Memory leak when using asynch

[oferh]

I've created a minimal asynchronous addon based on async_pi_estimate and ran it in a loop. It appears that there is a memory leak when using it because the code itself doesn't allocate dynamic memory but after running 200K iterations the memory footprint is as follows:
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
29684 ofer 20 0 813.3m 161.8m 7.1m S 0.0 2.0 0:03.29 node

The code is available in this gist

Node version: 0.12.7

[kkoopa]

Nothing there indicates a leak.

On October 26, 2015 11:19:37 AM GMT+02:00, Ofer Herman notifications@github.com wrote:

I've created a minimal asynchronous addon based on async_pi_estimate
and ran it in a loop. It appears that there is a memory leak when using
it because the code itself doesn't allocate dynamic memory but after
running 200K iterations the memory footprint is as follows:
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+
COMMAND

29684 ofer 20 0 813.3m 161.8m 7.1m S 0.0 2.0 0:03.29
node

The code is available in this
gist

---

Reply to this email directly or view it on GitHub:
#501

[oferh]

It looks as if there is no reuse of resources it's strange that the RES memory reaches 150M for it, but it might be my misunderstanding of how node/V8 allocates memory.

Changed the test to make 2 iterations of 2K calls each and the memory consumption goes higher between each iteration.

var addon = require('../');

for (var i=0; i<2000; i++){
  addon.asynctest(function(){});
}
global.gc();

for (var i=0; i<2000; i++){
  addon.asynctest(function(){});
}

global.gc();

This is the output after the first iteration:

==28951== LEAK SUMMARY:
==28951==    definitely lost: 288 bytes in 1 blocks
==28951==    indirectly lost: 0 bytes in 0 blocks
==28951==      possibly lost: 7,241 bytes in 51 blocks
==28951==    still reachable: 1,084,994 bytes in 222 blocks
==28951==         suppressed: 0 bytes in 0 blocks

And this is the output after the 2nd one:

==28966== LEAK SUMMARY:
==28966==    definitely lost: 288 bytes in 1 blocks
==28966==    indirectly lost: 0 bytes in 0 blocks
==28966==      possibly lost: 7,241 bytes in 51 blocks
==28966==    still reachable: 1,249,474 bytes in 238 blocks
==28966==         suppressed: 0 bytes in 0 blocks

[kkoopa]

You have not mentioned which version of Node this is, but I'll assume it's 4. Does not really matter, though, since I would not expect RSS to decrease here. nodejs/node#2631 (comment)

small chunks are allocated using sbrk and are not returned to the system (rss does not decrease)

You can also run node with --trace-gc to see when garbage collection happens. For reference, last time we had an actual leak, the system ran out of memory in 15 to 30 minutes.

[oferh]

Tried the same loop as in nodejs/node#2631 and it crashes after ~15 sec FATAL ERROR:CALL_AND_RETRY_LAST Allocation failed - process out of memory

Using node version 0.12.7

[oferh]

Looks like it's a nodejs issue not NAN http://stackoverflow.com/questions/33346385/how-can-i-use-uv-queue-work-multiple-times