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Your JVM process has suddenly crashed, which has resulted in the Oracle JRockit JVM creating a snapshot, crash files, of the state of the computer and the JVM process at the time of the crash. These crash files are written to disk and are called a bit different depending on which platform you are using and the kind of information contained within the file (see Figure 31-1). Automation studio 64 bits manager.
This page explains how you can easily convert a.mdmp file to a PDF using free and easy to use tools from PDF24. The methods to create PDF files explained here are free and easy to use. A PDF creator and a PDF converter makes the conversion possible. The PDF24 Creator installs for you a virtual PDF printer so that you can print your.mdmp file on that printer in order to convert your file to PDF. In the following table, you can find a list of programs that can open files with.mdmp extension.This list is created by collecting extension information reported by users through the 'send report' option of FileTypesMan utility. The product name, description, and company name are taken from the version information of the.exe file.The 'Actions' list is taken from the context menu items added.
You can use some the information in the crash files to determine the nature of the problem that caused the JVM to crash. The information contained in the crash files is also essential for the support organization within the JRockit JVM to help solving problems with the JVM. When submitting problem reports to the Oracle support organization, you need to include these crash files (see Submitting Problems to Oracle Support for more information).
This section provides information on the differences between the crash files and how to enable and disable them. You will also find example crash files and diagnostics leads on how to interpret the information in the text crash file, which will enable you to identify solutions to how to either fix your Java application or the way you use and set up the JRockit JVM.
This section includes information on the following subjects:
Differences Between Text dump Files and Binary core/mdmp Files
When the JRockit JVM crashes it creates two types of crash files (see Figure 31-1): a text crash file called dump and a binary crash file called mdmp (a Windows platform minidump) or core (a Linux and Sun platform core file). The format of the two types of crash files is:
jrockit.<pid>.dump
and jrockit.<pid>.mdmp/core
, where pid is the process id that appears as a number, for example, jrockit.72.dump
. Figure 31-1 JRockit JVM creates two types of crash files
The information contained in the text
dump
file is information about the JVM at the point of time for the crash. This information can give hints and leads to why the JVM has crashed. See Listing 31-1 through Listing 31-4 for an example of the information contained in a text dump
file. The text dump
file can be viewed in a regular text editor. To turn the creation of the text dump
file off, see Disabling Text dump Files. The information in the binary
core
or mdmp
crash file contains information about the entire JRockit JVM process and needs to be opened in a debugger. The size of the binary crash file is usually quite large, so you need to make sure there is enough disk space for the file to be completely written to disk. By default, the JVM records a full binary crash file. To set the size of the binary crash file, see Binary Crash File Sizing. To turn the creation of the binary crash file off, see Disabling the Binary Crash Files. Binary Crash File Sizing
The size of the binary
core
or mdmp
crash files vary tremendously. The text dump
file is normally a very small file, usually under 100kB. The binary crash files, on the other hand, are, by default, set to log the entire JRockit JVM process (see Figure 31-2) and therefore become very large, which demands greater storage capacity on your system. You can se the crash file size using the command line option
-XXdumpSize.
The default setting is -XXdumpSize:large
. A large dump contains the entire JVM process including the Java heap. While small
and normal
settings are also available, neither of these sizes are adequate for troubleshooting a JVM crash since the Java heap is excluded. If you don’t want a binary crash file, you can set
-XXdumpSize:none
. For more information on this option, see -XXdumpSize in the Oracle JRockit JVM Command-Line Reference. Figure 31-2 Difference in information saturation between small, normal, and large binary crash files
Note: | Remember that you need to provide a <large> binary core or mdmp crash file with any problem that you submit to the Oracle JRockit support organization. |
If there is not enough memory on the disk where the crash file is written for the entire binary crash file, the file will become as large as possible, i.e. fill up the disk.
