Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.

  * Copyright (c) 2020 SAP SE. 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 "jvm.h"

 #include "memory/allocation.inline.hpp"

 #include "os_aix.inline.hpp"

 #include "runtime/os.hpp"

 #include "runtime/os_perf.hpp"

 #include "vm_version_ext_ppc.hpp"

 #include <stdio.h>

 #include <stdarg.h>

 #include <unistd.h>

 #include <errno.h>

 #include <string.h>

 #include <sys/resource.h>

 #include <sys/types.h>

 #include <sys/stat.h>

 #include <dirent.h>

 #include <stdlib.h>

 #include <dlfcn.h>

 #include <pthread.h>

 #include <limits.h>

 /**

    /proc/[number]/stat

               Status information about the process.  This is used by ps(1).  It is defined in /usr/src/linux/fs/proc/array.c.

               The fields, in order, with their proper scanf(3) format specifiers, are:

               1. pid %d The process id.

               2. comm %s

                      The filename of the executable, in parentheses.  This is visible whether or not the executable is swapped out.

               3. state %c

                      One  character  from  the  string "RSDZTW" where R is running, S is sleeping in an interruptible wait, D is waiting in uninterruptible disk

                      sleep, Z is zombie, T is traced or stopped (on a signal), and W is paging.

               4. ppid %d

                      The PID of the parent.

               5. pgrp %d

                      The process group ID of the process.

               6. session %d

                      The session ID of the process.

               7. tty_nr %d

                      The tty the process uses.

               8. tpgid %d

                      The process group ID of the process which currently owns the tty that the process is connected to.

               9. flags %lu

                      The flags of the process.  The math bit is decimal 4, and the traced bit is decimal 10.

               10. minflt %lu

                      The number of minor faults the process has made which have not required loading a memory page from disk.

               11. cminflt %lu

                      The number of minor faults that the process's waited-for children have made.

               12. majflt %lu

                      The number of major faults the process has made which have required loading a memory page from disk.

               13. cmajflt %lu

                      The number of major faults that the process's waited-for children have made.

               14. utime %lu

                      The number of jiffies that this process has been scheduled in user mode.

               15. stime %lu

                      The number of jiffies that this process has been scheduled in kernel mode.

               16. cutime %ld

                      The number of jiffies that this process's waited-for children have been scheduled in user mode. (See also times(2).)

               17. cstime %ld

                      The number of jiffies that this process' waited-for children have been scheduled in kernel mode.

               18. priority %ld

                      The standard nice value, plus fifteen.  The value is never negative in the kernel.

               19. nice %ld

                      The nice value ranges from 19 (nicest) to -19 (not nice to others).

               20. 0 %ld  This value is hard coded to 0 as a placeholder for a removed field.

               21. itrealvalue %ld

                      The time in jiffies before the next SIGALRM is sent to the process due to an interval timer.

               22. starttime %lu

                      The time in jiffies the process started after system boot.

               23. vsize %lu

                      Virtual memory size in bytes.

               24. rss %ld

                      Resident Set Size: number of pages the process has in real memory, minus 3 for administrative purposes. This is just the pages which  count

                      towards text, data, or stack space.  This does not include pages which have not been demand-loaded in, or which are swapped out.

               25. rlim %lu

                      Current limit in bytes on the rss of the process (usually 4294967295 on i386).

               26. startcode %lu

                      The address above which program text can run.

               27. endcode %lu

                      The address below which program text can run.

               28. startstack %lu

                      The address of the start of the stack.

               29. kstkesp %lu

                      The current value of esp (stack pointer), as found in the kernel stack page for the process.

               30. kstkeip %lu

                      The current EIP (instruction pointer).

               31. signal %lu

                      The bitmap of pending signals (usually 0).

               32. blocked %lu

                      The bitmap of blocked signals (usually 0, 2 for shells).

               33. sigignore %lu

                      The bitmap of ignored signals.

               34. sigcatch %lu

                      The bitmap of catched signals.

               35. wchan %lu

                      This  is the "channel" in which the process is waiting.  It is the address of a system call, and can be looked up in a namelist if you need

                      a textual name.  (If you have an up-to-date /etc/psdatabase, then try ps -l to see the WCHAN field in action.)

