libsanitizer/sanitizer_common/sanitizer_allocator_combined.h

   1 //===-- sanitizer_allocator_combined.h --------------------------*- C++ -*-===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // Part of the Sanitizer Allocator.
   9 //
  10 //===----------------------------------------------------------------------===//
  11 #ifndef SANITIZER_ALLOCATOR_H
  12 #error This file must be included inside sanitizer_allocator.h
  13 #endif
  14
  15 // This class implements a complete memory allocator by using two
  16 // internal allocators:
  17 // PrimaryAllocator is efficient, but may not allocate some sizes (alignments).
  18 //  When allocating 2^x bytes it should return 2^x aligned chunk.
  19 // PrimaryAllocator is used via a local AllocatorCache.
  20 // SecondaryAllocator can allocate anything, but is not efficient.
  21 template <class PrimaryAllocator, class AllocatorCache,
  22           class SecondaryAllocator>  // NOLINT
  23 class CombinedAllocator {
  24  public:
  25   void InitCommon(bool may_return_null) {
  26     primary_.Init();
  27     atomic_store(&may_return_null_, may_return_null, memory_order_relaxed);
  28   }
  29
  30   void InitLinkerInitialized(bool may_return_null) {
  31     secondary_.InitLinkerInitialized(may_return_null);
  32     stats_.InitLinkerInitialized();
  33     InitCommon(may_return_null);
  34   }
  35
  36   void Init(bool may_return_null) {
  37     secondary_.Init(may_return_null);
  38     stats_.Init();
  39     InitCommon(may_return_null);
  40   }
  41
  42   void *Allocate(AllocatorCache *cache, uptr size, uptr alignment,
  43                  bool cleared = false, bool check_rss_limit = false) {
  44     // Returning 0 on malloc(0) may break a lot of code.
  45     if (size == 0)
  46       size = 1;
  47     if (size + alignment < size) return ReturnNullOrDieOnBadRequest();
  48     if (check_rss_limit && RssLimitIsExceeded()) return ReturnNullOrDieOnOOM();
  49     if (alignment > 8)
  50       size = RoundUpTo(size, alignment);
  51     void *res;
  52     bool from_primary = primary_.CanAllocate(size, alignment);
  53     if (from_primary)
  54       res = cache->Allocate(&primary_, primary_.ClassID(size));
  55     else
  56       res = secondary_.Allocate(&stats_, size, alignment);
  57     if (alignment > 8)
  58       CHECK_EQ(reinterpret_cast<uptr>(res) & (alignment - 1), 0);
  59     if (cleared && res && from_primary)
  60       internal_bzero_aligned16(res, RoundUpTo(size, 16));
  61     return res;
  62   }
  63
  64   bool MayReturnNull() const {
  65     return atomic_load(&may_return_null_, memory_order_acquire);
  66   }
  67
  68   void *ReturnNullOrDieOnBadRequest() {
  69     if (MayReturnNull())
  70       return nullptr;
  71     ReportAllocatorCannotReturnNull(false);
  72   }
  73
  74   void *ReturnNullOrDieOnOOM() {
  75     if (MayReturnNull()) return nullptr;
  76     ReportAllocatorCannotReturnNull(true);
  77   }
  78
  79   void SetMayReturnNull(bool may_return_null) {
  80     secondary_.SetMayReturnNull(may_return_null);
  81     atomic_store(&may_return_null_, may_return_null, memory_order_release);
  82   }
  83
  84   bool RssLimitIsExceeded() {
  85     return atomic_load(&rss_limit_is_exceeded_, memory_order_acquire);
  86   }
  87
  88   void SetRssLimitIsExceeded(bool rss_limit_is_exceeded) {
  89     atomic_store(&rss_limit_is_exceeded_, rss_limit_is_exceeded,
  90                  memory_order_release);
  91   }
  92
  93   void Deallocate(AllocatorCache *cache, void *p) {
  94     if (!p) return;
