SunOS process and thread support

Read binary psinfo for System.Diagnostic.Process on SunOS

Thanks for initial prototype help from:
Austin Wise <AustinWise@gmail.com>

Add Try prefix to SunOS Interop functions
Get rid of unsafe for procfs get methods

src/libraries/Common/src/Interop/SunOS/procfs/Interop.ProcFs.Definitions.cs

@@ -0,0 +1,155 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.InteropServices;
+
+// C# equivalents for <sys/procfs.h> structures. See: struct lwpsinfo, struct psinfo.
+// We read directly onto these from procfs, so the layouts and sizes of these structures
+// must _exactly_ match those in <sys/procfs.h>
+
+// analyzer incorrectly flags fixed buffer length const
+// (https://github.com/dotnet/roslyn/issues/37593)
+#pragma warning disable CA1823
+
+internal static partial class Interop
+{
+    internal static partial class @procfs
+    {
+        internal const string RootPath = "/proc/";
+        private const string psinfoFileName = "/psinfo";
+        private const string lwpDirName = "/lwp";
+        private const string lwpsinfoFileName = "/lwpsinfo";
+
+        // Constants from sys/procfs.h
+        private const int PRARGSZ = 80;
+        private const int PRCLSZ = 8;
+        private const int PRFNSZ = 16;
+
+        [StructLayout(LayoutKind.Sequential)]
+        internal struct @timestruc_t
+        {
+            public long tv_sec;
+            public long tv_nsec;
+        }
+
+        // lwp ps(1) information file.  /proc/<pid>/lwp/<lwpid>/lwpsinfo
+        // Equivalent to sys/procfs.h struct lwpsinfo
+        // "unsafe" because it has fixed sized arrays.
+        [StructLayout(LayoutKind.Sequential)]
+        internal unsafe struct @lwpsinfo
+        {
+            private     int     pr_flag;        /* lwp flags (DEPRECATED; do not use) */
+            public      uint    pr_lwpid;       /* lwp id */
+            private     long    pr_addr;        /* internal address of lwp */
+            private     long    pr_wchan;       /* wait addr for sleeping lwp */
+            public      byte    pr_stype;       /* synchronization event type */
+            public      byte    pr_state;       /* numeric lwp state */
+            public      byte    pr_sname;       /* printable character for pr_state */
+            public      byte    pr_nice;        /* nice for cpu usage */
+            private     short   pr_syscall;     /* system call number (if in syscall) */
+            private     byte    pr_oldpri;      /* pre-SVR4, low value is high priority */
+            private     byte    pr_cpu;         /* pre-SVR4, cpu usage for scheduling */
+            public      int     pr_pri;         /* priority, high value is high priority */
+            private     ushort  pr_pctcpu;      /* fixed pt. % of recent cpu time */
+            private     ushort  pr_pad;
+            public      timestruc_t pr_start;   /* lwp start time, from the epoch */
+            public      timestruc_t pr_time;    /* usr+sys cpu time for this lwp */
+            private     fixed byte pr_clname[PRCLSZ];   /* scheduling class name */
+            private     fixed byte pr_name[PRFNSZ];     /* name of system lwp */
+            private     int     pr_onpro;               /* processor which last ran this lwp */
+            private     int     pr_bindpro;     /* processor to which lwp is bound */
+            private     int     pr_bindpset;    /* processor set to which lwp is bound */
+            private     int     pr_lgrp;        /* lwp home lgroup */
+            private     fixed int       pr_filler[4];   /* reserved for future use */
+        }
+        private const int PR_LWPSINFO_SIZE = 128; // for debug assertions
+
+        // process ps(1) information file.  /proc/<pid>/psinfo
+        // Equivalent to sys/procfs.h struct psinfo
+        // "unsafe" because it has fixed sized arrays.
+        [StructLayout(LayoutKind.Sequential)]
+        internal unsafe struct @psinfo
+        {
+            private     int     pr_flag;        /* process flags (DEPRECATED; do not use) */
+            public      int     pr_nlwp;        /* number of active lwps in the process */
+            public      int     pr_pid;         /* unique process id */
+            public      int     pr_ppid;        /* process id of parent */
+            public      int     pr_pgid;        /* pid of process group leader */
+            public      int     pr_sid;         /* session id */
+            public      uint    pr_uid;         /* real user id */
+            public      uint    pr_euid;        /* effective user id */
+            public      uint    pr_gid;         /* real group id */
+            public      uint    pr_egid;        /* effective group id */
+            private     long    pr_addr;        /* address of process */
+            public      ulong   pr_size;        /* size of process image in Kbytes */
+            public      ulong   pr_rssize;      /* resident set size in Kbytes */
+            private     ulong   pr_pad1;
+            private     ulong   pr_ttydev;      /* controlling tty device (or PRNODEV) */
+            private     ushort  pr_pctcpu;      /* % of recent cpu time used by all lwps */
+            private     ushort  pr_pctmem;      /* % of system memory used by process */
+            public      timestruc_t pr_start;   /* process start time, from the epoch */
+            public      timestruc_t pr_time;    /* usr+sys cpu time for this process */
+            public      timestruc_t pr_ctime;   /* usr+sys cpu time for reaped children */
+            public      fixed byte pr_fname[PRFNSZ];    /* name of execed file */
+            public      fixed byte pr_psargs[PRARGSZ];  /* initial characters of arg list */
+            public      int     pr_wstat;       /* if zombie, the wait() status */
+            public      int     pr_argc;        /* initial argument count */
+            private     long pr_argv;   /* address of initial argument vector */
+            private     long pr_envp;   /* address of initial environment vector */
+            private     byte    pr_dmodel;      /* data model of the process */
+            private     fixed byte pr_pad2[3];
+            public      int     pr_taskid;      /* task id */
+            public      int     pr_projid;      /* project id */
+            public      int     pr_nzomb;       /* number of zombie lwps in the process */
+            public      int     pr_poolid;      /* pool id */
+            public      int     pr_zoneid;      /* zone id */
+            public      int     pr_contract;    /* process contract */
+            private     fixed int pr_filler[1]; /* reserved for future use */
+            public      lwpsinfo pr_lwp;        /* information for representative lwp */
+            // C# magic: Accessor method to get a Span for pr_psargs[]
+            // Does not affect the size or layout of this struct.
+            internal     ReadOnlySpan<byte> PsArgsSpan =>
+                MemoryMarshal.CreateReadOnlySpan(ref pr_psargs[0], PRARGSZ);
+        }
+        private const int PR_PSINFO_SIZE = 416; // for debug assertions
+
+        // Ouput type for TryGetThreadInfoById()
+        internal struct ThreadInfo
+        {
+            internal uint Tid;
+            internal int Priority;
+            internal int NiceVal;
+            internal char Status;
+            internal Interop.Sys.TimeSpec StartTime;
+            internal Interop.Sys.TimeSpec CpuTotalTime; // user+sys
+            // add more fields when needed.
+        }
+
+        // Ouput type for TryGetProcessInfoById()
+        internal struct ProcessInfo
+        {
+            internal int Pid;
+            internal int ParentPid;
+            internal int SessionId;
+            internal int Priority;
+            internal int NiceVal;
+            internal nuint VirtualSize;
+            internal nuint ResidentSetSize;
+            internal Interop.Sys.TimeSpec StartTime;
+            internal Interop.Sys.TimeSpec CpuTotalTime; // user+sys
+            internal string? Args;
+            // add more fields when needed.
+        }
+
+        internal static string GetInfoFilePathForProcess(int pid) =>
+            $"{RootPath}{(uint)pid}{psinfoFileName}";
+
+        internal static string GetLwpDirForProcess(int pid) =>
+            $"{RootPath}{(uint)pid}{lwpDirName}";
+
+        internal static string GetInfoFilePathForThread(int pid, int tid) =>
+            $"{RootPath}{(uint)pid}{lwpDirName}/{(uint)tid}{lwpsinfoFileName}";
+
+    }
+}

