From 7cb9788ba323448053f909e5dda86bd6a4f78442 Mon Sep 17 00:00:00 2001
From: Bin Liu <binliu@fb.com>
Date: Mon, 17 May 2021 18:37:50 -0700
Subject: [PATCH] track static array in reverse data map

Reviewed By: ottoni

Differential Revision: D22850373

fbshipit-source-id: 9a0516f2d2df225f16d875fd5ecfe71a629e2386
---
 hphp/runtime/base/array-data.cpp     |  4 ++++
 hphp/runtime/base/perf-mem-event.cpp |  4 ++++
 hphp/runtime/vm/reverse-data-map.cpp | 12 ++++++++++++
 hphp/runtime/vm/reverse-data-map.h   |  4 ++++
 4 files changed, 24 insertions(+)

diff --git a/hphp/runtime/base/array-data.cpp b/hphp/runtime/base/array-data.cpp
index 39bd4640424..234e625aebe 100644
--- a/hphp/runtime/base/array-data.cpp
+++ b/hphp/runtime/base/array-data.cpp
@@ -35,6 +35,7 @@
 #include "hphp/runtime/base/variable-serializer.h"
 #include "hphp/runtime/server/memory-stats.h"
 #include "hphp/runtime/vm/interp-helpers.h"
+#include "hphp/runtime/vm/reverse-data-map.h"
 
 #include "hphp/util/exception.h"
 
@@ -235,6 +236,9 @@ void ArrayData::GetScalarArray(ArrayData** parr) {
 
   // TODO(T68458896): allocSize rounds up to size class, which we shouldn't do.
   MemoryStats::LogAlloc(AllocKind::StaticArray, allocSize(ad));
+  if (RuntimeOption::EvalEnableReverseDataMap) {
+    data_map::register_start(ad);
+  }
 
   s_cachedHash.first = ad;
   assertx(hashArrayPortion(ad) == s_cachedHash.second);
diff --git a/hphp/runtime/base/perf-mem-event.cpp b/hphp/runtime/base/perf-mem-event.cpp
index 92a4edcccd6..d87b4a9aec9 100644
--- a/hphp/runtime/base/perf-mem-event.cpp
+++ b/hphp/runtime/base/perf-mem-event.cpp
@@ -227,6 +227,10 @@ bool record_vm_metadata_mem_event(data_map::result res, const void* addr,
   assertx(!res.empty());
   match<void>(
     res,
+    [&](const ArrayData* arr) {
+      record.setInt("offset", pos - reinterpret_cast<const char*>(arr));
+      record.setStr("kind", "Array");
+    },
     [&](const Class* cls) {
       record.setInt("offset", pos - reinterpret_cast<const char*>(cls));
       record.setStr("kind", "Class");
diff --git a/hphp/runtime/vm/reverse-data-map.cpp b/hphp/runtime/vm/reverse-data-map.cpp
index 9f1a789c2fb..d6a0d0d3d89 100644
--- a/hphp/runtime/vm/reverse-data-map.cpp
+++ b/hphp/runtime/vm/reverse-data-map.cpp
@@ -16,6 +16,9 @@
 
 #include "hphp/runtime/vm/reverse-data-map.h"
 
+#include "hphp/runtime/base/array-data.h"
+#include "hphp/runtime/base/memory-manager-defs.h"
+#include "hphp/runtime/base/packed-array-defs.h"
 #include "hphp/runtime/base/string-data.h"
 #include "hphp/runtime/vm/class.h"
 #include "hphp/runtime/vm/func.h"
@@ -37,6 +40,7 @@ namespace {
 ///////////////////////////////////////////////////////////////////////////////
 
 #define META_TYPES \
+  X(ArrayData)\
   X(Class)\
   X(Func)\
   X(NamedEntity)\
@@ -50,6 +54,7 @@ enum class Kind : uint8_t {
   NamedEntity = 3,
   StringData = 4,
   Unit = 5,
+  ArrayData = 6,
 };
 
 constexpr size_t kChunkSize = 1 << 21;
@@ -111,6 +116,13 @@ void deregister(Kind /*kind*/, const void* meta) {
  * These routines account for variable-length prefix or suffix allocations,
  * such as Class's funcVec and classVec, or StringData's data().
  */
+bool contains(const ArrayData* arr, const void* addr) {
+  auto const start = reinterpret_cast<const char*>(arr);
+  if (addr < start) return false;
+  size_t heapSize = allocSize(arr);
+  return addr < start + heapSize;
+}
+
 bool contains(const Class* cls, const void* addr) {
   return cls->funcVec() <= addr && addr < cls->mallocEnd();
 }
diff --git a/hphp/runtime/vm/reverse-data-map.h b/hphp/runtime/vm/reverse-data-map.h
index a54b0d5bad9..b10a1753c61 100644
--- a/hphp/runtime/vm/reverse-data-map.h
+++ b/hphp/runtime/vm/reverse-data-map.h
@@ -20,6 +20,7 @@
 
 namespace HPHP {
 
+struct ArrayData;
 struct Class;
 struct Func;
 struct NamedEntity;
@@ -39,6 +40,7 @@ namespace data_map {
  *
  * The object pointer must be 16-byte aligned.
  */
+void register_start(const ArrayData*);
 void register_start(const Class*);
 void register_start(const Func*);
 void register_start(const NamedEntity*);
@@ -51,6 +53,7 @@ void register_start(const Unit*);
  * Requires that register_start() was called on the object, and it has not yet
  * been deregistered.
  */
+void deregister(const ArrayData*);
 void deregister(const Class*);
 void deregister(const Func*);
 void deregister(const NamedEntity*);
@@ -67,6 +70,7 @@ void deregister(const Unit*);
  * Returns an empty result if `addr' is not mapped.
  */
 using result = folly::DiscriminatedPtr<
+  ArrayData,
   Class,
   Func,
   NamedEntity,
-- 
2.11.4.GIT