Re: Howto: Profiling GCJ code?

[Patrick Schäfer <ps at ekse dot de>]

Hi,

I tried exchanging java.nio with the apache portable runtime (APR)  
library which solves the issue with the garbage collector consuming  
most of the time (>80%) even while being idle. But it causes the  
application to spend most cycles in dynamically loading libraries at  
runtime under load. I am extensively using JNA (JNI) for Posix Message  
Queues and APR as transport layer which both use JNI for native  
library access.

It seems to me like those libraries are dynamically loaded for every  
method call. I couldn't find a way to statically bind the libraries on  
mac os x. Is there a way to cache methods or any other way to improve  
this?

Profile:

	Self		Total	Library
	0.0%	89.9%	Unknown Library	0x696d5f74 [unreadable]	
	0.0%	89.8%	libgcj.9.dylib	 _Jv_platform_dladdr(void*, _Jv_AddrInfo*)	
	0.0%	89.8%	libSystem.B.dylib	  dladdr	
	24.2%	82.9%	dyld	   dladdr	
	28.9%	28.9%	dyld	    ImageLoaderMachO::getSymbolAddress(macho_nlist  
const*, ImageLoader const*, ImageLoader::LinkContext const&) const	
	22.8%	22.8%	dyld	     
ImageLoaderMachO::getIndexedExportedSymbol(unsigned int) const	
	6.9%	6.9%	dyld	     
ImageLoaderMachO::getExportedSymbolAddress(ImageLoader::Symbol const*,  
ImageLoader::LinkContext const&, ImageLoader const*) const	
	0.0%	0.0%	dyld	    dyld::findImageContainingAddress(void const*)	
	0.0%	0.0%	dyld	    ImageLoader::containsAddress(void const*) const	
	0.0%	0.0%	dyld	     
ImageLoaderMachO::getExportedSymbolName(ImageLoader::Symbol const*)  
const	
	0.0%	0.0%	dyld	    ImageLoader::getLogicalPath() const	
	2.3%	2.3%	dyld	   ImageLoaderMachO::getIndexedExportedSymbol(unsigned  
int) const	
	2.3%	2.3%	dyld	    
ImageLoaderMachO::getExportedSymbolAddress(ImageLoader::Symbol const*,  
ImageLoader::LinkContext const&, ImageLoader const*) const	
	2.2%	2.2%	dyld	   ImageLoaderMachO::getSymbolAddress(macho_nlist  
const*, ImageLoader const*, ImageLoader::LinkContext const&) const	



thank you for any help

patrick