/* resource.cc: getrusage () and friends.

   Copyright 1996, 1997, 1998, 2000, 2001, 2002, 2003, 2005, 2008, 2009, 2010,
   2011, 2012, 2013, 2014 Red Hat, Inc.

   Written by Steve Chamberlain (sac@cygnus.com), Doug Evans (dje@cygnus.com),
   Geoffrey Noer (noer@cygnus.com) of Cygnus Support.
   Rewritten by Sergey S. Okhapkin (sos@prospect.com.ru)

This file is part of Cygwin.

This software is a copyrighted work licensed under the terms of the
Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
details. */

#include "winsup.h"
#include <unistd.h>
#include <sys/param.h>
#include "pinfo.h"
#include "psapi.h"
#include "cygtls.h"
#include "path.h"
#include "fhandler.h"
#include "pinfo.h"
#include "dtable.h"
#include "cygheap.h"
#include "ntdll.h"

/* add timeval values */
static void
add_timeval (struct timeval *tv1, struct timeval *tv2)
{
  tv1->tv_sec += tv2->tv_sec;
  tv1->tv_usec += tv2->tv_usec;
  if (tv1->tv_usec >= 1000000)
    {
      tv1->tv_usec -= 1000000;
      tv1->tv_sec++;
    }
}

/* add rusage values of r2 to r1 */
void __stdcall
add_rusage (struct rusage *r1, struct rusage *r2)
{
  add_timeval (&r1->ru_utime, &r2->ru_utime);
  add_timeval (&r1->ru_stime, &r2->ru_stime);
  r1->ru_maxrss += r2->ru_maxrss;
  r1->ru_ixrss += r2->ru_ixrss;
  r1->ru_idrss += r2->ru_idrss;
  r1->ru_isrss += r2->ru_isrss;
  r1->ru_minflt += r2->ru_minflt;
  r1->ru_majflt += r2->ru_majflt;
  r1->ru_nswap += r2->ru_nswap;
  r1->ru_inblock += r2->ru_inblock;
  r1->ru_oublock += r2->ru_oublock;
  r1->ru_msgsnd += r2->ru_msgsnd;
  r1->ru_msgrcv += r2->ru_msgrcv;
  r1->ru_nsignals += r2->ru_nsignals;
  r1->ru_nvcsw += r2->ru_nvcsw;
  r1->ru_nivcsw += r2->ru_nivcsw;
}

/* FIXME: what about other fields? */
void __stdcall
fill_rusage (struct rusage *r, HANDLE h)
{
  KERNEL_USER_TIMES kut;

  struct timeval tv;

  memset (&kut, 0, sizeof kut);
  memset (r, 0, sizeof *r);
  NtQueryInformationProcess (h, ProcessTimes, &kut, sizeof kut, NULL);
  totimeval (&tv, &kut.KernelTime, 0, 0);
  add_timeval (&r->ru_stime, &tv);
  totimeval (&tv, &kut.UserTime, 0, 0);
  add_timeval (&r->ru_utime, &tv);

  VM_COUNTERS vmc;
  NTSTATUS status = NtQueryInformationProcess (h, ProcessVmCounters, &vmc,
					       sizeof vmc, NULL);
  if (NT_SUCCESS (status))
    {
      r->ru_maxrss += (long) (vmc.WorkingSetSize / 1024);
      r->ru_majflt += vmc.PageFaultCount;
    }
}

extern "C" int
getrusage (int intwho, struct rusage *rusage_in)
{
  int res = 0;
  struct rusage r;

  if (intwho == RUSAGE_SELF)
    {
      memset (&r, 0, sizeof (r));
      fill_rusage (&r, GetCurrentProcess ());
      *rusage_in = r;
    }
  else if (intwho == RUSAGE_CHILDREN)
    *rusage_in = myself->rusage_children;
  else
    {
      set_errno (EINVAL);
      res = -1;
    }

  syscall_printf ("%R = getrusage(%d, %p)", res, intwho, rusage_in);
  return res;
}

extern "C" int
getrlimit (int resource, struct rlimit *rlp)
{
  __try
    {
      rlp->rlim_cur = RLIM_INFINITY;
      rlp->rlim_max = RLIM_INFINITY;

      switch (resource)
	{
	case RLIMIT_CPU:
	case RLIMIT_FSIZE:
	case RLIMIT_DATA:
	case RLIMIT_AS:
	  break;
	case RLIMIT_STACK:
	  PTEB teb;
	  /* 2015-06-26: Originally rlim_cur returned the size of the still
	     available stack area on the current stack, rlim_max the total size
	     of the current stack.  Two problems:

	     - Per POSIX, RLIMIT_STACK returns "the maximum size of the initial
	       thread's stack, in bytes. The implementation does not
	       automatically grow the stack beyond this limit".

	     - With the implementation of sigaltstack, the current stack is not
	       necessarily the "initial thread's stack" anymore.  Rather, when
	       called from a signal handler running on the alternate stack,
	       RLIMIT_STACK should return the size of the original stack.

	     rlim_cur is now the size of the stack.  For system-provided stacks
	     it's the size between DeallocationStack and StackBase.  For
	     application-provided stacks (via pthread_attr_setstack),
	     DeallocationStack is NULL, but StackLimit points to the bottom
	     of the stack.

	     rlim_max is set to RLIM_INFINITY since there's no hard limit
	     for stack sizes on Windows. */
	  teb = NtCurrentTeb ();
	  rlp->rlim_cur = (rlim_t) teb->Tib.StackBase
			  - (rlim_t) (teb->DeallocationStack
				      ?: teb->Tib.StackLimit);
	  break;
	case RLIMIT_NOFILE:
	  rlp->rlim_cur = getdtablesize ();
	  if (rlp->rlim_cur < OPEN_MAX)
	    rlp->rlim_cur = OPEN_MAX;
	  rlp->rlim_max = OPEN_MAX_MAX;
	  break;
	case RLIMIT_CORE:
	  rlp->rlim_cur = cygheap->rlim_core;
	  break;
	default:
	  set_errno (EINVAL);
	  __leave;
	}
      return 0;
    }
  __except (EFAULT) {}
  __endtry
  return -1;
}

extern "C" int
setrlimit (int resource, const struct rlimit *rlp)
{
  struct rlimit oldlimits;

  /* Check if the request is to actually change the resource settings.
     If it does not result in a change, take no action and do not fail. */
  if (getrlimit (resource, &oldlimits) < 0)
    return -1;

  __try
    {
      if (oldlimits.rlim_cur == rlp->rlim_cur &&
	  oldlimits.rlim_max == rlp->rlim_max)
	/* No change in resource requirements, succeed immediately */
	return 0;

      if (rlp->rlim_cur > rlp->rlim_max)
	{
	  set_errno (EINVAL);
	  __leave;
	}

      switch (resource)
	{
	case RLIMIT_CORE:
	  cygheap->rlim_core = rlp->rlim_cur;
	  break;
	case RLIMIT_NOFILE:
	  if (rlp->rlim_cur != RLIM_INFINITY)
	    return setdtablesize (rlp->rlim_cur);
	  break;
	default:
	  set_errno (EINVAL);
	  __leave;
	}
      return 0;
    }
  __except (EFAULT)
  __endtry
  return -1;
}