1 files changed, 2 insertions, 175 deletions

diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index d40578fb3..45eeda066 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -13,167 +13,11 @@
 ** This file contains code use to implement APIs that are part of the
 ** VDBE.
 **
-** $Id: vdbeapi.c,v 1.165 2009/06/06 14:13:27 danielk1977 Exp $
+** $Id: vdbeapi.c,v 1.166 2009/06/19 14:06:03 drh Exp $
 */
 #include "sqliteInt.h"
 #include "vdbeInt.h"
 
-#if 0 && defined(SQLITE_ENABLE_MEMORY_MANAGEMENT)
-/*
-** The following structure contains pointers to the end points of a
-** doubly-linked list of all compiled SQL statements that may be holding
-** buffers eligible for release when the sqlite3_release_memory() interface is
-** invoked. Access to this list is protected by the SQLITE_MUTEX_STATIC_LRU2
-** mutex.
-**
-** Statements are added to the end of this list when sqlite3_reset() is
-** called. They are removed either when sqlite3_step() or sqlite3_finalize()
-** is called. When statements are added to this list, the associated 
-** register array (p->aMem[1..p->nMem]) may contain dynamic buffers that
-** can be freed using sqlite3VdbeReleaseMemory().
-**
-** When statements are added or removed from this list, the mutex
-** associated with the Vdbe being added or removed (Vdbe.db->mutex) is
-** already held. The LRU2 mutex is then obtained, blocking if necessary,
-** the linked-list pointers manipulated and the LRU2 mutex relinquished.
-*/
-struct StatementLruList {
-  Vdbe *pFirst;
-  Vdbe *pLast;
-};
-static struct StatementLruList sqlite3LruStatements;
-
-/*
-** Check that the list looks to be internally consistent. This is used
-** as part of an assert() statement as follows:
-**
-**   assert( stmtLruCheck() );
-*/
-#ifndef NDEBUG
-static int stmtLruCheck(){
-  Vdbe *p;
-  for(p=sqlite3LruStatements.pFirst; p; p=p->pLruNext){
-    assert(p->pLruNext || p==sqlite3LruStatements.pLast);
-    assert(!p->pLruNext || p->pLruNext->pLruPrev==p);
-    assert(p->pLruPrev || p==sqlite3LruStatements.pFirst);
-    assert(!p->pLruPrev || p->pLruPrev->pLruNext==p);
-  }
-  return 1;
-}
-#endif
-
-/*
-** Add vdbe p to the end of the statement lru list. It is assumed that
-** p is not already part of the list when this is called. The lru list
-** is protected by the SQLITE_MUTEX_STATIC_LRU mutex.
-*/
-static void stmtLruAdd(Vdbe *p){
-  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
-
-  if( p->pLruPrev || p->pLruNext || sqlite3LruStatements.pFirst==p ){
-    sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
-    return;
-  }
-
-  assert( stmtLruCheck() );
-
-  if( !sqlite3LruStatements.pFirst ){
-    assert( !sqlite3LruStatements.pLast );
-    sqlite3LruStatements.pFirst = p;
-    sqlite3LruStatements.pLast = p;
-  }else{
-    assert( !sqlite3LruStatements.pLast->pLruNext );
-    p->pLruPrev = sqlite3LruStatements.pLast;
-    sqlite3LruStatements.pLast->pLruNext = p;
-    sqlite3LruStatements.pLast = p;
-  }
-
-  assert( stmtLruCheck() );
-
-  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
-}
-
-/*
-** Assuming the SQLITE_MUTEX_STATIC_LRU2 mutext is already held, remove
-** statement p from the least-recently-used statement list. If the 
-** statement is not currently part of the list, this call is a no-op.
-*/
-static void stmtLruRemoveNomutex(Vdbe *p){
-  if( p->pLruPrev || p->pLruNext || p==sqlite3LruStatements.pFirst ){
-    assert( stmtLruCheck() );
-    if( p->pLruNext ){
-      p->pLruNext->pLruPrev = p->pLruPrev;
-    }else{
-      sqlite3LruStatements.pLast = p->pLruPrev;
-    }
-    if( p->pLruPrev ){
-      p->pLruPrev->pLruNext = p->pLruNext;
-    }else{
-      sqlite3LruStatements.pFirst = p->pLruNext;
-    }
-    p->pLruNext = 0;
