feat(core): lock graph creation when running in another process (#29408)

## Current Behavior
Running Nx in multiple processes at the same time with the daemon
disabled can cripple a system due to excess memory usage when creating
the graph. This is due to plugin workers being started per-parent
process when there is no daemon. This change enables a file lock to
prevent the simultaneous processing, and read from the cache when the
first run completes.

Currently, running `nx show projects` 30 times in parallel looks
something like this:

30 processes exited within 37535ms

## Expected Behavior
30 processes exited within 6435ms

## Test Script
```js
//@ts-check

const { spawn } = require('child_process');

let alive = new Set();

let start = Date.now();
let iterations = 30;

for (let i = 0; i < iterations; i++) {
  const cp = spawn('npx nx show projects', [], {
    shell: true,
    env: {
      ...process.env,
      NX_DAEMON: 'false',
      NX_VERBOSE_LOGGING: 'true',
    },
  });
  alive.add(i);
  //   cp.stdout.on('data', (data) => {
  //     console.log(`stdout [${i}]: ${data}`);
  //   });
  cp.stderr.on('data', (data) => {
    console.error(`stderr [${i}]: ${data}`);
  });
  cp.on('exit', (code) => {
    console.log(`child process ${i} exited with code ${code}`);
    alive.delete(i);
  });
}

const i = setInterval(() => {
  if (alive.size > 0) {
  } else {
    clearInterval(i);
    console.log(
      `${iterations} processes exited within ${Date.now() - start}ms`
    );
  }
}, 1);

```

Cargo.lock

@@ -1509,6 +1509,7 @@ dependencies = [
  "swc_ecma_visit",
  "tempfile",
  "thiserror",
+ "tokio",
  "tracing",
  "tracing-subscriber",
  "walkdir",

docs/generated/devkit/README.md

@@ -20,6 +20,7 @@ It only uses language primitives and immutable objects
 ### Classes
 
 - [AggregateCreateNodesError](../../devkit/documents/AggregateCreateNodesError)
+- [StaleProjectGraphCacheError](../../devkit/documents/StaleProjectGraphCacheError)
 
 ### Interfaces
 

docs/generated/devkit/StaleProjectGraphCacheError.md

@@ -0,0 +1,144 @@
+# Class: StaleProjectGraphCacheError
+
+## Hierarchy
+
+- `Error`
+
+  ↳ **`StaleProjectGraphCacheError`**
+
+## Table of contents
+
+### Constructors
+
+- [constructor](../../devkit/documents/StaleProjectGraphCacheError#constructor)
+
+### Properties
+
+- [cause](../../devkit/documents/StaleProjectGraphCacheError#cause): unknown
+- [message](../../devkit/documents/StaleProjectGraphCacheError#message): string
+- [name](../../devkit/documents/StaleProjectGraphCacheError#name): string
+- [stack](../../devkit/documents/StaleProjectGraphCacheError#stack): string
+- [prepareStackTrace](../../devkit/documents/StaleProjectGraphCacheError#preparestacktrace): Function
+- [stackTraceLimit](../../devkit/documents/StaleProjectGraphCacheError#stacktracelimit): number
+
+### Methods
+
+- [captureStackTrace](../../devkit/documents/StaleProjectGraphCacheError#capturestacktrace)
+
+## Constructors
+
+### constructor
+
+• **new StaleProjectGraphCacheError**(): [`StaleProjectGraphCacheError`](../../devkit/documents/StaleProjectGraphCacheError)
+
+#### Returns
+
+[`StaleProjectGraphCacheError`](../../devkit/documents/StaleProjectGraphCacheError)
+
+#### Overrides
+
+Error.constructor
+
+## Properties
+
+### cause
+
+• `Optional` **cause**: `unknown`
+
+#### Inherited from
+
+Error.cause
+
+---
+
+### message
+
+• **message**: `string`
+
+#### Inherited from
+
+Error.message
+
+---
+
+### name
+
+• **name**: `string`
+
+#### Inherited from
+
+Error.name
+
+---
+
+### stack
+
+• `Optional` **stack**: `string`
+
+#### Inherited from
+
+Error.stack
+
+---
+
+### prepareStackTrace
+
+▪ `Static` `Optional` **prepareStackTrace**: (`err`: `Error`, `stackTraces`: `CallSite`[]) => `any`
+
+Optional override for formatting stack traces
+
+**`See`**
+
+https://v8.dev/docs/stack-trace-api#customizing-stack-traces
+
+#### Type declaration
+
+▸ (`err`, `stackTraces`): `any`
+
+##### Parameters
+
+| Name          | Type         |
+| :------------ | :----------- |
+| `err`         | `Error`      |
+| `stackTraces` | `CallSite`[] |
+
+##### Returns
+
+`any`
+
+#### Inherited from
+
+Error.prepareStackTrace
+
+---
+
+### stackTraceLimit
+
+▪ `Static` **stackTraceLimit**: `number`
+
+#### Inherited from
+
+Error.stackTraceLimit
+
+## Methods
+
+### captureStackTrace
+
+▸ **captureStackTrace**(`targetObject`, `constructorOpt?`): `void`
+
+Create .stack property on a target object
+
+#### Parameters
+
+| Name              | Type       |
+| :---------------- | :--------- |
+| `targetObject`    | `object`   |
+| `constructorOpt?` | `Function` |
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+Error.captureStackTrace

