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/********************* */
/*! \file context.cpp
** \verbatim
** Original author: mdeters
** Major contributors: barrett
** Minor contributors (to current version): none
** This file is part of the CVC4 prototype.
** Copyright (c) 2009, 2010 The Analysis of Computer Systems Group (ACSys)
** Courant Institute of Mathematical Sciences
** New York University
** See the file COPYING in the top-level source directory for licensing
** information.\endverbatim
**
** \brief Implementation of base context operations.
**
** Implementation of base context operations.
**/
#include <iostream>
#include <vector>
#include "context/context.h"
#include "util/Assert.h"
namespace CVC4 {
namespace context {
Context::Context() : d_pCNOpre(NULL), d_pCNOpost(NULL) {
// Create new memory manager
d_pCMM = new ContextMemoryManager();
// Create initial Scope
d_scopeList.push_back(new(d_pCMM) Scope(this, d_pCMM, 0));
}
Context::~Context() throw(AssertionException) {
// Delete all Scopes
popto(0);
// Delete the memory manager
delete d_pCMM;
// Clear ContextNotifyObj lists so there are no dangling pointers
ContextNotifyObj* pCNO;
while(d_pCNOpre != NULL) {
pCNO = d_pCNOpre;
pCNO->d_ppCNOprev = NULL;
d_pCNOpre = pCNO->d_pCNOnext;
pCNO->d_pCNOnext = NULL;
}
while(d_pCNOpost != NULL) {
pCNO = d_pCNOpost;
pCNO->d_ppCNOprev = NULL;
d_pCNOpost = pCNO->d_pCNOnext;
pCNO->d_pCNOnext = NULL;
}
}
void Context::push() {
Trace("pushpop") << std::string(2 * getLevel(), ' ') << "Push [to "
<< getLevel() + 1 << "] {" << std::endl;
// Create a new memory region
d_pCMM->push();
// Create a new top Scope
d_scopeList.push_back(new(d_pCMM) Scope(this, d_pCMM, getLevel()+1));
}
void Context::pop() {
Assert(getLevel() > 0, "Cannot pop below level 0");
// Notify the (pre-pop) ContextNotifyObj objects
ContextNotifyObj* pCNO = d_pCNOpre;
while(pCNO != NULL) {
pCNO->notify();
pCNO = pCNO->d_pCNOnext;
}
// Grab the top Scope
Scope* pScope = d_scopeList.back();
// Restore the previous Scope
d_scopeList.pop_back();
// Restore all objects in the top Scope
delete pScope;
// Pop the memory region
d_pCMM->pop();
// Notify the (post-pop) ContextNotifyObj objects
pCNO = d_pCNOpost;
while(pCNO != NULL) {
pCNO->notify();
pCNO = pCNO->d_pCNOnext;
}
Trace("pushpop") << std::string(2 * getLevel(), ' ') << "} Pop [to "
<< getLevel() << "]" << std::endl;
}
void Context::popto(int toLevel) {
// Pop scopes until there are none left or toLevel is reached
if(toLevel < 0) toLevel = 0;
while(toLevel < getLevel()) pop();
}
void Context::addNotifyObjPre(ContextNotifyObj* pCNO) {
// Insert pCNO at *front* of list
if(d_pCNOpre != NULL)
d_pCNOpre->prev() = &(pCNO->next());
pCNO->next() = d_pCNOpre;
pCNO->prev() = &d_pCNOpre;
d_pCNOpre = pCNO;
}
void Context::addNotifyObjPost(ContextNotifyObj* pCNO) {
// Insert pCNO at *front* of list
if(d_pCNOpost != NULL)
d_pCNOpost->prev() = &(pCNO->next());
pCNO->next() = d_pCNOpost;
pCNO->prev() = &d_pCNOpost;
d_pCNOpost = pCNO;
}
void ContextObj::update() throw(AssertionException) {
Debug("context") << "before update(" << this << "):" << std::endl
<< *getContext() << std::endl;
// Call save() to save the information in the current object
ContextObj* pContextObjSaved = save(d_pScope->getCMM());
Debug("context") << "in update(" << this << ") with restore "
<< pContextObjSaved << ": waypoint 1" << std::endl
<< *getContext() << std::endl;
// Check that base class data was saved
Assert( ( pContextObjSaved->d_pContextObjNext == d_pContextObjNext &&
pContextObjSaved->d_ppContextObjPrev == d_ppContextObjPrev &&
pContextObjSaved->d_pContextObjRestore == d_pContextObjRestore &&
pContextObjSaved->d_pScope == d_pScope ),
"save() did not properly copy information in base class" );
// Link the "saved" object in place of this ContextObj in the scope
// we're moving it FROM.