src/libraries/Common/src/Interop/SunOS/procfs/Interop.ProcFs.TryGetProcessInfoById.cs

@@ -0,0 +1,73 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.IO;
+using System.Text;
+
+internal static partial class Interop
+{
+    internal static partial class @procfs
+    {
+
+        /// <summary>
+        /// Attempts to get status info for the specified process ID.
+        /// </summary>
+        /// <param name="pid">PID of the process to read status info for.</param>
+        /// <param name="result">The pointer to ProcessInfo instance.</param>
+        /// <returns>
+        /// true if the process info was read; otherwise, false.
+        /// </returns>
+
+        // ProcessManager.SunOS.cs calls this
+        internal static bool TryGetProcessInfoById(int pid, out ProcessInfo result)
+        {
+            result = default;
+
+            try
+            {
+                string fileName = GetInfoFilePathForProcess(pid);
+                using FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
+                psinfo pr;
+                Unsafe.SkipInit(out pr);
+                Span<byte> prspan = MemoryMarshal.AsBytes(new Span<psinfo>(ref pr));
+                Debug.Assert(prspan.Length == PR_PSINFO_SIZE,
+                    $"psinfo struct size {prspan.Length} bytes not {PR_PSINFO_SIZE}.");
+                fs.ReadExactly(prspan);
+
+                result.Pid = pr.pr_pid;
+                result.ParentPid = pr.pr_ppid;
+                result.SessionId = pr.pr_sid;
+                result.VirtualSize = (nuint)pr.pr_size * 1024; // pr_size is in Kbytes
+                result.ResidentSetSize = (nuint)pr.pr_rssize * 1024; // pr_rssize is in Kbytes
+                result.StartTime.TvSec = pr.pr_start.tv_sec;
+                result.StartTime.TvNsec = pr.pr_start.tv_nsec;
+                result.CpuTotalTime.TvSec = pr.pr_time.tv_sec;
+                result.CpuTotalTime.TvNsec = pr.pr_time.tv_nsec;
+
+                // Get Args as a managed string, using accessor for pr_psargs[]
+                ReadOnlySpan<byte> argspan = pr.PsArgsSpan;
+                int argslen = argspan.IndexOf((byte)0);
+                argslen = (argslen >= 0) ? argslen : argspan.Length;
+                result.Args = Encoding.UTF8.GetString(argspan.Slice(0, argslen));
+
+                // A couple things from pr_lwp
+                result.Priority = pr.pr_lwp.pr_pri;
+                result.NiceVal  = (int)pr.pr_lwp.pr_nice;
+
+                return true;
+            }
+            catch (Exception e)
+            {
+                Debug.Fail($"Failed to read process info for PID {pid}: {e}");
+            }
+
+            return false;
+        }
+
+    }
+}

