void
initGlobals()
{
// LEAVE THIS STATEMENT
pthread_mutex_init(&outMutex, NULL);
// TODO: Complete this function
maleCount = 0;
femaleCount = 0;
sem_init(&male, 0, 1);
sem_init(&female, 0, 1);
pthread_mutex_init(&limitMaleMutex, NULL);
pthread_mutex_init(&limitFemaleMutex, NULL);
pthread_mutex_init(&maleCountMutex, NULL);
pthread_mutex_init(&femaleCountMutex, NULL);
// TODO: Complete for scheduler
addLock("limitMaleMutex", &limitMaleMutex);
addLock("limitFemaleMutex", &limitFemaleMutex);
addLock("maleCountMutex", &maleCountMutex);
addLock("femaleCountMutex", &femaleCountMutex);
addSemaphore("female", SEM_FEMALE_INITIAL, &female);
addSemaphore("male", SEM_MALE_INITIAL, &male);
}
/// \brief Check a function's CFG for thread-safety violations.
///
/// We traverse the blocks in the CFG, compute the set of mutexes that are held
/// at the end of each block, and issue warnings for thread safety violations.
/// Each block in the CFG is traversed exactly once.
void runThreadSafetyAnalysis(AnalysisContext &AC,
ThreadSafetyHandler &Handler) {
CFG *CFGraph = AC.getCFG();
if (!CFGraph) return;
const NamedDecl *D = dyn_cast_or_null<NamedDecl>(AC.getDecl());
if (!D)
return; // Ignore anonymous functions for now.
if (D->getAttr<NoThreadSafetyAnalysisAttr>())
return;
Lockset::Factory LocksetFactory;
// FIXME: Swith to SmallVector? Otherwise improve performance impact?
std::vector<Lockset> EntryLocksets(CFGraph->getNumBlockIDs(),
LocksetFactory.getEmptyMap());
std::vector<Lockset> ExitLocksets(CFGraph->getNumBlockIDs(),
LocksetFactory.getEmptyMap());
// We need to explore the CFG via a "topological" ordering.
// That way, we will be guaranteed to have information about required
// predecessor locksets when exploring a new block.
TopologicallySortedCFG SortedGraph(CFGraph);
CFGBlockSet VisitedBlocks(CFGraph);
if (!SortedGraph.empty() && D->hasAttrs()) {
const CFGBlock *FirstBlock = *SortedGraph.begin();
Lockset &InitialLockset = EntryLocksets[FirstBlock->getBlockID()];
const AttrVec &ArgAttrs = D->getAttrs();
for(unsigned i = 0; i < ArgAttrs.size(); ++i) {
Attr *Attr = ArgAttrs[i];
SourceLocation AttrLoc = Attr->getLocation();
if (SharedLocksRequiredAttr *SLRAttr
= dyn_cast<SharedLocksRequiredAttr>(Attr)) {
for (SharedLocksRequiredAttr::args_iterator
SLRIter = SLRAttr->args_begin(),
SLREnd = SLRAttr->args_end(); SLRIter != SLREnd; ++SLRIter)
InitialLockset = addLock(Handler, LocksetFactory, InitialLockset,
*SLRIter, D, LK_Shared,
AttrLoc);
} else if (ExclusiveLocksRequiredAttr *ELRAttr
= dyn_cast<ExclusiveLocksRequiredAttr>(Attr)) {
for (ExclusiveLocksRequiredAttr::args_iterator
ELRIter = ELRAttr->args_begin(),
ELREnd = ELRAttr->args_end(); ELRIter != ELREnd; ++ELRIter)
InitialLockset = addLock(Handler, LocksetFactory, InitialLockset,
*ELRIter, D, LK_Exclusive,
AttrLoc);
}
}
}
for (TopologicallySortedCFG::iterator I = SortedGraph.begin(),
E = SortedGraph.end(); I!= E; ++I) {
const CFGBlock *CurrBlock = *I;
int CurrBlockID = CurrBlock->getBlockID();
VisitedBlocks.insert(CurrBlock);
// Use the default initial lockset in case there are no predecessors.
Lockset &Entryset = EntryLocksets[CurrBlockID];
Lockset &Exitset = ExitLocksets[CurrBlockID];
// Iterate through the predecessor blocks and warn if the lockset for all
// predecessors is not the same. We take the entry lockset of the current
// block to be the intersection of all previous locksets.
// FIXME: By keeping the intersection, we may output more errors in future
// for a lock which is not in the intersection, but was in the union. We
// may want to also keep the union in future. As an example, let's say
// the intersection contains Mutex L, and the union contains L and M.
// Later we unlock M. At this point, we would output an error because we
// never locked M; although the real error is probably that we forgot to
// lock M on all code paths. Conversely, let's say that later we lock M.