docs/generated/devkit/readCachedProjectGraph.md

@@ -1,9 +1,15 @@
 # Function: readCachedProjectGraph
 
-▸ **readCachedProjectGraph**(): [`ProjectGraph`](../../devkit/documents/ProjectGraph)
+▸ **readCachedProjectGraph**(`minimumComputedAt?`): [`ProjectGraph`](../../devkit/documents/ProjectGraph)
 
 Synchronously reads the latest cached copy of the workspace's ProjectGraph.
 
+#### Parameters
+
+| Name                 | Type     | Description                                                                    |
+| :------------------- | :------- | :----------------------------------------------------------------------------- |
+| `minimumComputedAt?` | `number` | The minimum timestamp that the cached ProjectGraph must have been computed at. |
+
 #### Returns
 
 [`ProjectGraph`](../../devkit/documents/ProjectGraph)

docs/generated/packages/devkit/documents/nx_devkit.md

@@ -20,6 +20,7 @@ It only uses language primitives and immutable objects
 ### Classes
 
 - [AggregateCreateNodesError](../../devkit/documents/AggregateCreateNodesError)
+- [StaleProjectGraphCacheError](../../devkit/documents/StaleProjectGraphCacheError)
 
 ### Interfaces
 

packages/devkit/src/executors/parse-target-string.ts

@@ -40,7 +40,7 @@ export function parseTargetString(
   targetString: string,
   projectGraphOrCtx?: ProjectGraph | ExecutorContext
 ): Target {
-  let projectGraph =
+  let projectGraph: ProjectGraph =
     projectGraphOrCtx && 'projectGraph' in projectGraphOrCtx
       ? projectGraphOrCtx.projectGraph
       : (projectGraphOrCtx as ProjectGraph);

packages/nx/Cargo.toml

@@ -74,3 +74,5 @@ assert_fs = "1.0.10"
 # This is only used for unit tests
 swc_ecma_dep_graph = "0.109.1"
 tempfile = "3.13.0"
+# We only explicitly use tokio for async tests
+tokio = "1.38.0"

packages/nx/src/daemon/server/project-graph-incremental-recomputation.ts

@@ -299,7 +299,12 @@ async function processFilesAndCreateAndSerializeProjectGraph(
         };
       }
     }
-
+    writeCache(
+      g.projectFileMapCache,
+      g.projectGraph,
+      projectConfigurationsResult.sourceMaps,
+      errors
+    );
     if (errors.length > 0) {
       return {
         error: new DaemonProjectGraphError(
@@ -316,7 +321,6 @@ async function processFilesAndCreateAndSerializeProjectGraph(
         serializedSourceMaps: null,
       };
     } else {
-      writeCache(g.projectFileMapCache, g.projectGraph);
       return g;
     }
   } catch (err) {

packages/nx/src/devkit-exports.ts

@@ -63,7 +63,10 @@ export type {
   PostTasksExecutionContext,
 } from './project-graph/plugins';
 
-export { AggregateCreateNodesError } from './project-graph/error-types';
+export {
+  AggregateCreateNodesError,
+  StaleProjectGraphCacheError,
+} from './project-graph/error-types';
 
 export { createNodesFromFiles } from './project-graph/plugins';
 

packages/nx/src/native/db/initialize.rs

@@ -1,5 +1,4 @@
 use crate::native::db::connection::NxDbConnection;
-use fs4::fs_std::FileExt;
 use rusqlite::{Connection, OpenFlags};
 use std::fs::{remove_file, File};
 use std::path::{Path, PathBuf};
@@ -12,9 +11,7 @@ pub(super) struct LockFile {
 
 pub(super) fn unlock_file(lock_file: &LockFile) {
     if lock_file.path.exists() {
-        lock_file
-            .file
-            .unlock()
+        fs4::fs_std::FileExt::unlock(&lock_file.file)
             .and_then(|_| remove_file(&lock_file.path))
             .ok();
     }
@@ -26,8 +23,7 @@ pub(super) fn create_lock_file(db_path: &Path) -> anyhow::Result<LockFile> {
         .map_err(|e| anyhow::anyhow!("Unable to create db lock file: {:?}", e))?;
 
