From d63a4e4b22a25668ef527444745ed3411134ccd3 Mon Sep 17 00:00:00 2001
From: Aleksandar Micic <Aleksandar_Micic@ca.ibm.com>
Date: Wed, 13 Sep 2023 14:26:36 -0400
Subject: [PATCH] Cumulative thread allocation stats

Provide API to return allocation bytes since the start of VM. Return
false if the sum rolls over.

Signed-off-by: Aleksandar Micic <Aleksandar_Micic@ca.ibm.com>
---
 gc/stats/AllocationStats.cpp |  4 ++++
 gc/stats/AllocationStats.hpp | 13 +++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/gc/stats/AllocationStats.cpp b/gc/stats/AllocationStats.cpp
index cf6d46f5868..2bf49b19cec 100644
--- a/gc/stats/AllocationStats.cpp
+++ b/gc/stats/AllocationStats.cpp
@@ -26,6 +26,10 @@
 void
 MM_AllocationStats::clear()
 {
+	/* calculate cumulative stats before any clear */
+	_allocationBytesCumulative += bytesAllocated();
+
+
 #if defined(OMR_GC_THREAD_LOCAL_HEAP)
 	_tlhRefreshCountFresh = 0;
 	_tlhRefreshCountReused = 0;
diff --git a/gc/stats/AllocationStats.hpp b/gc/stats/AllocationStats.hpp
index f5554b4d64d..2132c39484c 100644
--- a/gc/stats/AllocationStats.hpp
+++ b/gc/stats/AllocationStats.hpp
@@ -49,6 +49,7 @@ class MM_AllocationStats : public MM_Base
 
 	uintptr_t _allocationCount;
 	uintptr_t _allocationBytes;
+	uintptr_t _allocationBytesCumulative;   /**< cumulative allocation up to last clear, excluding since last clear */
 	uintptr_t _ownableSynchronizerObjectCount;  /**< Number of Ownable Synchronizer Object allocations */
 	uintptr_t _continuationObjectCount;  /**< Number of Continuation Object allocations */
 	uintptr_t _discardedBytes;
@@ -86,6 +87,18 @@ class MM_AllocationStats : public MM_Base
 		return totalBytesAllocated;
 	}
 
+	bool bytesAllocatedCumulative(uintptr_t *cumulativeValue) {
+		if (NULL != cumulativeValue) {
+			/* sum the values up to last clear and since last clear */
+			*cumulativeValue = _allocationBytesCumulative + bytesAllocated();
+
+			/* return false if overflowing */
+			return (_allocationBytesCumulative <= *cumulativeValue);
+		}
+
+		return false;
+	}
+
 	MM_AllocationStats() :
 #if defined(OMR_GC_THREAD_LOCAL_HEAP)
 		_tlhRefreshCountFresh(0),