b3bc36209f
PR-URL: https://github.com/nodejs/node/pull/6684 Ref: https://github.com/nodejs/node/issues/6578 Reviewed-By: Ben Noorhduis <info@bnoordhuis.nl> Reviewed-By: Claudio Rodriguez <cjrodr@yahoo.com> Reviewed-By: Stephen Belanger <admin@stephenbelanger.com> Reviewed-By: Anna Henningsen <anna@addaleax.net>
2.4 KiB
V8
Stability: 2 - Stable
This module exposes events and interfaces specific to the version of V8 built with Node.js. These interfaces are subject to change by upstream and are therefore not covered under the stability index.
v8.getHeapStatistics()
Returns an object with the following properties
{
total_heap_size: 7326976,
total_heap_size_executable: 4194304,
total_physical_size: 7326976,
total_available_size: 1152656,
used_heap_size: 3476208,
heap_size_limit: 1535115264
}
v8.getHeapSpaceStatistics()
Returns statistics about the V8 heap spaces, i.e. the segments which make up
the V8 heap. Order of heap spaces nor availability of a heap space can be
guaranteed as the statistics are provided via the V8 GetHeapSpaceStatistics
function.
Example result:
[
{
"space_name": "new_space",
"space_size": 2063872,
"space_used_size": 951112,
"space_available_size": 80824,
"physical_space_size": 2063872
},
{
"space_name": "old_space",
"space_size": 3090560,
"space_used_size": 2493792,
"space_available_size": 0,
"physical_space_size": 3090560
},
{
"space_name": "code_space",
"space_size": 1260160,
"space_used_size": 644256,
"space_available_size": 960,
"physical_space_size": 1260160
},
{
"space_name": "map_space",
"space_size": 1094160,
"space_used_size": 201608,
"space_available_size": 0,
"physical_space_size": 1094160
},
{
"space_name": "large_object_space",
"space_size": 0,
"space_used_size": 0,
"space_available_size": 1490980608,
"physical_space_size": 0
}
]
v8.setFlagsFromString(string)
Set additional V8 command line flags. Use with care; changing settings after the VM has started may result in unpredictable behavior, including crashes and data loss. Or it may simply do nothing.
The V8 options available for a version of Node.js may be determined by running
node --v8-options. An unofficial, community-maintained list of options
and their effects is available here.
Usage:
// Print GC events to stdout for one minute.
const v8 = require('v8');
v8.setFlagsFromString('--trace_gc');
setTimeout(function() { v8.setFlagsFromString('--notrace_gc'); }, 60e3);