/*
 * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */
#include "precompiled.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/resourceArea.hpp"
#include "runtime/os.hpp"
#include "runtime/os_perf.hpp"
#include "vm_version_ext_x86.hpp"

#ifdef __APPLE__
  #import <libproc.h>
  #include <sys/time.h>
  #include <sys/sysctl.h>
  #include <mach/mach.h>
  #include <mach/task_info.h>
#endif

static const double NANOS_PER_SEC = 1000000000.0;

class CPUPerformanceInterface::CPUPerformance : public CHeapObj<mtInternal> {
   friend class CPUPerformanceInterface;
 private:
  long _total_cpu_nanos;
  long _total_csr_nanos;
  long _jvm_user_nanos;
  long _jvm_system_nanos;
  long _jvm_context_switches;
  long _used_ticks;
  long _total_ticks;
  int  _active_processor_count;

  bool now_in_nanos(long* resultp) {
    timeval current_time;
    if (gettimeofday(&current_time, NULL) != 0) {
      // Error getting current time
      return false;
    }
    *resultp = current_time.tv_sec * NANOS_PER_SEC + 1000L * current_time.tv_usec;
    return true;
  }

  double normalize(double value) {
    return MIN2<double>(MAX2<double>(value, 0.0), 1.0);
  }
  int cpu_load(int which_logical_cpu, double* cpu_load);
  int context_switch_rate(double* rate);
  int cpu_load_total_process(double* cpu_load);
  int cpu_loads_process(double* pjvmUserLoad, double* pjvmKernelLoad, double* psystemTotalLoad);

  CPUPerformance(const CPUPerformance& rhs); // no impl
  CPUPerformance& operator=(const CPUPerformance& rhs); // no impl
 public:
  CPUPerformance();
  bool initialize();
  ~CPUPerformance();
};

CPUPerformanceInterface::CPUPerformance::CPUPerformance() {
  _total_cpu_nanos= 0;
  _total_csr_nanos= 0;
  _jvm_context_switches = 0;
  _jvm_user_nanos = 0;
  _jvm_system_nanos = 0;
  _used_ticks = 0;
  _total_ticks = 0;
  _active_processor_count = 0;
}

bool CPUPerformanceInterface::CPUPerformance::initialize() {
  return true;
}

CPUPerformanceInterface::CPUPerformance::~CPUPerformance() {
}

int CPUPerformanceInterface::CPUPerformance::cpu_load(int which_logical_cpu, double* cpu_load) {
  return FUNCTIONALITY_NOT_IMPLEMENTED;
}

int CPUPerformanceInterface::CPUPerformance::cpu_load_total_process(double* cpu_load) {
#ifdef __APPLE__
  host_name_port_t host = mach_host_self();
  host_flavor_t flavor = HOST_CPU_LOAD_INFO;
  mach_msg_type_number_t host_info_count = HOST_CPU_LOAD_INFO_COUNT;
  host_cpu_load_info_data_t cpu_load_info;

  kern_return_t kr = host_statistics(host, flavor, (host_info_t)&cpu_load_info, &host_info_count);
  if (kr != KERN_SUCCESS) {
    return OS_ERR;
  }

  long used_ticks  = cpu_load_info.cpu_ticks[CPU_STATE_USER] + cpu_load_info.cpu_ticks[CPU_STATE_NICE] + cpu_load_info.cpu_ticks[CPU_STATE_SYSTEM];
  long total_ticks = used_ticks + cpu_load_info.cpu_ticks[CPU_STATE_IDLE];

  if (_used_ticks == 0 || _total_ticks == 0) {
    // First call, just set the values
    _used_ticks  = used_ticks;
    _total_ticks = total_ticks;
    return OS_ERR;
  }

  long used_delta  = used_ticks - _used_ticks;
  long total_delta = total_ticks - _total_ticks;

  _used_ticks  = used_ticks;
  _total_ticks = total_ticks;

  if (total_delta == 0) {
    // Avoid division by zero
    return OS_ERR;
  }

  *cpu_load = (double)used_delta / total_delta;

  return OS_OK;
#else
  return FUNCTIONALITY_NOT_IMPLEMENTED;
#endif
}

int CPUPerformanceInterface::CPUPerformance::cpu_loads_process(double* pjvmUserLoad, double* pjvmKernelLoad, double* psystemTotalLoad) {
#ifdef __APPLE__
  int result = cpu_load_total_process(psystemTotalLoad);
  mach_port_t task = mach_task_self();
  mach_msg_type_number_t task_info_count = TASK_INFO_MAX;
  task_info_data_t task_info_data;
  kern_return_t kr = task_info(task, TASK_ABSOLUTETIME_INFO, (task_info_t)task_info_data, &task_info_count);
  if (kr != KERN_SUCCESS) {
    return OS_ERR;
  }
  task_absolutetime_info_t absolutetime_info = (task_absolutetime_info_t)task_info_data;

