下面列出了java.lang.Math#min ( ) 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。
/**
* Get threads, blocks and shared memory for a reduce all operation
* @param gCtx a valid {@link GPUContext}
* @param n size of input array
* @return integer array containing {blocks, threads, shared memory}
*/
private static int[] getKernelParamsForReduceAll(GPUContext gCtx, int n) {
final int MAX_THREADS = getMaxThreads(gCtx);
final int MAX_BLOCKS = getMaxBlocks(gCtx);
final int WARP_SIZE = getWarpSize(gCtx);
int threads = (n < MAX_THREADS *2) ? nextPow2((n + 1)/ 2) : MAX_THREADS;
int blocks = (n + (threads * 2 - 1)) / (threads * 2);
blocks = Math.min(MAX_BLOCKS, blocks);
int sharedMemSize = threads * sizeOfDataType;
if (threads <= WARP_SIZE) {
sharedMemSize *= 2;
}
return new int[] {blocks, threads, sharedMemSize};
}
/**
* Get threads, blocks and shared memory for a reduce all operation
* @param gCtx a valid {@link GPUContext}
* @param n size of input array
* @return integer array containing {blocks, threads, shared memory}
*/
private static int[] getKernelParamsForReduceAll(GPUContext gCtx, int n) {
final int MAX_THREADS = getMaxThreads(gCtx);
final int MAX_BLOCKS = getMaxBlocks(gCtx);
final int WARP_SIZE = getWarpSize(gCtx);
int threads = (n < MAX_THREADS *2) ? nextPow2((n + 1)/ 2) : MAX_THREADS;
int blocks = (n + (threads * 2 - 1)) / (threads * 2);
blocks = Math.min(MAX_BLOCKS, blocks);
int sharedMemSize = threads * sizeOfDataType;
if (threads <= WARP_SIZE) {
sharedMemSize *= 2;
}
return new int[] {blocks, threads, sharedMemSize};
}
void zoomCircuit(int dy) {
double newScale;
double oldScale = transform[0];
double val = dy*.01;
newScale = Math.max(oldScale+val, .2);
newScale = Math.min(newScale, 2.5);
setCircuitScale(newScale);
}
/**
* Constructs a new <CODE>SnmpStringFixed</CODE> from the specified <CODE>Bytes</CODE> array
* with the specified length.
* @param l The length of the fixed-string.
* @param v The <CODE>Bytes</CODE> composing the fixed-string value.
* @exception IllegalArgumentException Either the length or the <CODE>Byte</CODE> array is not valid.
*/
public SnmpStringFixed(int l, Byte[] v) throws IllegalArgumentException {
if ((l <= 0) || (v == null)) {
throw new IllegalArgumentException() ;
}
int length = Math.min(l, v.length);
value = new byte[l] ;
for (int i = 0 ; i < length ; i++) {
value[i] = v[i].byteValue() ;
}
for (int i = length ; i < l ; i++) {
value[i] = 0 ;
}
}
/**
* Constructs a new <CODE>SnmpStringFixed</CODE> from the specified <CODE>bytes</CODE> array
* with the specified length.
* @param l The length of the fixed-string.
* @param v The <CODE>bytes</CODE> composing the fixed-string value.
* @exception IllegalArgumentException Either the length or the <CODE>byte</CODE> array is not valid.
*/
public SnmpStringFixed(int l, byte[] v) throws IllegalArgumentException {
if ((l <= 0) || (v == null)) {
throw new IllegalArgumentException() ;
}
int length = Math.min(l, v.length);
value = new byte[l] ;
for (int i = 0 ; i < length ; i++) {
value[i] = v[i] ;
}
for (int i = length ; i < l ; i++) {
value[i] = 0 ;
}
}
private static int[] getKernelParamsForReduceByCol(GPUContext gCtx, int rows, int cols) {
final int MAX_THREADS = getMaxThreads(gCtx);
final int MAX_BLOCKS = getMaxBlocks(gCtx);
final int WARP_SIZE = getWarpSize(gCtx);
int threads = Math.min(cols, MAX_THREADS);
int blocks = Math.min(cols/MAX_THREADS, MAX_BLOCKS);
if (cols % MAX_THREADS != 0) blocks++;
int sharedMemSize = threads * sizeOfDataType;
if (threads <= WARP_SIZE) {
sharedMemSize *=2;
}
return new int[] {blocks, threads, sharedMemSize};
}
public int read( byte b[], int off, int len ) throws IOException
{
dataAvailable=0;
int i=0, Minimum=0;
int intArray[] =
{
b.length,
InputBuffer,
len
};
/*
find the lowest nonzero value
timeout and threshold are handled on the native side
see NativeEnableReceiveTimeoutThreshold in
RS485Imp.c
*/
while(intArray[i]==0 && i < intArray.length) i++;
Minimum=intArray[i];
while( i < intArray.length )
{
if(intArray[i] > 0 )
{
Minimum=Math.min(Minimum,intArray[i]);
}
i++;
}
Minimum=Math.min(Minimum,threshold);
if(Minimum == 0) Minimum=1;
int Available=available();
int Ret = readArray( b, off, Minimum);
return Ret;
}
/**
* Constructs a new <CODE>SnmpStringFixed</CODE> from the specified <CODE>Bytes</CODE> array
* with the specified length.
