From 68c334c8c9fd5f6c887209e4ee8575a29f5143db Mon Sep 17 00:00:00 2001 From: Rich Trott Date: Wed, 30 Jun 2021 21:18:54 -0700 Subject: [PATCH] doc: move vm.measureMemory() to expected location in doc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit PR-URL: https://github.com/nodejs/node/pull/39211 Reviewed-By: Colin Ihrig Reviewed-By: Michaël Zasso Reviewed-By: Harshitha K P --- doc/api/vm.md | 152 +++++++++++++++++++++++++------------------------- 1 file changed, 76 insertions(+), 76 deletions(-) diff --git a/doc/api/vm.md b/doc/api/vm.md index 8177a7b38556be..df9dc824f6a094 100644 --- a/doc/api/vm.md +++ b/doc/api/vm.md @@ -302,82 +302,6 @@ console.log(globalVar); // 1000 ``` -## `vm.measureMemory([options])` - - - -> Stability: 1 - Experimental - -Measure the memory known to V8 and used by all contexts known to the -current V8 isolate, or the main context. - -* `options` {Object} Optional. - * `mode` {string} Either `'summary'` or `'detailed'`. In summary mode, - only the memory measured for the main context will be returned. In - detailed mode, the measure measured for all contexts known to the - current V8 isolate will be returned. - **Default:** `'summary'` - * `execution` {string} Either `'default'` or `'eager'`. With default - execution, the promise will not resolve until after the next scheduled - garbage collection starts, which may take a while (or never if the program - exits before the next GC). With eager execution, the GC will be started - right away to measure the memory. - **Default:** `'default'` -* Returns: {Promise} If the memory is successfully measured the promise will - resolve with an object containing information about the memory usage. - -The format of the object that the returned Promise may resolve with is -specific to the V8 engine and may change from one version of V8 to the next. - -The returned result is different from the statistics returned by -`v8.getHeapSpaceStatistics()` in that `vm.measureMemory()` measure the -memory reachable by each V8 specific contexts in the current instance of -the V8 engine, while the result of `v8.getHeapSpaceStatistics()` measure -the memory occupied by each heap space in the current V8 instance. - -```js -const vm = require('vm'); -// Measure the memory used by the main context. -vm.measureMemory({ mode: 'summary' }) - // This is the same as vm.measureMemory() - .then((result) => { - // The current format is: - // { - // total: { - // jsMemoryEstimate: 2418479, jsMemoryRange: [ 2418479, 2745799 ] - // } - // } - console.log(result); - }); - -const context = vm.createContext({ a: 1 }); -vm.measureMemory({ mode: 'detailed', execution: 'eager' }) - .then((result) => { - // Reference the context here so that it won't be GC'ed - // until the measurement is complete. - console.log(context.a); - // { - // total: { - // jsMemoryEstimate: 2574732, - // jsMemoryRange: [ 2574732, 2904372 ] - // }, - // current: { - // jsMemoryEstimate: 2438996, - // jsMemoryRange: [ 2438996, 2768636 ] - // }, - // other: [ - // { - // jsMemoryEstimate: 135736, - // jsMemoryRange: [ 135736, 465376 ] - // } - // ] - // } - console.log(result); - }); -``` - ## Class: `vm.Module` + +> Stability: 1 - Experimental + +Measure the memory known to V8 and used by all contexts known to the +current V8 isolate, or the main context. + +* `options` {Object} Optional. + * `mode` {string} Either `'summary'` or `'detailed'`. In summary mode, + only the memory measured for the main context will be returned. In + detailed mode, the measure measured for all contexts known to the + current V8 isolate will be returned. + **Default:** `'summary'` + * `execution` {string} Either `'default'` or `'eager'`. With default + execution, the promise will not resolve until after the next scheduled + garbage collection starts, which may take a while (or never if the program + exits before the next GC). With eager execution, the GC will be started + right away to measure the memory. + **Default:** `'default'` +* Returns: {Promise} If the memory is successfully measured the promise will + resolve with an object containing information about the memory usage. + +The format of the object that the returned Promise may resolve with is +specific to the V8 engine and may change from one version of V8 to the next. + +The returned result is different from the statistics returned by +`v8.getHeapSpaceStatistics()` in that `vm.measureMemory()` measure the +memory reachable by each V8 specific contexts in the current instance of +the V8 engine, while the result of `v8.getHeapSpaceStatistics()` measure +the memory occupied by each heap space in the current V8 instance. + +```js +const vm = require('vm'); +// Measure the memory used by the main context. +vm.measureMemory({ mode: 'summary' }) + // This is the same as vm.measureMemory() + .then((result) => { + // The current format is: + // { + // total: { + // jsMemoryEstimate: 2418479, jsMemoryRange: [ 2418479, 2745799 ] + // } + // } + console.log(result); + }); + +const context = vm.createContext({ a: 1 }); +vm.measureMemory({ mode: 'detailed', execution: 'eager' }) + .then((result) => { + // Reference the context here so that it won't be GC'ed + // until the measurement is complete. + console.log(context.a); + // { + // total: { + // jsMemoryEstimate: 2574732, + // jsMemoryRange: [ 2574732, 2904372 ] + // }, + // current: { + // jsMemoryEstimate: 2438996, + // jsMemoryRange: [ 2438996, 2768636 ] + // }, + // other: [ + // { + // jsMemoryEstimate: 135736, + // jsMemoryRange: [ 135736, 465376 ] + // } + // ] + // } + console.log(result); + }); +``` + ## `vm.runInContext(code, contextifiedObject[, options])`