Avoid second call to sysctlbyname on Apple M1

1 files changed, 7 insertions, 8 deletions

diff --git a/cpu.cpp b/cpu.cpp
index f8a4900e..e57556a5 100644
--- a/cpu.cpp
+++ b/cpu.cpp
@@ -219,17 +219,16 @@ public:
 		{

 			// M1 machine?

 			std::string brand;

-			size_t size = 0;

+			size_t size = 32;

 

-			if (sysctlbyname("machdep.cpu.brand_string", NULL, &size, NULL, 0) == 0 && size > 0)

+			// Supply an oversized buffer, and avoid

+			// an extra call to sysctlbyname.

+			brand.resize(size);

+			if (sysctlbyname("machdep.cpu.brand_string", &brand[0], &size, NULL, 0) == 0 && size > 0)

 			{

+				if (brand[size-1] == '\0')

+					size--;

 				brand.resize(size);

-				if (sysctlbyname("machdep.cpu.brand_string", &brand[0], &size, NULL, 0) == 0 && size > 0)

-				{

-					if (brand[size-1] == '\0')

-						size--;

-					brand.resize(size);

-				}

 			}

 

 			if (brand == "Apple M1")