Prevent reinit when zes/ze handles have already been retrieved (#192)

- Given ze or zes driver get has been called, then one cannot allow for
  the ddi table to be reinit to avoid breaking the user's existing
handles.

Signed-off-by: Neil R. Spruit <neil.r.spruit@intel.com>

scripts/templates/libapi.cpp.mako

@@ -127,6 +127,9 @@ ${th.make_func_name(n, tags, obj)}(
         else
             return ${X}_RESULT_ERROR_UNSUPPORTED_FEATURE;
     }
+%if re.match(r"\w+DriverGet$", th.make_func_name(n, tags, obj)):
+    ze_lib::context->${n}Inuse = true;
+%endif
 
     return ${th.make_pfn_name(n, tags, obj)}( ${", ".join(th.make_param_lines(n, tags, obj, format=["name"]))} );
 }

source/lib/ze_lib.cpp

@@ -112,10 +112,9 @@ namespace ze_lib
             auto sysmanEnv = getenv_tobool( "ZES_ENABLE_SYSMAN" );
             result = zelLoaderDriverCheck(flags, &ze_lib::context->initialzeDdiTable.Global, &ze_lib::context->initialzesDdiTable.Global, &requireDdiReinit, sysmanOnly);
             // If a driver was removed from the driver list, then the ddi tables need to be reinit to allow for passthru directly to the driver.
-            // If ZET_ENABLE_PROGRAM_INSTRUMENTATION is enabled, then reInit is not possible due to the functions being intercepted with the previous ddi tables.
-            auto programInstrumentationEnabled = getenv_tobool( "ZET_ENABLE_PROGRAM_INSTRUMENTATION" );
-            if (requireDdiReinit && !programInstrumentationEnabled) {
-                if (!sysmanOnly) {
+            if (requireDdiReinit) {
+                // If a user has already called the core apis, then ddi table reinit is not possible due to handles already being read by the user.
+                if (!sysmanOnly && !ze_lib::context->zeInuse) {
                     // reInit the ZE DDI Tables
                     if( ZE_RESULT_SUCCESS == result )
                     {
@@ -131,7 +130,8 @@ namespace ze_lib
                     // Translation is only required if the intercept layer is enabled for the ZE handle types.
                     loader::context->intercept_enabled = false;
                 }
-                if (sysmanOnly || sysmanEnv) {
+                // If a user has already called the zes/ze apis, then ddi table reinit is not possible due to handles already being read by the user.
+                if ((sysmanOnly || sysmanEnv) && !(ze_lib::context->zesInuse || ze_lib::context->zeInuse)) {
                     // reInit the ZES DDI Tables
                     if( ZE_RESULT_SUCCESS == result )
                     {

source/lib/ze_lib.h

@@ -59,6 +59,8 @@ namespace ze_lib
         HMODULE tracing_lib = nullptr;
         bool isInitialized = false;
         bool inTeardown = false;
+        bool zesInuse = false;
+        bool zeInuse = false;
     };
 
     extern context_t *context;

source/lib/ze_libapi.cpp

@@ -125,6 +125,7 @@ zeDriverGet(
         else
             return ZE_RESULT_ERROR_UNSUPPORTED_FEATURE;
     }
+    ze_lib::context->zeInuse = true;
 
     return pfnGet( pCount, phDrivers );
 }

source/lib/zes_libapi.cpp

@@ -120,6 +120,7 @@ zesDriverGet(
         else
             return ZE_RESULT_ERROR_UNSUPPORTED_FEATURE;
     }
+    ze_lib::context->zesInuse = true;
 
     return pfnGet( pCount, phDrivers );
 }