Populate PrivateMemorySize64 on macOS by nwoolls · Pull Request #131244 · dotnet/runtime

nwoolls · 2026-07-22T23:54:49Z

Process.PrivateMemorySize64 always returned 0 on macOS because proc_taskallinfo (via proc_pidinfo/PROC_PIDTASKALLINFO) only exposes virtual and resident memory size; it has no private memory field.

Populate it instead from proc_pid_rusage(RUSAGE_INFO_V3).ri_phys_footprint, the same value Activity Monitor's Memory column reports. Verified this call succeeds cross-process for processes owned by the current user (including sandboxed apps) without requiring task_for_pid()/root, and fails cleanly with EPERM for processes owned by other users, matching the existing permission behavior of proc_pidinfo already used in this file.

Fix #105665

Process.PrivateMemorySize64 always returned 0 on macOS because proc_taskallinfo (via proc_pidinfo/PROC_PIDTASKALLINFO) only exposes virtual and resident memory size; it has no private memory field. Populate it instead from proc_pid_rusage(RUSAGE_INFO_V4).ri_phys_footprint, the same value Activity Monitor's Memory column reports. Verified this call succeeds cross-process for processes owned by the current user (including sandboxed apps) without requiring task_for_pid()/root, and fails cleanly with EPERM for processes owned by other users, matching the existing permission behavior of proc_pidinfo already used in this file. Fix dotnet#105665

azure-pipelines · 2026-07-22T23:55:29Z

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dotnet-policy-service · 2026-07-22T23:56:08Z

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Copilot

Pull request overview

This PR updates the macOS implementation of System.Diagnostics.Process to populate ProcessInfo.PrivateBytes (and thus Process.PrivateMemorySize64) using proc_pid_rusage’s physical footprint value, and updates tests to assert the value is now non-zero on macOS.

Changes:

Add a new macOS libproc interop helper to retrieve physical footprint via proc_pid_rusage.
Populate ProcessInfo.PrivateBytes in ProcessManager.OSX.CreateProcessInfo.
Update ProcessTests to assert PrivateMemorySize64 / PrivateMemorySize are now > 0 on macOS.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems	Adds the new interop source to CoreLib build items on OSX/MacCatalyst.
src/libraries/System.Diagnostics.Process/tests/ProcessTests.cs	Updates assertions for private memory size to be non-zero (including on macOS).
src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.OSX.cs	Sets `ProcessInfo.PrivateBytes` from the new physical-footprint interop call.
src/libraries/System.Diagnostics.Process/src/System.Diagnostics.Process.csproj	Includes the new interop file for the Process library build on OSX/MacCatalyst.
src/libraries/Common/src/Interop/OSX/Interop.libproc.GetProcessPhysicalFootprint.cs	Introduces new `proc_pid_rusage`/`rusage_info_v4` interop and a helper to get `ri_phys_footprint`.

Address review feedback: Interop.libproc.cs already declared rusage_info_v3 (with ri_phys_footprint) and a proc_pid_rusage P/Invoke. The previous commit introduced a separate rusage_info_v4 struct and a second proc_pid_rusage binding for the same native symbol, risking a struct layout/size mismatch between the two. v4 only appends fields after ri_serviced_system_time; the field this fix needs, ri_phys_footprint, is already at the same offset in v3. Remove the v4 struct and duplicate binding entirely and add TryGetProcessPhysicalFootprint, a small non-throwing wrapper around the existing proc_pid_rusage(V3) call, matching the existing GetProcessInfoById's null/false-on-failure convention rather than the existing proc_pid_rusage(int) overload's throwing one.

Copilot

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Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

Copilot

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

…emorySize64

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jkotas · 2026-07-23T04:26:05Z

+            // PrivateMemorySize is unchecked((int)PrivateMemorySize64) and can be negative on
+            // high-memory processes - assert the cast relationship rather than a value range,
+            // matching TestVirtualMemorySize.


Suggested change

// PrivateMemorySize is unchecked((int)PrivateMemorySize64) and can be negative on

// high-memory processes - assert the cast relationship rather than a value range,

// matching TestVirtualMemorySize.

Unnecessary comment - match style of the rest of the file

Addressed in eea7796

…eMemorySize64 casting

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Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

adamsitnik

Overall it LGTM, but the Windows vs Linux vs macOS differences need to be documented in XML docs, preferably using <remarks> section.

