From a089c4ea3221ae8a21ccee5fbe51141713ec92ea Mon Sep 17 00:00:00 2001
From: Quantum <quantum2048@gmail.com>
Date: Thu, 18 Mar 2021 19:05:51 -0400
Subject: [PATCH] [host] service: introduce fatal errors for ivshmem failures

Also for failure to parse command line. For these errors, restarting
with exponential backoff will not help: no amount of restarting the
service could possibly make the ivshmem device exist or larger, so
we shouldn't try.
---
 host/include/interface/platform.h   |  2 ++
 host/platform/Windows/src/service.c |  4 ++++
 host/src/app.c                      | 24 ++++++++++++------------
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/host/include/interface/platform.h b/host/include/interface/platform.h
index 4331ab44..c9b1beef 100644
--- a/host/include/interface/platform.h
+++ b/host/include/interface/platform.h
@@ -29,6 +29,8 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #define LG_HOST_EXIT_KILLED  0x30
 // exit code for failed to start
 #define LG_HOST_EXIT_FAILED  0x40
+// exit code for failed to start, and no amount of restarting could help
+#define LG_HOST_EXIT_FATAL   0x50
 
 int  app_main(int argc, char * argv[]);
 bool app_init();
diff --git a/host/platform/Windows/src/service.c b/host/platform/Windows/src/service.c
index ea355158..b5a3970f 100644
--- a/host/platform/Windows/src/service.c
+++ b/host/platform/Windows/src/service.c
@@ -717,6 +717,10 @@ VOID WINAPI SvcMain(DWORD dwArgc, LPTSTR *lpszArgv)
               break;
             }
 
+            case LG_HOST_EXIT_FATAL:
+              doLog("Host application failed to start with fatal error; will not restart\n");
+              goto stopped;
+
             default:
               doLog("Host application failed due to unknown error; restarting\n");
               break;
diff --git a/host/src/app.c b/host/src/app.c
index fdc752e7..7f092117 100644
--- a/host/src/app.c
+++ b/host/src/app.c
@@ -440,7 +440,7 @@ int app_main(int argc, char * argv[])
   {
     option_free();
     DEBUG_ERROR("Failed to get the application's data path");
-    return LG_HOST_EXIT_FAILED;
+    return LG_HOST_EXIT_FATAL;
   }
 
   const size_t len = strlen(dataPath) + sizeof(CONFIG_FILE) + 1;
@@ -457,18 +457,18 @@ int app_main(int argc, char * argv[])
   {
     option_free();
     DEBUG_ERROR("Failure to parse the command line");
-    return LG_HOST_EXIT_FAILED;
+    return LG_HOST_EXIT_FATAL;
   }
 
   if (!option_validate())
   {
     option_free();
-    return LG_HOST_EXIT_FAILED;
+    return LG_HOST_EXIT_FATAL;
   }
 
   // perform platform specific initialization
   if (!app_init())
-    return LG_HOST_EXIT_FAILED;
+    return LG_HOST_EXIT_FATAL;
 
   DEBUG_INFO("Looking Glass Host (%s)", BUILD_VERSION);
 
@@ -476,13 +476,13 @@ int app_main(int argc, char * argv[])
   if (!ivshmemInit(&shmDev))
   {
     DEBUG_ERROR("Failed to find the IVSHMEM device");
-    return LG_HOST_EXIT_FAILED;
+    return LG_HOST_EXIT_FATAL;
   }
 
   if (!ivshmemOpen(&shmDev))
   {
     DEBUG_ERROR("Failed to open the IVSHMEM device");
-    return LG_HOST_EXIT_FAILED;
+    return LG_HOST_EXIT_FATAL;
   }
 
   int exitcode  = 0;
@@ -502,21 +502,21 @@ int app_main(int argc, char * argv[])
           sizeof(udata), (uint8_t *)&udata)) != LGMP_OK)
   {
     DEBUG_ERROR("lgmpHostInit Failed: %s", lgmpStatusString(status));
-    exitcode = LG_HOST_EXIT_FAILED;
+    exitcode = LG_HOST_EXIT_FATAL;
     goto fail_ivshmem;
   }
 
   if ((status = lgmpHostQueueNew(app.lgmp, FRAME_QUEUE_CONFIG, &app.frameQueue)) != LGMP_OK)
   {
     DEBUG_ERROR("lgmpHostQueueCreate Failed (Frame): %s", lgmpStatusString(status));
-    exitcode = LG_HOST_EXIT_FAILED;
+    exitcode = LG_HOST_EXIT_FATAL;
     goto fail_lgmp;
   }
 
   if ((status = lgmpHostQueueNew(app.lgmp, POINTER_QUEUE_CONFIG, &app.pointerQueue)) != LGMP_OK)
   {
     DEBUG_ERROR("lgmpHostQueueNew Failed (Pointer): %s", lgmpStatusString(status));
-    exitcode = LG_HOST_EXIT_FAILED;
+    exitcode = LG_HOST_EXIT_FATAL;
     goto fail_lgmp;
   }
 
@@ -525,7 +525,7 @@ int app_main(int argc, char * argv[])
     if ((status = lgmpHostMemAlloc(app.lgmp, MAX_POINTER_SIZE, &app.pointerMemory[i])) != LGMP_OK)
     {
       DEBUG_ERROR("lgmpHostMemAlloc Failed (Pointer): %s", lgmpStatusString(status));
-      exitcode = LG_HOST_EXIT_FAILED;
+      exitcode = LG_HOST_EXIT_FATAL;
       goto fail_lgmp;
     }
     memset(lgmpHostMemPtr(app.pointerMemory[i]), 0, MAX_POINTER_SIZE);
@@ -535,7 +535,7 @@ int app_main(int argc, char * argv[])
   if ((status = lgmpHostMemAlloc(app.lgmp, MAX_POINTER_SIZE, &app.pointerShape)) != LGMP_OK)
   {
     DEBUG_ERROR("lgmpHostMemAlloc Failed (Pointer Shape): %s", lgmpStatusString(status));
-    exitcode = LG_HOST_EXIT_FAILED;
+    exitcode = LG_HOST_EXIT_FATAL;
     goto fail_lgmp;
   }
 
@@ -550,7 +550,7 @@ int app_main(int argc, char * argv[])
     if ((status = lgmpHostMemAllocAligned(app.lgmp, app.maxFrameSize, sz, &app.frameMemory[i])) != LGMP_OK)
     {
       DEBUG_ERROR("lgmpHostMemAlloc Failed (Frame): %s", lgmpStatusString(status));
-      exitcode = LG_HOST_EXIT_FAILED;
+      exitcode = LG_HOST_EXIT_FATAL;
       goto fail_lgmp;
     }
   }