               36. nswap %lu

                      Number of pages swapped - not maintained.

               37. cnswap %lu

                      Cumulative nswap for child processes.

               38. exit_signal %d

                      Signal to be sent to parent when we die.

               39. processor %d

                      CPU number last executed on.

  ///// SSCANF FORMAT STRING. Copy and use.

 field:        1  2  3  4  5  6  7  8  9   10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38 39

 format:       %d %s %c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld %lu %lu %ld %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %d %d

 */

 struct CPUPerfTicks {

   uint64_t  used;

   uint64_t  usedKernel;

   uint64_t  total;

 };

 typedef enum {

   CPU_LOAD_VM_ONLY,

   CPU_LOAD_GLOBAL,

 } CpuLoadTarget;

 enum {

   UNDETECTED,

   UNDETECTABLE,

   LINUX26_NPTL,

   BAREMETAL

 };

 struct CPUPerfCounters {

   int   nProcs;

   CPUPerfTicks jvmTicks;

   CPUPerfTicks* cpus;

 };

 static double get_cpu_load(int which_logical_cpu, CPUPerfCounters* counters, double* pkernelLoad, CpuLoadTarget target);

 /** reads /proc/<pid>/stat data, with some checks and some skips.

  *  Ensure that 'fmt' does _NOT_ contain the first two "%d %s"

  */

 static int vread_statdata(const char* procfile, const char* fmt, va_list args) {

   FILE*f;

   int n;

   char buf[2048];

   if ((f = fopen(procfile, "r")) == NULL) {

     return -1;

   }

   if ((n = fread(buf, 1, sizeof(buf), f)) != -1) {

     char *tmp;

     buf[n-1] = '\0';

     /** skip through pid and exec name. */

     if ((tmp = strrchr(buf, ')')) != NULL) {

       // skip the ')' and the following space

       // but check that buffer is long enough

       tmp += 2;

       if (tmp < buf + n) {

         n = vsscanf(tmp, fmt, args);

       }

     }

   }

   fclose(f);

   return n;

 }

 static int read_statdata(const char* procfile, const char* fmt, ...) {

   int   n;

   va_list args;

   va_start(args, fmt);

   n = vread_statdata(procfile, fmt, args);

   va_end(args);

   return n;

 }

 static FILE* open_statfile(void) {

   FILE *f;

   if ((f = fopen("/proc/stat", "r")) == NULL) {

     static int haveWarned = 0;

     if (!haveWarned) {

       haveWarned = 1;

     }

   }

   return f;

 }

 static void

 next_line(FILE *f) {

   int c;

   do {

     c = fgetc(f);

   } while (c != '\n' && c != EOF);

 }

 /**

  * Return the total number of ticks since the system was booted.

  * If the usedTicks parameter is not NULL, it will be filled with

  * the number of ticks spent on actual processes (user, system or

  * nice processes) since system boot. Note that this is the total number

  * of "executed" ticks on _all_ CPU:s, that is on a n-way system it is

  * n times the number of ticks that has passed in clock time.

  *

  * Returns a negative value if the reading of the ticks failed.

  */

 static OSReturn get_total_ticks(int which_logical_cpu, CPUPerfTicks* pticks) {

   FILE*         fh;

   uint64_t      userTicks, niceTicks, systemTicks, idleTicks;

   uint64_t      iowTicks = 0, irqTicks = 0, sirqTicks= 0;

   int           logical_cpu = -1;

   const int     expected_assign_count = (-1 == which_logical_cpu) ? 4 : 5;

   int           n;

   if ((fh = open_statfile()) == NULL) {

     return OS_ERR;

   }

   if (-1 == which_logical_cpu) {

     n = fscanf(fh, "cpu " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "

             UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT,

             &userTicks, &niceTicks, &systemTicks, &idleTicks,

             &iowTicks, &irqTicks, &sirqTicks);

   } else {

     // Move to next line

     next_line(fh);

     // find the line for requested cpu faster to just iterate linefeeds?

     for (int i = 0; i < which_logical_cpu; i++) {

       next_line(fh);

     }

     n = fscanf(fh, "cpu%u " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "

                UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT,

                &logical_cpu, &userTicks, &niceTicks,

                &systemTicks, &idleTicks, &iowTicks, &irqTicks, &sirqTicks);

