Class EmptyLongBuf
long
and the message length is 0. When a
message is received into an EmptyLongBuf, the message item type must be
long
, but all items in the message are discarded.- Version:
- 19-Nov-2007
- Author:
- Alan Kaminsky
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Field Summary
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionvoid
Copy items from the given buffer to this buffer.long
get
(int i) Obtain the given item from this buffer.getReductionBuf
(Op op) Create a buffer for performing parallel reduction using the given binary operation.void
put
(int i, long item) Store the given item in this buffer.protected int
receiveItems
(int i, int num, ByteBuffer buffer) Receive as many items as possible from the given byte buffer to this buffer.protected int
sendItems
(int i, ByteBuffer buffer) Send as many items as possible from this buffer to the given byte buffer.Methods inherited from class edu.rit.mp.LongBuf
buffer, buffer, buffer, buffer, buffer, buffer, colSliceBuffer, colSliceBuffers, defaultCopy, emptyBuffer, fill, getTemporaryBuf, patchBuffer, patchBuffers, rowSliceBuffer, rowSliceBuffers, sliceBuffer, sliceBuffer, sliceBuffers, sliceBuffers
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Constructor Details
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EmptyLongBuf
public EmptyLongBuf()Construct a new empty long buffer.
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Method Details
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get
public long get(int i) Obtain the given item from this buffer.The
get()
method must not block the calling thread; if it does, all message I/O in MP will be blocked. Obtain the given item from this buffer.The
get()
method must not block the calling thread; if it does, all message I/O in MP will be blocked. -
put
public void put(int i, long item) Store the given item in this buffer.The
put()
method must not block the calling thread; if it does, all message I/O in MP will be blocked. Store the given item in this buffer.The
put()
method must not block the calling thread; if it does, all message I/O in MP will be blocked. -
copy
Copy items from the given buffer to this buffer. The number of items copied is this buffer's length ortheSrc
's length, whichever is smaller. IftheSrc
is this buffer, thecopy()
method does nothing. Copy items from the given buffer to this buffer. The number of items copied is this buffer's length ortheSrc
's length, whichever is smaller. IftheSrc
is this buffer, thecopy()
method does nothing.The default implementation of the
copy()
method calls thedefaultCopy()
method. A subclass can override thecopy()
method to use a more efficient algorithm. Copy items from the given buffer to this buffer. The number of items copied is this buffer's length ortheSrc
's length, whichever is smaller. IftheSrc
is this buffer, thecopy()
method does nothing.- Overrides:
copy
in classLongBuf
- Parameters:
theSrc
- Source of items to copy into this buffer.- Throws:
ClassCastException
- (unchecked exception) Thrown iftheSrc
's item data type is not the same as this buffer's item data type.
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getReductionBuf
Create a buffer for performing parallel reduction using the given binary operation. The results of the reduction are placed into this buffer.Operations performed on the returned reduction buffer have the same effect as operations performed on this buffer, except whenever a source item S is put into a destination item D in this buffer, D is set to D op S, that is, the reduction of D and S using the given binary operation (rather than just setting D to S). Create a buffer for performing parallel reduction using the given binary operation. The results of the reduction are placed into this buffer.
Operations performed on the returned reduction buffer have the same effect as operations performed on this buffer, except whenever a source item S is put into a destination item D in this buffer, D is set to D op S, that is, the reduction of D and S using the given binary operation (rather than just setting D to S).
- Specified by:
getReductionBuf
in classBuf
- Parameters:
op
- Binary operation.- Returns:
- a
Buf
object. - Throws:
ClassCastException
- (unchecked exception) Thrown if this buffer's element data type and the given binary operation's argument data type are not the same.
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sendItems
Send as many items as possible from this buffer to the given byte buffer.The
sendItems()
method must not block the calling thread; if it does, all message I/O in MP will be blocked. Send as many items as possible from this buffer to the given byte buffer.The
sendItems()
method must not block the calling thread; if it does, all message I/O in MP will be blocked. -
receiveItems
Receive as many items as possible from the given byte buffer to this buffer.The
receiveItems()
method must not block the calling thread; if it does, all message I/O in MP will be blocked. Receive as many items as possible from the given byte buffer to this buffer.The
receiveItems()
method must not block the calling thread; if it does, all message I/O in MP will be blocked.- Specified by:
receiveItems
in classBuf
- Parameters:
i
- Index of first item to receive, in the range 0 ..length
-1.num
- Maximum number of items to receive.buffer
- Byte buffer.- Returns:
- Number of items received.
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