root/base/process/process_metrics_mac.cc

DEFINITIONS

1. GetTaskInfo
2. GetCPUTypeForProcess
3. IsAddressInSharedRegion
4. CreateProcessMetrics
5. GetPagefileUsage
6. GetPeakPagefileUsage
7. GetWorkingSetSize
8. GetPeakWorkingSetSize
9. GetMemoryBytes
10. GetCommittedKBytes
11. GetWorkingSetKBytes
12. GetCPUUsage
13. GetIdleWakeupsPerSecond
14. GetIOCounters
15. port_provider_
16. TaskForPid
17. GetSystemCommitCharge

// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/process/process_metrics.h"

#include <mach/mach.h>
#include <mach/mach_vm.h>
#include <mach/shared_region.h>
#include <sys/sysctl.h>

#include "base/containers/hash_tables.h"
#include "base/logging.h"
#include "base/mac/scoped_mach_port.h"
#include "base/sys_info.h"

#if !defined(TASK_POWER_INFO)
// Doesn't exist in the 10.6 or 10.7 SDKs.
#define TASK_POWER_INFO        21
struct task_power_info {
        uint64_t                total_user;
        uint64_t                total_system;
        uint64_t                task_interrupt_wakeups;
        uint64_t                task_platform_idle_wakeups;
        uint64_t                task_timer_wakeups_bin_1;
        uint64_t                task_timer_wakeups_bin_2;
};
typedef struct task_power_info        task_power_info_data_t;
typedef struct task_power_info        *task_power_info_t;
#define TASK_POWER_INFO_COUNT        ((mach_msg_type_number_t) \
                (sizeof (task_power_info_data_t) / sizeof (natural_t)))
#endif

namespace base {

namespace {

bool GetTaskInfo(mach_port_t task, task_basic_info_64* task_info_data) {
  if (task == MACH_PORT_NULL)
    return false;
  mach_msg_type_number_t count = TASK_BASIC_INFO_64_COUNT;
  kern_return_t kr = task_info(task,
                               TASK_BASIC_INFO_64,
                               reinterpret_cast<task_info_t>(task_info_data),
                               &count);
  // Most likely cause for failure: |task| is a zombie.
  return kr == KERN_SUCCESS;
}

bool GetCPUTypeForProcess(pid_t pid, cpu_type_t* cpu_type) {
  size_t len = sizeof(*cpu_type);
  int result = sysctlbyname("sysctl.proc_cputype",
                            cpu_type,
                            &len,
                            NULL,
                            0);
  if (result != 0) {
    DPLOG(ERROR) << "sysctlbyname(""sysctl.proc_cputype"")";
    return false;
  }

  return true;
}

bool IsAddressInSharedRegion(mach_vm_address_t addr, cpu_type_t type) {
  if (type == CPU_TYPE_I386) {
    return addr >= SHARED_REGION_BASE_I386 &&
           addr < (SHARED_REGION_BASE_I386 + SHARED_REGION_SIZE_I386);
  } else if (type == CPU_TYPE_X86_64) {
    return addr >= SHARED_REGION_BASE_X86_64 &&
           addr < (SHARED_REGION_BASE_X86_64 + SHARED_REGION_SIZE_X86_64);
  } else {
    return false;
  }
}

}  // namespace

// Getting a mach task from a pid for another process requires permissions in
// general, so there doesn't really seem to be a way to do these (and spinning
// up ps to fetch each stats seems dangerous to put in a base api for anyone to
// call). Child processes ipc their port, so return something if available,
// otherwise return 0.

// static
ProcessMetrics* ProcessMetrics::CreateProcessMetrics(
    ProcessHandle process,
    ProcessMetrics::PortProvider* port_provider) {
  return new ProcessMetrics(process, port_provider);
}

size_t ProcessMetrics::GetPagefileUsage() const {
  task_basic_info_64 task_info_data;
  if (!GetTaskInfo(TaskForPid(process_), &task_info_data))
    return 0;
  return task_info_data.virtual_size;
}

size_t ProcessMetrics::GetPeakPagefileUsage() const {
  return 0;
}

size_t ProcessMetrics::GetWorkingSetSize() const {
  task_basic_info_64 task_info_data;
  if (!GetTaskInfo(TaskForPid(process_), &task_info_data))
    return 0;
  return task_info_data.resident_size;
}

size_t ProcessMetrics::GetPeakWorkingSetSize() const {
  return 0;
}

// This is a rough approximation of the algorithm that libtop uses.
// private_bytes is the size of private resident memory.
// shared_bytes is the size of shared resident memory.
bool ProcessMetrics::GetMemoryBytes(size_t* private_bytes,
                                    size_t* shared_bytes) {
  kern_return_t kr;
  size_t private_pages_count = 0;
  size_t shared_pages_count = 0;

  if (!private_bytes && !shared_bytes)
    return true;

  mach_port_t task = TaskForPid(process_);
  if (task == MACH_PORT_NULL) {
    DLOG(ERROR) << "Invalid process";
    return false;
  }

  cpu_type_t cpu_type;
  if (!GetCPUTypeForProcess(process_, &cpu_type))
    return false;