src/libraries/Common/src/Interop/SunOS/procfs/Interop.ProcFs.TryGetThreadInfoById.cs

@@ -0,0 +1,62 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.IO;
+
+internal static partial class Interop
+{
+    internal static partial class @procfs
+    {
+
+        /// <summary>
+        /// Attempts to get status info for the specified thread ID.
+        /// </summary>
+        /// <param name="pid">PID of the process to read status info for.</param>
+        /// <param name="tid">TID of the thread to read status info for.</param>
+        /// <param name="result">The pointer to ThreadInfo instance.</param>
+        /// <returns>
+        /// true if the thread info was read; otherwise, false.
+        /// </returns>
+
+        // ProcessManager.SunOS.cs calls this
+        internal static bool TryGetThreadInfoById(int pid, int tid, out ThreadInfo result)
+        {
+            result = default;
+
+            try
+            {
+                string fileName = GetInfoFilePathForThread(pid, tid);
+                using FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
+                lwpsinfo pr;
+                Unsafe.SkipInit(out pr);
+                Span<byte> prspan = MemoryMarshal.AsBytes(new Span<lwpsinfo>(ref pr));
+                Debug.Assert(prspan.Length == PR_LWPSINFO_SIZE,
+                    $"psinfo struct size {prspan.Length} bytes not {PR_LWPSINFO_SIZE}.");
+                fs.ReadExactly(prspan);
+
+                result.Tid = pr.pr_lwpid;
+                result.Priority = pr.pr_pri;
+                result.NiceVal = (int)pr.pr_nice;
+                result.Status = (char)pr.pr_sname;
+                result.StartTime.TvSec = pr.pr_start.tv_sec;
+                result.StartTime.TvNsec = pr.pr_start.tv_nsec;
+                result.CpuTotalTime.TvSec = pr.pr_time.tv_sec;
+                result.CpuTotalTime.TvNsec = pr.pr_time.tv_nsec;
+
+                return true;
+            }
+            catch (Exception e)
+            {
+                Debug.Fail($"Failed to read thread info for PID {pid} TID {tid}: {e}");
+            }
+
+            return false;
+        }
+
+    }
+}

src/libraries/Common/src/Interop/Unix/System.Native/Interop.TimeSpec.cs

@@ -0,0 +1,17 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.InteropServices;
+
+internal static partial class Interop
+{
+    internal static partial class Sys
+    {
+        internal struct TimeSpec
+        {
+            internal long TvSec;
+            internal long TvNsec;
+        }
+    }
+}

src/libraries/Common/src/Interop/Unix/System.Native/Interop.UTimensat.cs

@@ -8,12 +8,6 @@ internal static partial class Interop
 {
     internal static partial class Sys
     {
-        internal struct TimeSpec
-        {
-            internal long TvSec;
-            internal long TvNsec;
-        }
-
         /// <summary>
         /// Sets the last access and last modified time of a file
         /// </summary>

src/libraries/Common/tests/TestUtilities/System/PlatformDetection.cs

@@ -47,6 +47,7 @@ public static partial class PlatformDetection
         public static bool IsNotMacCatalyst => !IsMacCatalyst;
         public static bool Isillumos => RuntimeInformation.IsOSPlatform(OSPlatform.Create("ILLUMOS"));
         public static bool IsSolaris => RuntimeInformation.IsOSPlatform(OSPlatform.Create("SOLARIS"));
+        public static bool IsSunOS => Isillumos || IsSolaris;
         public static bool IsBrowser => RuntimeInformation.IsOSPlatform(OSPlatform.Create("BROWSER"));
         public static bool IsWasi => RuntimeInformation.IsOSPlatform(OSPlatform.Create("WASI"));
         public static bool IsNotBrowser => !IsBrowser;