WIN32_WCE
-		#include <process.h>
-	#endif
-#elif USE_POSIX_THREADS
-	#include <time.h>
-	#include <assert.h>
-	#include <stdlib.h>
-	#include <unistd.h>
-	#include <sys/time.h>
-
-	#if defined(__FreeBSD__) || defined(__APPLE__)
-		#include <sys/types.h>
-		#include <sys/sysctl.h>
-	#elif defined(_GNU_SOURCE)
-		#include <sys/sysinfo.h>
-	#endif
-#endif
-
-
 // for setName
 #if defined(__linux__)
 	#include <sys/prctl.h>
@@ -70,8 +45,6 @@ DEALINGS IN THE SOFTWARE.
 // for bindToProcessor
 #if __FreeBSD_version >= 702106
 	typedef cpuset_t cpu_set_t;
-#elif defined(__linux__)
-	#include <sched.h>
 #elif defined(__sun) || defined(sun)
 	#include <sys/types.h>
 	#include <sys/processor.h>
@@ -121,28 +94,12 @@ bool Thread::start()
 	// The mutex may already be locked if the thread is being restarted
 	m_start_finished_mutex.try_lock();
 
-#if USE_CPP11_THREADS
-
 	try {
 		m_thread_obj = new std::thread(threadProc, this);
 	} catch (const std::system_error &e) {
 		return false;
 	}
 
-#elif USE_WIN_THREADS
-
-	m_thread_handle = CreateThread(NULL, 0, threadProc, this, 0, &m_thread_id);
-	if (!m_thread_handle)
-		return false;
-
-#elif USE_POSIX_THREADS
-
-	int status = pthread_create(&m_thread_handle, NULL, threadProc, this);
-	if (status)
-		return false;
-
-#endif
-
 	// Allow spawned thread to continue
 	m_start_finished_mutex.unlock();
 
@@ -169,31 +126,12 @@ bool Thread::wait()
 	if (!m_joinable)
 		return false;
 
-#if USE_CPP11_THREADS
 
 	m_thread_obj->join();
 
 	delete m_thread_obj;
 	m_thread_obj = NULL;
 
-#elif USE_WIN_THREADS
-
-	int ret = WaitForSingleObject(m_thread_handle, INFINITE);
-	assert(ret == WAIT_OBJECT_0);
-	UNUSED(ret);
-
-	CloseHandle(m_thread_handle);
-	m_thread_handle = NULL;
-	m_thread_id = -1;
-
-#elif USE_POSIX_THREADS
-
-	int ret = pthread_join(m_thread_handle, NULL);
-	assert(ret == 0);
-	UNUSED(ret);
-
-#endif
-
 	assert(m_running == false);
 	m_joinable = false;
 	return true;
@@ -209,9 +147,10 @@ bool Thread::kill()
 
 	m_running = false;
 
-#if USE_WIN_THREADS
-	TerminateThread(m_thread_handle, 0);
-	CloseHandle(m_thread_handle);
+#if defined(_WIN32)
+	// See https://msdn.microsoft.com/en-us/library/hh920601.aspx#thread__native_handle_method
+	TerminateThread((HANDLE) m_thread_obj->native_handle(), 0);
+	CloseHandle((HANDLE) m_thread_obj->native_handle());
 #else
 	// We need to pthread_kill instead on Android since NDKv5's pthread
 	// implementation is incomplete.
@@ -241,13 +180,7 @@ bool Thread::getReturnValue(void **ret)
 }
 
 
-#if USE_CPP11_THREADS || USE_POSIX_THREADS
 void *Thread::threadProc(void *param)
-#elif defined(_WIN32_WCE)
-DWORD Thread::threadProc(LPVOID param)
-#elif defined(_WIN32)
-DWORD WINAPI Thread::threadProc(LPVOID param)
-#endif
 {
 	Thread *thr = (Thread *)param;
 
@@ -325,46 +258,7 @@ void Thread::setName(const std::string &name)
 
 unsigned int Thread::getNumberOfProcessors()
 {
-#if USE_CPP11_THREADS
-
 	return std::thread::hardware_concurrency();
-
-#elif USE_WIN_THREADS
-
-	SYSTEM_INFO sysinfo;
-	GetSystemInfo(&sysinfo);
-	return sysinfo.dwNumberOfProcessors;
-
-#elif defined(_SC_NPROCESSORS_ONLN)
-
-	return sysconf(_SC_NPROCESSORS_ONLN);
-
-#elif defined(__FreeBSD__) || defined(__NetBSD__) || \
-	defined(__DragonFly__) || defined(__APPLE__)
-
-	unsigned int num_cpus = 1;
-	size_t len = sizeof(num_cpus);
-
-	int mib[2];
-	mib[0] = CTL_HW;
-	mib[1] = HW_NCPU;
-
-	sysctl(mib, 2, &num_cpus, &len, NULL, 0);
-	return num_cpus;
-
-#elif defined(_GNU_SOURCE)
-
-	return get_nprocs();
-
-#elif defined(PTW32_VERSION) || defined(__hpux)
-
-	return pthread_num_processors_np();
-
-#else
-
-	return 1;
-
-#endif
 }
 
 
diff --git a/src/threading/thread.h b/src/threading/thread.h
index ab943f094..6292d9ed7 100644
--- a/src/threading/thread.h
+++ b/src/threading/thread.h
@@ -23,8 +23,7 @@ FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 DEALINGS IN THE SOFTWARE.
 */
 
