cpumask.hpp

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/**
 * @file
 * @ingroup numapp_numa
 * @copyright ESO 2024 - European Southern Observatory
 *
 * @brief Contains declarations for CpumaskTrait
 */
#ifndef NUMAPP_CPUMASK_HPP_
#define NUMAPP_CPUMASK_HPP_
#include <numa.h>
#include <system_error>
 
#include <system_error>
 
#include "bitmask.hpp"
 
namespace numapp {
 
/**
 * Type-safe CPU mask
 *
 * @sa ForEach
 * @ingroup numapp_numa
 */
class Cpumask : public Bitmask<Cpumask> {
public:
    /**
     * Inherit constructors from Bitmask.
     */
    using Bitmask<Cpumask>::Bitmask;
 
    /**
     * Construct Cpumask from cpustring that does not consider current cpuset.
     *
     * @note Uses @c numa_parse_cpustring_all to parse.
     *
     * @manpages
     * @manpage{numa,3}
     *
     * @param cpustring Mask expressed as cpustring in the form of comma separated list of cpu
     * numbers or ranges, e.g. `1,3-8`. See man page for additional details.
     * @throws std::system_error containing error code if parsing fails.
     */
    [[nodiscard]] static Cpumask MakeFromCpuStringAll(char const* cpustring) {
        // note: numa_parse_cpustring_all is used rather than numa_parse_cpustring
        // to *not* consider current cpuset, which would e.g. exclude CPUs isolated with
        // isolcpus.
        return MakeFromString(cpustring, numa_parse_cpustring_all);
    }
 
    /**
     * Construct Cpumask from cpustring that considers current cpuset.
     *
     * @note Uses @c numa_parse_cpustring to parse.
     *
     * @manpages
     * @manpage{numa,3}
     *
     * @param cpustring Mask expressed as cpustring in the form of comma separated list of cpu
     * numbers or ranges, e.g. `1,3-8`. See man page for additional details.
     * @throws std::system_error containing error code if parsing fails.
     */
    [[nodiscard]] static Cpumask MakeFromCpuString(char const* cpustring) {
        return MakeFromString(cpustring, numa_parse_cpustring);
    }
 
protected:
    using ParseFunc = struct bitmask* (*)(const char*);
    [[nodiscard]] static Cpumask MakeFromString(char const* cpustring, ParseFunc func) {
        // note: numa_parse functions do not set errc.
        auto* mask_ptr = func(cpustring);
        if (mask_ptr == nullptr) {
            throw std::system_error(std::make_error_code(std::errc::invalid_argument),
                                    "Could not parse cpustring");
        } else {
            return Cpumask(NumaBitmaskPtr(mask_ptr, &numa_free_cpumask));
        }
    }
    friend class Bitmask<Cpumask>;
    [[nodiscard]] static NumaBitmaskPtr Alloc() {
        return NumaBitmaskPtr(numa_allocate_cpumask(), &numa_free_cpumask);
    }
};
 
/**
 * Formats @a mask and inserts it to @a os.
 *
 * Mask up to number of configured CPUs are formatted if no higher bits are set.
 *
 * @param os output stream to insert into.
 * @param mask Cpumask to format.
 * @returns @a os
 *
 * @ingroup numapp_numa
 */
inline std::ostream& operator<<(std::ostream& os, Cpumask const& mask) {
    return FormatBitmask(os, mask, numa_num_configured_cpus());
}
 
}  // namespace numapp
 
#endif  // #ifndef NUMAPP_CPUMASK_HPP_