Profiling is used to identify memory leaks inside a program. In computer science, a memory leak is a type of resource leak that occurs when a computer program incorrectly manages memory allocations in such a way that memory which is no longer needed is not released. A memory leak may also happen when an object is stored in memory but cannot be accessed by the running code. A memory leak has symptoms similar to a number of other problems and generally can only be diagnosed by a programmer with access to the programs' source code.
A space leak occurs when a computer program uses more memory than necessary. In contrast to memory leaks, where the leaked memory is never released, the memory consumed by a space leak is released, but later than expected.
Because they can exhaust available system memory as an application runs, memory leaks are often the cause of or a contributing factor to software aging.
Valgrind is an instrumentation framework for building dynamic analysis tools. It can automatically detect many memory management and threading bugs, and profile your programs in detail.
bazel run --copt=-O0 -c dbg --run_under='valgrind --leak-check=yes' //path/to:target
Callgrind is a call-graph generating cache and branch prediction profiler.
To use this tool, you must specify --tool=callgrind on the Valgrind command line.
vallgrind --tool=callgrind /path/to/executable
sudo apt install vallgrind callgrind graphviz
You can also install gprof2dot. This is a Python script to convert the output from many profilers into a dot graph:
git clone https://github.com/jrfonseca/gprof2dot.git
chmod +x gprof2dot.py
-
Create callgrind.out file:
valgrind --tool=callgrind /path/to/executable -
Create .dot callmap with gprof2dot:
./gprof2dot.py --format=callgrind --output=out.dot callgrind.out.PID -
Convert .dot callmap to .png:
dot -Tpng out.dot -o graph.png -
Open png file:
display graph.png