-    p->pLruPrev = 0;
-    assert( stmtLruCheck() );
-  }
-}
-
-/*
-** Assuming the SQLITE_MUTEX_STATIC_LRU2 mutext is not held, remove
-** statement p from the least-recently-used statement list. If the 
-** statement is not currently part of the list, this call is a no-op.
-*/
-static void stmtLruRemove(Vdbe *p){
-  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
-  stmtLruRemoveNomutex(p);
-  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
-}
-
-/*
-** Try to release n bytes of memory by freeing buffers associated 
-** with the memory registers of currently unused vdbes.
-*/
-int sqlite3VdbeReleaseMemory(int n){
-  Vdbe *p;
-  Vdbe *pNext;
-  int nFree = 0;
-
-  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
-  for(p=sqlite3LruStatements.pFirst; p && nFree<n; p=pNext){
-    pNext = p->pLruNext;
-
-    /* For each statement handle in the lru list, attempt to obtain the
-    ** associated database mutex. If it cannot be obtained, continue
-    ** to the next statement handle. It is not possible to block on
-    ** the database mutex - that could cause deadlock.
-    */
-    if( SQLITE_OK==sqlite3_mutex_try(p->db->mutex) ){
-      nFree += sqlite3VdbeReleaseBuffers(p);
-      stmtLruRemoveNomutex(p);
-      sqlite3_mutex_leave(p->db->mutex);
-    }
-  }
-  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU2));
-
-  return nFree;
-}
-
-/*
-** Call sqlite3Reprepare() on the statement. Remove it from the
-** lru list before doing so, as Reprepare() will free all the
-** memory register buffers anyway.
-*/
-int vdbeReprepare(Vdbe *p){
-  stmtLruRemove(p);
-  return sqlite3Reprepare(p);
-}
-
-#else       /* !SQLITE_ENABLE_MEMORY_MANAGEMENT */
-  #define stmtLruRemove(x)
-  #define stmtLruAdd(x)
-  #define vdbeReprepare(x) sqlite3Reprepare(x)
-#endif
-
-
 #ifndef SQLITE_OMIT_DEPRECATED
 /*
 ** Return TRUE (non-zero) of the statement supplied as an argument needs
@@ -209,7 +53,6 @@ int sqlite3_finalize(sqlite3_stmt *pStmt){
     sqlite3_mutex *mutex = v->db->mutex;
 #endif
     sqlite3_mutex_enter(mutex);
-    stmtLruRemove(v);
     rc = sqlite3VdbeFinalize(v);
     rc = sqlite3ApiExit(db, rc);
     sqlite3_mutex_leave(mutex);
@@ -233,7 +76,6 @@ int sqlite3_reset(sqlite3_stmt *pStmt){
     Vdbe *v = (Vdbe*)pStmt;
     sqlite3_mutex_enter(v->db->mutex);
     rc = sqlite3VdbeReset(v);
-    stmtLruAdd(v);
     sqlite3VdbeMakeReady(v, -1, 0, 0, 0);
     assert( (rc & (v->db->errMask))==rc );
     rc = sqlite3ApiExit(v->db, rc);
@@ -477,7 +319,6 @@ static int sqlite3Step(Vdbe *p){
     db->activeVdbeCnt++;
     if( p->readOnly==0 ) db->writeVdbeCnt++;
     p->pc = 0;
-    stmtLruRemove(p);
   }
 #ifndef SQLITE_OMIT_EXPLAIN
   if( p->explain ){
@@ -537,19 +378,6 @@ end_of_step:
 ** sqlite3Step() to do most of the work.  If a schema error occurs,
 ** call sqlite3Reprepare() and try again.
 */
-#ifdef SQLITE_OMIT_PARSER
-int sqlite3_step(sqlite3_stmt *pStmt){
-  int rc = SQLITE_MISUSE;
-  if( pStmt ){
-    Vdbe *v;
-    v = (Vdbe*)pStmt;
-    sqlite3_mutex_enter(v->db->mutex);
-    rc = sqlite3Step(v);
-    sqlite3_mutex_leave(v->db->mutex);
-  }
-  return rc;
-}
-#else
 int sqlite3_step(sqlite3_stmt *pStmt){
   int rc = SQLITE_MISUSE;
   if( pStmt ){
@@ -559,7 +387,7 @@ int sqlite3_step(sqlite3_stmt *pStmt){
     sqlite3_mutex_enter(db->mutex);
     while( (rc = sqlite3Step(v))==SQLITE_SCHEMA
            && cnt++ < 5
-           && (rc = vdbeReprepare(v))==SQLITE_OK ){
+           && (rc = sqlite3Reprepare(v))==SQLITE_OK ){
       sqlite3_reset(pStmt);
       v->expired = 0;
     }
@@ -586,7 +414,6 @@ int sqlite3_step(sqlite3_stmt *pStmt){
   }
   return rc;
 }
-#endif
 
 /*
 ** Extract the user data from a sqlite3_context structure and return a