encapsulate and instrument

include/xrpl/basics/MallocTrim.h

@@ -0,0 +1,42 @@
+#ifndef XRPL_BASICS_MALLOCTRIM_H_INCLUDED
+#define XRPL_BASICS_MALLOCTRIM_H_INCLUDED
+
+#include <xrpl/beast/utility/Journal.h>
+
+#include <optional>
+#include <string>
+
+namespace ripple {
+
+struct MallocTrimReport
+{
+    bool supported{false};
+    int trimResult{-1};
+    long rssBeforeKB{-1};
+    long rssAfterKB{-1};
+
+    long
+    deltaKB() const
+    {
+        return rssAfterKB - rssBeforeKB;
+    }
+};
+
+/** Attempt to return freed memory to the operating system.
+ *
+ * This function is only effective on Linux with glibc. On other platforms,
+ * it returns a report indicating the operation is unsupported.
+ *
+ * @param tag Optional identifier for logging/debugging purposes
+ * @param journal Journal for logging diagnostic information
+ * @return Report containing before/after memory metrics
+ *
+ * @note This is intended for use after cache sweeps or other operations
+ *       that free significant amounts of memory.
+ */
+MallocTrimReport
+mallocTrim(std::optional<std::string> const& tag, beast::Journal journal);
+
+}  // namespace ripple
+
+#endif

include/xrpl/basics/TaggedCache.ipp

@@ -2,12 +2,9 @@
 #define XRPL_BASICS_TAGGEDCACHE_IPP_INCLUDED
 
 #include <xrpl/basics/IntrusivePointer.ipp>
+#include <xrpl/basics/MallocTrim.h>
 #include <xrpl/basics/TaggedCache.h>
 
-#ifdef __GLIBC__
-#include <malloc.h>
-#endif
-
 namespace ripple {
 
 template <
@@ -331,9 +328,7 @@ TaggedCache<
                .count()
         << "ms";
 
-#ifdef __GLIBC__
-    (void)malloc_trim(0);
-#endif
+    mallocTrim(std::optional<std::string>(m_name), m_journal);
 }
 
 template <