[sanitizers] split sanitizer_allocator.h into a number of smaller .h files; NFC

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@276195 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 268 insertions, 0 deletions

diff --git a/lib/sanitizer_common/sanitizer_allocator_secondary.h b/lib/sanitizer_common/sanitizer_allocator_secondary.h
new file mode 100644
index 000000000..383eccf06
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_allocator_secondary.h
@@ -0,0 +1,268 @@
+//===-- sanitizer_allocator_secondary.h -------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Part of the Sanitizer Allocator.
+//
+//===----------------------------------------------------------------------===//
+#ifndef SANITIZER_ALLOCATOR_H
+#error This file must be included inside sanitizer_allocator.h
+#endif
+
+// This class can (de)allocate only large chunks of memory using mmap/unmap.
+// The main purpose of this allocator is to cover large and rare allocation
+// sizes not covered by more efficient allocators (e.g. SizeClassAllocator64).
+template <class MapUnmapCallback = NoOpMapUnmapCallback>
+class LargeMmapAllocator {
+ public:
+  void InitLinkerInitialized(bool may_return_null) {
+    page_size_ = GetPageSizeCached();
+    atomic_store(&may_return_null_, may_return_null, memory_order_relaxed);
+  }
+
+  void Init(bool may_return_null) {
+    internal_memset(this, 0, sizeof(*this));
+    InitLinkerInitialized(may_return_null);
+  }
+
+  void *Allocate(AllocatorStats *stat, uptr size, uptr alignment) {
+    CHECK(IsPowerOfTwo(alignment));
+    uptr map_size = RoundUpMapSize(size);
+    if (alignment > page_size_)
+      map_size += alignment;
+    // Overflow.
+    if (map_size < size)
+      return ReturnNullOrDie();
+    uptr map_beg = reinterpret_cast<uptr>(
+        MmapOrDie(map_size, "LargeMmapAllocator"));
+    CHECK(IsAligned(map_beg, page_size_));
+    MapUnmapCallback().OnMap(map_beg, map_size);
+    uptr map_end = map_beg + map_size;
+    uptr res = map_beg + page_size_;
+    if (res & (alignment - 1))  // Align.
+      res += alignment - (res & (alignment - 1));
+    CHECK(IsAligned(res, alignment));
+    CHECK(IsAligned(res, page_size_));
+    CHECK_GE(res + size, map_beg);
+    CHECK_LE(res + size, map_end);
+    Header *h = GetHeader(res);
+    h->size = size;
+    h->map_beg = map_beg;
+    h->map_size = map_size;
+    uptr size_log = MostSignificantSetBitIndex(map_size);
+    CHECK_LT(size_log, ARRAY_SIZE(stats.by_size_log));
+    {
+      SpinMutexLock l(&mutex_);
+      uptr idx = n_chunks_++;
+      chunks_sorted_ = false;
+      CHECK_LT(idx, kMaxNumChunks);
+      h->chunk_idx = idx;
+      chunks_[idx] = h;
+      stats.n_allocs++;
+      stats.currently_allocated += map_size;
+      stats.max_allocated = Max(stats.max_allocated, stats.currently_allocated);
+      stats.by_size_log[size_log]++;
+      stat->Add(AllocatorStatAllocated, map_size);
+      stat->Add(AllocatorStatMapped, map_size);
+    }
+    return reinterpret_cast<void*>(res);
+  }
+
+  void *ReturnNullOrDie() {
+    if (atomic_load(&may_return_null_, memory_order_acquire))
+      return nullptr;
+    ReportAllocatorCannotReturnNull();
+  }
+
+  void SetMayReturnNull(bool may_return_null) {
+    atomic_store(&may_return_null_, may_return_null, memory_order_release);
+  }
+
+  void Deallocate(AllocatorStats *stat, void *p) {
+    Header *h = GetHeader(p);
+    {
+      SpinMutexLock l(&mutex_);
+      uptr idx = h->chunk_idx;
+      CHECK_EQ(chunks_[idx], h);
+      CHECK_LT(idx, n_chunks_);
+      chunks_[idx] = chunks_[n_chunks_ - 1];
+      chunks_[idx]->chunk_idx = idx;
+      n_chunks_--;
+      chunks_sorted_ = false;
+      stats.n_frees++;
+      stats.currently_allocated -= h->map_size;
+      stat->Sub(AllocatorStatAllocated, h->map_size);
+      stat->Sub(AllocatorStatMapped, h->map_size);
+    }
+    MapUnmapCallback().OnUnmap(h->map_beg, h->map_size);
+    UnmapOrDie(reinterpret_cast<void*>(h->map_beg), h->map_size);
+  }
+
+  uptr TotalMemoryUsed() {
+    SpinMutexLock l(&mutex_);
+    uptr res = 0;
+    for (uptr i = 0; i < n_chunks_; i++) {
+      Header *h = chunks_[i];
+      CHECK_EQ(h->chunk_idx, i);
+      res += RoundUpMapSize(h->size);
+    }
+    return res;
+  }
+
+  bool PointerIsMine(const void *p) {
+    return GetBlockBegin(p) != nullptr;
+  }
+
+  uptr GetActuallyAllocatedSize(void *p) {
+    return RoundUpTo(GetHeader(p)->size, page_size_);
+  }
+
+  // At least page_size_/2 metadata bytes is available.