   }

   fclose(fh);

   if (n < expected_assign_count || logical_cpu != which_logical_cpu) {

 #ifdef DEBUG_LINUX_PROC_STAT

     vm_fprintf(stderr, "[stat] read failed");

 #endif

     return OS_ERR;

   }

 #ifdef DEBUG_LINUX_PROC_STAT

   vm_fprintf(stderr, "[stat] read "

           UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " "

           UINT64_FORMAT " " UINT64_FORMAT " " UINT64_FORMAT " \n",

           userTicks, niceTicks, systemTicks, idleTicks,

           iowTicks, irqTicks, sirqTicks);

 #endif

   pticks->used       = userTicks + niceTicks;

   pticks->usedKernel = systemTicks + irqTicks + sirqTicks;

   pticks->total      = userTicks + niceTicks + systemTicks + idleTicks +

                        iowTicks + irqTicks + sirqTicks;

   return OS_OK;

 }

 static int get_systemtype(void) {

   static int procEntriesType = UNDETECTED;

   DIR *taskDir;

   if (procEntriesType != UNDETECTED) {

     return procEntriesType;

   }

   // Check whether we have a task subdirectory

   if ((taskDir = opendir("/proc/self/task")) == NULL) {

     procEntriesType = UNDETECTABLE;

   } else {

     // The task subdirectory exists; we're on a Linux >= 2.6 system

     closedir(taskDir);

     procEntriesType = LINUX26_NPTL;

   }

   return procEntriesType;

 }

 /** read user and system ticks from a named procfile, assumed to be in 'stat' format then. */

 static int read_ticks(const char* procfile, uint64_t* userTicks, uint64_t* systemTicks) {

   return read_statdata(procfile, "%*c %*d %*d %*d %*d %*d %*u %*u %*u %*u %*u " UINT64_FORMAT " " UINT64_FORMAT,

     userTicks, systemTicks);

 }

 /**

  * Return the number of ticks spent in any of the processes belonging

  * to the JVM on any CPU.

  */

 static OSReturn get_jvm_ticks(CPUPerfTicks* pticks) {

   uint64_t userTicks;

   uint64_t systemTicks;

   if (get_systemtype() != LINUX26_NPTL) {

     return OS_ERR;

   }

   if (read_ticks("/proc/self/stat", &userTicks, &systemTicks) != 2) {

     return OS_ERR;

   }

   // get the total

   if (get_total_ticks(-1, pticks) != OS_OK) {

     return OS_ERR;

   }

   pticks->used       = userTicks;

   pticks->usedKernel = systemTicks;

   return OS_OK;

 }

 /**

  * Return the load of the CPU as a double. 1.0 means the CPU process uses all

  * available time for user or system processes, 0.0 means the CPU uses all time

  * being idle.

  *

  * Returns a negative value if there is a problem in determining the CPU load.

  */

 static double get_cpu_load(int which_logical_cpu, CPUPerfCounters* counters, double* pkernelLoad, CpuLoadTarget target) {

   uint64_t udiff, kdiff, tdiff;

   CPUPerfTicks* pticks;

   CPUPerfTicks  tmp;

   double user_load;

   *pkernelLoad = 0.0;

   if (target == CPU_LOAD_VM_ONLY) {

     pticks = &counters->jvmTicks;

   } else if (-1 == which_logical_cpu) {

     pticks = &counters->cpus[counters->nProcs];

   } else {

     pticks = &counters->cpus[which_logical_cpu];

   }

   tmp = *pticks;

   if (target == CPU_LOAD_VM_ONLY) {

     if (get_jvm_ticks(pticks) != OS_OK) {

       return -1.0;

     }

   } else if (get_total_ticks(which_logical_cpu, pticks) != OS_OK) {

     return -1.0;

   }

   // seems like we sometimes end up with less kernel ticks when

   // reading /proc/self/stat a second time, timing issue between cpus?

   if (pticks->usedKernel < tmp.usedKernel) {

     kdiff = 0;

   } else {

     kdiff = pticks->usedKernel - tmp.usedKernel;

   }

   tdiff = pticks->total - tmp.total;

   udiff = pticks->used - tmp.used;

   if (tdiff == 0) {

     return 0.0;

