SystemResources.cpp

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// ======================================================================
// \title  MacOs/SystemResources.cpp
// \author mstarch
// \brief  hpp file for SystemResources component implementation class
//
// \copyright
// Copyright 2021, by the California Institute of Technology.
// ALL RIGHTS RESERVED.  United States Government Sponsorship
// acknowledged.
//
// ======================================================================
#include <mach/mach_error.h>
#include <mach/mach_host.h>
#include <mach/mach_init.h>
#include <mach/mach_types.h>
#include <mach/message.h>
#include <Fw/Types/Assert.hpp>
#include <Os/SystemResources.hpp>
 
namespace Os {
kern_return_t vm_stat_helper(FwSizeType& used, FwSizeType& total) {
    mach_msg_type_number_t count = HOST_VM_INFO_COUNT;
    vm_statistics_data_t vmstat;
    vm_size_t vmsize;
 
    kern_return_t stat1 = host_statistics(mach_host_self(), HOST_VM_INFO, reinterpret_cast<host_info_t>(&vmstat), &count);
    kern_return_t stat2 = host_page_size(mach_host_self(), &vmsize);
 
    if (KERN_SUCCESS == stat1 and KERN_SUCCESS == stat2) {
        // Wired (permanently in RAM), active (recently used), and inactive (not recently used) pages
        used = vmstat.wire_count + vmstat.active_count + vmstat.inactive_count;
        total = used + vmstat.free_count;
 
        // Pages to totals
        used *= vmsize;
        total *= vmsize;
    }
    return (stat1 == KERN_SUCCESS) ? stat2 : stat1;
}
 
kern_return_t cpu_data_helper(processor_cpu_load_info_t& cpu_load_info, U32& cpu_count) {
    mach_msg_type_number_t processor_msg_count;
    kern_return_t stat = host_processor_info(mach_host_self(), PROCESSOR_CPU_LOAD_INFO, &cpu_count,
                                             reinterpret_cast<processor_info_array_t*>(&cpu_load_info), &processor_msg_count);
    return stat;
}
kern_return_t cpu_by_index(U32 cpu_index, FwSizeType& used, FwSizeType& total) {
    processor_cpu_load_info_t cpu_load_info;
    U32 cpu_count = 0;
    kern_return_t stat = cpu_data_helper(cpu_load_info, cpu_count);
 
    // Failure for CPU index
    if (cpu_count <= cpu_index) {
        stat = KERN_FAILURE;
    } else if (KERN_SUCCESS == stat) {
        FW_ASSERT(cpu_count > cpu_index, cpu_count, cpu_index);  // Will fail if the CPU count changes while running
        processor_cpu_load_info per_cpu_info = cpu_load_info[(cpu_count > cpu_index) ? cpu_index : 0];
 
        // Total the ticks across the different states: idle, system, user, etc...
        total = 0;
        for (U32 i = 0; i < CPU_STATE_MAX; i++) {
            total += per_cpu_info.cpu_ticks[i];
        }
        used = total - per_cpu_info.cpu_ticks[CPU_STATE_IDLE];
    }
    return stat;
}
 
SystemResources::SystemResourcesStatus SystemResources::getCpuCount(U32& cpuCount) {
    processor_cpu_load_info_t cpu_load_info;
    if (KERN_SUCCESS == cpu_data_helper(cpu_load_info, cpuCount)) {
        return SYSTEM_RESOURCES_OK;
    }
    cpuCount = 0;
    return SYSTEM_RESOURCES_ERROR;
}
 
SystemResources::SystemResourcesStatus SystemResources::getCpuTicks(CpuTicks& cpu_ticks, U32 cpu_index) {
    // Fallbacks in case of error
    cpu_ticks.used = 1;
    cpu_ticks.total = 1;
    kern_return_t stat = cpu_by_index(cpu_index, cpu_ticks.used, cpu_ticks.total);
    return (stat == KERN_SUCCESS) ? SYSTEM_RESOURCES_OK : SYSTEM_RESOURCES_ERROR;
}
 
 
SystemResources::SystemResourcesStatus SystemResources::getMemUtil(MemUtil& memory_util) {
    // Call out VM helper
    if (KERN_SUCCESS == vm_stat_helper(memory_util.used, memory_util.total)) {
        return SYSTEM_RESOURCES_OK;
    }
    // Force something sensible, while preventing divide by zero
    memory_util.total = 1;
    memory_util.used = 1;
    return SYSTEM_RESOURCES_ERROR;
}
}  // namespace Os