     trace!("Getting lock on db lock file");
-    lock_file
-        .lock_exclusive()
+    fs4::fs_std::FileExt::lock_exclusive(&lock_file)
         .inspect(|_| trace!("Got lock on db lock file"))
         .map_err(|e| anyhow::anyhow!("Unable to lock the db lock file: {:?}", e))?;
     Ok(LockFile {
@@ -77,7 +73,10 @@ pub(super) fn initialize_db(nx_version: String, db_path: &Path) -> anyhow::Resul
             Ok(c)
         }
         Err(reason) => {
-            trace!("Unable to connect to existing database because: {:?}", reason);
+            trace!(
+                "Unable to connect to existing database because: {:?}",
+                reason
+            );
             trace!("Removing existing incompatible database");
             remove_file(db_path)?;
 

packages/nx/src/native/index.d.ts

@@ -13,6 +13,15 @@ export declare class ChildProcess {
   onOutput(callback: (message: string) => void): void
 }
 
+export declare class FileLock {
+  locked: boolean
+  constructor(lockFilePath: string)
+  unlock(): void
+  check(): boolean
+  wait(): Promise<void>
+  lock(): void
+}
+
 export declare class HashPlanner {
   constructor(nxJson: NxJson, projectGraph: ExternalObject<ProjectGraph>)
   getPlans(taskIds: Array<string>, taskGraph: TaskGraph): Record<string, string[]>

packages/nx/src/native/native-bindings.js

@@ -362,6 +362,7 @@ if (!nativeBinding) {
 }
 
 module.exports.ChildProcess = nativeBinding.ChildProcess
+module.exports.FileLock = nativeBinding.FileLock
 module.exports.HashPlanner = nativeBinding.HashPlanner
 module.exports.ImportResult = nativeBinding.ImportResult
 module.exports.NxCache = nativeBinding.NxCache

packages/nx/src/native/nx.wasi-browser.js

@@ -85,15 +85,18 @@ function __napi_rs_initialize_modules(__napiInstance) {
   __napiInstance.exports['__napi_register__ExternalDependenciesInput_struct_36']?.()
   __napiInstance.exports['__napi_register__DepsOutputsInput_struct_37']?.()
   __napiInstance.exports['__napi_register__NxJson_struct_38']?.()
-  __napiInstance.exports['__napi_register__WorkspaceContext_struct_39']?.()
-  __napiInstance.exports['__napi_register__WorkspaceContext_impl_48']?.()
-  __napiInstance.exports['__napi_register__WorkspaceErrors_49']?.()
-  __napiInstance.exports['__napi_register__NxWorkspaceFiles_struct_50']?.()
-  __napiInstance.exports['__napi_register__NxWorkspaceFilesExternals_struct_51']?.()
-  __napiInstance.exports['__napi_register__UpdatedWorkspaceFiles_struct_52']?.()
-  __napiInstance.exports['__napi_register__FileMap_struct_53']?.()
-  __napiInstance.exports['__napi_register____test_only_transfer_file_map_54']?.()
+  __napiInstance.exports['__napi_register__FileLock_struct_39']?.()
+  __napiInstance.exports['__napi_register__FileLock_impl_41']?.()
+  __napiInstance.exports['__napi_register__WorkspaceContext_struct_42']?.()
+  __napiInstance.exports['__napi_register__WorkspaceContext_impl_51']?.()
+  __napiInstance.exports['__napi_register__WorkspaceErrors_52']?.()
+  __napiInstance.exports['__napi_register__NxWorkspaceFiles_struct_53']?.()
+  __napiInstance.exports['__napi_register__NxWorkspaceFilesExternals_struct_54']?.()
+  __napiInstance.exports['__napi_register__UpdatedWorkspaceFiles_struct_55']?.()
+  __napiInstance.exports['__napi_register__FileMap_struct_56']?.()
+  __napiInstance.exports['__napi_register____test_only_transfer_file_map_57']?.()
 }
+export const FileLock = __napiModule.exports.FileLock
 export const HashPlanner = __napiModule.exports.HashPlanner
 export const ImportResult = __napiModule.exports.ImportResult
 export const TaskHasher = __napiModule.exports.TaskHasher

