XrdSsiScale Class Reference

#include <XrdSsiScale.hh>

Collaboration diagram for XrdSsiScale:

Public Member Functions
	XrdSsiScale ()
	~XrdSsiScale ()
int	getEnt ()
void	retEnt (int xEnt)
bool	rsvEnt (int xEnt)
void	setSpread (short sval)

Static Public Attributes
static const uint16_t	defSprd = 4
static const uint16_t	maxPend = 64000
static const uint16_t	maxSprd = 1024
static const uint16_t	maxTune = 128
static const uint16_t	midTune = 64
static const uint16_t	minTune = 3
static const uint16_t	zipTune = 512

Detailed Description

Definition at line 37 of file XrdSsiScale.hh.

Constructor & Destructor Documentation

XrdSsiScale()

XrdSsiScale::XrdSsiScale ( )

inline

Definition at line 57 of file XrdSsiScale.hh.

                    : Active(0), reActive(0), begEnt(0), nowEnt(0),
                      curSpread(defSprd), autoTune(false), needTune(false)
                      {memset(pendCnt, 0, sizeof(uint16_t)*maxSprd);}

References maxSprd.

~XrdSsiScale()

XrdSsiScale::~XrdSsiScale ( )

inline

Definition at line 61 of file XrdSsiScale.hh.

{}

Member Function Documentation

getEnt()

int XrdSsiScale::getEnt

(

)

Definition at line 50 of file XrdSsiScale.cc.

{
   static const int tuneMLen = 80;
   char tuneMsg[tuneMLen]; *tuneMsg = 0;
 
// We assign channel in a round-robbin fashion. This can be across all
// channels or only the subset that was recently added due to tuning. Note
// that we apply tuning only if we are working in the partitioned channels
// as the non-partitioned channels should no longer be getting requests.
//
   entMutex.Lock();
   uint16_t endEnt = curSpread;
   do {for (uint16_t i = nowEnt; i < endEnt; i++)
           {if (pendCnt[i] < maxPend)
               {pendCnt[i]++;
                nowEnt = i+1;
                if (!begEnt || i < begEnt) Active++;
                   else reActive++;
                entMutex.UnLock();
                if (*tuneMsg) Log.Emsg("Scale", tuneMsg);
                return int(i);
               }
           }
 
    // If we did a whole round and cannot autotune up, then we have failed.
    // If we didn't do the whole round or did tune, try again.
    //
       if (nowEnt == begEnt)
          {if (!autoTune || !Tune(tuneMsg, tuneMLen)) break;
           endEnt = curSpread;
          } else endEnt = nowEnt;
       nowEnt = begEnt;
      } while(true);
 
// We have no more stream resources left.
//
   entMutex.UnLock();
   if (*tuneMsg) Log.Emsg("Scale", tuneMsg);
   return -1;
}

References XrdSysError::Emsg(), XrdSysMutex::Lock(), XrdSsi::Log, maxPend, and XrdSysMutex::UnLock().

Referenced by XrdSsiServReal::ProcessRequest().

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retEnt()

void XrdSsiScale::retEnt

(

int

xEnt

)

Definition at line 95 of file XrdSsiScale.cc.

{
 
// Perform action only if the specified channel is valid. Retune the channels
// if necessary.
//
   if (xEnt >= 0 && xEnt < int(maxSprd))
      {entMutex.Lock();
       if (pendCnt[xEnt])
          {pendCnt[xEnt]--;
           if (!begEnt || xEnt < (int)begEnt)
              {if (Active) Active--;
               if (begEnt && needTune && Active <= (reActive + (reActive>>1)))
                  {Retune();  // Unlocks the entMutex!
                   return;
                  }
              } else if (reActive) reActive--;
          }
      }
 
// Unlock the mutex as we are done.
//
   entMutex.UnLock();
}

References XrdSysMutex::Lock(), maxSprd, and XrdSysMutex::UnLock().

Referenced by XrdSsiServReal::ProcessRequest(), XrdSsiSessReal::Provision(), and XrdSsiSessReal::TaskFinished().

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rsvEnt()

bool XrdSsiScale::rsvEnt

(

int

xEnt

)

Definition at line 154 of file XrdSsiScale.cc.

{
 
// If the channel number is within range see if we can reserve a slot.
//
   if (xEnt >= 0 && xEnt < int(maxSprd))
      {entMutex.Lock();
       if (pendCnt[xEnt] < maxPend)
          {pendCnt[xEnt]++;
           entMutex.UnLock();
           return true;
          }
       entMutex.UnLock();
      }
   return false;
}

References XrdSysMutex::Lock(), maxPend, maxSprd, and XrdSysMutex::UnLock().

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setSpread()

void XrdSsiScale::setSpread

(

short

sval

)

Definition at line 175 of file XrdSsiScale.cc.

{
   entMutex.Lock();
 
   if (sval <= 0)
      {autoTune = true;
       if (sval < 0) sval = -sval;
      } else {
       autoTune = needTune = false;
       begEnt = 0;
      }
 
   if (sval)
      {uint16_t newSpread;
       if (sval < short(maxSprd)) newSpread = static_cast<uint16_t>(sval);
          else newSpread = maxSprd;
       if (autoTune && newSpread < curSpread)
          {needTune = false;
           begEnt = 0;
          }
       curSpread = newSpread;
      }
 
   entMutex.UnLock();
}

References XrdSysMutex::Lock(), maxSprd, and XrdSysMutex::UnLock().

Referenced by XrdSsiClientProvider::SetSpread().

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Member Data Documentation

defSprd

const uint16_t XrdSsiScale::defSprd = 4

static

Definition at line 41 of file XrdSsiScale.hh.

maxPend

const uint16_t XrdSsiScale::maxPend = 64000

static

Definition at line 43 of file XrdSsiScale.hh.

Referenced by getEnt(), and rsvEnt().

maxSprd

const uint16_t XrdSsiScale::maxSprd = 1024

static

Definition at line 42 of file XrdSsiScale.hh.

Referenced by XrdSsiScale(), retEnt(), rsvEnt(), and setSpread().

maxTune

const uint16_t XrdSsiScale::maxTune = 128

static

Definition at line 46 of file XrdSsiScale.hh.

midTune

const uint16_t XrdSsiScale::midTune = 64

static

Definition at line 45 of file XrdSsiScale.hh.

minTune

const uint16_t XrdSsiScale::minTune = 3

static

Definition at line 44 of file XrdSsiScale.hh.

zipTune

const uint16_t XrdSsiScale::zipTune = 512

static

Definition at line 47 of file XrdSsiScale.hh.

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The documentation for this class was generated from the following files:

• XrdSsiScale.hh
• XrdSsiScale.cc