*** empty log message ***

git-svn-id: https://ceph.svn.sf.net/svnroot/ceph@317 29311d96-e01e-0410-9327-a35deaab8ce9

diff --git a/ceph/include/lru.h b/ceph/include/lru.h
index da4ceab937775175c334f5835c15fe8426012398..be730bd5b848d3b6135cdc14c57356553f386207 100644 (file)
--- a/ceph/include/lru.h
+++ b/ceph/include/lru.h
@@ -9,23 +9,30 @@ using namespace std;
 #include "include/config.h"
 
 
+#define LRU_POS_NONE    0
+#define LRU_POS_TOP     1
+#define LRU_POS_BOT     2
+#define LRU_POS_PINTAIL 3
+
+
 class LRUObject {
  private:
   LRUObject *lru_next, *lru_prev;
-  bool lru_in_top;
-  //bool lru_in_lru;
+  char lru_pos;
   bool lru_expireable;
   class LRU *lru;
 
  public:
   LRUObject() {
        lru_next = lru_prev = NULL;
-       lru_in_top = false;
-       //lru_in_lru = false;
-       lru = 0;
+       lru_pos = LRU_POS_NONE;
        lru_expireable = true;
+       lru = 0;
   }
 
+  bool lru_get_pos() { return lru_pos; }
+  void lru_set_pos(char p) { lru_pos = p; }
+
   // pin/unpin item in cache
   void lru_pin(); 
   void lru_unpin();
@@ -40,6 +47,7 @@ class LRUObject {
 class LRU {
  protected:
   LRUObject *lru_tophead, *lru_toptail, *lru_bothead, *lru_bottail;
+  LRUObject *lru_pintailhead, *lru_pintailtail;
   __uint32_t lru_ntop, lru_nbot, lru_num, lru_num_pinned;
   double lru_midpoint;
   __uint32_t lru_max;   // max items
@@ -52,6 +60,7 @@ class LRU {
        lru_num_pinned = 0;
        lru_tophead = lru_toptail = NULL;
        lru_bothead = lru_bottail = NULL;
+       lru_pintailhead = lru_pintailtail = NULL;
        lru_midpoint = .9;
        lru_max = 0;
   }
@@ -80,7 +89,7 @@ class LRU {
        assert(!o->lru);
        o->lru = this;
 
-       o->lru_in_top = true;
+       o->lru_set_pos( LRU_POS_TOP );
        o->lru_next = lru_tophead;
        o->lru_prev = NULL;
        if (lru_tophead) {
@@ -102,7 +111,7 @@ class LRU {
        assert(!o->lru);
        o->lru = this;
 
-       o->lru_in_top = false;
+       o->lru_set_pos( LRU_POS_BOT );
        o->lru_next = lru_bothead;
        o->lru_prev = NULL;
        if (lru_bothead) {
@@ -121,7 +130,7 @@ class LRU {
        assert(!o->lru);
        o->lru = this;
 
-       o->lru_in_top = false;
+       o->lru_set_pos( LRU_POS_BOT );
        o->lru_next = NULL;
        o->lru_prev = lru_bottail;
        if (lru_bottail) {
@@ -143,7 +152,7 @@ class LRU {
        if (!lru_max) return;
 
        __uint32_t topwant = (__uint32_t)(lru_midpoint * (double)lru_max);
-       while (lru_ntop > topwant) {
+       while (lru_ntop > topwant && lru_toptail) {
          // remove from tail of top, stick at head of bot
          // FIXME: this could be way more efficient by moving a whole chain of items.
          lru_insert_mid( lru_remove( lru_toptail) );
@@ -159,7 +168,7 @@ class LRU {
        if (!o->lru) return o;
 
 
-       if (o->lru_in_top) {
+       if (o->lru_get_pos() == LRU_POS_TOP) {
          //cout << "removing " << o << " from top" << endl;
          // top
          if (o->lru_next)
@@ -171,7 +180,8 @@ class LRU {
          else
                lru_tophead = o->lru_next;
          lru_ntop--;
-       } else {
+       } 
+       else if (o->lru_get_pos() == LRU_POS_BOT) {
          //cout << "removing " << o << " from bot" << endl;
          // bot
          if (o->lru_next)
@@ -184,10 +194,22 @@ class LRU {
                lru_bothead = o->lru_next;
          lru_nbot--;
        }
+       else {
+         assert(o->lru_get_pos() == LRU_POS_PINTAIL);
+         if (o->lru_next)
+               o->lru_next->lru_prev = o->lru_prev;
+         else
+               lru_pintailtail = o->lru_prev;
+         if (o->lru_prev)
+               o->lru_prev->lru_next = o->lru_next;
+         else
+               lru_pintailhead = o->lru_next;
+         lru_nbot--;
+       }
        lru_num--;
        lru_num_pinned -= !o->lru_expireable;
        o->lru_next = o->lru_prev = NULL;
-       //o->lru_in_lru = false;
+       o->lru_set_pos(LRU_POS_NONE);
        o->lru = 0;
        return o;
   }
@@ -201,8 +223,8 @@ class LRU {
 
   // touch item -- move to midpoint (unless already higher)
   bool lru_midtouch(LRUObject *o) {
-       if (o->lru_in_top) return false;
-
+       if (o->lru_get_pos() == LRU_POS_TOP) return false;
+       
        lru_remove(o);
        lru_insert_mid(o);
        return true;
@@ -221,12 +243,22 @@ class LRU {
        LRUObject *p;
 
        // look through tail of bot
-       p = lru_bottail;
-       while (p) {
+       while (lru_bottail) {
+         p = lru_remove( lru_bottail );
          if (p->lru_expireable) 
-               return lru_remove( p );
-         //cout << "p " << p << " no expireable" << endl;
-         p = p->lru_prev;
+               return p;   // yay.
+         
+         // pinned, move to pintail
+         p->lru_next = lru_pintailhead;
+         p->lru_prev = NULL;
+         if (lru_pintailhead) {
+               lru_pintailhead->lru_prev = p;
+         } else {
+               lru_pintailtail = p;
+         }
+         lru_pintailhead = p;
+         
+         p->lru_set_pos( LRU_POS_PINTAIL );
        }
 
        // ok, try head then
@@ -257,7 +289,15 @@ inline void LRUObject::lru_pin()
 }
 inline void LRUObject::lru_unpin() {
   lru_expireable = true;
-  if (lru) lru->lru_num_pinned--;
+  if (lru) {
+       lru->lru_num_pinned--;
+
+       // move out of tail?
+       if (lru_get_pos() == LRU_POS_PINTAIL) {
+         lru->lru_remove(this);
+         lru->lru_insert_bot(this);
+       }
+  }
 }
 
 #endif