packages/nx/src/native/nx.wasi.cjs

@@ -116,15 +116,18 @@ function __napi_rs_initialize_modules(__napiInstance) {
   __napiInstance.exports['__napi_register__ExternalDependenciesInput_struct_36']?.()
   __napiInstance.exports['__napi_register__DepsOutputsInput_struct_37']?.()
   __napiInstance.exports['__napi_register__NxJson_struct_38']?.()
-  __napiInstance.exports['__napi_register__WorkspaceContext_struct_39']?.()
-  __napiInstance.exports['__napi_register__WorkspaceContext_impl_48']?.()
-  __napiInstance.exports['__napi_register__WorkspaceErrors_49']?.()
-  __napiInstance.exports['__napi_register__NxWorkspaceFiles_struct_50']?.()
-  __napiInstance.exports['__napi_register__NxWorkspaceFilesExternals_struct_51']?.()
-  __napiInstance.exports['__napi_register__UpdatedWorkspaceFiles_struct_52']?.()
-  __napiInstance.exports['__napi_register__FileMap_struct_53']?.()
-  __napiInstance.exports['__napi_register____test_only_transfer_file_map_54']?.()
+  __napiInstance.exports['__napi_register__FileLock_struct_39']?.()
+  __napiInstance.exports['__napi_register__FileLock_impl_41']?.()
+  __napiInstance.exports['__napi_register__WorkspaceContext_struct_42']?.()
+  __napiInstance.exports['__napi_register__WorkspaceContext_impl_51']?.()
+  __napiInstance.exports['__napi_register__WorkspaceErrors_52']?.()
+  __napiInstance.exports['__napi_register__NxWorkspaceFiles_struct_53']?.()
+  __napiInstance.exports['__napi_register__NxWorkspaceFilesExternals_struct_54']?.()
+  __napiInstance.exports['__napi_register__UpdatedWorkspaceFiles_struct_55']?.()
+  __napiInstance.exports['__napi_register__FileMap_struct_56']?.()
+  __napiInstance.exports['__napi_register____test_only_transfer_file_map_57']?.()
 }
+module.exports.FileLock = __napiModule.exports.FileLock
 module.exports.HashPlanner = __napiModule.exports.HashPlanner
 module.exports.ImportResult = __napiModule.exports.ImportResult
 module.exports.TaskHasher = __napiModule.exports.TaskHasher

packages/nx/src/native/tests/__fixtures__/file-lock.fixture.js

@@ -0,0 +1,20 @@
+const { FileLock } = require('../../native-bindings.js');
+const ora = require('ora');
+const tmp = require('os').tmpdir();
+
+(async () => {
+  const lock = new FileLock(
+    require('path').join(tmp, 'nx-unit-tests', 'file-lock-fixture')
+  );
+  if (lock.locked) {
+    const s = ora('Waiting for lock').start();
+    await lock.wait();
+    s.stop();
+    console.log('waited for lock');
+  } else {
+    await lock.lock();
+    await new Promise((resolve) => setTimeout(resolve, 5000));
+    console.log('ran with lock');
+    await lock.unlock();
+  }
+})();

packages/nx/src/native/tests/file-lock.spec.ts

@@ -0,0 +1,44 @@
+import { fork } from 'child_process';
+import { join } from 'path';
+
+describe('file-lock', () => {
+  it('should block the second call until the first one is done', async () => {
+    let combinedOutputs = [];
+    let a = fork(join(__dirname, './__fixtures__/file-lock.fixture.js'), {
+      env: {
+        LABEL: 'a',
+        NX_NATIVE_LOGGING: 'trace',
+      },
+      stdio: 'pipe',
+      execArgv: ['--require', 'ts-node/register'],
+    });
+
+    // Gives a bit of time to make the outputs of the tests more predictable...
+    // if both start at the same time, its hard to guarantee that a will get the lock before b.
+    await new Promise((r) => setTimeout(r, 500));
+
+    let b = fork(join(__dirname, './__fixtures__/file-lock.fixture.js'), {
+      env: {
+        LABEL: 'b',
+        NX_NATIVE_LOGGING: 'trace',
+      },
+      stdio: 'pipe',
+      execArgv: ['--require', 'ts-node/register'],
+    });
+
+    a.stdout.on('data', (data) => {
+      combinedOutputs.push('A: ' + data.toString().trim());
+    });
+    b.stdout.on('data', (data) => {
+      combinedOutputs.push('B: ' + data.toString().trim());
+    });
+
+    a.stderr.pipe(process.stderr);
+    b.stderr.pipe(process.stderr);
+
+    await Promise.all([a, b].map((p) => new Promise((r) => p.once('exit', r))));
+
+    expect(combinedOutputs).toContain('A: ran with lock');
+    expect(combinedOutputs).toContain('B: waited for lock');
+  });
+});

