Remove process object from PAL (#128975)

The pseudo handle for current process is still used by various api.
There's no need to keep the object and ProcLocalData behind.

---------

Co-authored-by: Jan Kotas <jkotas@microsoft.com>

Author: huoyaoyuan

src/coreclr/pal/src/handlemgr/handleapi.cpp

@@ -107,31 +107,9 @@ CorUnix::InternalDuplicateHandle(
     PAL_ERROR palError = NO_ERROR;
     IPalObject *pobjSource = NULL;
 
-    DWORD source_process_id;
-    DWORD target_process_id;
-    DWORD cur_process_id;
-
-    cur_process_id = GetCurrentProcessId();
-    source_process_id = PROCGetProcessIDFromHandle(hSourceProcess);
-    target_process_id = PROCGetProcessIDFromHandle(hTargetProcess);
-
-    /* Check validity of process handles */
-    if (0 == source_process_id || 0 == target_process_id)
-    {
-        ASSERT("Can't duplicate handle: invalid source or destination process");
-        palError = ERROR_INVALID_PARAMETER;
-        goto InternalDuplicateHandleExit;
-    }
-
-    /* At least source or target process should be the current process. */
-    if (source_process_id != cur_process_id
-        && target_process_id != cur_process_id)
-    {
-        ASSERT("Can't duplicate handle : neither source or destination"
-               "processes are from current process");
-        palError = ERROR_INVALID_PARAMETER;
-        goto InternalDuplicateHandleExit;
-    }
+    /* We do not support other process in PAL */
+    _ASSERTE(hSourceProcess == hPseudoCurrentProcess);
+    _ASSERTE(hTargetProcess == hPseudoCurrentProcess);
 
     if (FALSE != bInheritHandle)
     {
@@ -169,16 +147,6 @@ CorUnix::InternalDuplicateHandle(
         goto InternalDuplicateHandleExit;
     }
 
-    // Handles can't be remoted cross-process.
-    // Just return the same handle.
-    if (source_process_id != cur_process_id
-        || target_process_id != cur_process_id)
-    {
-        *phDuplicate = hSource;
-        palError = NO_ERROR;
-        goto InternalDuplicateHandleExit;
-    }
-
     //
     // Obtain the source IPalObject
     //
@@ -200,10 +168,10 @@ CorUnix::InternalDuplicateHandle(
     }
     else if (hPseudoCurrentProcess == hSource)
     {
+        /* The only pseudo handle is invariant */
         TRACE("Duplicating process pseudo handle(%p)\n", hSource);
-
-        pobjSource = g_pobjProcess;
-        pobjSource->AddReference();
+        *phDuplicate = hPseudoCurrentProcess;
+        goto InternalDuplicateHandleExit;
     }
     else if (hPseudoCurrentThread == hSource)
     {

src/coreclr/pal/src/include/pal/corunix.hpp

@@ -163,7 +163,6 @@ namespace CorUnix
         otiFile,
         otiFileMapping,
         otiSocket,
-        otiProcess,
         otiThread,
         otiIOCompletionPort,
         ObjectTypeIdCount    // This entry must come last in the enumeration

src/coreclr/pal/src/include/pal/palinternal.h

@@ -332,6 +332,4 @@ const char StackOverflowMessage[] = "Stack overflow.\n";
 
 #endif // __cplusplus
 
-DWORD PALAPI GetCurrentSessionId();
-
 #endif /* _PAL_INTERNAL_H_ */

src/coreclr/pal/src/include/pal/process.h

@@ -37,9 +37,8 @@ extern "C"
 */
 extern Volatile<LONG> terminator;
 
-// The process and session ID of this process, so we can avoid excessive calls to getpid() and getsid().
+// The process ID of this process, so we can avoid excessive calls to getpid().
 extern DWORD gPID;
-extern DWORD gSID;
 
 extern LPWSTR pAppDir;
 
@@ -50,15 +49,6 @@ extern int gApplicationGroupIdLength;
 #endif // __APPLE__
 extern PathCharString *gSharedFilesPath;
 
-/*++
-Function:
-  PROCGetProcessIDFromHandle
-
-Abstract
-  Return the process ID from a process handle
---*/
-DWORD PROCGetProcessIDFromHandle(HANDLE hProcess);
-
 /*++
 Function:
   PROCCreateInitialProcess

src/coreclr/pal/src/include/pal/procobj.hpp

@@ -23,43 +23,6 @@ Module Name:
 
 namespace CorUnix
 {
-    extern CObjectType otProcess;
-
-    //
-    // Ideally dwProcessId would be part of the process object's immutable
-    // data. Doing so, though, creates complications in CreateProcess. The
-    // contents of the immutable data for a new object must be set before
-    // that object is registered with the object manager (as the object
-    // manager may make a copy of the immutable data). The PID for a new
-    // process, though, is not known until after creation. Registering the
-    // process object after process creation creates an undesirable error path
-    // -- if we are not able to register the process object (say, because of
-    // a low resource condition) we would be forced to return an error to
-    // the caller of CreateProcess, even though the new process was actually
-    // created...
-    //
-    // Note: we could work around this by effectively always going down
-    // the create suspended path. That is, the new process would not exec until
-    // the parent process released it. It's unclear how much benefit this would
-    // provide us.
-    //
-
-    class CProcProcessLocalData
-    {
-    public:
-        CProcProcessLocalData()
-            :
-            dwProcessId(0)
-        {
-        };
-
-        ~CProcProcessLocalData()
-        {
-        };
-
-        DWORD dwProcessId;
-    };
-
     PAL_ERROR
     InitializeProcessCommandLine(
         LPWSTR lpwstrCmdLine,
@@ -70,8 +33,6 @@ namespace CorUnix
     CreateInitialProcessAndThreadObjects(
         CPalThread *pThread
         );
-
-    extern IPalObject *g_pobjProcess;
 }
 
 #endif // _PAL_PROCOBJ_HPP_

src/coreclr/pal/src/init/pal.cpp

@@ -331,9 +331,8 @@ Initialize(
 
     if (init_count == 0)
     {
-        // Set our pid and sid.
+        // Set our pid.
         gPID = getpid();
-        gSID = getsid(gPID);
 
         // Initialize the thread local storage
         if (FALSE == TLSInitialize())