Location of Crash Files
Both the binary crash files and the text
dump
files are saved to your current working directory (see Enabling Binary core Crash Files on Linux and Sun Solaris). If you want to save the crash files in a different location, use the environment variable JROCKIT_DUMP_PATH
and specify where you want the information located. The path that you specify must exist and be writable. Enabling Binary core Crash Files on Linux and Sun Solaris
For the Linux and Sun Solaris systems, you need to set
ulimit
-c
<value>
to something greater than zero, for example, ulimit -c unlimited
. This value is measured in blocks, with each block equaling one kilobyte. You can set the value from either the command line or in a shell script. To disable crash files on Linux and Solaris, set ulimit -c 0
. To specify the where the JRockit JVM should put the binary
core
crash file, enter the following: Enabling Binary mdmp Crash Files on Windows
Binary
mdmp
files are always created on Windows. If you do not specify the variable JROCKIT_DUMP_PATH
Gameboy advance emulator for mac version. , the crash files end up in the current directory (the directory from where you start the JVM). To specify the where JRockit JVM should put the crash file, enter the following:
Disabling Crash Files
The crash files are enabled by default so that you will be sure to get as much information as possible about your application and the JRockit JVM process as possible in the event of a crash; however, there might be times when you do not want the JVM to create any type of crash file, for example, if you have limited disk space.
Before turning the creation of the crash files off, please remember that the text
dump
file is a small and good source of information to get an initial grasp of what has gone wrong with the JVM and the binary core
or mdmp
crash file is essential when creating a support case for the Oracle JRockit support organization. Disabling Text dump Files
If you suspect problems with the creation of text
dump
files you can turn off the text dump
file by using the option: -XXnoJrDump.
Disabling the Binary Crash Files
You can turn off the binary crash file by using the option:
-XXdumpSize:none
. Extracting Information From a Text dump File
A JVM crash means that something has happened that the JVM couldn’t handle gracefully. The cause can be a programming error in the JVM, but a crash may also indicate a problem in the Java code or in the JVM setup. The
dump
file is a good source of initial troubleshooting information to help you identify the problem. Symptoms to Look For
A
dump
file will not necessarily tell you exactly why the crash occurred, but it describes the environment where the JRockit JVM was running and the state of the JVM when the crash occurred. This gives some hints on where to start looking and can give an idea of the crash type. There are however some easily identified symptoms that you can look for in the dump
file: - Check the
StackOverFlow
field in thedump
file. If this field indicates that stack overflow errors have occurred, the crash is likely to have been caused by a stack overflow. See Stack Overflow Crash for information on how to deal with stack overflow crashes. - Check for reports of
Stack Overflow
in theError message
field or in the stack trace near the bottom of thedump
file. Such occurrences may also indicate a stack overflow. See Stack Overflow Crash for information on how to deal with stack overflow crashes. - Check the
C Heap
field in thedump
file. If this field indicates that memory allocations have failed, the process may have run out of virtual memory. See Out Of Virtual Memory Crash for information on how to deal with out of virtual memory errors. - Check the
LD_ASSUME_KERNEL
field in thedump
file. Having this Linux-specific environment variable set usually leads to the JRockit JVM using unsupported system libraries and becoming unstable. See Unsupported Linux Configuration Crash for information on dealing with unsupported Linux configuration problems.
If none of these symptoms apply to your
dump
file you can try troubleshooting further using the information in JVM Crash or open a support case. To open a support case you must have a service agreement with Oracle. Example of a Text dump File
Mdmp File Format
This section shows an example of what a text
dump
file might look like and explains the parts of the dump
file. The text dump
file that has been used in this example is a combination of many different dump
files, so that more crash scenarios can be covered. Remember that the text crash files are not full descriptions of what has happened in the crash and the layout of the text crash file the JVM produces might differ from the examples given here.