   } else if (tdiff < (udiff + kdiff)) {

     tdiff = udiff + kdiff;

   }

   *pkernelLoad = (kdiff / (double)tdiff);

   // BUG9044876, normalize return values to sane values

   *pkernelLoad = MAX2<double>(*pkernelLoad, 0.0);

   *pkernelLoad = MIN2<double>(*pkernelLoad, 1.0);

   user_load = (udiff / (double)tdiff);

   user_load = MAX2<double>(user_load, 0.0);

   user_load = MIN2<double>(user_load, 1.0);

   return user_load;

 }

 static int parse_stat(const char* fmt, ...) {

   FILE *f;

   va_list args;

   va_start(args, fmt);

   if ((f = open_statfile()) == NULL) {

     va_end(args);

     return OS_ERR;

   }

   for (;;) {

     char line[80];

     if (fgets(line, sizeof(line), f) != NULL) {

       if (vsscanf(line, fmt, args) == 1) {

         fclose(f);

         va_end(args);

         return OS_OK;

       }

     } else {

         fclose(f);

         va_end(args);

         return OS_ERR;

     }

   }

 }

 static int get_noof_context_switches(uint64_t* switches) {

   return parse_stat("ctxt " UINT64_FORMAT "\n", switches);

 }

 /** returns boot time in _seconds_ since epoch */

 static int get_boot_time(uint64_t* time) {

   return parse_stat("btime " UINT64_FORMAT "\n", time);

 }

 static int perf_context_switch_rate(double* rate) {

   static pthread_mutex_t contextSwitchLock = PTHREAD_MUTEX_INITIALIZER;

   static uint64_t      lastTime;

   static uint64_t      lastSwitches;

   static double        lastRate;

   uint64_t lt = 0;

   int res = 0;

   if (lastTime == 0) {

     uint64_t tmp;

     if (get_boot_time(&tmp) < 0) {

       return OS_ERR;

     }

     lt = tmp * 1000;

   }

   res = OS_OK;

   pthread_mutex_lock(&contextSwitchLock);

   {

     uint64_t sw;

     s8 t, d;

     if (lastTime == 0) {

       lastTime = lt;

     }

     t = os::javaTimeMillis();

     d = t - lastTime;

     if (d == 0) {

       *rate = lastRate;

     } else if (!get_noof_context_switches(&sw)) {

       *rate      = ( (double)(sw - lastSwitches) / d ) * 1000;

       lastRate     = *rate;

       lastSwitches = sw;

       lastTime     = t;

     } else {

       *rate = 0;

       res   = OS_ERR;

     }

     if (*rate <= 0) {

       *rate = 0;

       lastRate = 0;

     }

   }

   pthread_mutex_unlock(&contextSwitchLock);

   return res;

 }

 class CPUPerformanceInterface::CPUPerformance : public CHeapObj<mtInternal> {

   friend class CPUPerformanceInterface;

  private:

   CPUPerfCounters _counters;

   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);

  public:

   CPUPerformance();

   bool initialize();

   ~CPUPerformance();

 };

 CPUPerformanceInterface::CPUPerformance::CPUPerformance() {

   _counters.nProcs = os::active_processor_count();

   _counters.cpus = NULL;

 }

 bool CPUPerformanceInterface::CPUPerformance::initialize() {

   size_t tick_array_size = (_counters.nProcs +1) * sizeof(CPUPerfTicks);

   _counters.cpus = (CPUPerfTicks*)NEW_C_HEAP_ARRAY(char, tick_array_size, mtInternal);

   if (NULL == _counters.cpus) {

     return false;

   }

   memset(_counters.cpus, 0, tick_array_size);

   // For the CPU load total

   get_total_ticks(-1, &_counters.cpus[_counters.nProcs]);

   // For each CPU

   for (int i = 0; i < _counters.nProcs; i++) {

     get_total_ticks(i, &_counters.cpus[i]);

   }

   // For JVM load

   get_jvm_ticks(&_counters.jvmTicks);

   // initialize context switch system

   // the double is only for init

   double init_ctx_switch_rate;

   perf_context_switch_rate(&init_ctx_switch_rate);

   return true;

