1.4.2 • Published 3 years ago

gc-profiler v1.4.2

Weekly downloads
3,897
License
MIT
Repository
github
Last release
3 years ago

node-gc-profiler

A cross-platform (tested on Linux, Windows, and OSX) profiler for the v8 garbage collector running inside Node.js. It will emit an event after every GC cycle providing you information about the duration and type of cycle.

npm install gc-profiler

Example:

var profiler = require('gc-profiler');
profiler.on('gc', function (info) {
  console.log(info);
});

The info object contains the following properties:

PropertyTypeDescription
dateDateThe approximate start time of the GC cycle. This uses the c++ time library internally, which only has one-second resolution.
durationnumberThe duration of the GC cycle in milliseconds.
typestringEither Scavenge or MarkSweepCompact depending on the type of GC cycle.
forcedbooleanTrue for a forced cycle.
flagsnumberThe raw GCCallbackFlags provided from v8.

The profiler.GCCallbackFlags enumeration is provided to help decode the flags property.

profiler.GCCallbackFlags = {
  kNoGCCallbackFlags: 0,
  kGCCallbackFlagCompacted: 1 << 0, // this flag is never set in v8 versions >= 3.6.5
  kGCCallbackFlagConstructRetainedObjectInfos: 1 << 1,
  kGCCallbackFlagForced: 1 << 2
};