The Beginning of the Text dump File
Listing 31-1 shows an example of the first part of a
dump
file. Listing 31-1 The initial information of a text dump file
JRockit JVM Dump (Crash File) Produced
Listing 31-1 shows the start of the text
dump
file. This section contains information about when the crash occurred and for how long the JVM has been running. The file locations refer to the location of both text and binary crash files. Support Case Information
If you have a service agreement with Oracle, you can file a support case with your Oracle service provider. If you do not have a service agreement, you can post your problem on the Oracle JRockit JDK developer forum under
jrockit.developer.interest.general
. Posting your problem on the forum is no guarantee to get it resolved, but the forum is a good source for information on JRockit JVM problems. Error Message from OS
The information block that starts with Error Message, shows the actual error message that the operation threw at the time of the crash. Check your operating system vendor users information to find out more about the error.
JRockit JVMVersion and Garbage Collector Information
Use the Version description to see if you are running the latest version of the JRockit JVM, seeOracle JRockit Supported Configurations for a complete list of supported versions.
GC stands for Garbage Collector and this description states which garbage collector that has been used. In this example, the generational concurrent (gencon) garbage collector has been used. Since the generational garbage collector has been used, there is a listing of where in the memory the nursery starts and ends. The
mmStartCompaction
and mmEndCompaction
values are a description of where in the heap the compaction of the heap has taken place during the current or latest garbage collection. For more information on memory management in the JRockit JVM, see Understanding Memory Management.
CPU and Memory Information
The information block that starts with CPU, describes how many CPUs that have been used and how much memory (Tot Phys Mem) that has been consumed by the Java process, application, or the JRockit JVM.
Operating System Version Information
The OS version states the operating system version that you are running on. Please make sure that you are running on a supported operating system version, seeOracle JRockit JDK Supported Configurations.
Thread and State Information
The Thread field indicates the thread system that the JRockit JVM used at the time of the crash. In this example the JVM used the Native POSIX Thread Library (NPTL).
The State of the JVM at the time of the crash was that it was running. Other valid states could be starting up or shutting down.
Command Line and Environment Information
The second part of the example, see Listing 31-2, starts with the text
Command Line
. Listing 31-2 Looking at information about command line options in a text crash file
Command Line Option Information
Command Line lists all startup options that were sent to the JRockit JVM at startup. The example in Listing 31-2 has used command line options for setting a generational concurrent garbage collector (
-Xgc:gencon
), with an initial minimum and maximum Java heap (-Xms
and -Xmx
), and a nursery size setting (-Xns
). JAVA_HOME and _JAVA_OPTIONS
JAVA_HOME
is the path to your Java home catalog; that is, where the JRockit JVM is installed. _JAVA_OPTIONS
is a list of command line options that will be automatically passed to all newly started JRockit JVMs. LD_LIBRARY_PATH
LD_LIBRARY_PATH
is a Linux /Solaris specific environment variable that can make the JRockit JVM find libraries other than the default system libraries. Sometimes, you need to set this variable for running JNI code. You can set this variable so that the JVM starts using unsupported libraries on otherwise supported platforms. LD_ASSUME_KERNEL, C Heap, StackOverFlow, and OutOfMemory Information
The information block that starts with
LD_ASSUME_KERNEL
lists information of what might have gone wrong prior to the crash. See Symptoms to Look For for more information on what to look for in these fields. Registers and Stack Information
The third part of the example, see Listing 31-3, starts with the text
Registers
. Listing 31-3 Verifying that the text crash file is correct.
Registers
The Registers section is only useful to Oracle Support personnel troubleshooting your issues. You can ensure that the text crash file is not corrupt if the register ESP and the first number of the stack match (Listing 31-3). If these two numbers do not match, you can suspect that the text
dump
file itself is incorrect. Mdmp File Viewer Online
Stack Information
If the stack information says “
unreadable
” instead of showing numbers, the crash is probably due to stack overflow. The Stack information section is usually much longer than the one shown in Listing 31-3. Stack Trace Information
The information block that starts with Stack, see Listing 31-4, describes what has happened and where it happened in the thread stack at the point of the crash.
The Thread Stack Trace shows what the crashing thread was doing when the JRockit JVM crashed; for example, Listing 31-4 shows that a crash occurred during code generation. Splinter cell blacklist dlc unlocker for windows.
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