  // The same region can be referenced multiple times. To avoid double counting
  // we need to keep track of which regions we've already counted.
  base::hash_set<int> seen_objects;

  // We iterate through each VM region in the task's address map. For shared
  // memory we add up all the pages that are marked as shared. Like libtop we
  // try to avoid counting pages that are also referenced by other tasks. Since
  // we don't have access to the VM regions of other tasks the only hint we have
  // is if the address is in the shared region area.
  //
  // Private memory is much simpler. We simply count the pages that are marked
  // as private or copy on write (COW).
  //
  // See libtop_update_vm_regions in
  // http://www.opensource.apple.com/source/top/top-67/libtop.c
  mach_vm_size_t size = 0;
  for (mach_vm_address_t address = MACH_VM_MIN_ADDRESS;; address += size) {
    vm_region_top_info_data_t info;
    mach_msg_type_number_t info_count = VM_REGION_TOP_INFO_COUNT;
    mach_port_t object_name;
    kr = mach_vm_region(task,
                        &address,
                        &size,
                        VM_REGION_TOP_INFO,
                        (vm_region_info_t)&info,
                        &info_count,
                        &object_name);
    if (kr == KERN_INVALID_ADDRESS) {
      // We're at the end of the address space.
      break;
    } else if (kr != KERN_SUCCESS) {
      DLOG(ERROR) << "Calling mach_vm_region failed with error: "
                 << mach_error_string(kr);
      return false;
    }

    if (IsAddressInSharedRegion(address, cpu_type) &&
        info.share_mode != SM_PRIVATE)
      continue;

    if (info.share_mode == SM_COW && info.ref_count == 1)
      info.share_mode = SM_PRIVATE;

    switch (info.share_mode) {
      case SM_PRIVATE:
        private_pages_count += info.private_pages_resident;
        private_pages_count += info.shared_pages_resident;
        break;
      case SM_COW:
        private_pages_count += info.private_pages_resident;
        // Fall through
      case SM_SHARED:
        if (seen_objects.count(info.obj_id) == 0) {
          // Only count the first reference to this region.
          seen_objects.insert(info.obj_id);
          shared_pages_count += info.shared_pages_resident;
        }
        break;
      default:
        break;
    }
  }

  vm_size_t page_size;
  kr = host_page_size(task, &page_size);
  if (kr != KERN_SUCCESS) {
    DLOG(ERROR) << "Failed to fetch host page size, error: "
               << mach_error_string(kr);
    return false;
  }

  if (private_bytes)
    *private_bytes = private_pages_count * page_size;
  if (shared_bytes)
    *shared_bytes = shared_pages_count * page_size;

  return true;
}

void ProcessMetrics::GetCommittedKBytes(CommittedKBytes* usage) const {
}

bool ProcessMetrics::GetWorkingSetKBytes(WorkingSetKBytes* ws_usage) const {
  size_t priv = GetWorkingSetSize();
  if (!priv)
    return false;
  ws_usage->priv = priv / 1024;
  ws_usage->shareable = 0;
  ws_usage->shared = 0;
  return true;
}

#define TIME_VALUE_TO_TIMEVAL(a, r) do {  \
  (r)->tv_sec = (a)->seconds;             \
  (r)->tv_usec = (a)->microseconds;       \
} while (0)

double ProcessMetrics::GetCPUUsage() {
  mach_port_t task = TaskForPid(process_);
  if (task == MACH_PORT_NULL)
    return 0;

  kern_return_t kr;

  // Libtop explicitly loops over the threads (libtop_pinfo_update_cpu_usage()
  // in libtop.c), but this is more concise and gives the same results:
  task_thread_times_info thread_info_data;
  mach_msg_type_number_t thread_info_count = TASK_THREAD_TIMES_INFO_COUNT;
  kr = task_info(task,
                 TASK_THREAD_TIMES_INFO,
                 reinterpret_cast<task_info_t>(&thread_info_data),
                 &thread_info_count);
  if (kr != KERN_SUCCESS) {
    // Most likely cause: |task| is a zombie.
    return 0;
  }

  task_basic_info_64 task_info_data;
  if (!GetTaskInfo(task, &task_info_data))
    return 0;

