I'm using Valgrind Massif to measure the memory usage of my program. Actually I know where I allocate or release memory(roughly), so I want to manually take snapshots. Moreover, I want to compare the result from multiple runs, so manually taking snapshots makes more sense in comparison.
Is there a programmatic way to do this?
You can instruct massif to take a snapshot using massif monitor commands.
See https://www.valgrind.org/docs/manual/ms-manual.html#ms-manual.monitor-commands
Such monitor commands can be done from a shell, using vgdb or from within your program, using the client request VALGRIND_MONITOR_COMMAND.
See https://www.valgrind.org/docs/manual/manual-core-adv.html#manual-core-adv.clientreq
Note that if you have a specific client request corresponding to a monitor command, it is better to use the specific client request rather than the 'generic' VALGRIND_MONITOR_COMMAND.
In the case of massif, there are no specific client requests.