Debug("context") << "in update(" << this
<< "): next() == " << next() << std::endl;
if(next() != NULL) {
Debug("context") << "in update(" << this
<< "): next()->prev() == " << next()->prev() << std::endl;
next()->prev() = &pContextObjSaved->next();
Debug("context") << "in update(" << this
<< "): next()->prev() is now "
<< next()->prev() << std::endl;
}
Debug("context") << "in update(" << this
<< "): prev() == " << prev() << std::endl;
Debug("context") << "in update(" << this
<< "): *prev() == " << *prev() << std::endl;
*prev() = pContextObjSaved;
Debug("context") << "in update(" << this
<< "): *prev() is now " << *prev() << std::endl;
Debug("context") << "in update(" << this << ") with restore "
<< pContextObjSaved << ": waypoint 3" << std::endl
<< *getContext() << std::endl;
// Update Scope pointer to current top Scope
d_pScope = d_pScope->getContext()->getTopScope();
// Store the saved copy in the restore pointer
d_pContextObjRestore = pContextObjSaved;
// Insert object into the list of objects that need to be restored when this
// Scope is popped.
d_pScope->addToChain(this);
Debug("context") << "after update(" << this << ") with restore "
<< pContextObjSaved << ":" << std::endl
<< *getContext() << std::endl;
}
ContextObj* ContextObj::restoreAndContinue() throw(AssertionException) {
// Variable to hold next object in list
ContextObj* pContextObjNext;
// Check the restore pointer. If NULL, this must be the bottom Scope
if(d_pContextObjRestore == NULL) {
// might not be bottom scope, since objects allocated in context
// memory don't get linked to scope 0
//
// Assert(d_pScope == d_pScope->getContext()->getBottomScope(),
// "Expected bottom scope");
pContextObjNext = d_pContextObjNext;
// Nothing else to do
} else {
// Call restore to update the subclass data
restore(d_pContextObjRestore);
// Remember the next object in the list
pContextObjNext = d_pContextObjNext;
// Restore the base class data
d_pScope = d_pContextObjRestore->d_pScope;
next() = d_pContextObjRestore->d_pContextObjNext;
prev() = d_pContextObjRestore->d_ppContextObjPrev;
d_pContextObjRestore = d_pContextObjRestore->d_pContextObjRestore;
// Re-link this ContextObj to the list in this scope
if(next() != NULL) {
next()->prev() = &next();
}
*prev() = this;
}
// Return the next object in the list
return pContextObjNext;
}
void ContextObj::destroy() throw(AssertionException) {
/* Context can be big and complicated, so we only want to process this output
* if we're really going to use it. (Same goes below.) */
Debug("context") << "before destroy " << this << " (level " << getLevel()
<< "):" << std::endl << *getContext() << std::endl;
for(;;) {
// If valgrind reports invalid writes on the next few lines,
// here's a hint: make sure all classes derived from ContextObj in
// the system properly call destroy() in their destructors.
// That's needed to maintain this linked list properly.
if(next() != NULL) {
next()->prev() = prev();
}
*prev() = next();
if(d_pContextObjRestore == NULL) {
break;
}
Debug("context") << "in destroy " << this << ", restore object is "
<< d_pContextObjRestore << " at level "
<< d_pContextObjRestore->getLevel() << ":" << std::endl
<< *getContext() << std::endl;
restoreAndContinue();
}
Debug("context") << "after destroy " << this << ":" << std::endl
<< *getContext() << std::endl;
}
ContextObj::ContextObj(Context* pContext) :
d_pContextObjRestore(NULL) {
Assert(pContext != NULL, "NULL context pointer");
Debug("context") << "create new ContextObj(" << this << ")" << std::endl;
d_pScope = pContext->getBottomScope();
d_pScope->addToChain(this);
}
ContextObj::ContextObj(bool allocatedInCMM, Context* pContext) :
d_pContextObjRestore(NULL) {
Assert(pContext != NULL, "NULL context pointer");
Debug("context") << "create new ContextObj(" << this << ")" << std::endl;
if(allocatedInCMM) {
d_pScope = pContext->getTopScope();
} else {
d_pScope = pContext->getBottomScope();
}
d_pScope->addToChain(this);
}
ContextNotifyObj::ContextNotifyObj(Context* pContext, bool preNotify) {
if(preNotify) {
pContext->addNotifyObjPre(this);
} else {
pContext->addNotifyObjPost(this);
}
}
ContextNotifyObj::~ContextNotifyObj() throw(AssertionException) {
if(d_pCNOnext != NULL) {
d_pCNOnext->d_ppCNOprev = d_ppCNOprev;
}
if(d_ppCNOprev != NULL) {
*d_ppCNOprev = d_pCNOnext;
}
}
std::ostream& operator<<(std::ostream& out,
const Context& context) throw(AssertionException) {
static const std::string separator(79, '-');
int level = context.d_scopeList.size() - 1;
typedef std::vector<Scope*>::const_reverse_iterator const_reverse_iterator;
for(const_reverse_iterator i = context.d_scopeList.rbegin();
i != context.d_scopeList.rend();
++i, --level) {
Scope* pScope = *i;
Assert(pScope->getLevel() == level);
Assert(pScope->getContext() == &context);
out << separator << std::endl
<< *pScope << std::endl;
}
return out << separator << std::endl;
}
std::ostream& operator<<(std::ostream& out,
const Scope& scope) throw(AssertionException) {
out << "Scope " << scope.d_level << ":";
ContextObj* pContextObj = scope.d_pContextObjList;
Assert(pContextObj == NULL ||
pContextObj->prev() == &scope.d_pContextObjList);
while(pContextObj != NULL) {
out << " <--> " << pContextObj;
Assert(pContextObj->d_pScope == &scope);
Assert(pContextObj->next() == NULL ||
pContextObj->next()->prev() == &pContextObj->next());
pContextObj = pContextObj->next();
}
return out << " --> NULL";
}
} /* CVC4::context namespace */
} /* CVC4 namespace */
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