NABoolean ex_queue::allocateAtps(CollHeap * space,
atp_struct * atps,
queue_index numNewAtps,
Int32 atpSize,
NABoolean failureIsFatal)
{
queue_index i;
// remember that we need ATPs for this queue
needsAtps_ = TRUE;
// if the number of needed ATPs is not passed in, assume that all
// queue entries need an ATP
if (atps == NULL)
{
// initially try to get a whole array of ATP's rather than one
// at a time We are sent back the size of the atp struct since
// it also allocates space for number of tuples per criDesc.
numNewAtps = size_;
#pragma nowarn(1506) // warning elimination
atps = allocateAtpArray( criDesc_, numNewAtps, &atpSize, space, failureIsFatal);
#pragma warn(1506) // warning elimination
}
// check whether the caller provided the ATPs or whether we were
// successful in allocating them as an array
if (atps)
{
ex_assert(atpSize >= sizeof(atp_struct),
"Invalid ATP size passed to ex_queue::allocateAtps()");
for(i = 0; i < size_; i++)
{
if (queue_[i].atp_ == NULL)
{
ex_assert(numNewAtps != 0,
"There are more empty queue entries than new ATPs");
numNewAtps--;
queue_[i].atp_ = atps;
atps = (atp_struct *) ((char *)atps + atpSize);
}
}
}
else
// Didn't get enough space to get all of them at one shot so do
// it one at a time.
// Allocate space for the tuples in each atp
// Allocate the atp if it has not been allocated yet
for(i = 0; i<size_; i++)
{
if (queue_[i].atp_ == NULL)
{
queue_[i].atp_ = allocateAtpArray(criDesc_, 1, &atpSize, space, failureIsFatal);
if (!failureIsFatal && queue_[i].atp_ == NULL)
return FALSE; // let user handle the failure
ex_assert(queue_[i].atp_,"Memory Allocation Fatal Failure Expected but Jump Buffer does not seem to be set!");
}
}
atpsAllocated_ = TRUE;
return TRUE;
}
queue_index ex_queue::resize(ex_tcb * tcb,
queue_index newSize)
{
queue_index sizeDelta;
Space *space = tcb->getSpace();
ex_queue_entry *newQueue;
queue_index newMask;
Int32 queueWasFull = isFull();
NABoolean needAtps = needsAtps();
Int32 atpSize = 0;
atp_struct *atps = NULL;
queue_index numAllocatedAtps = 0;
ex_tcb_private_state *pstates = NULL;
Lng32 numAllocatedPstates = 0;
Lng32 pstateLength = 0;
queue_index qi;
queue_index lastEntryToCopy;
ex_queue_entry *oldQueue = queue_;
const queue_index oldSize = size_;
const queue_index oldMask = mask_;
// the new size must be a power of 2, round up to the next power of 2
queue_index p2 = size_;
while (p2 < newSize && p2 != 0)
p2 = p2 << 1;
// p2 is now a power of 2 that is >= newSize, except that
// it is 0 in some unsupported cases, like size_ being 0 or newSize
// being too large to be rounded up to a power of 2
newSize = p2;
// can't resize to a smaller size
if (newSize <= size_)
return size_;
sizeDelta = newSize - size_;
newMask = newSize - 1;
// try to allocate the needed memory first and give up if that's not
// possible
// allocate new array of ex_queue_entry structs
newQueue = (ex_queue_entry *) (space->allocateMemory(
newSize * sizeof(ex_queue_entry),FALSE));
if (newQueue == NULL)
return size_; // out of memory
// allocate array of ATPs if needed
if (needAtps)
{
atps = allocateAtpArray(criDesc_, sizeDelta, &atpSize, space, FALSE);
// for now, give up if it wasn't possible to allocate the ATPs in
// one piece (one could try to allocate them one by one)
if (atps == NULL)
return size_;
numAllocatedAtps = sizeDelta;
}
// allocate an array of pstate objects if needed
if (needsPstates_)
{
numAllocatedPstates = sizeDelta;
pstates = tcb->allocatePstates(numAllocatedPstates,pstateLength);
if (pstates == NULL)
{
// either the TCB doesn't support the allocatePstates()
// method yet (it would be a dumb thing for a TCB not to
// support this AND to call the resize method) or we don't
// have enough memory. Give up without changing the size.
return size_;
}
}
// at this point we have allocated everything we need, so we
// should be in good shape from now on
// initialize the new queue
for(qi = 0; qi < newSize; qi++)
{
// Initialize private state pointer
newQueue[qi].pstate = NULL;
// initialize the public state
newQueue[qi].initializeState(upDown_);
// Initialize the pointer to the atp_struct
newQueue[qi].atp_ = NULL;
}
// calculate last entry to copy (the addition here may wrap around
// such that <lastEntryToCopy> is actually smaller than <head_>)
lastEntryToCopy = head_ + size_;
// Copy all queue entries (whether they are in use or not) over to
// the new queue. Do this in such a way that the used entries move
// to the new queue entry that corresponds to their index. Note
// that we will start copying the used entries (if any) first, and
// that those are the first entries until (but not including) the
// entry where qi is equal to <tail_>.
for (qi = head_; qi != lastEntryToCopy; qi++)
{
newQueue[qi & newMask] = queue_[qi & mask_];
}
// At this point, <size_> elements of the new queue are initialized
// with actual queue entries, while <sizeDelta> entries may still
// need ATPs and/or pstates (if applicable). These sizeDelta entries
// will be taken care of next by using the regular allocation methods
// for new queues. Note that the ATPs and PSTATEs of the remaining
// entries may or may not be contiguous.
// reset counter that counts empty/full transitions
resizePoints_ = 0;
needsResize_ = FALSE;
// set the data member to point to the newly allocated structures
queue_ = newQueue;
size_ = newSize;
mask_ = newMask;
NABoolean finalAllocSucceeded = TRUE;
// initialize the uninitialized ATPs if required to do so
if (needAtps)
finalAllocSucceeded = allocateAtps(space,
atps,
numAllocatedAtps,
atpSize,
FALSE);
// allocate PSTATEs for the uninitialized queue entries if this
// queue needs PSTATEs
if (needsPstates_ && finalAllocSucceeded)
{
finalAllocSucceeded = allocatePstate(tcb,
pstates,
numAllocatedPstates,
pstateLength,
FALSE);
}
if (finalAllocSucceeded)
{
// schedule the unblock subtask of the queue if the queue was full
// before the resize and now is no longer full (a deadlock could
// occur if we wouldn't schedule the unblock task for a full to
// not full transition of a queue)
if (queueWasFull)
unblockSubtask_->schedule();
}
else
{
// We failed during allocation of ATPs or PStates. Undo the switch
// to the new, resized queue and restore the queue to its old state.
queue_ = oldQueue;
size_ = oldSize;
mask_ = oldMask;
}
return size_;
}