The goal of this exercise is to understand the memory use and performance of std::vector. You will get familiar with the IgProf profiler tool.

Steps

Go to the exercise directory:
```
 cd esc15/hands-on/memory
```
Examine the little test programs in this directory. You use them for dedicated little studies on container memory allocation behaviour:
- vvvi-build-and-copy.cc: Build triply nested vector of ints, and make a copy of it; drops profile heap snapshots part way. This example was used in the presentation.
- vvvi-reserve.cc: Same as vvvi-build-and-snapshot.cc, but uses the reserve() method correctly to avoid vector resizes. This example was used in the presentation.
Build each program. The command is mentioned in each source file. To build all in one go:
```
 grep -h Compile *.cc | sed 's|// Compile: ||' | sh -x
```

Run the programs under the igprof profiler:

 rm -f *.gz
 igprof -mp ./vvvi-build-and-copy
 igprof -mp ./vvvi-reserve

Analyse the profiles using:

 for f in *.gz; do
   igprof-analyse --sqlite -d -v -g -r MEM_TOTAL $f |
     sqlite3 ~/public_html/cgi-bin/data/${f}_tot.sql3
   igprof-analyse --sqlite -d -v -g -r MEM_LIVE $f |
     sqlite3 ~/public_html/cgi-bin/data/${f}_live.sql3
   igprof-analyse --sqlite -d -v -g -r MEM_LIVE --value peak $f |
     sqlite3 ~/public_html/cgi-bin/data/${f}_live_peak.sql3
 done

This results in profiles such as: http://esc-gw.pd.infn.it:61100/~<student>/cgi-bin/igprof-navigator.py/vvvi-copy.gz_tot/.

Vector memory use

Steps