  95     if (primary_.PointerIsMine(p))
  96       cache->Deallocate(&primary_, primary_.GetSizeClass(p), p);
  97     else
  98       secondary_.Deallocate(&stats_, p);
  99   }
 100
 101   void *Reallocate(AllocatorCache *cache, void *p, uptr new_size,
 102                    uptr alignment) {
 103     if (!p)
 104       return Allocate(cache, new_size, alignment);
 105     if (!new_size) {
 106       Deallocate(cache, p);
 107       return nullptr;
 108     }
 109     CHECK(PointerIsMine(p));
 110     uptr old_size = GetActuallyAllocatedSize(p);
 111     uptr memcpy_size = Min(new_size, old_size);
 112     void *new_p = Allocate(cache, new_size, alignment);
 113     if (new_p)
 114       internal_memcpy(new_p, p, memcpy_size);
 115     Deallocate(cache, p);
 116     return new_p;
 117   }
 118
 119   bool PointerIsMine(void *p) {
 120     if (primary_.PointerIsMine(p))
 121       return true;
 122     return secondary_.PointerIsMine(p);
 123   }
 124
 125   bool FromPrimary(void *p) {
 126     return primary_.PointerIsMine(p);
 127   }
 128
 129   void *GetMetaData(const void *p) {
 130     if (primary_.PointerIsMine(p))
 131       return primary_.GetMetaData(p);
 132     return secondary_.GetMetaData(p);
 133   }
 134
 135   void *GetBlockBegin(const void *p) {
 136     if (primary_.PointerIsMine(p))
 137       return primary_.GetBlockBegin(p);
 138     return secondary_.GetBlockBegin(p);
 139   }
 140
 141   // This function does the same as GetBlockBegin, but is much faster.
 142   // Must be called with the allocator locked.
 143   void *GetBlockBeginFastLocked(void *p) {
 144     if (primary_.PointerIsMine(p))
 145       return primary_.GetBlockBegin(p);
 146     return secondary_.GetBlockBeginFastLocked(p);
 147   }
 148
 149   uptr GetActuallyAllocatedSize(void *p) {
 150     if (primary_.PointerIsMine(p))
 151       return primary_.GetActuallyAllocatedSize(p);
 152     return secondary_.GetActuallyAllocatedSize(p);
 153   }
 154
 155   uptr TotalMemoryUsed() {
 156     return primary_.TotalMemoryUsed() + secondary_.TotalMemoryUsed();
 157   }
 158
 159   void TestOnlyUnmap() { primary_.TestOnlyUnmap(); }
 160
 161   void InitCache(AllocatorCache *cache) {
 162     cache->Init(&stats_);
 163   }
 164
 165   void DestroyCache(AllocatorCache *cache) {
 166     cache->Destroy(&primary_, &stats_);
 167   }
 168
 169   void SwallowCache(AllocatorCache *cache) {
 170     cache->Drain(&primary_);
 171   }
 172
 173   void GetStats(AllocatorStatCounters s) const {
 174     stats_.Get(s);
 175   }
 176
 177   void PrintStats() {
 178     primary_.PrintStats();
 179     secondary_.PrintStats();
 180   }
 181
 182   // ForceLock() and ForceUnlock() are needed to implement Darwin malloc zone
 183   // introspection API.
 184   void ForceLock() {
 185     primary_.ForceLock();
 186     secondary_.ForceLock();
 187   }
 188
 189   void ForceUnlock() {
 190     secondary_.ForceUnlock();
 191     primary_.ForceUnlock();
 192   }
 193
 194   void ReleaseToOS() { primary_.ReleaseToOS(); }
 195
 196   // Iterate over all existing chunks.
 197   // The allocator must be locked when calling this function.
 198   void ForEachChunk(ForEachChunkCallback callback, void *arg) {
 199     primary_.ForEachChunk(callback, arg);
 200     secondary_.ForEachChunk(callback, arg);
 201   }
 202
 203  private:
 204   PrimaryAllocator primary_;
 205   SecondaryAllocator secondary_;
 206   AllocatorGlobalStats stats_;
 207   atomic_uint8_t may_return_null_;
 208   atomic_uint8_t rss_limit_is_exceeded_;
 209 };