cache_line_size.c

#include "cache_line_size.h"

#if defined(__APPLE__)

#include <sys/sysctl.h>
size_t cache_line_size() {
	size_t lineSize = 0;
	size_t sizeOfLineSize = sizeof(lineSize);
	sysctlbyname("hw.cachelinesize", &lineSize, &sizeOfLineSize, 0, 0);
	return lineSize;
}

#elif defined(_WIN32)

#include <stdlib.h>
#include <windows.h>
size_t cache_line_size() {
	size_t lineSize = 0;
	DWORD bufferSize = 0;
	DWORD i = 0;
	SYSTEM_LOGICAL_PROCESSOR_INFORMATION * buffer = 0;

	GetLogicalProcessorInformation(0, &bufferSize);
	buffer = (SYSTEM_LOGICAL_PROCESSOR_INFORMATION *) malloc(bufferSize);
	GetLogicalProcessorInformation(&buffer[0], &bufferSize);

	for (i = 0; i != bufferSize / sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION); ++i) {
		if (buffer[i].Relationship == RelationCache && buffer[i].Cache.Level == 1) {
			lineSize = buffer[i].Cache.LineSize;
			break;
		}
	}

	free(buffer);
	return lineSize;
}

#elif defined(__linux__)

#include <unistd.h>
size_t cache_line_size() {
	long lineSize = sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
	return lineSize < 0 ? 0 : (size_t)lineSize;
}

#else
#error Unrecognized platform
#endif