packages/nx/src/native/utils/file_lock.rs

@@ -0,0 +1,156 @@
+use napi::bindgen_prelude::*;
+use std::{
+    fs::{self, OpenOptions},
+    path::Path,
+};
+use tracing::trace;
+
+#[cfg(not(target_arch = "wasm32"))]
+use fs4::fs_std::FileExt;
+
+#[napi]
+pub struct FileLock {
+    #[napi]
+    pub locked: bool,
+    file: fs::File,
+    lock_file_path: String,
+}
+
+/// const lock = new FileLock('lockfile.lock');
+/// if (lock.locked) {
+///   lock.wait()
+///   readFromCache()
+/// } else {
+///  lock.lock()
+///  ... do some work
+///  writeToCache()
+///  lock.unlock()
+/// }
+
+#[napi]
+#[cfg(not(target_arch = "wasm32"))]
+impl FileLock {
+    #[napi(constructor)]
+    pub fn new(lock_file_path: String) -> anyhow::Result<Self> {
+        // Creates the directory where the lock file will be stored
+        fs::create_dir_all(Path::new(&lock_file_path).parent().unwrap())?;
+
+        // Opens the lock file
+        let file = OpenOptions::new()
+            .read(true)
+            .write(true)
+            .create(true)
+            .open(&lock_file_path)?;
+
+        trace!("Locking file {}", lock_file_path);
+
+        // Check if the file is locked
+        let file_lock: std::result::Result<(), std::io::Error> = file.try_lock_exclusive();
+
+        if file_lock.is_ok() {
+            // Checking if the file is locked, locks it, so unlock it.
+            fs4::fs_std::FileExt::unlock(&file)?;
+        }
+
+        Ok(Self {
+            file: file,
+            locked: file_lock.is_err(),
+            lock_file_path,
+        })
+    }
+
+    #[napi]
+    pub fn unlock(&mut self) -> Result<()> {
+        fs4::fs_std::FileExt::unlock(&self.file)?;
+        self.locked = false;
+        Ok(())
+    }
+
+    #[napi]
+    pub fn check(&mut self) -> Result<bool> {
+        // Check if the file is locked
+        let file_lock: std::result::Result<(), std::io::Error> = self.file.try_lock_exclusive();
+
+        if file_lock.is_ok() {
+            // Checking if the file is locked, locks it, so unlock it.
+            fs4::fs_std::FileExt::unlock(&self.file)?;
+        }
+
+        self.locked = file_lock.is_err();
+        Ok(self.locked)
+    }
+
+    #[napi(ts_return_type = "Promise<void>")]
+    pub fn wait(&mut self, env: Env) -> napi::Result<napi::JsObject> {
+        if self.locked {
+            let lock_file_path = self.lock_file_path.clone();
+            self.locked = false;
+            env.spawn_future(async move {
+                let file = OpenOptions::new()
+                    .read(true)
+                    .write(true)
+                    .create(true)
+                    .open(&lock_file_path)?;
+                fs4::fs_std::FileExt::lock_shared(&file)?;
+                fs4::fs_std::FileExt::unlock(&file)?;
+                Ok(())
+            })
+        } else {
+            env.spawn_future(async move { Ok(()) })
+        }
+    }
+
+    #[napi]
+    pub fn lock(&mut self) -> napi::Result<()> {
+        self.file.lock_exclusive()?;
+        self.locked = true;
+        Ok(())
+    }
+}
+
+#[napi]
+#[cfg(target_arch = "wasm32")]
+impl FileLock {
+    #[napi(constructor)]
+    pub fn new(lock_file_path: String) -> anyhow::Result<Self> {
+        anyhow::bail!("FileLock is not supported on WASM")
+    }
+}
+
+// TODO: Fix the tests
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    use assert_fs::prelude::*;
+    use assert_fs::TempDir;
+
+    #[test]
+    fn test_new_lock() {
+        let tmp_dir = TempDir::new().unwrap();
+        let lock_file = tmp_dir.child("test_lock_file");
+        let lock_file_path = lock_file.path().to_path_buf();
+        let lock_file_path_str = lock_file_path.into_os_string().into_string().unwrap();
+        let mut file_lock = FileLock::new(lock_file_path_str).unwrap();
+        assert_eq!(file_lock.locked, false);
+        let _ = file_lock.lock();
+        assert_eq!(file_lock.locked, true);
+        assert!(lock_file.exists());
+        let _ = file_lock.unlock();
+        assert_eq!(file_lock.locked, false);
+    }
+
+    #[test]
+    fn test_drop() {
+        let tmp_dir = TempDir::new().unwrap();
+        let lock_file = tmp_dir.child("test_lock_file");
+        let lock_file_path = lock_file.path().to_path_buf();
+        let lock_file_path_str = lock_file_path.into_os_string().into_string().unwrap();
+        {
+            let mut file_lock = FileLock::new(lock_file_path_str.clone()).unwrap();
+            let _ = file_lock.lock();
+        }
+        let file_lock = FileLock::new(lock_file_path_str.clone());
+        assert_eq!(file_lock.unwrap().locked, false);
+    }
+}

packages/nx/src/native/utils/mod.rs

@@ -11,5 +11,6 @@ pub use normalize_trait::Normalize;
 #[cfg_attr(target_arch = "wasm32", path = "atomics/wasm.rs")]
 pub mod atomics;
 pub mod ci;
+pub mod file_lock;
 
 pub use atomics::*;

packages/nx/src/project-graph/error-types.ts

@@ -6,22 +6,31 @@ import { ProjectConfiguration } from '../config/workspace-json-project-json';
 import { ProjectGraph } from '../config/project-graph';
 import { CreateNodesFunctionV2 } from './plugins/public-api';
 
