[tsan] more code for a specialized tsan allocator

llvm-svn: 158991
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_allocator64.h b/compiler-rt/lib/sanitizer_common/sanitizer_allocator64.h
index 2129681..1d76fc7 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_allocator64.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_allocator64.h
@@ -22,7 +22,7 @@
 
 namespace __sanitizer {
 
-// Maps size class to size and back.
+// Maps size class id to size and back.
 class DefaultSizeClassMap {
  private:
   // Here we use a spline composed of 5 polynomials of oder 1.
@@ -53,19 +53,20 @@
  public:
   static const uptr kNumClasses = u4 + 1;
   static const uptr kMaxSize = l5;
+  static const uptr kMinSize = l0;
 
   COMPILER_CHECK(kNumClasses <= 256);
   COMPILER_CHECK((kMaxSize & (kMaxSize - 1)) == 0);
 
-  static uptr Size(uptr size_class) {
-    if (size_class <= u0) return l0 + s0 * (size_class - 0);
-    if (size_class <= u1) return l1 + s1 * (size_class - u0);
-    if (size_class <= u2) return l2 + s2 * (size_class - u1);
-    if (size_class <= u3) return l3 + s3 * (size_class - u2);
-    if (size_class <= u4) return l4 + s4 * (size_class - u3);
+  static uptr Size(uptr class_id) {
+    if (class_id <= u0) return l0 + s0 * (class_id - 0);
+    if (class_id <= u1) return l1 + s1 * (class_id - u0);
+    if (class_id <= u2) return l2 + s2 * (class_id - u1);
+    if (class_id <= u3) return l3 + s3 * (class_id - u2);
+    if (class_id <= u4) return l4 + s4 * (class_id - u3);
     return 0;
   }
-  static uptr Class(uptr size) {
+  static uptr ClassID(uptr size) {
     if (size <= l1) return 0  + (size - l0 + s0 - 1) / s0;
     if (size <= l2) return u0 + (size - l1 + s1 - 1) / s1;
     if (size <= l3) return u1 + (size - l2 + s2 - 1) / s2;
@@ -75,6 +76,129 @@
   }
 };
 
+// Space: a portion of address space of kSpaceSize bytes starting at
+// a fixed address (kSpaceBeg). Both constants are powers of two and
+// kSpaceBeg is kSpaceSize-aligned.
+//
+// Region: a part of Space dedicated to a single size class.
+// There are kNumClasses Regions of equal size.
+//
+// UserChunk: a piece of memory returned to user.
+// MetaChunk: kMetadataSize bytes of metadata associated with a UserChunk.
+//
+// A Region looks like this:
+// UserChunk1 ... UserChunkN <gap> MetaChunkN ... MetaChunk1
+template <const uptr kSpaceBeg, const uptr kSpaceSize,
+          const uptr kMetadataSize, class SizeClassMap>
+class SizeClassAllocator64 {
+ public:
+  void Init() {
+    CHECK_EQ(AllocBeg(), reinterpret_cast<uptr>(MmapFixedNoReserve(
+             AllocBeg(), AllocSize())));
+  }
+  void *Allocate(uptr size) {
+    CHECK_LE(size, SizeClassMap::kMaxSize);
+    return AllocateBySizeClass(SizeClassMap::ClassID(size));
+  }
+  void Deallocate(void *p) {
+    DeallocateBySizeClass(p, GetSizeClass(p));
+  }
+  bool PointerIsMine(void *p) {
+    return reinterpret_cast<uptr>(p) / kSpaceSize == kSpaceBeg / kSpaceSize;
+  }
+  uptr GetSizeClass(void *p) {
+    return (reinterpret_cast<uptr>(p) / kRegionSize) % kNumClasses;
+  }
+
+  uptr TotalMemoryUsedIncludingFreeLists() {
+    uptr res = 0;
+    for (uptr i = 0; i < kNumClasses; i++)
+      res += GetRegionInfo(i)->allocated;
+    return res;
+  }
+
+  // Test-only.
+  void TestOnlyUnmap() {
+    UnmapOrDie(reinterpret_cast<void*>(AllocBeg()), AllocSize());
+  }
+ private:
+  static const uptr kNumClasses = 256;  // Power of two <= 256
+  COMPILER_CHECK(kNumClasses <= SizeClassMap::kNumClasses);
+  static const uptr kRegionSize = kSpaceSize / kNumClasses;
+  // Populate the free list with at most this number of bytes at once
+  // or with one element if its size is greater.
+  static const uptr kPopulateSize = 1 << 18;
+
+  struct LifoListNode {
+    LifoListNode *next;
+  };
+
+  struct RegionInfo {
+    uptr mutex;  // FIXME
+    LifoListNode *free_list;
+    uptr allocated;
+    char padding[kCacheLineSize -
+                 sizeof(mutex) - sizeof(free_list) - sizeof(allocated)];
+  };
+  COMPILER_CHECK(sizeof(RegionInfo) == kCacheLineSize);
+
+  uptr AdditionalSize() { return sizeof(RegionInfo) * kNumClasses; }
+  uptr AllocBeg()  { return kSpaceBeg  - AdditionalSize(); }
+  uptr AllocSize() { return kSpaceSize + AdditionalSize(); }
+
+  RegionInfo *GetRegionInfo(uptr class_id) {
+    CHECK_LT(class_id, kNumClasses);
+    RegionInfo *regions = reinterpret_cast<RegionInfo*>(kSpaceBeg);
+    return &regions[-1 - class_id];
+  }
+
+  void PushLifoList(LifoListNode **list, LifoListNode *node) {
+    node->next = *list;
+    *list = node;
+  }
+
+  LifoListNode *PopLifoList(LifoListNode **list) {
+    LifoListNode *res = *list;
+    *list = (*list)->next;
+    return res;
+  }
+
+  LifoListNode *PopulateFreeList(uptr class_id, RegionInfo *region) {
+    uptr size = SizeClassMap::Size(class_id);
+    uptr beg_idx = region->allocated;
+    uptr end_idx = beg_idx + kPopulateSize;
+    LifoListNode *res = 0;
+    uptr region_beg = kSpaceBeg + kRegionSize * class_id;
+    uptr idx = beg_idx;
+    do {  // do-while loop because we need to put at least one item.
+      uptr p = region_beg + idx;
+      PushLifoList(&res, reinterpret_cast<LifoListNode*>(p));
+      idx += size;
+    } while (idx < end_idx);
+    CHECK_LT(idx, kRegionSize);
+    region->allocated += idx - beg_idx;
+    return res;
+  }
+
+  void *AllocateBySizeClass(uptr class_id) {
+    CHECK_LT(class_id, kNumClasses);
+    RegionInfo *region = GetRegionInfo(class_id);
+    // FIXME: Lock region->mutex;
+    if (!region->free_list) {
+      region->free_list = PopulateFreeList(class_id, region);
+    }
+    CHECK_NE(region->free_list, 0);
+    LifoListNode *node = PopLifoList(&region->free_list);
+    return reinterpret_cast<void*>(node);
+  }
+
+  void DeallocateBySizeClass(void *p, uptr class_id) {
+    RegionInfo *region = GetRegionInfo(class_id);
+    // FIXME: Lock region->mutex;
+    PushLifoList(&region->free_list, reinterpret_cast<LifoListNode*>(p));
+  }
+};
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_ALLOCATOR_H