1 files changed, 109 insertions, 0 deletions
diff --git a/src/common/tuklib_cpucores.c b/src/common/tuklib_cpucores.c
new file mode 100644
index 0000000..bb3f2f7
--- /dev/null
+++ b/src/common/tuklib_cpucores.c
@@ -0,0 +1,109 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       tuklib_cpucores.c
+/// \brief      Get the number of CPU cores online
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "tuklib_cpucores.h"
+
+#if defined(_WIN32) || defined(__CYGWIN__)
+#	ifndef _WIN32_WINNT
+#		define _WIN32_WINNT 0x0500
+#	endif
+#	include <windows.h>
+
+// glibc >= 2.9
+#elif defined(TUKLIB_CPUCORES_SCHED_GETAFFINITY)
+#	include <sched.h>
+
+// FreeBSD
+#elif defined(TUKLIB_CPUCORES_CPUSET)
+#	include <sys/param.h>
+#	include <sys/cpuset.h>
+
+#elif defined(TUKLIB_CPUCORES_SYSCTL)
+#	ifdef HAVE_SYS_PARAM_H
+#		include <sys/param.h>
+#	endif
+#	include <sys/sysctl.h>
+
+#elif defined(TUKLIB_CPUCORES_SYSCONF)
+#	include <unistd.h>
+
+// HP-UX
+#elif defined(TUKLIB_CPUCORES_PSTAT_GETDYNAMIC)
+#	include <sys/param.h>
+#	include <sys/pstat.h>
+#endif
+
+
+extern uint32_t
+tuklib_cpucores(void)
+{
+	uint32_t ret = 0;
+
+#if defined(_WIN32) || defined(__CYGWIN__)
+	SYSTEM_INFO sysinfo;
+	GetSystemInfo(&sysinfo);
+	ret = sysinfo.dwNumberOfProcessors;
+
+#elif defined(TUKLIB_CPUCORES_SCHED_GETAFFINITY)
+	cpu_set_t cpu_mask;
+	if (sched_getaffinity(0, sizeof(cpu_mask), &cpu_mask) == 0)
+		ret = (uint32_t)CPU_COUNT(&cpu_mask);
+
+#elif defined(TUKLIB_CPUCORES_CPUSET)
+	cpuset_t set;
+	if (cpuset_getaffinity(CPU_LEVEL_WHICH, CPU_WHICH_PID, -1,
+			sizeof(set), &set) == 0) {
+#	ifdef CPU_COUNT
+		ret = (uint32_t)CPU_COUNT(&set);
+#	else
+		for (unsigned i = 0; i < CPU_SETSIZE; ++i)
+			if (CPU_ISSET(i, &set))
+				++ret;
+#	endif
+	}
+
+#elif defined(TUKLIB_CPUCORES_SYSCTL)
+	// On OpenBSD HW_NCPUONLINE tells the number of processor cores that
+	// are online so it is preferred over HW_NCPU which also counts cores
+	// that aren't currently available. The number of cores online is
+	// often less than HW_NCPU because OpenBSD disables simultaneous
+	// multi-threading (SMT) by default.
+#	ifdef HW_NCPUONLINE
+	int name[2] = { CTL_HW, HW_NCPUONLINE };
+#	else
+	int name[2] = { CTL_HW, HW_NCPU };
+#	endif
+	int cpus;
+	size_t cpus_size = sizeof(cpus);
+	if (sysctl(name, 2, &cpus, &cpus_size, NULL, 0) != -1
+			&& cpus_size == sizeof(cpus) && cpus > 0)
+		ret = (uint32_t)cpus;
+
+#elif defined(TUKLIB_CPUCORES_SYSCONF)
+#	ifdef _SC_NPROCESSORS_ONLN
+	// Most systems
+	const long cpus = sysconf(_SC_NPROCESSORS_ONLN);
+#	else
+	// IRIX
+	const long cpus = sysconf(_SC_NPROC_ONLN);
+#	endif
+	if (cpus > 0)
+		ret = (uint32_t)cpus;
+
+#elif defined(TUKLIB_CPUCORES_PSTAT_GETDYNAMIC)
+	struct pst_dynamic pst;
+	if (pstat_getdynamic(&pst, sizeof(pst), 1, 0) != -1)
+		ret = (uint32_t)pst.psd_proc_cnt;
+#endif
+
+	return ret;
+}