* @param l The length of the fixed-string.
* @param v The <CODE>Bytes</CODE> composing the fixed-string value.
* @exception IllegalArgumentException Either the length or the <CODE>Byte</CODE> array is not valid.
*/
public SnmpStringFixed(int l, Byte[] v) throws IllegalArgumentException {
if ((l <= 0) || (v == null)) {
throw new IllegalArgumentException() ;
}
int length = Math.min(l, v.length);
value = new byte[l] ;
for (int i = 0 ; i < length ; i++) {
value[i] = v[i].byteValue() ;
}
for (int i = length ; i < l ; i++) {
value[i] = 0 ;
}
}
/**
* Constructs a new <CODE>SnmpStringFixed</CODE> from the specified <CODE>String</CODE>
* with the specified length.
* @param l The length of the fixed-string.
* @param s The <CODE>String</CODE> composing the fixed-string value.
* @exception IllegalArgumentException Either the length or the <CODE>String</CODE> is not valid.
*/
public SnmpStringFixed(int l, String s) throws IllegalArgumentException {
if ((l <= 0) || (s == null)) {
throw new IllegalArgumentException() ;
}
byte[] v = s.getBytes();
int length = Math.min(l, v.length);
value = new byte[l] ;
for (int i = 0 ; i < length ; i++) {
value[i] = v[i] ;
}
for (int i = length ; i < l ; i++) {
value[i] = 0 ;
}
}
/**
* Constructs a new <CODE>SnmpStringFixed</CODE> from the specified <CODE>bytes</CODE> array
* with the specified length.
* @param l The length of the fixed-string.
* @param v The <CODE>bytes</CODE> composing the fixed-string value.
* @exception IllegalArgumentException Either the length or the <CODE>byte</CODE> array is not valid.
*/
public SnmpStringFixed(int l, byte[] v) throws IllegalArgumentException {
if ((l <= 0) || (v == null)) {
throw new IllegalArgumentException() ;
}
int length = Math.min(l, v.length);
value = new byte[l] ;
for (int i = 0 ; i < length ; i++) {
value[i] = v[i] ;
}
for (int i = length ; i < l ; i++) {
value[i] = 0 ;
}
}
public int read( byte b[], int off, int len ) throws IOException
{
dataAvailable=0;
int i=0, Minimum=0;
int intArray[] =
{
b.length,
InputBuffer,
len
};
/*
find the lowest nonzero value
timeout and threshold are handled on the native side
see NativeEnableReceiveTimeoutThreshold in
RawImp.c
*/
while(intArray[i]==0 && i < intArray.length) i++;
Minimum=intArray[i];
while( i < intArray.length )
{
if(intArray[i] > 0 )
{
Minimum=Math.min(Minimum,intArray[i]);
}
i++;
}
Minimum=Math.min(Minimum,threshold);
if(Minimum == 0) Minimum=1;
int Available=available();
int Ret = readArray( b, off, Minimum);
return Ret;
}
/**
* Constructs a new <CODE>SnmpStringFixed</CODE> from the specified <CODE>String</CODE>
* with the specified length.
* @param l The length of the fixed-string.
* @param s The <CODE>String</CODE> composing the fixed-string value.
* @exception IllegalArgumentException Either the length or the <CODE>String</CODE> is not valid.