  int active_processor_count = os::active_processor_count();
  long jvm_user_nanos = absolutetime_info->total_user;
  long jvm_system_nanos = absolutetime_info->total_system;

  long total_cpu_nanos;
  if(!now_in_nanos(&total_cpu_nanos)) {
    return OS_ERR;
  }

  if (_total_cpu_nanos == 0 || active_processor_count != _active_processor_count) {
    // First call or change in active processor count
    result = OS_ERR;
  }

  long delta_nanos = active_processor_count * (total_cpu_nanos - _total_cpu_nanos);
  if (delta_nanos == 0) {
    // Avoid division by zero
    return OS_ERR;
  }

  *pjvmUserLoad = normalize((double)(jvm_user_nanos - _jvm_user_nanos)/delta_nanos);
  *pjvmKernelLoad = normalize((double)(jvm_system_nanos - _jvm_system_nanos)/delta_nanos);

  _active_processor_count = active_processor_count;
  _total_cpu_nanos = total_cpu_nanos;
  _jvm_user_nanos = jvm_user_nanos;
  _jvm_system_nanos = jvm_system_nanos;

  return result;
#else
  return FUNCTIONALITY_NOT_IMPLEMENTED;
#endif
}

int CPUPerformanceInterface::CPUPerformance::context_switch_rate(double* rate) {
#ifdef __APPLE__
  mach_port_t task = mach_task_self();
  mach_msg_type_number_t task_info_count = TASK_INFO_MAX;
  task_info_data_t task_info_data;
  kern_return_t kr = task_info(task, TASK_EVENTS_INFO, (task_info_t)task_info_data, &task_info_count);
  if (kr != KERN_SUCCESS) {
    return OS_ERR;
  }

  int result = OS_OK;
  if (_total_csr_nanos == 0 || _jvm_context_switches == 0) {
    // First call just set initial values.
    result = OS_ERR;
  }

  long jvm_context_switches = ((task_events_info_t)task_info_data)->csw;

  long total_csr_nanos;
  if(!now_in_nanos(&total_csr_nanos)) {
    return OS_ERR;
  }
  double delta_in_sec = (double)(total_csr_nanos - _total_csr_nanos) / NANOS_PER_SEC;
  if (delta_in_sec == 0.0) {
    // Avoid division by zero
    return OS_ERR;
  }

  *rate = (jvm_context_switches - _jvm_context_switches) / delta_in_sec;

  _jvm_context_switches = jvm_context_switches;
  _total_csr_nanos = total_csr_nanos;

  return result;
#else
  return FUNCTIONALITY_NOT_IMPLEMENTED;
#endif
}

CPUPerformanceInterface::CPUPerformanceInterface() {
  _impl = NULL;
}

bool CPUPerformanceInterface::initialize() {
  _impl = new CPUPerformanceInterface::CPUPerformance();
  return _impl != NULL && _impl->initialize();
}

CPUPerformanceInterface::~CPUPerformanceInterface() {
  if (_impl != NULL) {
    delete _impl;
  }
}

int CPUPerformanceInterface::cpu_load(int which_logical_cpu, double* cpu_load) const {
  return _impl->cpu_load(which_logical_cpu, cpu_load);
}

int CPUPerformanceInterface::cpu_load_total_process(double* cpu_load) const {
  return _impl->cpu_load_total_process(cpu_load);
}

int CPUPerformanceInterface::cpu_loads_process(double* pjvmUserLoad, double* pjvmKernelLoad, double* psystemTotalLoad) const {
  return _impl->cpu_loads_process(pjvmUserLoad, pjvmKernelLoad, psystemTotalLoad);
}

int CPUPerformanceInterface::context_switch_rate(double* rate) const {
  return _impl->context_switch_rate(rate);
}

class SystemProcessInterface::SystemProcesses : public CHeapObj<mtInternal> {
  friend class SystemProcessInterface;
 private:
  SystemProcesses();
  bool initialize();
  SystemProcesses(const SystemProcesses& rhs); // no impl
  SystemProcesses& operator=(const SystemProcesses& rhs); // no impl
  ~SystemProcesses();

  //information about system processes
  int system_processes(SystemProcess** system_processes, int* no_of_sys_processes) const;
};

