process: expose uv_rusage on process.resourceUsage()

doc/api/process.md

@@ -1815,6 +1815,91 @@ process.report.writeReport();
 
 Additional documentation is available in the [report documentation][].
 
+## process.resourceUsage()
+<!-- YAML
+added: REPLACEME
+-->
+
+* Returns: {Object}
+    * `userCPUTime` {integer}
+    * `systemCPUTime` {integer}
+    * `maxRSS` {integer}
+    * `sharedMemorySize` {integer}
+    * `unsharedDataSize` {integer}
+    * `unsharedStackSize` {integer}
+    * `minorPageFault` {integer}
+    * `majorPageFault` {integer}
+    * `swapedOut` {integer}
+    * `fsRead` {integer}
+    * `fsWrite` {integer}
+    * `ipcSent` {integer}
+    * `ipcReceived` {integer}
+    * `signalsCount` {integer}
+    * `voluntaryContextSwitches` {integer}
+    * `involuntaryContextSwitches` {integer}
+
+The `process.resourceUsage()` method returns the resource usage
+for the current process.
+All of these values come from the `uv_getrusage` call which returns
+[this struct][uv_rusage_t], here the mapping between node and libuv:
+- `userCPUTime` maps to `ru_utime` computed in microseconds.
+It is the values as [`process.cpuUsage().user`][process.cpuUsage]
+- `systemCPUTime` maps to `ru_stime` computed in microseconds.
+It is the value as [`process.cpuUsage().system`][process.cpuUsage]
+- `maxRSS` maps to `ru_maxrss` which is the maximum resident set size
+used (in kilobytes).
+- `sharedMemorySize` maps to `ru_ixrss` but is not supported by any platform.
+- `unsharedDataSize` maps to `ru_idrss` but is not supported by any platform.
+- `unsharedStackSize` maps to `ru_isrss` but is not supported by any platform.
+- `minorPageFault` maps to `ru_minflt` which is the number of minor page fault
+for the process, see [this article for more details][wikipedia_minor_fault]
+- `majorPageFault` maps to `ru_majflt` which is the number of major page fault
+for the process, see [this article for more details][wikipedia_major_fault].
+This field is not supported on Windows platforms.
+- `swappedOut` maps to `ru_nswap` which is not supported by any platform.
+- `fsRead` maps to `ru_inblock` which is the number of times the file system
+had to perform input.
+- `fsWrite` maps to `ru_oublock` which is the number of times the file system
+had to perform output.
+- `ipcSent` maps to `ru_msgsnd` but is not supported by any platform.
+- `ipcReceived` maps to `ru_msgrcv` but is not supported by any platform.
+- `signalsCount` maps to `ru_nsignals` but is not supported by any platform.
+- `voluntaryContextSwitches` maps to `ru_nvcsw` which is the number of times
+a CPU context switch resulted due to a process voluntarily giving up the
+processor before its time slice was completed
+(usually to await availability of a resource).
+This field is not supported on Windows platforms.
+- `involuntaryContextSwitches` maps to `ru_nivcsw` which is the number of times
+a CPU context switch resulted due to a higher priority process becoming runnable
+ or because the current process exceeded its time slice.
+This field is not supported on Windows platforms.
+
+
+```js
+console.log(process.resourceUsage());
+/*
+  Will output:
+  {
+    userCPUTime: 82872,
+    systemCPUTime: 4143,
+    maxRSS: 33164,
+    sharedMemorySize: 0,
+    unsharedDataSize: 0,
+    unsharedStackSize: 0,
+    minorPageFault: 2469,
+    majorPageFault: 0,
+    swapedOut: 0,
+    fsRead: 0,
+    fsWrite: 8,
+    ipcSent: 0,
+    ipcReceived: 0,
+    signalsCount: 0,
+    voluntaryContextSwitches: 79,
+    involuntaryContextSwitches: 1
+  }
+*/
+```
+
 ## process.send(message[, sendHandle[, options]][, callback])
 <!-- YAML
 added: v0.5.9
@@ -2329,6 +2414,10 @@ cases:
 [Writable]: stream.html#stream_writable_streams
 [debugger]: debugger.html
 [note on process I/O]: process.html#process_a_note_on_process_i_o
+[process.cpuUsage]: #process_process_cpuusage_previousvalue
 [process_emit_warning]: #process_process_emitwarning_warning_type_code_ctor
 [process_warning]: #process_event_warning
 [report documentation]: report.html
+[uv_rusage_t]: http://docs.libuv.org/en/v1.x/misc.html#c.uv_rusage_t
+[wikipedia_minor_fault]: https://en.wikipedia.org/wiki/Page_fault#Minor
+[wikipedia_major_fault]: https://en.wikipedia.org/wiki/Page_fault#Major

lib/internal/bootstrap/node.js

@@ -110,6 +110,7 @@ if (isMainThread) {
   process.hrtime = wrapped.hrtime;
   process.hrtime.bigint = wrapped.hrtimeBigInt;
   process.cpuUsage = wrapped.cpuUsage;
+  process.resourceUsage = wrapped.resourceUsage;
   process.memoryUsage = wrapped.memoryUsage;
   process.kill = wrapped.kill;
   process.exit = wrapped.exit;

lib/internal/process/per_thread.js

@@ -35,7 +35,8 @@ function wrapProcessMethods(binding) {
     hrtime: _hrtime,
     hrtimeBigInt: _hrtimeBigInt,
     cpuUsage: _cpuUsage,
-    memoryUsage: _memoryUsage
+    memoryUsage: _memoryUsage,
+    resourceUsage: _resourceUsage
   } = binding;
 
   function _rawDebug(...args) {
@@ -190,12 +191,36 @@ function wrapProcessMethods(binding) {
     return true;
   }
 
