From e469c54f76f6d24f92389b4e8a27b9cce7152888 Mon Sep 17 00:00:00 2001
From: sfan5 <sfan5@live.de>
Date: Wed, 9 Mar 2022 22:39:25 +0100
Subject: [PATCH] Fix COSOperator::getSystemMemory

The values it returns are in Kilobytes and it was broken on macOS.
---
 include/IOSOperator.h           |  4 ++--
 source/Irrlicht/COSOperator.cpp | 18 +++++++++---------
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/include/IOSOperator.h b/include/IOSOperator.h
index 5d2d42aa..b195aed7 100644
--- a/include/IOSOperator.h
+++ b/include/IOSOperator.h
@@ -33,8 +33,8 @@ public:
 	virtual const c8* getTextFromClipboard() const = 0;
 
 	//! Get the total and available system RAM
-	/** \param totalBytes: will contain the total system memory in bytes
-	\param availableBytes: will contain the available memory in bytes
+	/** \param totalBytes: will contain the total system memory in Kilobytes (1024 B)
+	\param availableBytes: will contain the available memory in Kilobytes (1024 B)
 	\return True if successful, false if not */
 	virtual bool getSystemMemory(u32* totalBytes, u32* availableBytes) const = 0;
 
diff --git a/source/Irrlicht/COSOperator.cpp b/source/Irrlicht/COSOperator.cpp
index a6f9461d..25b04ad8 100644
--- a/source/Irrlicht/COSOperator.cpp
+++ b/source/Irrlicht/COSOperator.cpp
@@ -163,24 +163,19 @@ bool COSOperator::getSystemMemory(u32* Total, u32* Avail) const
 		*Avail = (u32)(MemoryStatusEx.ullAvailPhys>>10);
 	return true;
 
-#elif defined(_IRR_POSIX_API_) && !defined(__FreeBSD__)
-#if defined(_SC_PHYS_PAGES) && defined(_SC_AVPHYS_PAGES)
+#elif defined(_IRR_POSIX_API_) && defined(_SC_PHYS_PAGES) && defined(_SC_AVPHYS_PAGES)
         long ps = sysconf(_SC_PAGESIZE);
         long pp = sysconf(_SC_PHYS_PAGES);
         long ap = sysconf(_SC_AVPHYS_PAGES);
 
-	if ((ps==-1)||(pp==-1)||(ap==-1))
+	if (ps == -1 || (Total && pp == -1) || (Avail && ap == -1))
 		return false;
 
 	if (Total)
-		*Total = (u32)((ps*(long long)pp)>>10);
+		*Total = (u32)((pp>>10)*ps);
 	if (Avail)
-		*Avail = (u32)((ps*(long long)ap)>>10);
+		*Avail = (u32)((ap>>10)*ps);
 	return true;
-#else
-	// TODO: implement for non-availability of symbols/features
-	return false;
-#endif
 #elif defined(_IRR_OSX_PLATFORM_)
 	int mib[2];
 	int64_t physical_memory;
@@ -191,6 +186,11 @@ bool COSOperator::getSystemMemory(u32* Total, u32* Avail) const
 	mib[1] = HW_MEMSIZE;
 	length = sizeof(int64_t);
 	sysctl(mib, 2, &physical_memory, &length, NULL, 0);
+
+	if (Total)
+		*Total = (u32)(physical_memory>>10);
+	if (Avail)
+		*Avail = (u32)(physical_memory>>10); // we don't know better
 	return true;
 #else
 	// TODO: implement for others