VILLASnode/common/include/villas/cpuset.hpp

/* Human readable cpusets.
 *
 * Author: Steffen Vogel <post@steffenvogel.de>
 * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
 * SPDX-License-Identifier: Apache-2.0
 */

#pragma once

#ifdef __linux__

#include <sched.h>
#include <cstdint>

#include <villas/exceptions.hpp>

namespace villas {
namespace utils {

class CpuSet {

protected:
	cpu_set_t *setp;

	unsigned num_cpus;
	size_t sz;

public:

	CpuSet() :
		num_cpus(sizeof(uintmax_t) * 8),
		sz(CPU_ALLOC_SIZE(num_cpus))
	{

		setp = CPU_ALLOC(num_cpus);
		if (!setp)
			throw MemoryAllocationError();

		zero();
	}

	// Parses string with list of CPU ranges.
	//
	// @param str Human readable representation of the set.
	CpuSet(const std::string &str);

	CpuSet(const char *str);

	// Convert integer to cpu_set_t.
	//
	// @param set An integer number which is used as the mask
	CpuSet(uintmax_t set);

	// Convert cpu_set_t to an integer. */
	operator uintmax_t();

	operator const cpu_set_t*()
	{
		return setp;
	}

	// Returns human readable representation of the cpuset.
	//
	// The output format is a list of CPUs with ranges (for example, "0,1,3-9").
	operator std::string();

	~CpuSet()
	{
		CPU_FREE(setp);
	}

	CpuSet(const CpuSet &src) :
		CpuSet(src.num_cpus)
	{
		memcpy(setp, src.setp, sz);
	}

	bool empty() const
	{
		return count() == 0;
	}

	bool full() const
	{
		return count() == num_cpus;
	}

	unsigned count() const
	{
		return CPU_COUNT_S(sz, setp);
	}

	void zero()
	{
		CPU_ZERO_S(sz, setp);
	}

	size_t size() const
	{
		return sz;
	}

	CpuSet operator~()
	{
		CpuSet full = UINTMAX_MAX;

		return full ^ *this;
	}

	bool operator==(const CpuSet &rhs)
	{
		return CPU_EQUAL_S(sz, setp, rhs.setp);
	}

	CpuSet & operator&=(const CpuSet &rhs)
	{
		CPU_AND_S(sz, setp, setp, rhs.setp);
		return *this;
	}

	CpuSet & operator|=(const CpuSet &rhs)
	{
		CPU_OR_S(sz, setp, setp, rhs.setp);
		return *this;
	}

	CpuSet & operator^=(const CpuSet &rhs)
	{
		CPU_XOR_S(sz, setp, setp, rhs.setp);
		return *this;
	}

	friend CpuSet operator&(CpuSet lhs, const CpuSet &rhs)
	{
		lhs &= rhs;
		return lhs;
	}

	friend CpuSet operator|(CpuSet lhs, const CpuSet &rhs)
	{
		lhs |= rhs;
		return lhs;
	}

	friend CpuSet operator^(CpuSet lhs, const CpuSet &rhs)
	{
		lhs ^= rhs;
		return lhs;
	}

	bool operator[](size_t cpu) const
	{
		return isSet(cpu);
	}

	bool isSet(size_t cpu) const
	{
		return CPU_ISSET_S(cpu, sz, setp);
	}

	void clear(size_t cpu)
	{
		CPU_CLR_S(cpu, sz, setp);
	}

	void set(size_t cpu)
	{
		CPU_SET_S(cpu, sz, setp);
	}
};

} // namespace utils
} // namespace villas

#endif