+export type ProjectGraphErrorTypes =
+  | AggregateCreateNodesError
+  | MergeNodesError
+  | CreateMetadataError
+  | ProjectsWithNoNameError
+  | MultipleProjectsWithSameNameError
+  | ProcessDependenciesError
+  | WorkspaceValidityError;
+
+export class StaleProjectGraphCacheError extends Error {
+  constructor() {
+    super(
+      'The project graph cache was stale. Ensure that it has been recently created before using `readCachedProjectGraph`.'
+    );
+  }
+}
+
 export class ProjectGraphError extends Error {
   readonly #partialProjectGraph: ProjectGraph;
   readonly #partialSourceMaps: ConfigurationSourceMaps;
 
   constructor(
-    private readonly errors: Array<
-      | AggregateCreateNodesError
-      | MergeNodesError
-      | ProjectsWithNoNameError
-      | MultipleProjectsWithSameNameError
-      | ProcessDependenciesError
-      | CreateMetadataError
-      | WorkspaceValidityError
-    >,
+    private readonly errors: Array<ProjectGraphErrorTypes>,
     partialProjectGraph: ProjectGraph,
-    partialSourceMaps: ConfigurationSourceMaps
+    partialSourceMaps: ConfigurationSourceMaps | null
   ) {
     const messageFragments = ['Failed to process project graph.'];
     const mergeNodesErrors = [];

packages/nx/src/project-graph/nx-deps-cache.ts

@@ -18,6 +18,12 @@ import {
 } from '../utils/fileutils';
 import { PackageJson } from '../utils/package-json';
 import { nxVersion } from '../utils/versions';
+import { ConfigurationSourceMaps } from './utils/project-configuration-utils';
+import {
+  ProjectGraphError,
+  ProjectGraphErrorTypes,
+  StaleProjectGraphCacheError,
+} from './error-types';
 
 export interface FileMapCache {
   version: string;
@@ -34,6 +40,8 @@ export const nxProjectGraph = join(
 );
 export const nxFileMap = join(workspaceDataDirectory, 'file-map.json');
 
+export const nxSourceMaps = join(workspaceDataDirectory, 'source-maps.json');
+
 export function ensureCacheDirectory(): void {
   try {
     if (!existsSync(workspaceDataDirectory)) {
@@ -77,28 +85,94 @@ export function readFileMapCache(): null | FileMapCache {
   return data ?? null;
 }
 
-export function readProjectGraphCache(): null | ProjectGraph {
+export function readProjectGraphCache(
+  minimumComputedAt?: number
+): null | ProjectGraph {
   performance.mark('read project-graph:start');
   ensureCacheDirectory();
 
-  let data = null;
   try {
     if (fileExists(nxProjectGraph)) {
-      data = readJsonFile(nxProjectGraph);
+      const {
+        computedAt,
+        errors,
+        ...projectGraphCache
+      }: ProjectGraph & {
+        errors?: Error[];
+        computedAt?: number;
+      } = readJsonFile(nxProjectGraph);
+
+      if (
+        minimumComputedAt &&
+        (!computedAt || computedAt < minimumComputedAt)
+      ) {
+        throw new StaleProjectGraphCacheError();
+      }
+
+      if (errors && errors.length > 0) {
+        if (!minimumComputedAt) {
+          // If you didn't pass minimum computed at, we do not know if
+          // the errors on the cached graph would be relevant to what you
+          // are running. Prior to adding error handling here, the graph
+          // would not have been written to the cache. As such, this matches
+          // existing behavior of the public API.
+          return null;
+        }
+        throw new ProjectGraphError(
+          errors,
+          projectGraphCache,
+          readSourceMapsCache()
+        );
+      }
+
+      return projectGraphCache;
+    } else {
+      return null;
     }
   } catch (error) {
+    if (
+      error instanceof StaleProjectGraphCacheError ||
+      error instanceof ProjectGraphError
+    ) {
+      throw error;
+    }
     console.log(
       `Error reading '${nxProjectGraph}'. Continue the process without the cache.`
     );
     console.log(error);
-  }
-
+    return null;
+  } finally {
     performance.mark('read project-graph:end');
     performance.measure(
       'read cache',
       'read project-graph:start',
       'read project-graph:end'
     );
+  }
+}
+
+export function readSourceMapsCache(): null | ConfigurationSourceMaps {
+  performance.mark('read source-maps:start');
+  ensureCacheDirectory();
+
+  let data = null;
+  try {
+    if (fileExists(nxSourceMaps)) {
+      data = readJsonFile(nxSourceMaps);
+    }
+  } catch (error) {
+    console.log(
+      `Error reading '${nxSourceMaps}'. Continue the process without the cache.`
+    );
+    console.log(error);
+  }
+
+  performance.mark('read source-maps:end');
+  performance.measure(
+    'read cache',
+    'read source-maps:start',
+    'read source-maps:end'
+  );
   return data ?? null;
 }
 
