From ad89ec6aecd391f8529a36a49562dd220ee56498 Mon Sep 17 00:00:00 2001
From: testercengdong <zengdong@natureselect.ai>
Date: Tue, 12 May 2026 09:38:02 +0800
Subject: [PATCH] fix(macos,process_info): address Copilot review feedback

- Add 30s (host:port) -> pid cache in ProcessInfoUtils so the synchronous
  libproc scan stays off the request hot path for keep-alive flows
  (typical HTTP client reuses the same source port across requests in
  a connection).
- Lift sockView ByteData out of the inner fd loop so the buffer wrapper
  is reused across all fds in a scan (saves per-fd allocations).
- Bail out of the scan after 16 consecutive proc_pidfdinfo size
  mismatches, in case a future macOS bumps the socket_fdinfo layout --
  avoids wasted syscalls instead of scanning every fd just to return
  null at the end.

Re-verified end-to-end on macOS 26.4: 500 concurrent curl, 0 fork
leaks, 9099 freed immediately on app exit, no errors in logs.
---
 lib/network/util/process_info.dart       | 16 ++++++++++++++--
 lib/network/util/process_info_macos.dart | 18 ++++++++++++++++--
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/lib/network/util/process_info.dart b/lib/network/util/process_info.dart
index 62d1496..088d6fc 100644
--- a/lib/network/util/process_info.dart
+++ b/lib/network/util/process_info.dart
@@ -38,6 +38,13 @@ void main() async {
 class ProcessInfoUtils {
   static final processInfoCache = ExpiringCache<String, ProcessInfo>(const Duration(minutes: 5));
 
+  // (host:port) -> pid short cache. Keeps the FFI / Process.run lookup off
+  // the request hot path for the typical HTTP keep-alive case where many
+  // requests share a single client TCP connection (and thus a single
+  // remote socket address). Greatly reduces how often the synchronous
+  // libproc scan runs on the main isolate.
+  static final _pidCache = ExpiringCache<String, int>(const Duration(seconds: 30));
+
   static Future<ProcessInfo?> getProcessByPort(InetSocketAddress socketAddress, String cacheKeyPre) async {
     try {
       if (Platform.isAndroid) {
@@ -51,8 +58,13 @@ class ProcessInfoUtils {
         return null;
       }
 
-      var pid = await _getPid(socketAddress);
-      if (pid == null) return null;
+      var addrKey = "${socketAddress.host}:${socketAddress.port}";
+      var pid = _pidCache.get(addrKey);
+      if (pid == null) {
+        pid = await _getPid(socketAddress);
+        if (pid == null) return null;
+        _pidCache.set(addrKey, pid);
+      }
 
       String cacheKey = "$cacheKeyPre:$pid";
       var processInfo = processInfoCache.get(cacheKey);
diff --git a/lib/network/util/process_info_macos.dart b/lib/network/util/process_info_macos.dart
index b65ce3d..7ee02f8 100644
--- a/lib/network/util/process_info_macos.dart
+++ b/lib/network/util/process_info_macos.dart
@@ -98,6 +98,16 @@ class MacosProcessInfo {
 
     final pidBuf = calloc<Uint8>(pidBufSize);
     final sockBuf = calloc<Uint8>(_kSizeofSocketFdInfo);
+    // Reuse the same ByteData view across all fds; the underlying native
+    // buffer is overwritten in place by each proc_pidfdinfo call.
+    final sockView = ByteData.sublistView(sockBuf.asTypedList(_kSizeofSocketFdInfo));
+
+    // If proc_pidfdinfo keeps returning a size smaller than expected, the
+    // struct layout has changed (e.g. a future macOS bumped the size) and
+    // continuing the scan can't possibly find anything. Bail out early
+    // after enough consecutive mismatches to avoid wasting syscalls.
+    var consecutiveLayoutMismatch = 0;
+    const layoutMismatchThreshold = 16;
 
     try {
       final actual = _procListPids(_kProcAllPids, 0, pidBuf.cast(), pidBufSize);
@@ -107,6 +117,7 @@ class MacosProcessInfo {
 
       for (final pid in pidView) {
         if (pid <= 0) continue;
+        if (consecutiveLayoutMismatch >= layoutMismatchThreshold) break;
 
         final fdSize = _procPidInfo(pid, _kProcPidListFds, 0, nullptr, 0);
         if (fdSize <= 0) continue;
@@ -127,9 +138,12 @@ class MacosProcessInfo {
             final fd = fdView.getInt32(entryOff + _kOffProcFd, Endian.host);
 
             final n = _procPidFdInfo(pid, fd, _kProcPidFdSocketInfo, sockBuf.cast(), _kSizeofSocketFdInfo);
-            if (n < _kSizeofSocketFdInfo) continue;
+            if (n < _kSizeofSocketFdInfo) {
+              consecutiveLayoutMismatch++;
+              continue;
+            }
+            consecutiveLayoutMismatch = 0;
 
-            final sockView = ByteData.sublistView(sockBuf.asTypedList(_kSizeofSocketFdInfo));
             final soiKind = sockView.getInt32(_kOffSoiKind, Endian.host);
             if (soiKind != _kSockInfoTcp) continue;