+  void *GetMetaData(const void *p) {
+    // Too slow: CHECK_EQ(p, GetBlockBegin(p));
+    if (!IsAligned(reinterpret_cast<uptr>(p), page_size_)) {
+      Printf("%s: bad pointer %p\n", SanitizerToolName, p);
+      CHECK(IsAligned(reinterpret_cast<uptr>(p), page_size_));
+    }
+    return GetHeader(p) + 1;
+  }
+
+  void *GetBlockBegin(const void *ptr) {
+    uptr p = reinterpret_cast<uptr>(ptr);
+    SpinMutexLock l(&mutex_);
+    uptr nearest_chunk = 0;
+    // Cache-friendly linear search.
+    for (uptr i = 0; i < n_chunks_; i++) {
+      uptr ch = reinterpret_cast<uptr>(chunks_[i]);
+      if (p < ch) continue;  // p is at left to this chunk, skip it.
+      if (p - ch < p - nearest_chunk)
+        nearest_chunk = ch;
+    }
+    if (!nearest_chunk)
+      return nullptr;
+    Header *h = reinterpret_cast<Header *>(nearest_chunk);
+    CHECK_GE(nearest_chunk, h->map_beg);
+    CHECK_LT(nearest_chunk, h->map_beg + h->map_size);
+    CHECK_LE(nearest_chunk, p);
+    if (h->map_beg + h->map_size <= p)
+      return nullptr;
+    return GetUser(h);
+  }
+
+  // This function does the same as GetBlockBegin, but is much faster.
+  // Must be called with the allocator locked.
+  void *GetBlockBeginFastLocked(void *ptr) {
+    mutex_.CheckLocked();
+    uptr p = reinterpret_cast<uptr>(ptr);
+    uptr n = n_chunks_;
+    if (!n) return nullptr;
+    if (!chunks_sorted_) {
+      // Do one-time sort. chunks_sorted_ is reset in Allocate/Deallocate.
+      SortArray(reinterpret_cast<uptr*>(chunks_), n);
+      for (uptr i = 0; i < n; i++)
+        chunks_[i]->chunk_idx = i;
+      chunks_sorted_ = true;
+      min_mmap_ = reinterpret_cast<uptr>(chunks_[0]);
+      max_mmap_ = reinterpret_cast<uptr>(chunks_[n - 1]) +
+          chunks_[n - 1]->map_size;
+    }
+    if (p < min_mmap_ || p >= max_mmap_)
+      return nullptr;
+    uptr beg = 0, end = n - 1;
+    // This loop is a log(n) lower_bound. It does not check for the exact match
+    // to avoid expensive cache-thrashing loads.
+    while (end - beg >= 2) {
+      uptr mid = (beg + end) / 2;  // Invariant: mid >= beg + 1
+      if (p < reinterpret_cast<uptr>(chunks_[mid]))
+        end = mid - 1;  // We are not interested in chunks_[mid].
+      else
+        beg = mid;  // chunks_[mid] may still be what we want.
+    }
+
+    if (beg < end) {
+      CHECK_EQ(beg + 1, end);
+      // There are 2 chunks left, choose one.
+      if (p >= reinterpret_cast<uptr>(chunks_[end]))
+        beg = end;
+    }
+
+    Header *h = chunks_[beg];
+    if (h->map_beg + h->map_size <= p || p < h->map_beg)
+      return nullptr;
+    return GetUser(h);
+  }
+
+  void PrintStats() {
+    Printf("Stats: LargeMmapAllocator: allocated %zd times, "
+           "remains %zd (%zd K) max %zd M; by size logs: ",
+           stats.n_allocs, stats.n_allocs - stats.n_frees,
+           stats.currently_allocated >> 10, stats.max_allocated >> 20);
+    for (uptr i = 0; i < ARRAY_SIZE(stats.by_size_log); i++) {
+      uptr c = stats.by_size_log[i];
+      if (!c) continue;
+      Printf("%zd:%zd; ", i, c);
+    }
+    Printf("\n");
+  }
+
+  // ForceLock() and ForceUnlock() are needed to implement Darwin malloc zone
+  // introspection API.
+  void ForceLock() {
+    mutex_.Lock();
+  }
+
+  void ForceUnlock() {
+    mutex_.Unlock();
+  }
+
+  // Iterate over all existing chunks.
+  // The allocator must be locked when calling this function.
+  void ForEachChunk(ForEachChunkCallback callback, void *arg) {
+    for (uptr i = 0; i < n_chunks_; i++)
+      callback(reinterpret_cast<uptr>(GetUser(chunks_[i])), arg);
+  }
+
+ private:
+  static const int kMaxNumChunks = 1 << FIRST_32_SECOND_64(15, 18);
+  struct Header {
+    uptr map_beg;
+    uptr map_size;
+    uptr size;
+    uptr chunk_idx;
+  };
+
+  Header *GetHeader(uptr p) {
+    CHECK(IsAligned(p, page_size_));
+    return reinterpret_cast<Header*>(p - page_size_);
+  }
+  Header *GetHeader(const void *p) {
+    return GetHeader(reinterpret_cast<uptr>(p));
+  }
+
+  void *GetUser(Header *h) {
+    CHECK(IsAligned((uptr)h, page_size_));
+    return reinterpret_cast<void*>(reinterpret_cast<uptr>(h) + page_size_);
+  }
+
+  uptr RoundUpMapSize(uptr size) {
+    return RoundUpTo(size, page_size_) + page_size_;
+  }
+
+  uptr page_size_;
+  Header *chunks_[kMaxNumChunks];
+  uptr n_chunks_;
+  uptr min_mmap_, max_mmap_;
+  bool chunks_sorted_;
+  struct Stats {
+    uptr n_allocs, n_frees, currently_allocated, max_allocated, by_size_log[64];
+  } stats;
+  atomic_uint8_t may_return_null_;
+  SpinMutex mutex_;
+};
+
+