-#ifndef THREADING_THREAD_H
-#define THREADING_THREAD_H
+#pragma once
 
 #include "util/basic_macros.h"
 #include "threads.h"
@@ -93,17 +92,8 @@ public:
 	inline bool isRunning() { return m_running; }
 	inline bool stopRequested() { return m_request_stop; }
 
-#if USE_CPP11_THREADS
 	inline threadid_t getThreadId() { return m_thread_obj->get_id(); }
 	inline threadhandle_t getThreadHandle() { return m_thread_obj->native_handle(); }
-#else
-#  if USE_WIN_THREADS
-	inline threadid_t getThreadId() { return m_thread_id; }
-#  else
-	inline threadid_t getThreadId() { return m_thread_handle; }
-#  endif
-	inline threadhandle_t getThreadHandle() { return m_thread_handle; }
-#endif
 
 	/*
 	 * Gets the thread return value.
@@ -156,14 +146,7 @@ private:
 	std::mutex m_mutex;
 	std::mutex m_start_finished_mutex;
 
-#if USE_CPP11_THREADS
 	std::thread *m_thread_obj;
-#else
-	threadhandle_t m_thread_handle;
-#   if USE_WIN_THREADS
-        threadid_t m_thread_id;
-#   endif
-#endif
 
 	static ThreadStartFunc threadProc;
 
@@ -172,9 +155,6 @@ private:
 	// available to us, so we maintain one ourselves.  This is set on thread start.
 	tid_t m_kernel_thread_id;
 #endif
-
-	DISABLE_CLASS_COPY(Thread);
+	Thread(const Thread &) = delete;
 };
 
-#endif
-
diff --git a/src/threads.h b/src/threads.h
index 9731dcb5e..ea84abd3e 100644
--- a/src/threads.h
+++ b/src/threads.h
@@ -1,6 +1,7 @@
 /*
 Minetest
 Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+Copyright (C) 2017 nerzhul, Loic Blot <loic.blot@unix-experience.fr>
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU Lesser General Public License as published by
@@ -17,92 +18,34 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
-#ifndef THREADS_HEADER
-#define THREADS_HEADER
-
-//
-// Determine which threading APIs we will use
-//
-#if __cplusplus >= 201103L
-	#define USE_CPP11_THREADS 1
-#elif defined(_WIN32)
-	#define USE_WIN_THREADS 1
-#else
-	#define USE_POSIX_THREADS 1
-#endif
-
-#if defined(_WIN32)
-	// Prefer critical section API because std::mutex is much slower on Windows
-	#define USE_WIN_MUTEX 1
-#elif __cplusplus >= 201103L
-	#define USE_CPP11_MUTEX 1
-#else
-	#define USE_POSIX_MUTEX 1
-#endif
+#pragma once
 
 ///////////////
-
-
-#if USE_CPP11_THREADS
-	#include <thread>
-#elif USE_POSIX_THREADS
-	#include <pthread.h>
-#else
-	#ifndef WIN32_LEAN_AND_MEAN
-		#define WIN32_LEAN_AND_MEAN
-	#endif
-	#include <windows.h>
-#endif
+#include <thread>
 
 //
 // threadid_t, threadhandle_t
 //
-#if USE_CPP11_THREADS
-	typedef std::thread::id threadid_t;
-	typedef std::thread::native_handle_type threadhandle_t;
-#elif USE_WIN_THREADS
-	typedef DWORD threadid_t;
-	typedef HANDLE threadhandle_t;
-#elif USE_POSIX_THREADS
-	typedef pthread_t threadid_t;
-	typedef pthread_t threadhandle_t;
-#endif
+typedef std::thread::id threadid_t;
+typedef std::thread::native_handle_type threadhandle_t;
 
 //
 // ThreadStartFunc
 //
-#if USE_CPP11_THREADS || USE_POSIX_THREADS
-	typedef void *ThreadStartFunc(void *param);
-#elif defined(_WIN32_WCE)
-	typedef DWORD ThreadStartFunc(LPVOID param);
-#elif defined(_WIN32)
-	typedef DWORD WINAPI ThreadStartFunc(LPVOID param);
-#endif
+typedef void *ThreadStartFunc(void *param);
 
 
 inline threadid_t thr_get_current_thread_id()
 {
-#if USE_CPP11_THREADS
 	return std::this_thread::get_id();
-#elif USE_WIN_THREADS
-	return GetCurrentThreadId();
-#elif USE_POSIX_THREADS
-	return pthread_self();
-#endif
 }
 
 inline bool thr_compare_thread_id(threadid_t thr1, threadid_t thr2)
 {
-#if USE_POSIX_THREADS
-	return pthread_equal(thr1, thr2);
-#else
 	return thr1 == thr2;
-#endif
 }
 
 inline bool thr_is_current_thread(threadid_t thr)
 {
 	return thr_compare_thread_id(thr_get_current_thread_id(), thr);
 }
-
-#endif