added a lightweight GC profiling option (#22866)

added a profiling event mask in the high 32-bit, COR_PRF_HIGH_BASIC_GC, for basic GC monitoring. it can be set via `ICorProfilerInfo5::SetEventMask2`. all this gives you is

    * GC start callback

    * GC end callback

    * update generational bounds


note that one different behavior between this and the existing COR_PRF_MONITOR_GC is, aside from the obvious that it doesn't give you any info beyond the above, is that the GC end callback + update generational bounds are enabled for _all_ GCs, not just non concurrent GCs. I kept the behavior the same for COR_PRF_MONITOR_GC because I don't want to risk breaking existing profiling tools that do not anticipate these for concurrent GCs.

1 files changed, 8 insertions, 1 deletions

diff --git a/src/vm/gcenv.ee.cpp b/src/vm/gcenv.ee.cpp
index 6ecd325a08..f27d3f32c8 100644
--- a/src/vm/gcenv.ee.cpp
+++ b/src/vm/gcenv.ee.cpp
@@ -742,7 +742,7 @@ void GCToEEInterface::DiagGCStart(int gen, bool isInduced)
 void GCToEEInterface::DiagUpdateGenerationBounds()
 {
 #ifdef GC_PROFILING
-    if (CORProfilerTrackGC())
+    if (CORProfilerTrackGC() || CORProfilerTrackBasicGC())
         UpdateGenerationBounds();
 #endif // GC_PROFILING
 }
@@ -750,9 +750,16 @@ void GCToEEInterface::DiagUpdateGenerationBounds()
 void GCToEEInterface::DiagGCEnd(size_t index, int gen, int reason, bool fConcurrent)
 {
 #ifdef GC_PROFILING
+    // We were only doing generation bounds and GC finish callback for non concurrent GCs so
+    // I am keeping that behavior to not break profilers. But if BasicGC monitoring is enabled
+    // we will do these for all GCs.
     if (!fConcurrent)
     {
         GCProfileWalkHeap();
+    }
+
+    if (CORProfilerTrackBasicGC() || (!fConcurrent && CORProfilerTrackGC()))
+    {
         DiagUpdateGenerationBounds();
         GarbageCollectionFinishedCallback();
     }