Debugger transport pipe file cleanup - Part 2

Clean up the pipe files in /tmp for unhandled managed exception termination.

Added a simple PAL shutdown API to set (one) shutdown callback handler which is used
by the debugger code to cleanup the transport thus removing the pipe files from /tmp.

This callback is executed PAL_Shutdown, ExitProcess and TerminateProcess, the later used
to terminate the process for an unhandled managed exception.

Add the __attribute__((destructor)) to the ShutdownTransport function to cover the case if
the if a third party host, the managed runtime or third party pinvoked code calls exit().

2 files changed, 47 insertions, 7 deletions

diff --git a/src/pal/inc/pal.h b/src/pal/inc/pal.h
index 660b4086c0..cec19c290e 100644
--- a/src/pal/inc/pal.h
+++ b/src/pal/inc/pal.h
@@ -569,6 +569,24 @@ PALAPI
 PAL_TerminateEx(
     int exitCode);
 
+/*++
+Function:
+  PAL_SetShutdownCallback
+
+Abstract:
+  Sets a callback that is executed when the PAL is shut down because of
+  ExitProcess, TerminateProcess or PAL_Shutdown but not PAL_Terminate/Ex.
+
+  NOTE: Currently only one callback can be set at a time.
+--*/
+typedef VOID (*PSHUTDOWN_CALLBACK)(void);
+
+PALIMPORT
+VOID
+PALAPI
+PAL_SetShutdownCallback(
+    IN PSHUTDOWN_CALLBACK callback);
+
 PALIMPORT
 void
 PALAPI
diff --git a/src/pal/src/thread/process.cpp b/src/pal/src/thread/process.cpp
index 0953bf0172..4e2a9c5571 100644
--- a/src/pal/src/thread/process.cpp
+++ b/src/pal/src/thread/process.cpp
@@ -105,46 +105,43 @@ CAllowedObjectTypes aotProcess(otiProcess);
 //
 // The representative IPalObject for this process
 //
-
 IPalObject* CorUnix::g_pobjProcess;
 
 //
 // Critical section that protects process data (e.g., the
 // list of active threads)/
 //
-
 CRITICAL_SECTION g_csProcess;
 
 //
 // List and count of active threads
 //
-
 CPalThread* CorUnix::pGThreadList;
 DWORD g_dwThreadCount;
 
 //
 // The command line and app name for the process
 //
-
 LPWSTR g_lpwstrCmdLine = NULL;
 LPWSTR g_lpwstrAppDir = NULL;
 
-/* Thread ID of thread that has started the ExitProcess process */
+// Thread ID of thread that has started the ExitProcess process 
 Volatile<LONG> terminator = 0;
 
 // Process ID of this process.
 DWORD gPID = (DWORD) -1;
 
+// Function to call during PAL/process shutdown
+PSHUTDOWN_CALLBACK g_shutdownCallback = nullptr;
+
 //
 // Key used for associating CPalThread's with the underlying pthread
 // (through pthread_setspecific)
 //
-
 pthread_key_t CorUnix::thObjKey;
 
 #define PROCESS_PELOADER_FILENAME  "clix"
 
-
 static WCHAR W16_WHITESPACE[]= {0x0020, 0x0009, 0x000D, 0};
 static WCHAR W16_WHITESPACE_DQUOTE[]= {0x0020, 0x0009, 0x000D, '"', 0};
 
@@ -1398,6 +1395,26 @@ static BOOL PROCEndProcess(HANDLE hProcess, UINT uExitCode, BOOL bTerminateUncon
 
 /*++
 Function:
+  PAL_SetShutdownCallback
+
+Abstract:
+  Sets a callback that is executed when the PAL is shut down because of
+  ExitProcess, TerminateProcess or PAL_Shutdown but not PAL_Terminate/Ex.
+
+  NOTE: Currently only one callback can be set at a time.
+--*/
+PALIMPORT
+VOID
+PALAPI
+PAL_SetShutdownCallback(
+    IN PSHUTDOWN_CALLBACK callback)
+{
+    _ASSERTE(g_shutdownCallback == nullptr);
+    g_shutdownCallback = callback;
+}
+
+/*++
+Function:
   PROCCleanupProcess
   
   Do all cleanup work for TerminateProcess, but don't terminate the process.
@@ -1407,6 +1424,11 @@ Function:
 --*/
 void PROCCleanupProcess(BOOL bTerminateUnconditionally)
 {
+    if (g_shutdownCallback != nullptr)
+    {
+        g_shutdownCallback();
+    }
+
     /* Declare the beginning of shutdown */
     PALSetShutdownIntent();