+  const resourceValues = new Float64Array(16);
+  function resourceUsage() {
+    _resourceUsage(resourceValues);
+    return {
+      userCPUTime: resourceValues[0],
+      systemCPUTime: resourceValues[1],
+      maxRSS: resourceValues[2],
+      sharedMemorySize: resourceValues[3],
+      unsharedDataSize: resourceValues[4],
+      unsharedStackSize: resourceValues[5],
+      minorPageFault: resourceValues[6],
+      majorPageFault: resourceValues[7],
+      swappedOut: resourceValues[8],
+      fsRead: resourceValues[9],
+      fsWrite: resourceValues[10],
+      ipcSent: resourceValues[11],
+      ipcReceived: resourceValues[12],
+      signalsCount: resourceValues[13],
+      voluntaryContextSwitches: resourceValues[14],
+      involuntaryContextSwitches: resourceValues[15]
+    };
+  }
+
 
   return {
     _rawDebug,
     hrtime,
     hrtimeBigInt,
     cpuUsage,
+    resourceUsage,
     memoryUsage,
     kill,
     exit

src/node_process_methods.cc

@@ -285,6 +285,38 @@ void GetActiveHandles(const FunctionCallbackInfo<Value>& args) {
       Array::New(env->isolate(), handle_v.data(), handle_v.size()));
 }
 
+static void ResourceUsage(const FunctionCallbackInfo<Value>& args) {
+  Environment* env = Environment::GetCurrent(args);
+
+  uv_rusage_t rusage;
+  int err = uv_getrusage(&rusage);
+  if (err)
+    return env->ThrowUVException(err, "uv_getrusage");
+
+  CHECK(args[0]->IsFloat64Array());
+  Local<Float64Array> array = args[0].As<Float64Array>();
+  CHECK_EQ(array->Length(), 16);
+  Local<ArrayBuffer> ab = array->Buffer();
+  double* fields = static_cast<double*>(ab->GetContents().Data());
+
+  fields[0] = MICROS_PER_SEC * rusage.ru_utime.tv_sec + rusage.ru_utime.tv_usec;
+  fields[1] = MICROS_PER_SEC * rusage.ru_stime.tv_sec + rusage.ru_stime.tv_usec;
+  fields[2] = rusage.ru_maxrss;
+  fields[3] = rusage.ru_ixrss;
+  fields[4] = rusage.ru_idrss;
+  fields[5] = rusage.ru_isrss;
+  fields[6] = rusage.ru_minflt;
+  fields[7] = rusage.ru_majflt;
+  fields[8] = rusage.ru_nswap;
+  fields[9] = rusage.ru_inblock;
+  fields[10] = rusage.ru_oublock;
+  fields[11] = rusage.ru_msgsnd;
+  fields[12] = rusage.ru_msgrcv;
+  fields[13] = rusage.ru_nsignals;
+  fields[14] = rusage.ru_nvcsw;
+  fields[15] = rusage.ru_nivcsw;
+}
+
 #ifdef __POSIX__
 static void DebugProcess(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
@@ -426,6 +458,7 @@ static void InitializeProcessMethods(Local<Object> target,
   env->SetMethod(target, "cpuUsage", CPUUsage);
   env->SetMethod(target, "hrtime", Hrtime);
   env->SetMethod(target, "hrtimeBigInt", HrtimeBigInt);
+  env->SetMethod(target, "resourceUsage", ResourceUsage);
 
   env->SetMethod(target, "_getActiveRequests", GetActiveRequests);
   env->SetMethod(target, "_getActiveHandles", GetActiveHandles);

test/parallel/test-resource-usage.js

@@ -0,0 +1,27 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+
+const rusage = process.resourceUsage();
+
+[
+  'userCPUTime',
+  'systemCPUTime',
+  'maxRSS',
+  'sharedMemorySize',
+  'unsharedDataSize',
+  'unsharedStackSize',
+  'minorPageFault',
+  'majorPageFault',
+  'swappedOut',
+  'fsRead',
+  'fsWrite',
+  'ipcSent',
+  'ipcReceived',
+  'signalsCount',
+  'voluntaryContextSwitches',
+  'involuntaryContextSwitches'
+].forEach((n) => {
+  assert.strictEqual(typeof rusage[n], 'number', `${n} should be a number`);
+  assert(rusage[n] >= 0, `${n} should be above or equal 0`);
+});