ScalaCL and memory leaks.

[ochafik]

From @jopasserat on January 2, 2012 21:53

Hi Olivier,

My second problem succeeding to issue #221 close is the following:

Having rebuilt the ScalaCL sbaz integrating your recent changes, I now encounter memory leaks. When running the ScalaCL code of your tutorial directly in the scala shell (http://code.google.com/p/scalacl/wiki/FAQ), I get an OutOfMemoryError exception when invoking map on the 1,000,000 entries CLArray.

This code used to process without any problem with ScalaCL 0.2 on two different machines running JVM 6 and 7.

A certainly related problem appears when running a small project of mine built with Maven (my local repository is up to date with ScalaCL since I rebuilt it on the same machine). The program runs well but crashes when quitting:

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007fec86122000, pid=5987, tid=140653859129088
#
# JRE version: 7.0_147-b147
# Java VM: OpenJDK 64-Bit Server VM (21.0-b17 mixed mode linux-amd64 compressed oops)
# Derivative: IcedTea7 2.0
# Distribution: Debian GNU/Linux unstable (sid), package 7~b147-2.0-1
# Problematic frame:
# C  0x00007fec86122000
[error occurred during error reporting (printing problematic frame), id 0xb]

# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
# An error report file with more information is saved as:
# /tmp/hs_err_pid5987.log
#
# If you would like to submit a bug report, please include
# instructions on how to reproduce the bug and visit:
#   http://icedtea.classpath.org/bugzilla
#
Aborted

Here is a part of the aforementioned hs_err_pid5987.log file that could interest you:

Instructions: (pc=0x00007fec86122000)
0x00007fec86121fe0:
[error occurred during error reporting (printing registers, top of stack, instructions near pc), id 0xb]

Register to memory mapping:

RAX=0x0000000000000000 is an unknown value
RBX=0x0000000749f73228 is an oop
java.lang.Class
 - klass: 'java/lang/Class'
RCX=0x0000000000000002 is an unknown value
RDX=0x00007fec874f3310 is pointing into the stack for thread: 0x0000000000ead800
RSP=0x00007fec874f3308 is pointing into the stack for thread: 0x0000000000ead800
RBP=0x00007fec874f3360 is pointing into the stack for thread: 0x0000000000ead800
RSI=0x00007fec874f3340 is pointing into the stack for thread: 0x0000000000ead800
RDI=0x0000000000ead9d0 is an unknown value
R8 =0x000000074774a220 is an oop
com.nativelibs4java.opencl.CLEvent
 - klass: 'com/nativelibs4java/opencl/CLEvent'
R9 =0x00007fec874f3588 is pointing into the stack for thread: 0x0000000000ead800
R10=0x0000000000000002 is an unknown value
R11=0x000000074774a220 is an oop
com.nativelibs4java.opencl.CLEvent
 - klass: 'com/nativelibs4java/opencl/CLEvent'
R12=0x0000000000000000 is an unknown value
R13=0x00007fec874f3348 is pointing into the stack for thread: 0x0000000000ead800
R14=0x00007fec874f3340 is pointing into the stack for thread: 0x0000000000ead800
R15=0x0000000000ead800 is a thread


Stack: [0x00007fec873f4000,0x00007fec874f5000],  sp=0x00007fec874f3308,  free space=1020k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
C  0x00007fec86122000
[error occurred during error reporting (printing native stack), id 0xb]

Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
J  com.nativelibs4java.opencl.library.OpenCLLibrary.clReleaseEvent(Lcom/nativelibs4java/opencl/library/OpenCLLibrary$cl_event;)I
J  com.nativelibs4java.opencl.CLAbstractEntity.finalize()V
v  ~StubRoutines::call_stub
J  java.lang.ref.Finalizer.invokeFinalizeMethod(Ljava/lang/Object;)V
J  java.lang.ref.Finalizer.access$100(Ljava/lang/ref/Finalizer;)V
J  java.lang.ref.Finalizer$FinalizerThread.run()V
v  ~StubRoutines::call_stub

Regards,

Copied from original issue: nativelibs4java/nativelibs4java#223

[ochafik]

Hi jHack,

Thanks for your report !
I've started to see this issue myself recently, will investigate asap (might be caused by BridJ, since not much has changed in JavaCL & ScalaCL Collections).

Cheers