 }

 CPUPerformanceInterface::CPUPerformance::~CPUPerformance() {

   if (_counters.cpus != NULL) {

     FREE_C_HEAP_ARRAY(char, _counters.cpus, mtInternal);

   }

 }

 int CPUPerformanceInterface::CPUPerformance::cpu_load(int which_logical_cpu, double* cpu_load) {

   double u, s;

   u = get_cpu_load(which_logical_cpu, &_counters, &s, CPU_LOAD_GLOBAL);

   if (u < 0) {

     *cpu_load = 0.0;

     return OS_ERR;

   }

   // Cap total systemload to 1.0

   *cpu_load = MIN2<double>((u + s), 1.0);

   return OS_OK;

 }

 int CPUPerformanceInterface::CPUPerformance::cpu_load_total_process(double* cpu_load) {

   double u, s;

   u = get_cpu_load(-1, &_counters, &s, CPU_LOAD_VM_ONLY);

   if (u < 0) {

     *cpu_load = 0.0;

     return OS_ERR;

   }

   *cpu_load = u + s;

   return OS_OK;

 }

 int CPUPerformanceInterface::CPUPerformance::cpu_loads_process(double* pjvmUserLoad, double* pjvmKernelLoad, double* psystemTotalLoad) {

   double u, s, t;

   assert(pjvmUserLoad != NULL, "pjvmUserLoad not inited");

   assert(pjvmKernelLoad != NULL, "pjvmKernelLoad not inited");

   assert(psystemTotalLoad != NULL, "psystemTotalLoad not inited");

   u = get_cpu_load(-1, &_counters, &s, CPU_LOAD_VM_ONLY);

   if (u < 0) {

     *pjvmUserLoad = 0.0;

     *pjvmKernelLoad = 0.0;

     *psystemTotalLoad = 0.0;

     return OS_ERR;

   }

   cpu_load(-1, &t);

   // clamp at user+system and 1.0

   if (u + s > t) {

     t = MIN2<double>(u + s, 1.0);

   }

   *pjvmUserLoad = u;

   *pjvmKernelLoad = s;

   *psystemTotalLoad = t;

   return OS_OK;

 }

 int CPUPerformanceInterface::CPUPerformance::context_switch_rate(double* rate) {

   return perf_context_switch_rate(rate);

 }

 CPUPerformanceInterface::CPUPerformanceInterface() {

   _impl = NULL;

 }

 bool CPUPerformanceInterface::initialize() {

   _impl = new CPUPerformanceInterface::CPUPerformance();

   return NULL == _impl ? false : _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:

   class ProcessIterator : public CHeapObj<mtInternal> {

     friend class SystemProcessInterface::SystemProcesses;

    private:

     DIR*           _dir;

     struct dirent* _entry;

     bool           _valid;

     char           _exeName[PATH_MAX];

     char           _exePath[PATH_MAX];

     ProcessIterator();

     ~ProcessIterator();

     bool initialize();

     bool is_valid() const { return _valid; }

     bool is_valid_entry(struct dirent* entry) const;

     bool is_dir(const char* name) const;

     int  fsize(const char* name, uint64_t& size) const;

     char* allocate_string(const char* str) const;

     void  get_exe_name();

     char* get_exe_path();

     char* get_cmdline();

     int current(SystemProcess* process_info);

     int next_process();

   };

   ProcessIterator* _iterator;

   SystemProcesses();

   bool initialize();

   ~SystemProcesses();

   //information about system processes

   int system_processes(SystemProcess** system_processes, int* no_of_sys_processes) const;

 };

 bool SystemProcessInterface::SystemProcesses::ProcessIterator::is_dir(const char* name) const {

   struct stat mystat;

   int ret_val = 0;

   ret_val = stat(name, &mystat);

   if (ret_val < 0) {

     return false;

   }

   ret_val = S_ISDIR(mystat.st_mode);

   return ret_val > 0;

 }

 int SystemProcessInterface::SystemProcesses::ProcessIterator::fsize(const char* name, uint64_t& size) const {

   assert(name != NULL, "name pointer is NULL!");

   size = 0;

   struct stat fbuf;

   if (stat(name, &fbuf) < 0) {

     return OS_ERR;

   }

   size = fbuf.st_size;

   return OS_OK;