@@ -123,7 +197,9 @@ export function createProjectFileMapCache(
 
 export function writeCache(
   cache: FileMapCache,
-  projectGraph: ProjectGraph
+  projectGraph: ProjectGraph,
+  sourceMaps: ConfigurationSourceMaps,
+  errors: ProjectGraphErrorTypes[]
 ): void {
   performance.mark('write cache:start');
   let retry = 1;
@@ -137,13 +213,21 @@ export function writeCache(
     const unique = (Math.random().toString(16) + '0000000').slice(2, 10);
     const tmpProjectGraphPath = `${nxProjectGraph}~${unique}`;
     const tmpFileMapPath = `${nxFileMap}~${unique}`;
+    const tmpSourceMapPath = `${nxSourceMaps}~${unique}`;
 
     try {
-      writeJsonFile(tmpProjectGraphPath, projectGraph);
+      writeJsonFile(tmpProjectGraphPath, {
+        ...projectGraph,
+        errors,
+        computedAt: Date.now(),
+      });
       renameSync(tmpProjectGraphPath, nxProjectGraph);
 
       writeJsonFile(tmpFileMapPath, cache);
       renameSync(tmpFileMapPath, nxFileMap);
+
+      writeJsonFile(tmpSourceMapPath, sourceMaps);
+      renameSync(tmpSourceMapPath, nxSourceMaps);
       done = true;
     } catch (err: any) {
       if (err instanceof Error) {

packages/nx/src/project-graph/project-graph.ts

@@ -21,10 +21,12 @@ import {
   isAggregateProjectGraphError,
   ProjectConfigurationsError,
   ProjectGraphError,
+  StaleProjectGraphCacheError,
 } from './error-types';
 import {
   readFileMapCache,
   readProjectGraphCache,
+  readSourceMapsCache,
   writeCache,
 } from './nx-deps-cache';
 import { ConfigurationResult } from './utils/project-configuration-utils';
@@ -34,13 +36,21 @@ import {
 } from './utils/retrieve-workspace-files';
 import { getPlugins } from './plugins/get-plugins';
 import { logger } from '../utils/logger';
+import { FileLock, IS_WASM } from '../native';
+import { join } from 'path';
+import { workspaceDataDirectory } from '../utils/cache-directory';
+import { DelayedSpinner } from '../utils/delayed-spinner';
 
 /**
  * Synchronously reads the latest cached copy of the workspace's ProjectGraph.
+ *
+ * @param {number} [minimumComputedAt] - The minimum timestamp that the cached ProjectGraph must have been computed at.
  * @throws {Error} if there is no cached ProjectGraph to read from
  */
-export function readCachedProjectGraph(): ProjectGraph {
-  const projectGraphCache: ProjectGraph = readProjectGraphCache();
+export function readCachedProjectGraph(
+  minimumComputedAt?: number
+): ProjectGraph {
+  const projectGraphCache = readProjectGraphCache(minimumComputedAt);
   if (!projectGraphCache) {
     const angularSpecificError = fileExists(`${workspaceRoot}/angular.json`)
       ? stripIndents`
@@ -163,12 +173,13 @@ export async function buildProjectGraphAndSourceMapsWithoutDaemon() {
     ...(projectGraphError?.errors ?? []),
   ];
 
+  if (cacheEnabled) {
+    writeCache(projectFileMapCache, projectGraph, sourceMaps, errors);
+  }
+
   if (errors.length > 0) {
     throw new ProjectGraphError(errors, projectGraph, sourceMaps);
   } else {
-    if (cacheEnabled) {
-      writeCache(projectFileMapCache, projectGraph);
-    }
     return { projectGraph, sourceMaps };
   }
 }
@@ -203,6 +214,20 @@ export function handleProjectGraphError(opts: { exitOnError: boolean }, e) {
   }
 }
 
