ytoshima’s gists

ytoshima / cpumem.cpp

Created May 23, 2012 09:05

Simple stress program

	/*
	* A small cpu and memory stress program
	* compile: CC cpumem.cpp -o cpumem -lpthread
	* or: make LDFLAGS=-lpthread cpumem
	*/
	#include <pthread.h>
	#include <iostream>
	#include <vector>
	#include <sys/types.h>
	#include <assert.h>

ytoshima / javamem.scala

Last active October 5, 2015 06:48

misc snippets

	import collection.JavaConversions._
	import java.lang.management._
	val MB = (1024*1024).toFloat

	def b2mb(bval: Long): Float = bval / MB

	def mpoolSum(mp: MemoryPoolMXBean) = "%s: use %.2f comm %.2f max %.2f".format(mp.getName, b2mb(mp.getUsage.getUsed), b2mb(mp.getUsage.getCommitted), b2mb(mp.getUsage.getMax))

	def minfo = ManagementFactory.getMemoryPoolMXBeans.filter(_.getType == MemoryType.HEAP).map(mpoolSum).mkString("\n")

ytoshima / PmapFilter.scala

Created April 24, 2012 10:59

A filter for pmap putout

	object PmapFilter {
	case class Mr(start: Long, end: Long, desc: String) {
	override def toString =
	"%08x-%08x %6dk %s".format(start, end, (end-start)/1024, desc)
	}
	def process(path: String) : String = {
	import scala.io.Source
	def procMr(current: Mr, prevEnd: Long) = prevEnd match {
	case 0 => current.toString
	case x if prevEnd == current.start => current.toString

ytoshima / CoreAmap.scala

Created March 12, 2012 04:40

Prints address map with gap size between segment within a core file

	/**
	* Prints address map with gap size between segment
	* within a core file. This program uses readelf
	* command and expects the output is same as the
	* readelf on Linux.
	*/
	object CoreAmap {
	def main(args: Array[String]) {
	for (a <- args) doAmapCore(a)
	}

ytoshima / gist:1814611

Created February 13, 2012 07:27

TraceMethodHandles sample output

	$ ~/local/jdk1.7.0-b147/fastdebug/bin/java -cp classes:lib/asm-4.0.jar name.yt.icache.Pet
	D: bsm: type: (Object)void
	D: bsm: fallback: MethodHandle(Object)void
	D: bsm: fallback: MethodHandle(Object)void
	D: fallback: type: (Object)void
	D: fallback: type.dropParameterTypes(0,1): ()void
	D: fallback: receiverClass: class name.yt.icache.Cat
	D: fallback: target: MethodHandle(Cat)void
	D: fallback: target after asType: MethodHandle(Object)void
	D: fallback: test: MethodHandle(Object)boolean

ytoshima / JniEx.cpp

Created February 2, 2012 17:41

Simple JNI examples for certain crashes

	#include "JniEx.h"
	#include <stdlib.h>

	void bad_func()
	{
	int ip = (int)0xbffffffe;
	*ip = 1;
	}

	JNIEXPORT void JNICALL Java_JniEx_crash (JNIEnv *env, jclass cls) {

ytoshima / gist:1381429

Created November 21, 2011 02:22

PrintEscapeAnalysis output example

	$ ~/local/jdk1.7.0-b147/fastdebug/bin/java -XX:+Verbose -XX:+PrintEscapeAnalysis -jar ~/local/jdk1.6.0_26/demo/jfc/Java2D/Java2Demo.jar
	VM option '+Verbose'
	VM option '+PrintEscapeAnalysis'


	======== Connection graph for java.util.Properties$LineReader::readLine
	519 JavaObject GlobalEscape NSR [[ 578F 589F 623F 624F 452F 468F 469F 602F 606F]] 519 AllocateArray === 503 199 501 8 1 ( 517 506 512 505 10 438 281 22 65 22 384 68 22 1 1 ) [[ 520 521 522 529 530 531 ]] rawptr:NotNull ( int:>=0, java/lang/Object:NotNull *, bool, int ) java.util.Properties$LineReader::readLine @ bci:286 Type:{0:control, 1:abIO, 2:memory, 3:rawptr:BotPTR, 4:return_address, 5:rawptr:NotNull} !jvms: java.util.Properties$LineReader::readLine @ bci:286
	LocalVar [[ 519P]] 531 Proj === 519 [[ 532 536 ]] #5 Type:rawptr:NotNull !jvms: java.util.Properties$LineReader::readLine @ bci:286
	LocalVar [[ 519P]] 536 CheckCastPP === 533 531 [[ 655 678 655 624 578 578 589 589 624 623 ]] Type:char[i

ytoshima / c1-result.txt

Created November 18, 2011 16:39

Code comparison between C1 and C2

	C1

	$ ~/jdk1.7.0-b147/fastdebug/bin/java -XX:CompileOnly=gvnex::doHashSum -XX:+PrintLIR -client gvnex
	VM option 'CompileOnly=gvnex::doHashSum'
	VM option '+PrintLIR'
	CompileOnly: compileonly gvnex.doHashSum
	LIR:
	B1 [0, 0] sux: B0
	__id_Instruction___________________________________________
	0 label [label:0x939c62c]

ytoshima / sum.java

Created November 18, 2011 16:02

PrintOptoAssembly output example

	// -XX::CompileOnly=sum::doit would narrow down the method to compile, but it
	// is not used here.

	$ ~/jdk1.7.0-b147/fastdebug/bin/java -XX:+PrintOptoAssembly sum
	VM option '+PrintOptoAssembly'
	{method}
	- klass: {other class}
	- this oop: 0x911f8110
	- method holder: 'sum'
	- constants: 0x911f7e10 constant pool [32] for 'sum' cache=0x911f86b0

ytoshima / gist:1369697

Created November 16, 2011 09:46

TraceOptoParse output example