 }

 // if it has a numeric name, is a directory and has a 'stat' file in it

 bool SystemProcessInterface::SystemProcesses::ProcessIterator::is_valid_entry(struct dirent* entry) const {

   char buffer[PATH_MAX];

   uint64_t size = 0;

   if (atoi(entry->d_name) != 0) {

     jio_snprintf(buffer, PATH_MAX, "/proc/%s", entry->d_name);

     buffer[PATH_MAX - 1] = '\0';

     if (is_dir(buffer)) {

       jio_snprintf(buffer, PATH_MAX, "/proc/%s/stat", entry->d_name);

       buffer[PATH_MAX - 1] = '\0';

       if (fsize(buffer, size) != OS_ERR) {

         return true;

       }

     }

   }

   return false;

 }

 // get exe-name from /proc/<pid>/stat

 void SystemProcessInterface::SystemProcesses::ProcessIterator::get_exe_name() {

   FILE* fp;

   char  buffer[PATH_MAX];

   jio_snprintf(buffer, PATH_MAX, "/proc/%s/stat", _entry->d_name);

   buffer[PATH_MAX - 1] = '\0';

   if ((fp = fopen(buffer, "r")) != NULL) {

     if (fgets(buffer, PATH_MAX, fp) != NULL) {

       char* start, *end;

       // exe-name is between the first pair of ( and )

       start = strchr(buffer, '(');

       if (start != NULL && start[1] != '\0') {

         start++;

         end = strrchr(start, ')');

         if (end != NULL) {

           size_t len;

           len = MIN2<size_t>(end - start, sizeof(_exeName) - 1);

           memcpy(_exeName, start, len);

           _exeName[len] = '\0';

         }

       }

     }

     fclose(fp);

   }

 }

 // get command line from /proc/<pid>/cmdline

 char* SystemProcessInterface::SystemProcesses::ProcessIterator::get_cmdline() {

   FILE* fp;

   char  buffer[PATH_MAX];

   char* cmdline = NULL;

   jio_snprintf(buffer, PATH_MAX, "/proc/%s/cmdline", _entry->d_name);

   buffer[PATH_MAX - 1] = '\0';

   if ((fp = fopen(buffer, "r")) != NULL) {

     size_t size = 0;

     char   dummy;

     // find out how long the file is (stat always returns 0)

     while (fread(&dummy, 1, 1, fp) == 1) {

       size++;

     }

     if (size > 0) {

       cmdline = NEW_C_HEAP_ARRAY(char, size + 1, mtInternal);

       if (cmdline != NULL) {

         cmdline[0] = '\0';

         if (fseek(fp, 0, SEEK_SET) == 0) {

           if (fread(cmdline, 1, size, fp) == size) {

             // the file has the arguments separated by '\0',

             // so we translate '\0' to ' '

             for (size_t i = 0; i < size; i++) {

               if (cmdline[i] == '\0') {

                 cmdline[i] = ' ';

               }

             }

             cmdline[size] = '\0';

           }

         }

       }

     }

     fclose(fp);

   }

   return cmdline;

 }

 // get full path to exe from /proc/<pid>/exe symlink

 char* SystemProcessInterface::SystemProcesses::ProcessIterator::get_exe_path() {

   char buffer[PATH_MAX];

   jio_snprintf(buffer, PATH_MAX, "/proc/%s/exe", _entry->d_name);

   buffer[PATH_MAX - 1] = '\0';

   return realpath(buffer, _exePath);

 }

 char* SystemProcessInterface::SystemProcesses::ProcessIterator::allocate_string(const char* str) const {

   if (str != NULL) {

     size_t len = strlen(str);

     char* tmp = NEW_C_HEAP_ARRAY(char, len+1, mtInternal);

     strncpy(tmp, str, len);

     tmp[len] = '\0';

     return tmp;

   }

   return NULL;

 }

 int SystemProcessInterface::SystemProcesses::ProcessIterator::current(SystemProcess* process_info) {

   if (!is_valid()) {

     return OS_ERR;

   }

   process_info->set_pid(atoi(_entry->d_name));

   get_exe_name();

   process_info->set_name(allocate_string(_exeName));

   if (get_exe_path() != NULL) {

      process_info->set_path(allocate_string(_exePath));

   }

   char* cmdline = NULL;

   cmdline = get_cmdline();

   if (cmdline != NULL) {

     process_info->set_command_line(allocate_string(cmdline));

     FREE_C_HEAP_ARRAY(char, cmdline, mtInternal);

   }

   return OS_OK;

 }

 int SystemProcessInterface::SystemProcesses::ProcessIterator::next_process() {

   if (!is_valid()) {

     return OS_ERR;

   }

   do {

     _entry = os::readdir(_dir);

     if (_entry == NULL) {

       // Error or reached end.  Could use errno to distinguish those cases.