// In this case, we should compare against the intersection instead of the
// union because the real error is probably that we forgot to unlock M on
// all code paths.
bool LocksetInitialized = false;
for (CFGBlock::const_pred_iterator PI = CurrBlock->pred_begin(),
PE = CurrBlock->pred_end(); PI != PE; ++PI) {
// if *PI -> CurrBlock is a back edge
if (*PI == 0 || !VisitedBlocks.alreadySet(*PI))
continue;
int PrevBlockID = (*PI)->getBlockID();
if (!LocksetInitialized) {
Entryset = ExitLocksets[PrevBlockID];
LocksetInitialized = true;
} else {
Entryset = intersectAndWarn(Handler, Entryset,
ExitLocksets[PrevBlockID], LocksetFactory,
LEK_LockedSomePredecessors);
}
}
BuildLockset LocksetBuilder(Handler, Entryset, LocksetFactory);
for (CFGBlock::const_iterator BI = CurrBlock->begin(),
BE = CurrBlock->end(); BI != BE; ++BI) {
if (const CFGStmt *CfgStmt = dyn_cast<CFGStmt>(&*BI))
LocksetBuilder.Visit(const_cast<Stmt*>(CfgStmt->getStmt()));
}
Exitset = LocksetBuilder.getLockset();
// For every back edge from CurrBlock (the end of the loop) to another block
// (FirstLoopBlock) we need to check that the Lockset of Block is equal to
// the one held at the beginning of FirstLoopBlock. We can look up the
// Lockset held at the beginning of FirstLoopBlock in the EntryLockSets map.
for (CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin(),
SE = CurrBlock->succ_end(); SI != SE; ++SI) {
// if CurrBlock -> *SI is *not* a back edge
if (*SI == 0 || !VisitedBlocks.alreadySet(*SI))
continue;
CFGBlock *FirstLoopBlock = *SI;
Lockset PreLoop = EntryLocksets[FirstLoopBlock->getBlockID()];
Lockset LoopEnd = ExitLocksets[CurrBlockID];
intersectAndWarn(Handler, LoopEnd, PreLoop, LocksetFactory,
LEK_LockedSomeLoopIterations);
}
}
Lockset InitialLockset = EntryLocksets[CFGraph->getEntry().getBlockID()];
Lockset FinalLockset = ExitLocksets[CFGraph->getExit().getBlockID()];
// FIXME: Should we call this function for all blocks which exit the function?
intersectAndWarn(Handler, InitialLockset, FinalLockset, LocksetFactory,
LEK_LockedAtEndOfFunction);
}
str
OPToltpImplementation(Client cntxt, MalBlkPtr mb, MalStkPtr stk, InstrPtr pci)
{ int i, limit, slimit, updates=0;
InstrPtr p, q, lcks;
int actions = 0;
InstrPtr *old;
lng usec = GDKusec();
OLTPlocks wlocks, rlocks;
char buf[256];
str msg = MAL_SUCCEED;
(void) pci;
(void) cntxt;
(void) stk; /* to fool compilers */
old= mb->stmt;
limit= mb->stop;
slimit = mb->ssize;
// We use a fake collection of objects to speed up the checking later.
OLTPclear(wlocks);
OLTPclear(rlocks);
for (i = 0; i < limit; i++) {
p = old[i];
if( getModuleId(p) == sqlRef && getFunctionId(p) == bindRef)
addLock(cntxt,rlocks, mb, p, p->retc + 1, p->retc + 2);
else
if( getModuleId(p) == sqlRef && getFunctionId(p) == bindidxRef)
addLock(cntxt,rlocks, mb, p, p->retc + 1, p->retc + 2);
else
if( getModuleId(p) == sqlRef && getFunctionId(p) == appendRef ){
addLock(cntxt,wlocks, mb, p, p->retc + 1, p->retc + 2);
updates++;
} else
if( getModuleId(p) == sqlRef && getFunctionId(p) == updateRef ){
addLock(cntxt,wlocks, mb, p, p->retc + 1, p->retc + 2);
updates++;
} else
if( getModuleId(p) == sqlRef && getFunctionId(p) == deleteRef ){
addLock(cntxt,wlocks, mb, p, p->retc + 1, p->retc + 2);
updates++;
} else
if( getModuleId(p) == sqlcatalogRef ){
addLock(cntxt,wlocks, mb, p, 0,0);
updates++;
}
}
if( updates == 0)
return 0;
// Get a free instruction, don't get it from mb
lcks= newInstruction(0, oltpRef,lockRef);
getArg(lcks,0)= newTmpVariable(mb, TYPE_void);
for( i = 0; i< MAXOLTPLOCKS; i++)
if( wlocks[i])
lcks = pushInt(mb, lcks, i);
else
if( rlocks[i])
lcks = pushInt(mb, lcks, -i);
if( lcks->argc == 1 ){
freeInstruction(lcks);
return MAL_SUCCEED;
}
// Now optimize the code
if ( newMalBlkStmt(mb,mb->ssize + 6) < 0) {
freeInstruction(lcks);
return 0;
}
pushInstruction(mb,old[0]);
pushInstruction(mb,lcks);
for (i = 1; i < limit; i++) {
p = old[i];
if( p->token == ENDsymbol){
// unlock all if there is an error
q= newCatchStmt(mb,"MALexception");
q= newExitStmt(mb,"MALexception");
q= newCatchStmt(mb,"SQLexception");
q= newExitStmt(mb,"SQLexception");
q= copyInstruction(lcks);
if( q == NULL){
for(; i<slimit; i++)
if( old[i])
freeInstruction(old[i]);
GDKfree(old);
throw(MAL,"optimizer.oltp", SQLSTATE(HY001) MAL_MALLOC_FAIL);
}
setFunctionId(q, releaseRef);
pushInstruction(mb,q);
}
pushInstruction(mb,p);
}
for(; i<slimit; i++)
if( old[i])
freeInstruction(old[i]);
GDKfree(old);
/* Defense line against incorrect plans */
chkTypes(cntxt->usermodule, mb, FALSE);
//chkFlow(mb);
//chkDeclarations(mb);
/* keep all actions taken as a post block comment */
usec = GDKusec()- usec;
snprintf(buf,256,"%-20s actions=%2d time=" LLFMT " usec","oltp",actions, usec);
newComment(mb,buf);
if( actions >= 0)
addtoMalBlkHistory(mb);
return msg;
}