*/
public SnmpStringFixed(int l, String s) throws IllegalArgumentException {
if ((l <= 0) || (s == null)) {
throw new IllegalArgumentException() ;
}
byte[] v = s.getBytes();
int length = Math.min(l, v.length);
value = new byte[l] ;
for (int i = 0 ; i < length ; i++) {
value[i] = v[i] ;
}
for (int i = length ; i < l ; i++) {
value[i] = 0 ;
}
}
/**
* Constructs a new <CODE>SnmpStringFixed</CODE> from the specified <CODE>Bytes</CODE> array
* with the specified length.
* @param l The length of the fixed-string.
* @param v The <CODE>Bytes</CODE> composing the fixed-string value.
* @exception IllegalArgumentException Either the length or the <CODE>Byte</CODE> array is not valid.
*/
public SnmpStringFixed(int l, Byte[] v) throws IllegalArgumentException {
if ((l <= 0) || (v == null)) {
throw new IllegalArgumentException() ;
}
int length = Math.min(l, v.length);
value = new byte[l] ;
for (int i = 0 ; i < length ; i++) {
value[i] = v[i].byteValue() ;
}
for (int i = length ; i < l ; i++) {
value[i] = 0 ;
}
}
private int getNumberOfAvailableProcessors() {
int jobs = Runtime.getRuntime().availableProcessors();
return Math.min(jobs, MAXIMUM_NUMBER_OF_PROCESSORS);
}
private void moveUp() {
top = Math.max(top - pageSize, 1);
bottom = Math.min(top + pageSize - 1, selection.size());
}
public ReduceCopier(TaskUmbilicalProtocol umbilical, JobConf conf,
TaskReporter reporter
)throws ClassNotFoundException, IOException {
configureClasspath(conf);
this.reporter = reporter;
this.shuffleClientMetrics = new ShuffleClientMetrics(conf);
this.umbilical = umbilical;
this.reduceTask = ReduceTask.this;
this.scheduledCopies = new ArrayList<MapOutputLocation>(100);
this.copyResults = new ArrayList<CopyResult>(100);
this.numCopiers = conf.getInt("mapred.reduce.parallel.copies", 5);
this.maxInFlight = 4 * numCopiers;
Counters.Counter combineInputCounter =
reporter.getCounter(Task.Counter.COMBINE_INPUT_RECORDS);
this.combinerRunner = CombinerRunner.create(conf, getTaskID(),
combineInputCounter,
reporter, null);
if (combinerRunner != null) {
combineCollector =
new CombineOutputCollector(reduceCombineOutputCounter);
}
this.ioSortFactor = conf.getInt("io.sort.factor", 10);
this.abortFailureLimit = Math.max(30, numMaps / 10);
this.maxFetchFailuresBeforeReporting = conf.getInt(
"mapreduce.reduce.shuffle.maxfetchfailures", REPORT_FAILURE_LIMIT);
this.maxFailedUniqueFetches = Math.min(numMaps,
this.maxFailedUniqueFetches);
this.maxInMemOutputs = conf.getInt("mapred.inmem.merge.threshold", 1000);
this.maxInMemCopyPer =
conf.getFloat("mapred.job.shuffle.merge.percent", 0.66f);
final float maxRedPer =
conf.getFloat("mapred.job.reduce.input.buffer.percent", 0f);
if (maxRedPer > 1.0 || maxRedPer < 0.0) {
throw new IOException("mapred.job.reduce.input.buffer.percent" +
maxRedPer);
}
this.maxInMemReduce = (int)Math.min(
Runtime.getRuntime().maxMemory() * maxRedPer, Integer.MAX_VALUE);
// Setup the RamManager
ramManager = new ShuffleRamManager(conf);
localFileSys = FileSystem.getLocal(conf);
rfs = ((LocalFileSystem)localFileSys).getRaw();
// hosts -> next contact time
this.penaltyBox = new LinkedHashMap<String, Long>();
// hostnames
this.uniqueHosts = new HashSet<String>();
// Seed the random number generator with a reasonably globally unique seed
long randomSeed = System.nanoTime() +
(long)Math.pow(this.reduceTask.getPartition(),
(this.reduceTask.getPartition()%10)
);
this.random = new Random(randomSeed);
this.maxMapRuntime = 0;
this.reportReadErrorImmediately =
conf.getBoolean("mapreduce.reduce.shuffle.notify.readerror", true);
}
final boolean runAttempt(boolean lowball) throws InterruptedException {
float under = _estimate * (1-_uncertainty/2);
float over = _estimate * (1+_uncertainty/2);
float target = lowball? under : over;
// Run an experiment
//
if (VERBOSE)
out().println("attempt(" + target + ")");
float result = attempt(target);
// Analyze the results
//
boolean runSucceeded; // Was the target score achieved?