       _valid = false;

       return OS_ERR;

     }

   } while(!is_valid_entry(_entry));

   _valid = true;

   return OS_OK;

 }

 SystemProcessInterface::SystemProcesses::ProcessIterator::ProcessIterator() {

   _dir = NULL;

   _entry = NULL;

   _valid = false;

 }

 bool SystemProcessInterface::SystemProcesses::ProcessIterator::initialize() {

   // Not yet implemented.

   return false;

 }

 SystemProcessInterface::SystemProcesses::ProcessIterator::~ProcessIterator() {

   if (_dir != NULL) {

     os::closedir(_dir);

   }

 }

 SystemProcessInterface::SystemProcesses::SystemProcesses() {

   _iterator = NULL;

 }

 bool SystemProcessInterface::SystemProcesses::initialize() {

   _iterator = new SystemProcessInterface::SystemProcesses::ProcessIterator();

   return NULL == _iterator ? false : _iterator->initialize();

 }

 SystemProcessInterface::SystemProcesses::~SystemProcesses() {

   if (_iterator != NULL) {

     delete _iterator;

   }

 }

 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 pointers is NULL!");

   assert(_iterator != NULL, "iterator is NULL!");

   // initialize pointers

   *no_of_sys_processes = 0;

   *system_processes = NULL;

   while (_iterator->is_valid()) {

     SystemProcess* tmp = new SystemProcess();

     _iterator->current(tmp);

     //if already existing head

     if (*system_processes != NULL) {

       //move "first to second"

       tmp->set_next(*system_processes);

     }

     // new head

     *system_processes = tmp;

     // increment

     (*no_of_sys_processes)++;

     // step forward

     _iterator->next_process();

   }

   return OS_OK;

 }

 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 NULL == _impl ? false : _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, mtInternal);

       _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, mtInternal);

       _cpu_info->set_cpu_description(NULL);

     }

     delete _cpu_info;

   }

 }

 int CPUInformationInterface::cpu_information(CPUInformation& cpu_info) {

   if (_cpu_info == NULL) {

     return OS_ERR;

   }

   cpu_info = *_cpu_info; // shallow copy assignment

   return OS_OK;

 }

 class NetworkPerformanceInterface::NetworkPerformance : public CHeapObj<mtInternal> {

   friend class NetworkPerformanceInterface;

  private:

   NetworkPerformance();

   NetworkPerformance(const NetworkPerformance& rhs); // no impl

   NetworkPerformance& operator=(const NetworkPerformance& rhs); // no impl

   bool initialize();

   ~NetworkPerformance();

   int network_utilization(NetworkInterface** network_interfaces) const;

 };

 NetworkPerformanceInterface::NetworkPerformance::NetworkPerformance() {

 }

 bool NetworkPerformanceInterface::NetworkPerformance::initialize() {

   return true;

 }

 NetworkPerformanceInterface::NetworkPerformance::~NetworkPerformance() {

 }

 int NetworkPerformanceInterface::NetworkPerformance::network_utilization(NetworkInterface** network_interfaces) const

 {

   return FUNCTIONALITY_NOT_IMPLEMENTED;

 }

 NetworkPerformanceInterface::NetworkPerformanceInterface() {

   _impl = NULL;

 }

 NetworkPerformanceInterface::~NetworkPerformanceInterface() {

   if (_impl != NULL) {

     delete _impl;

   }

 }

 bool NetworkPerformanceInterface::initialize() {

   _impl = new NetworkPerformanceInterface::NetworkPerformance();

   return _impl != NULL && _impl->initialize();

 }

 int NetworkPerformanceInterface::network_utilization(NetworkInterface** network_interfaces) const {

   return _impl->network_utilization(network_interfaces);

 }