From b261dd4d3a15d17f4f559d4669eb1784df8012ab Mon Sep 17 00:00:00 2001
From: mptyl <mp@tylconsulting.it>
Date: Tue, 18 Aug 2026 14:49:56 +0200
Subject: [PATCH] fix(windows): serialize private root contention

---
 .../internal/safeio/private_root_windows.go   | 29 +++++++++++++++----
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/tools/tht/internal/safeio/private_root_windows.go b/tools/tht/internal/safeio/private_root_windows.go
index e57b9735..16885053 100644
--- a/tools/tht/internal/safeio/private_root_windows.go
+++ b/tools/tht/internal/safeio/private_root_windows.go
@@ -82,7 +82,7 @@ func openWindowsPrivateDirectoryAt(parent windows.Handle, name string, ensure bo
 		return 0, false, ErrUnsafeFile
 	}
 	for attempt := 0; attempt < 2; attempt++ {
-		handle, err := openWindowsRelativeDirectory(parent, name)
+		handle, err := openWindowsRelativePrivateDirectoryWithRetry(parent, name)
 		if err == nil {
 			return handle, true, nil
 		}
@@ -100,6 +100,19 @@ func openWindowsPrivateDirectoryAt(parent windows.Handle, name string, ensure bo
 	return 0, false, ErrUnsafeFile
 }
 
+func openWindowsRelativePrivateDirectoryWithRetry(parent windows.Handle, name string) (windows.Handle, error) {
+	for attempt := 0; ; attempt++ {
+		handle, err := openWindowsRelativeDirectory(parent, name)
+		if !isWindowsRelativeSharingViolation(err) {
+			return handle, err
+		}
+		if attempt == windowsPrivateSharingRetries {
+			return 0, err
+		}
+		time.Sleep(time.Millisecond)
+	}
+}
+
 func openWindowsRelativeDirectory(parent windows.Handle, name string) (windows.Handle, error) {
 	handle, err := openWindowsRelativeObject(
 		parent,
@@ -280,6 +293,11 @@ func isWindowsRelativeCollision(err error) bool {
 		errors.Is(err, windows.STATUS_OBJECT_NAME_COLLISION)
 }
 
+func isWindowsRelativeSharingViolation(err error) bool {
+	return errors.Is(err, windows.ERROR_SHARING_VIOLATION) ||
+		errors.Is(err, windows.STATUS_SHARING_VIOLATION)
+}
+
 func (directory *windowsPrivateDirectory) captureAndValidate() error {
 	if directory == nil || directory.handle == 0 {
 		return ErrUnsafeFile
@@ -953,7 +971,7 @@ func windowsRelativeClaimAbsentOrOrphan(directory *windowsPrivateDirectory, sour
 	return false, ErrUnsafeFile
 }
 
-const windowsClaimSharingRetries = 100
+const windowsPrivateSharingRetries = 100
 
 func waitForWindowsRelativeClaimLoss(directory *windowsPrivateDirectory, source, claim string) (bool, error) {
 	for attempt := 0; ; attempt++ {
@@ -965,7 +983,7 @@ func waitForWindowsRelativeClaimLoss(directory *windowsPrivateDirectory, source,
 		if absentErr == nil && absent {
 			return true, nil
 		}
-		if attempt == windowsClaimSharingRetries {
+		if attempt == windowsPrivateSharingRetries {
 			return false, ErrUnsafeFile
 		}
 		time.Sleep(time.Millisecond)
@@ -980,11 +998,10 @@ func openWindowsPrivateClaimRegular(
 ) (*windowsPrivateRegularAt, error) {
 	for attempt := 0; ; attempt++ {
 		value, err := openWindowsPrivateRegularAt(directory, name, access, allowedLinks)
-		if !errors.Is(err, windows.ERROR_SHARING_VIOLATION) &&
-			!errors.Is(err, windows.STATUS_SHARING_VIOLATION) {
+		if !isWindowsRelativeSharingViolation(err) {
 			return value, err
 		}
-		if attempt == windowsClaimSharingRetries {
+		if attempt == windowsPrivateSharingRetries {
 			return nil, err
 		}
 		time.Sleep(time.Millisecond)