Thank you for your contribution @nwoolls !

adamsitnik · 2026-07-23T11:36:23Z

                procInfo.SessionId = sessionId;
            }

+            // Get the process's physical memory footprint (private/unique memory usage). This can fail


Please add XML docs to the public API here based on this existing doc and extend it with the description of Windows vs Linux vs macOS differences.

Addressed in 4750949

adamsitnik · 2026-07-23T11:39:25Z

            CreateDefaultProcess();

-            AssertNonZeroAllZeroDarwin(_process.PrivateMemorySize64);
+            Assert.InRange(_process.PrivateMemorySize64, 1, long.MaxValue);


The existing test just checks whether the returned value is not zero:

https://github.com/nwoolls/dotnet-runtime/blob/eea779642db7911fc6a093086b8bab68cd32fd04/src/libraries/System.Diagnostics.Process/tests/ProcessTests.cs#L82

Ensuring that it's not negative value is an improvement 👍

Another improvement we could make would be merging the TestPrivateMemorySize64 and TestPrivateMemorySize test into one, so our test suite could spawn one less process (and run slightly faster). Not a blocker, just something to consider.

Addressed in 7b4d697

…morySize with platform-specific remarks

…rySize and consolidate assertions for PrivateMemorySize64

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Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

…surement and update comments for consistency

…ement details on Linux and macOS

Copilot

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

…s on macOS

Copilot

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Copilot reviewed 4 out of 4 changed files in this pull request and generated no new comments.

Copilot AI review requested due to automatic review settings July 22, 2026 23:54

github-actions Bot added the area-System.Diagnostics.Process label Jul 22, 2026

dotnet-policy-service Bot added the community-contribution Indicates that the PR has been added by a community member label Jul 22, 2026

Copilot started reviewing on behalf of nwoolls July 22, 2026 23:55 View session

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Comment thread src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems Outdated

Comment thread src/libraries/Common/src/Interop/OSX/Interop.libproc.GetProcessPhysicalFootprint.cs Outdated

nwoolls added 2 commits July 22, 2026 20:39

Remove unused Interop.libproc.GetProcessPhysicalFootprint binding

5bfdff3

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Comment thread src/libraries/System.Diagnostics.Process/tests/ProcessTests.cs Outdated

Remove outdated comments related to macOS PrivateMemorySize64 handling

369216b

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Comment thread src/libraries/System.Diagnostics.Process/tests/ProcessTests.cs Outdated

Comment thread src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.OSX.cs

nwoolls added 2 commits July 22, 2026 21:28

Update TestPrivateMemorySize to assert cast relationship for PrivateM…

1573a46

…emorySize64

Clamp PrivateBytes to long.MaxValue in macOS process info retrieval

56e7c09

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build-analysis Bot mentioned this pull request Jul 23, 2026

XHarness package install failure on iOS due to devicectl NSPOSIXErrorDomain error 49 #123796

Open

Remove unnecessary comments in TestPrivateMemorySize regarding Privat…

eea7796

…eMemorySize64 casting

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Comment thread src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.OSX.cs Outdated

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adamsitnik added this to the 11.0.0 milestone Jul 23, 2026

build-analysis Bot mentioned this pull request Jul 23, 2026

[wasm] OpenQA.Selenium.WebDriverTimeoutException: timeout: Timed out receiving message from renderer #117486

Open

nwoolls added 2 commits July 23, 2026 09:27

Enhance documentation for PrivateMemorySize64 and deprecate PrivateMe…

4750949

…morySize with platform-specific remarks

Rename TestPrivateMemorySize to TestPrivateMemorySize64AndPrivateMemo…

7b4d697

…rySize and consolidate assertions for PrivateMemorySize64

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Comment thread src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.cs

Comment thread src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.OSX.cs Outdated

Comment thread src/libraries/Common/src/Interop/OSX/Interop.libproc.cs

nwoolls added 2 commits July 23, 2026 09:56

Refine memory footprint documentation to clarify accounting-based mea…

cc098aa

…surement and update comments for consistency

Update documentation for PrivateMemorySize64 to clarify memory measur…

8514361

…ement details on Linux and macOS

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Comment thread src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.OSX.cs Outdated

Comment thread src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.cs Outdated

Clarify comments regarding process memory footprint retrieval failure…

a95dca0

…s on macOS

Copilot AI review requested due to automatic review settings July 23, 2026 14:19

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	// PrivateMemorySize is unchecked((int)PrivateMemorySize64) and can be negative on
	// high-memory processes - assert the cast relationship rather than a value range,
	// matching TestVirtualMemorySize.

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nwoolls commented Jul 22, 2026 •

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