Memory debugger


A memory debugger is a debugger for finding software memory problems such as memory leaks and buffer overflows. These are due to bugs related to the allocation and deallocation of dynamic memory. Programs written in languages that have garbage collection, such as managed code, might also need memory debuggers, e.g. for memory leaks due to "living" references in collections.

Overview

Memory debuggers work by monitoring memory access, allocations, and deallocation of memory. Many memory debuggers require applications to be recompiled with special dynamic memory allocation libraries, whose APIs are mostly compatible with conventional dynamic memory allocation libraries, or else use dynamic linking. Electric Fence is such a debugger which debugs memory allocation with malloc. Some memory debuggers work by running the executable in a virtual machine-like environment, monitoring memory access, allocation and deallocation so that no recompilation with special memory allocation libraries is required.
Finding memory issues such as leaks can be extremely time consuming as they may not manifest themselves except under certain conditions. Using a tool to detect memory misuse makes the process much faster and easier.
As abnormally high memory utilization can be a contributing factor in software aging, memory debuggers can help programmers to avoid software anomalies that would exhaust the computer system memory, thus ensuring high reliability of the software even for long runtimes.

Comparison to static analyzer

Some static analysis tools can also help find memory errors. Memory debuggers operate as part of an application while it's running while static code analysis is performed by analyzing the code without executing it. These different techniques will typically find different instances of problems, and using them both together yields the best result.

List of memory debugging tools

This is a list of tools useful for memory debugging. A profiler can be used in conjunction with a memory debugger.
NameOSLicenseLanguagesTechnique
AddressSanitizerLinux, Mac OSFree/open source C, C++.Compile-time instrumentation and specialized library
Allinea DDTLinux, Blue GeneProprietary commercialC, C++ and F90. Also for parallel programs on supercomputersRuntime - through dynamic linking
AQtimeWindows Proprietary commercial.NET, C++, Java, Silverlight, JScript, VBScriptRuntime
BcheckSolaris
BoundsCheckerWindows Proprietary commercialC++Runtime intercepts or compile-time
DaikonUnix, Windows, Mac OS XFree/open sourceJava, C/C++, Perl, and EiffelRuntime dynamic invariant detection
Debug_newC++Compile-time override
DeleakerWindows Proprietary commercialC++,.Net, DelphiRuntime intercepts
dmallocAnyFree/open sourceCCompile-time override
Android, Linux, WindowsFree/open source AnyRuntime intercepts
Electric FenceUnixFree/open source C, C++Compile-time override
FASTMM4WindowsFree/open source DelphiCompile-time override
IBM Rational PurifyUnix, WindowsProprietary commercialC++, Java,.NETRuntime
Insure++Windows, UnixProprietary commercialC, C++source code instrumentation
Intel InspectorWindows Proprietary commercialC, C++
libcwdLinux Free/open sourceC, C++Compile-time override
libumemSolarisBundled with SolarisLink-time override
MemwatchAny Free/open sourceCCompile-time override
mtraceVariousFree/open source GNU C libraryBuilt-in, outputs accesses
MTunerVariousFreeC, C++Runtime intercepts, Link-time override, Leak detection
Oracle Solaris Studio Linux, SolarisProprietary freewareC, C++, Fortran
OLIVER MVS, MVS/EXA, DOS/VSEProprietary softwareIBM AssemblerRuntime intercepts, Hypervisor - Type 2
TotalViewUnix, Mac OS XProprietary commercialC, C++, FortranRuntime
Linux, Mac OS, AndroidFree/open source AnyRuntime intercepts
WinDbgWindowsProprietary freewareC, C++,.NET, PythonRuntime