[compiler-rt] [scudo] Use MemMap in BufferPool and RegionPageMap (PR #66788)

[via llvm-commits]

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@@ -130,53 +143,33 @@ class BufferPool {
     if (index >= StaticBufferCount)
       return getDynamicBuffer(NumElements);
 
-    const uptr Offset = index * StaticBufferNumElements;
-    memset(&RawBuffer[Offset], 0, StaticBufferNumElements * sizeof(uptr));
-    return &RawBuffer[Offset];
+    Buffer Buf;
+    Buf.Data = &RawBuffer[index * StaticBufferNumElements];
+    Buf.BufferIndex = index;
+    memset(Buf.Data, 0, StaticBufferNumElements * sizeof(uptr));
+    return Buf;
   }
 
-  void releaseBuffer(uptr *Buffer, const uptr NumElements) {
-    const uptr index = getStaticBufferIndex(Buffer, NumElements);
-    if (index < StaticBufferCount) {
+  void releaseBuffer(Buffer Buf) {
+    DCHECK(Buf.Data != nullptr);
+    DCHECK_LE(Buf.BufferIndex, StaticBufferCount);
+    if (Buf.BufferIndex != StaticBufferCount) {
       ScopedLock L(Mutex);
-      DCHECK_EQ((Mask & (static_cast<uptr>(1) << index)), 0U);
-      Mask |= static_cast<uptr>(1) << index;
+      DCHECK_EQ((Mask & (static_cast<uptr>(1) << Buf.BufferIndex)), 0U);
+      Mask |= static_cast<uptr>(1) << Buf.BufferIndex;
     } else {
-      const uptr MappedSize =
-          roundUp(NumElements * sizeof(uptr), getPageSizeCached());
-      unmap(reinterpret_cast<void *>(Buffer), MappedSize);
+      Buf.MemMap.unmap(Buf.MemMap.getBase(), Buf.MemMap.getCapacity());
     }
   }
 
-  bool isStaticBufferTestOnly(uptr *Buffer, uptr NumElements) {
-    return getStaticBufferIndex(Buffer, NumElements) < StaticBufferCount;
+  bool isStaticBufferTestOnly(const Buffer &Buf) {
+    DCHECK(Buf.Data != nullptr);
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ChiaHungDuan wrote:

DCHECK_NE(Buf.Data, nullptr)

https://github.com/llvm/llvm-project/pull/66788