From e4bff8be94c0db4f94e63ad448d0eeb869ccdbbd Mon Sep 17 00:00:00 2001
From: ShadowNinja <shadowninja@minetest.net>
Date: Tue, 7 Apr 2015 06:13:12 -0400
Subject: Clean up threading

  * Rename everything.
    * Strip J prefix.
    * Change UpperCamelCase functions to lowerCamelCase.
  * Remove global (!) semaphore count mutex on OSX.
  * Remove semaphore count getter (unused, unsafe, depended on internal
    API functions on Windows, and used a hack on OSX).
  * Add `Atomic<type>`.
  * Make `Thread` handle thread names.
  * Add support for C++11 multi-threading.
  * Combine pthread and win32 sources.
  * Remove `ThreadStarted` (unused, unneeded).
  * Move some includes from the headers to the sources.
  * Move all of `Event` into its header (allows inlining with no new includes).
  * Make `Event` use `Semaphore` (except on Windows).
  * Move some porting functions into `Thread`.
  * Integrate logging with `Thread`.
  * Add threading test.
---
 src/threading/semaphore.cpp | 161 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 161 insertions(+)
 create mode 100644 src/threading/semaphore.cpp

(limited to 'src/threading/semaphore.cpp')

diff --git a/src/threading/semaphore.cpp b/src/threading/semaphore.cpp
new file mode 100644
index 000000000..00332eaa0
--- /dev/null
+++ b/src/threading/semaphore.cpp
@@ -0,0 +1,161 @@
+/*
+Minetest
+Copyright (C) 2013 sapier <sapier AT gmx DOT net>
+
+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
+the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser 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 "threading/semaphore.h"
+
+#include <iostream>
+#include <cstdlib>
+#include <cassert>
+
+#define UNUSED(expr) do { (void)(expr); } while (0)
+
+#ifdef _WIN32
+	#define MAX_SEMAPHORE_COUNT LONG_MAX - 1
+#else
+	#include <cerrno>
+	#include <sys/time.h>
+	#include <pthread.h>
+	#if defined(__MACH__) && defined(__APPLE__)
+		#include <mach/mach.h>
+		#include <mach/task.h>
+		#include <mach/semaphore.h>
+		#include <sys/semaphore.h>
+		#include <unistd.h>
+
+		#undef sem_t
+		#undef sem_init
+		#undef sem_wait
+		#undef sem_post
+		#undef sem_destroy
+		#define sem_t             semaphore_t
+		#define sem_init(s, p, c) semaphore_create(mach_task_self(), (s), 0, (c))
+		#define sem_wait(s)       semaphore_wait(*(s))
+		#define sem_post(s)       semaphore_signal(*(s))
+		#define sem_destroy(s)    semaphore_destroy(mach_task_self(), *(s))
+	#endif
+#endif
+
+
+Semaphore::Semaphore(int val)
+{
+#ifdef _WIN32
+	semaphore = CreateSemaphore(NULL, val, MAX_SEMAPHORE_COUNT, NULL);
+#else
+	int ret = sem_init(&semaphore, 0, val);
+	assert(!ret);
+	UNUSED(ret);
+#endif
+}
+
+
+Semaphore::~Semaphore()
+{
+#ifdef _WIN32
+	CloseHandle(semaphore);
+#else
+	int ret = sem_destroy(&semaphore);
+#ifdef __ANDROID__
+	// Workaround for broken bionic semaphore implementation!
+	assert(!ret || errno == EBUSY);
+#else
+	assert(!ret);
+#endif
+	UNUSED(ret);
+#endif
+}
+
+
+void Semaphore::post(unsigned int num)
+{
+	assert(num > 0);
+#ifdef _WIN32
+	ReleaseSemaphore(semaphore, num, NULL);
+#else
+	for (unsigned i = 0; i < num; i++) {
+		int ret = sem_post(&semaphore);
+		assert(!ret);
+		UNUSED(ret);
+	}
+#endif
+}
+
+
+void Semaphore::wait()
+{
+#ifdef _WIN32
+	WaitForSingleObject(semaphore, INFINITE);
+#else
+	int ret = sem_wait(&semaphore);
+	assert(!ret);
+	UNUSED(ret);
+#endif
+}
+
+
+bool Semaphore::wait(unsigned int time_ms)
+{
+#ifdef _WIN32
+	unsigned int ret = WaitForSingleObject(semaphore, time_ms);
+
+	if (ret == WAIT_OBJECT_0) {
+		return true;
+	} else {
+		assert(ret == WAIT_TIMEOUT);
+		return false;
+	}
+#else
+# if defined(__MACH__) && defined(__APPLE__)
+	mach_timespec_t wait_time;
+	wait_time.tv_sec = time_ms / 1000;
+	wait_time.tv_nsec = 1000000 * (time_ms % 1000);
+
+	errno = 0;
+	int ret = semaphore_timedwait(semaphore, wait_time);
+	switch (ret) {
+	case KERN_OPERATION_TIMED_OUT:
+		errno = ETIMEDOUT;
+		break;
+	case KERN_ABORTED:
+		errno = EINTR;
+		break;
+	default:
+		if (ret)
+			errno = EINVAL;
+	}
+# else
+	struct timespec wait_time;
+	struct timeval now;
+
+	if (gettimeofday(&now, NULL) == -1) {
+		std::cerr << "Semaphore::wait(ms): Unable to get time with gettimeofday!" << std::endl;
+		abort();
+	}
+
+	wait_time.tv_nsec = ((time_ms % 1000) * 1000 * 1000) + (now.tv_usec * 1000);
+	wait_time.tv_sec  = (time_ms / 1000) + (wait_time.tv_nsec / (1000 * 1000 * 1000)) + now.tv_sec;
+	wait_time.tv_nsec %= 1000 * 1000 * 1000;
+
+	int ret = sem_timedwait(&semaphore, &wait_time);
+# endif
+
+	assert(!ret || (errno == ETIMEDOUT || errno == EINTR));
+	return !ret;
+#endif
+}
+
-- 
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