SDK: No bg thread if no clients use SDK (#123)

* SDK: No bg thread if no clients use SDK

* Update CHANGELOG

---------

Co-authored-by: Jonathan R. Madsen <jonathanrmadsen@gmail.com>

tests/c-tool/CMakeLists.txt

@@ -36,7 +36,8 @@ set_tests_properties(
         PASS_REGULAR_EXPRESSION
         "Test C tool \\(priority=0\\) is using rocprofiler-sdk v([0-9]+\\.[0-9]+\\.[0-9]+)"
         FAIL_REGULAR_EXPRESSION
-        "${ROCPROFILER_DEFAULT_FAIL_REGEX}")
+        "${ROCPROFILER_DEFAULT_FAIL_REGEX}|Internal thread for rocprofiler-sdk should not be created"
+    )
 
 # this test uses ROCP_TOOL_LIBRARIES instead of LD_PRELOAD
 add_test(NAME test-c-tool-rocp-tool-lib-execute COMMAND $<TARGET_FILE:transpose> 1)
@@ -59,4 +60,5 @@ set_tests_properties(
         PASS_REGULAR_EXPRESSION
         "Test C tool \\(priority=0\\) is using rocprofiler-sdk v([0-9]+\\.[0-9]+\\.[0-9]+)"
         FAIL_REGULAR_EXPRESSION
-        "${ROCPROFILER_DEFAULT_FAIL_REGEX}")
+        "${ROCPROFILER_DEFAULT_FAIL_REGEX}|Internal thread for rocprofiler-sdk should not be created"
+    )

tests/tools/c-tool.c

@@ -34,6 +34,29 @@
 #include <rocprofiler-sdk/registration.h>
 #include <rocprofiler-sdk/rocprofiler.h>
 
+#include <stdio.h>
+#include <stdlib.h>
+
+static void
+thread_precreate(rocprofiler_runtime_library_t lib, void* tool_data)
+{
+    uint32_t* priority = (uint32_t*) tool_data;
+
+    if(priority && *priority == 0)
+    {
+        fprintf(
+            stderr,
+            "Internal thread for rocprofiler-sdk should not be created when all tools return NULL "
+            "from rocprofiler_configure\n");
+        fflush(stderr);
+        abort();
+    }
+
+    (void) lib;
+}
+
+static uint32_t tool_priority = 0;
+
 rocprofiler_tool_configure_result_t*
 rocprofiler_configure(uint32_t                 version,
                       const char*              runtime_version,
@@ -43,6 +66,8 @@ rocprofiler_configure(uint32_t                 version,
     // set the client name
     id->name = "Test C tool";
 
+    tool_priority = priority;
+
     // compute major/minor/patch version info
     uint32_t major = version / 10000;
     uint32_t minor = (version % 10000) / 100;
@@ -57,6 +82,9 @@ rocprofiler_configure(uint32_t                 version,
            patch,
            runtime_version);
 
+    rocprofiler_at_internal_thread_create(
+        thread_precreate, NULL, ROCPROFILER_LIBRARY, &tool_priority);
+
     // return pointer to configure data
     return NULL;
 }