SystemProcessInterface::SystemProcesses::SystemProcesses() {
}

bool SystemProcessInterface::SystemProcesses::initialize() {
  return true;
}

SystemProcessInterface::SystemProcesses::~SystemProcesses() {
}
int SystemProcessInterface::SystemProcesses::system_processes(SystemProcess** system_processes, int* no_of_sys_processes) const {
  assert(system_processes != NULL, "system_processes pointer is NULL!");
  assert(no_of_sys_processes != NULL, "system_processes counter pointer is NULL!");
#ifdef __APPLE__
  pid_t* pids = NULL;
  int pid_count = 0;
  ResourceMark rm;

  int try_count = 0;
  while (pids == NULL) {
    // Find out buffer size
    size_t pids_bytes = proc_listpids(PROC_ALL_PIDS, 0, NULL, 0);
    if (pids_bytes <= 0) {
      return OS_ERR;
    }
    pid_count = pids_bytes / sizeof(pid_t);
    pids = NEW_RESOURCE_ARRAY(pid_t, pid_count);
    memset(pids, 0, pids_bytes);

    pids_bytes = proc_listpids(PROC_ALL_PIDS, 0, pids, pids_bytes);
    if (pids_bytes <= 0) {
       // couldn't fit buffer, retry.
      FREE_RESOURCE_ARRAY(pid_t, pids, pid_count);
      pids = NULL;
      try_count++;
      if (try_count > 3) {
      return OS_ERR;
      }
    } else {
      pid_count = pids_bytes / sizeof(pid_t);
    }
  }

  int process_count = 0;
  SystemProcess* next = NULL;
  for (int i = 0; i < pid_count; i++) {
    pid_t pid = pids[i];
    if (pid != 0) {
      char buffer[PROC_PIDPATHINFO_MAXSIZE];
      memset(buffer, 0 , sizeof(buffer));
      if (proc_pidpath(pid, buffer, sizeof(buffer)) != -1) {
        int length = strlen(buffer);
        if (length > 0) {
          SystemProcess* current = new SystemProcess();
          char * path = NEW_C_HEAP_ARRAY(char, length + 1, mtInternal);
          strcpy(path, buffer);
          current->set_path(path);
          current->set_pid((int)pid);
          current->set_next(next);
          next = current;
          process_count++;
        }
      }
    }
  }

  *no_of_sys_processes = process_count;
  *system_processes = next;

  return OS_OK;
#endif
  return FUNCTIONALITY_NOT_IMPLEMENTED;
}

int SystemProcessInterface::system_processes(SystemProcess** system_procs, int* no_of_sys_processes) const {
  return _impl->system_processes(system_procs, no_of_sys_processes);
}

SystemProcessInterface::SystemProcessInterface() {
  _impl = NULL;
}

bool SystemProcessInterface::initialize() {
  _impl = new SystemProcessInterface::SystemProcesses();
  return _impl != NULL && _impl->initialize();
}

SystemProcessInterface::~SystemProcessInterface() {
  if (_impl != NULL) {
    delete _impl;
 }
}

CPUInformationInterface::CPUInformationInterface() {
  _cpu_info = NULL;
}

bool CPUInformationInterface::initialize() {
  _cpu_info = new CPUInformation();

  if (NULL == _cpu_info) {
    return false;
  }
  _cpu_info->set_number_of_hardware_threads(VM_Version_Ext::number_of_threads());
  _cpu_info->set_number_of_cores(VM_Version_Ext::number_of_cores());
  _cpu_info->set_number_of_sockets(VM_Version_Ext::number_of_sockets());
  _cpu_info->set_cpu_name(VM_Version_Ext::cpu_name());
  _cpu_info->set_cpu_description(VM_Version_Ext::cpu_description());

  return true;
}

CPUInformationInterface::~CPUInformationInterface() {
  if (_cpu_info != NULL) {
    if (_cpu_info->cpu_name() != NULL) {
      const char* cpu_name = _cpu_info->cpu_name();
      FREE_C_HEAP_ARRAY(char, cpu_name);
      _cpu_info->set_cpu_name(NULL);
    }
    if (_cpu_info->cpu_description() != NULL) {
      const char* cpu_desc = _cpu_info->cpu_description();
      FREE_C_HEAP_ARRAY(char, cpu_desc);
      _cpu_info->set_cpu_description(NULL);
    }
    delete _cpu_info;
  }
}

int CPUInformationInterface::cpu_information(CPUInformation& cpu_info) {
  if (NULL == _cpu_info) {
    return OS_ERR;
  }

  cpu_info = *_cpu_info; // shallow copy assignment
  return OS_OK;
}