+async function readCachedGraphAndHydrateFileMap(minimumComputedAt?: number) {
+  const graph = readCachedProjectGraph(minimumComputedAt);
+  const projectRootMap = Object.fromEntries(
+    Object.entries(graph.nodes).map(([project, { data }]) => [
+      data.root,
+      project,
+    ])
+  );
+  const { allWorkspaceFiles, fileMap, rustReferences } =
+    await retrieveWorkspaceFiles(workspaceRoot, projectRootMap);
+  hydrateFileMap(fileMap, allWorkspaceFiles, rustReferences);
+  return graph;
+}
+
 /**
  * Computes and returns a ProjectGraph.
  *
@@ -232,19 +257,13 @@ export async function createProjectGraphAsync(
 ): Promise<ProjectGraph> {
   if (process.env.NX_FORCE_REUSE_CACHED_GRAPH === 'true') {
     try {
-      const graph = readCachedProjectGraph();
-      const projectRootMap = Object.fromEntries(
-        Object.entries(graph.nodes).map(([project, { data }]) => [
-          data.root,
-          project,
-        ])
-      );
-      const { allWorkspaceFiles, fileMap, rustReferences } =
-        await retrieveWorkspaceFiles(workspaceRoot, projectRootMap);
-      hydrateFileMap(fileMap, allWorkspaceFiles, rustReferences);
-      return graph;
       // If no cached graph is found, we will fall through to the normal flow
+      const graph = await readCachedGraphAndHydrateFileMap();
+      return graph;
     } catch (e) {
+      if (e instanceof ProjectGraphError) {
+        throw e;
+      }
       logger.verbose('Unable to use cached project graph', e);
     }
   }
@@ -264,6 +283,57 @@ export async function createProjectGraphAndSourceMapsAsync(
   performance.mark('create-project-graph-async:start');
 
   if (!daemonClient.enabled()) {
+    const lock = !IS_WASM
+      ? new FileLock(join(workspaceDataDirectory, 'project-graph.lock'))
+      : null;
+    let locked = lock?.locked;
+    while (locked) {
+      logger.verbose(
+        'Waiting for graph construction in another process to complete'
+      );
+      const spinner = new DelayedSpinner(
+        'Waiting for graph construction in another process to complete'
+      );
+      const start = Date.now();
+      await lock.wait();
+      spinner.cleanup();
+
+      // Note: This will currently throw if any of the caches are missing...
+      // It would be nice if one of the processes that was waiting for the lock
+      // could pick up the slack and build the graph if it's missing, but
+      // we wouldn't want either of the below to happen:
+      // - All of the waiting processes to build the graph
+      // - Even one of the processes building the graph on a legitimate error
+
+      try {
+        // Ensuring that computedAt was after this process started
+        // waiting for the graph to complete, means that the graph
+        // was computed by the process was already working.
+        const graph = await readCachedGraphAndHydrateFileMap(start);
+
+        const sourceMaps = readSourceMapsCache();
+        if (!sourceMaps) {
+          throw new Error(
+            'The project graph was computed in another process, but the source maps are missing.'
+          );
+        }
+
+        return {
+          projectGraph: graph,
+          sourceMaps,
+        };
+      } catch (e) {
+        // If the error is that the cached graph is stale after unlock,
+        // the process that was working on the graph must have been canceled,
+        // so we will fall through to the normal flow to ensure
+        // its created by one of the processes that was waiting
+        if (!(e instanceof StaleProjectGraphCacheError)) {
+          throw e;
+        }
+      }
+      locked = lock.check();
+    }
+    lock?.lock();
     try {
       const res = await buildProjectGraphAndSourceMapsWithoutDaemon();
       performance.measure(
@@ -290,6 +360,8 @@ export async function createProjectGraphAndSourceMapsAsync(
       return res;
     } catch (e) {
       handleProjectGraphError(opts, e);
+    } finally {
+      lock.unlock();
     }
   } else {
     try {

packages/nx/src/utils/project-graph-utils.ts

@@ -26,7 +26,7 @@ export function projectHasTargetAndConfiguration(
 
 export function getSourceDirOfDependentProjects(
   projectName: string,
-  projectGraph = readCachedProjectGraph()
+  projectGraph: ProjectGraph = readCachedProjectGraph()
 ): [projectDirs: string[], warnings: string[]] {
   if (!projectGraph.nodes[projectName]) {
     throw new Error(
@@ -58,7 +58,7 @@ export function getSourceDirOfDependentProjects(
  */
 export function findAllProjectNodeDependencies(
   parentNodeName: string,
-  projectGraph = readCachedProjectGraph(),
+  projectGraph: ProjectGraph = readCachedProjectGraph(),
   includeExternalDependencies = false
 ): string[] {
   const dependencyNodeNames = new Set<string>();

packages/nx/tsconfig.spec.json

@@ -11,6 +11,8 @@
     "**/*.spec.tsx",
     "**/*.spec.js",
     "**/*.spec.jsx",
+    "**/*.fixture.js",
+    "**/*.fixture.ts",
     "**/*.d.ts",
     "./src/internal-testing-utils/**/*.ts",
     "jest.config.ts"