Fix hsa_support::timestamp_ns if HSA is not yet initialized

Default to the HSA runtime's hsa_system_get_info if the saved HSA
functions table is not yet initialized.

Change-Id: I3659095a5ad662f7ca8b0d92bd035901c6d66bb0

test/directed/dlopen.cpp

@@ -0,0 +1,94 @@
+/* Copyright (c) 2022 Advanced Micro Devices, Inc.
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ THE SOFTWARE. */
+
+
+#include "roctracer.h"
+
+#include <dlfcn.h>
+#include <hsa/hsa.h>
+
+#include <cassert>
+
+using get_timestamp_t = decltype(roctracer_get_timestamp);
+using hsa_init_t = decltype(hsa_init);
+using hsa_shut_down_t = decltype(hsa_shut_down);
+
+int main() {
+  // CASE 1: HSA is not loaded.
+  //
+  {
+    void* tracer_library = dlopen("libroctracer64.so", RTLD_LAZY);
+    assert(tracer_library != nullptr);
+
+    auto* get_timestamp =
+        reinterpret_cast<get_timestamp_t*>(dlsym(tracer_library, "roctracer_get_timestamp"));
+    assert(get_timestamp != nullptr);
+
+    roctracer_timestamp_t timestamp;
+    (*get_timestamp)(&timestamp);
+    dlclose(tracer_library);
+  }
+
+  // CASE 2 Load the roctracer after hsa_init().
+  //
+  void* hsa_library = dlopen("libhsa-runtime64.so.1", RTLD_LAZY);
+  assert(hsa_library != nullptr);
+
+  auto* hsa_init = reinterpret_cast<hsa_init_t*>(dlsym(hsa_library, "hsa_init"));
+  auto* hsa_shut_down = reinterpret_cast<hsa_shut_down_t*>(dlsym(hsa_library, "hsa_shut_down"));
+  assert(hsa_init != nullptr && hsa_shut_down != nullptr);
+
+  {
+    (*hsa_init)();
+
+    void* tracer_library = dlopen("libroctracer64.so", RTLD_LAZY);
+    assert(tracer_library != nullptr);
+
+    auto* get_timestamp =
+        reinterpret_cast<get_timestamp_t*>(dlsym(tracer_library, "roctracer_get_timestamp"));
+    assert(get_timestamp != nullptr);
+
+    roctracer_timestamp_t timestamp;
+    (*get_timestamp)(&timestamp);
+
+    dlclose(tracer_library);
+    (*hsa_shut_down)();
+  }
+
+  // CASE 3: Load and use the roctracer before hsa_init().
+  //
+  {
+    void* tracer_library = dlopen("libroctracer64.so", RTLD_LAZY);
+    assert(tracer_library != nullptr);
+
+    auto* get_timestamp =
+        reinterpret_cast<get_timestamp_t*>(dlsym(tracer_library, "roctracer_get_timestamp"));
+    assert(get_timestamp != nullptr);
+
+    roctracer_timestamp_t timestamp;
+    (*get_timestamp)(&timestamp);
+
+    (*hsa_init)();
+    (*hsa_shut_down)();
+    dlclose(tracer_library);
+  }
+
+  return 0;
+}