boolean guessWasCorrect; // Was runSucceeded what we expected it to be based on the lowball/highball setting?
boolean newEstimateWasSpecified = false; // Did the run provide an estimate of the score it can achieve?
float oldEstimate = _estimate;
if (result >= target && result < Float.POSITIVE_INFINITY) {
runSucceeded = true;
recordSuccess(target);
guessWasCorrect = lowball;
_estimate = result;
newEstimateWasSpecified = true;
} else if (result <= 0F) {
// UNSPECIFIED_FAILURE
runSucceeded = false;
guessWasCorrect = !lowball;
_estimate = lowball? _estimate * (1-_uncertainty) : _estimate;
} else if (result < target) {
runSucceeded = false;
guessWasCorrect = !lowball;
_estimate = result; // This is why we can't handle result==0 here. Estimate hits zero and never recovers
newEstimateWasSpecified = true;
} else {
// UNSPECIFIED_SUCCESS
runSucceeded = true;
recordSuccess(target);
guessWasCorrect = lowball;
_estimate = lowball? _estimate : _estimate * (1+_uncertainty);
}
if (_recentPeak == _maxPeak) {
if (under <= _maxPeak && _maxPeak <= over)
_maxPeakUncertainty = Math.min(_maxPeakUncertainty, _uncertainty);
}
if (!runSucceeded && target < _recentPeak)
_recentPeak = Float.NEGATIVE_INFINITY;
float oldUncertainty = _uncertainty;
if (runSucceeded && target >= Float.POSITIVE_INFINITY) {
// lowball guess or not, if we thought it was infinitely fast and the
// runSucceeded, we were right. Otherwise, we may never terminate,
// always attempting to increase the already-infinite target score ever higher.
guessWasCorrect = true;
}
if (newEstimateWasSpecified) {
float impliedUncertainty = Math.abs(oldEstimate - result) / target;
if (impliedUncertainty > _uncertainty) {
if (TAME_UNCERTAINTY) {
// If the estimate was way off, just bump up the _uncertainty as though our guess was incorrect
_uncertainty *= INCORRECT_GUESS_ADJUSTMENT;
} else {
_uncertainty = impliedUncertainty;
}
} else {
_uncertainty *= guessWasCorrect? CORRECT_GUESS_ADJUSTMENT : INCORRECT_GUESS_ADJUSTMENT;
}
} else {
_uncertainty *= guessWasCorrect? CORRECT_GUESS_ADJUSTMENT : INCORRECT_GUESS_ADJUSTMENT;
}
_uncertainty = Math.min(_uncertainty, MAX_UNCERTAINTY);
report(target, result, oldUncertainty, lowball, guessWasCorrect, runSucceeded);
return guessWasCorrect;
}
/**
* A server-side method to respond to a getfile http request
* Copies the contents of the local file into the output stream.
*/
static void getFileServer(OutputStream outstream, File localfile, DataTransferThrottler throttler)
throws IOException {
byte buf[] = new byte[BUFFER_SIZE];
FileInputStream infile = null;
long totalReads = 0, totalSends = 0;
try {
infile = new FileInputStream(localfile);
if (ErrorSimulator.getErrorSimulation(2)
&& localfile.getAbsolutePath().contains("secondary")) {
// throw exception only when the secondary sends its image
throw new IOException("If this exception is not caught by the " +
"name-node fs image will be truncated.");
}
if (ErrorSimulator.getErrorSimulation(3)
&& localfile.getAbsolutePath().contains("fsimage")) {
// Test sending image shorter than localfile
long len = localfile.length();
buf = new byte[(int)Math.min(len/2, BUFFER_SIZE)];
// This will read at most half of the image
// and the rest of the image will be sent over the wire
infile.read(buf);
}
int num = 1;
while (num > 0) {
long startRead = System.currentTimeMillis();
num = infile.read(buf);
if (num <= 0) {
break;
}
outstream.write(buf, 0, num);
if (throttler != null) {
throttler.throttle(num);
}
}
} finally {
if (infile != null) {
infile.close();
}
}
}
public static MR_long min ( MR_long x, MR_long y ) { return new MR_long(Math.min(x.get(),y.get())); } public static MR_double min ( MR_double x, MR_double y ) { return new MR_double(Math.min(x.get(),y.get())); }