  /* Set total_time. */
  // thread info contains live time...
  struct timeval user_timeval, system_timeval, task_timeval;
  TIME_VALUE_TO_TIMEVAL(&thread_info_data.user_time, &user_timeval);
  TIME_VALUE_TO_TIMEVAL(&thread_info_data.system_time, &system_timeval);
  timeradd(&user_timeval, &system_timeval, &task_timeval);

  // ... task info contains terminated time.
  TIME_VALUE_TO_TIMEVAL(&task_info_data.user_time, &user_timeval);
  TIME_VALUE_TO_TIMEVAL(&task_info_data.system_time, &system_timeval);
  timeradd(&user_timeval, &task_timeval, &task_timeval);
  timeradd(&system_timeval, &task_timeval, &task_timeval);

  struct timeval now;
  int retval = gettimeofday(&now, NULL);
  if (retval)
    return 0;

  int64 time = TimeValToMicroseconds(now);
  int64 task_time = TimeValToMicroseconds(task_timeval);

  if (last_cpu_time_ == 0) {
    // First call, just set the last values.
    last_cpu_time_ = time;
    last_system_time_ = task_time;
    return 0;
  }

  int64 system_time_delta = task_time - last_system_time_;
  int64 time_delta = time - last_cpu_time_;
  DCHECK_NE(0U, time_delta);
  if (time_delta == 0)
    return 0;

  last_cpu_time_ = time;
  last_system_time_ = task_time;

  return static_cast<double>(system_time_delta * 100.0) / time_delta;
}

int ProcessMetrics::GetIdleWakeupsPerSecond() {
  mach_port_t task = TaskForPid(process_);
  if (task == MACH_PORT_NULL)
    return 0;

  kern_return_t kr;

  task_power_info power_info_data;
  mach_msg_type_number_t power_info_count = TASK_POWER_INFO_COUNT;
  kr = task_info(task,
                 TASK_POWER_INFO,
                 reinterpret_cast<task_info_t>(&power_info_data),
                 &power_info_count);
  if (kr != KERN_SUCCESS) {
    // Most likely cause: |task| is a zombie, or this is on a pre-10.8.4 system
    // where TASK_POWER_INFO isn't supported yet.
    return 0;
  }
  uint64_t absolute_idle_wakeups = power_info_data.task_platform_idle_wakeups;

  struct timeval now;
  int retval = gettimeofday(&now, NULL);
  if (retval)
    return 0;

  int64 time = TimeValToMicroseconds(now);

  if (last_idle_wakeups_time_ == 0) {
    // First call, just set the last values.
    last_idle_wakeups_time_ = time;
    last_absolute_idle_wakeups_ = absolute_idle_wakeups;
    return 0;
  }

  int64 wakeups_delta = absolute_idle_wakeups - last_absolute_idle_wakeups_;
  int64 time_delta = time - last_idle_wakeups_time_;
  DCHECK_NE(0U, time_delta);
  if (time_delta == 0)
    return 0;

  last_idle_wakeups_time_ = time;
  last_absolute_idle_wakeups_ = absolute_idle_wakeups;

  // Round to average wakeups per second.
  const int kMicrosecondsPerSecond = 1000 * 1000;
  return (wakeups_delta * kMicrosecondsPerSecond + time_delta/2) / time_delta;
}

bool ProcessMetrics::GetIOCounters(IoCounters* io_counters) const {
  return false;
}

ProcessMetrics::ProcessMetrics(ProcessHandle process,
                               ProcessMetrics::PortProvider* port_provider)
    : process_(process),
      last_cpu_time_(0),
      last_system_time_(0),
      last_idle_wakeups_time_(0),
      last_absolute_idle_wakeups_(0),
      port_provider_(port_provider) {
  processor_count_ = SysInfo::NumberOfProcessors();
}

mach_port_t ProcessMetrics::TaskForPid(ProcessHandle process) const {
  mach_port_t task = MACH_PORT_NULL;
  if (port_provider_)
    task = port_provider_->TaskForPid(process_);
  if (task == MACH_PORT_NULL && process_ == getpid())
    task = mach_task_self();
  return task;
}

// Bytes committed by the system.
size_t GetSystemCommitCharge() {
  base::mac::ScopedMachPort host(mach_host_self());
  mach_msg_type_number_t count = HOST_VM_INFO_COUNT;
  vm_statistics_data_t data;
  kern_return_t kr = host_statistics(host, HOST_VM_INFO,
                                     reinterpret_cast<host_info_t>(&data),
                                     &count);
  if (kr) {
    DLOG(WARNING) << "Failed to fetch host statistics.";
    return 0;
  }

  vm_size_t page_size;
  kr = host_page_size(host, &page_size);
  if (kr) {
    DLOG(ERROR) << "Failed to fetch host page size.";
    return 0;
  }

  return (data.active_count * page_size) / 1024;
}

}  // namespace base