BDE 4.14.0 Production release
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#include <bdlcc_multipriorityqueue.h>
Public Member Functions | |
BSLMF_NESTED_TRAIT_DECLARATION (MultipriorityQueue, bslma::UsesBslmaAllocator) | |
MultipriorityQueue (bslma::Allocator *basicAllocator=0) | |
MultipriorityQueue (int numPriorities, bslma::Allocator *basicAllocator=0) | |
~MultipriorityQueue () | |
void | popFront (TYPE *item, int *itemPriority=0) |
int | pushBack (const TYPE &item, int itemPriority) |
int | pushBack (bslmf::MovableRef< TYPE > item, int itemPriority) |
void | pushBackMultipleRaw (const TYPE &item, int itemPriority, int numItems) |
void | pushFrontMultipleRaw (const TYPE &item, int itemPriority, int numItems) |
int | tryPopFront (TYPE *item, int *itemPriority=0) |
void | removeAll () |
Remove and destroy all items from this multi-priority queue. | |
void | enable () |
void | disable () |
int | numPriorities () const |
int | length () const |
Return the total number of items in this multi-priority queue. | |
bool | isEmpty () const |
bool | isEnabled () const |
This class implements a thread-enabled multipriority queue whose priorities are restricted to a (small) set of contiguous N
integer values, [ 0 .. N - 1 ]
, with 0 being the most urgent.
This class does have a notion of value, namely the sequence of priority/element pairs, constrained to be in decreasing order of urgency (i.e., monotonically increasing priority values). However, no value-semantic operations are implemented. Note that elements having the same priority are maintained in First-In-First-Out (FIFO) order. Note that the current implementation supports up to a maximum of sizeof(int) * CHAR_BIT
priorities.
This class is implemented as a set of linked lists, one for each priority. Two vectors are used to maintain head and tail pointers for the lists.
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explicit |
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explicit |
Create a multipriority queue. Optionally specify numPriorities
, the number of distinct priorities supported by the multipriority queue. If numPriorities
is not specified, the (implementation-imposed maximum) number 32 is used. Optionally specify a basicAllocator
used to supply memory. If basicAllocator
is 0, the currently installed default allocator is used. The behavior is undefined unless 1 <= numPriorities <= 32
(if specified).
bdlcc::MultipriorityQueue< TYPE >::~MultipriorityQueue | ( | ) |
Destroy this container. The behavior is undefined unless all access or modification of the container has completed prior to this call.
bdlcc::MultipriorityQueue< TYPE >::BSLMF_NESTED_TRAIT_DECLARATION | ( | MultipriorityQueue< TYPE > | , |
bslma::UsesBslmaAllocator | |||
) |
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inline |
Disable pushes to this multipriority queue. This method has no effect unless the queue was enabled.
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inline |
Enable pushes to this multipriority queue. This method has no effect unless the queue was disabled.
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inline |
Return true
if there are no items in this multi-priority queue, and false
otherwise.
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inline |
Return true
if this multipriority queue is enable and false
otherwise.
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inline |
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inline |
Return the number of distinct priorities (indicated at construction) that are supported by this multi-priority queue.
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inline |
Remove the least-recently added item having the most urgent priority (lowest value) from this multi-priority queue and load its value into the specified item
. If this queue is empty, this method blocks the calling thread until an item becomes available. If the optionally specified itemPriority
is non-null, load the priority of the popped item into itemPriority
. The behavior is undefined unless item
is non-null. Note this is unaffected by the enabled / disabled state of the queue.
int bdlcc::MultipriorityQueue< TYPE >::pushBack | ( | bslmf::MovableRef< TYPE > | item, |
int | itemPriority | ||
) |
Insert the value of the specified item
with the specified itemPriority
into this multipriority queue before any queued items having a less urgent priority (higher value) than itemPriority
, and after any items having the same or more urgent priority (lower value) than itemPriority
. item
is left in a valid but unspecified state. If the multipriority queue is enabled, the push succeeds and 0
is returned, otherwise the push fails, the queue remains unchanged, and a nonzero value is returned. The behavior is undefined unless 0 <= itemPriority < numPriorities()
.
int bdlcc::MultipriorityQueue< TYPE >::pushBack | ( | const TYPE & | item, |
int | itemPriority | ||
) |
Insert the value of the specified item
with the specified itemPriority
into this multipriority queue before any queued items having a less urgent priority (higher value) than itemPriority
, and after any items having the same or more urgent priority (lower value) than itemPriority
. If the multipriority queue is enabled, the push succeeds and 0
is returned, otherwise the push fails, the queue remains unchanged, and a nonzero value is returned. The behavior is undefined unless 0 <= itemPriority < numPriorities()
.
void bdlcc::MultipriorityQueue< TYPE >::pushBackMultipleRaw | ( | const TYPE & | item, |
int | itemPriority, | ||
int | numItems | ||
) |
Insert the value of the specified item
with the specified itemPriority
onto the back of this multipriority queue before any queued items having a less urgent priority (higher value) than itemPriority
, and after any items having the same or more urgent priority (lower value) than itemPriority
. All of the specified numItems
items are pushed as a single atomic action, unless the copy constructor for one of them throws an exception, in which case a possibly empty subset of the pushes will have completed and no memory will be leaked. Raw
means that the push will succeed even if the multipriority queue is disabled. Note that this method is targeted for specific use by the class bdlmt::MultipriorityThreadPool
. The behavior is undefined unless 0 <= itemPriority < numPriorities()
.
void bdlcc::MultipriorityQueue< TYPE >::pushFrontMultipleRaw | ( | const TYPE & | item, |
int | itemPriority, | ||
int | numItems | ||
) |
Insert the value of the specified item
with the specified itemPriority
into the front of this multipriority queue the specified numItems
times, before any queued items having the same or less urgent priority (higher value) than itemPriority
, and after any items having more urgent priority (lower value) than itemPriority
. All numItems
items are pushed as a single atomic action, unless the copy constructor throws while creating one of them, in which case a possibly empty subset of the pushes will have completed and no memory will be leaked. Raw
means that the push will succeed even if the multipriority queue is disabled. The behavior is undefined unless 0 <= itemPriority < numPriorities()
. Note that this method is targeted at specific uses by the class bdlmt::MultipriorityThreadPool
.
void bdlcc::MultipriorityQueue< TYPE >::removeAll | ( | ) |
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inline |
Attempt to remove (immediately) the least-recently added item having the most urgent priority (lowest value) from this multi-priority queue. On success, load the value of the popped item into the specified item
; if the optionally specified itemPriority
is non-null, load the priority of the popped item into itemPriority
; and return 0. Otherwise, leave item
and itemPriority
unmodified, and return a non-zero value indicating that this queue was empty. The behavior is undefined unless item
is non-null. Note this is unaffected by the enabled / disabled state of the queue.