[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, 186 insertions, 0 deletions

diff --git a/lib/sanitizer_common/sanitizer_allocator_size_class_map.h b/lib/sanitizer_common/sanitizer_allocator_size_class_map.h
new file mode 100644
index 000000000..612064ec2
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_allocator_size_class_map.h
@@ -0,0 +1,186 @@
+//===-- sanitizer_allocator_size_class_map.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
+
+// SizeClassMap maps allocation sizes into size classes and back.
+// Class 0 corresponds to size 0.
+// Classes 1 - 16 correspond to sizes 16 to 256 (size = class_id * 16).
+// Next 4 classes: 256 + i * 64  (i = 1 to 4).
+// Next 4 classes: 512 + i * 128 (i = 1 to 4).
+// ...
+// Next 4 classes: 2^k + i * 2^(k-2) (i = 1 to 4).
+// Last class corresponds to kMaxSize = 1 << kMaxSizeLog.
+//
+// This structure of the size class map gives us:
+//   - Efficient table-free class-to-size and size-to-class functions.
+//   - Difference between two consequent size classes is betweed 14% and 25%
+//
+// This class also gives a hint to a thread-caching allocator about the amount
+// of chunks that need to be cached per-thread:
+//  - kMaxNumCached is the maximal number of chunks per size class.
+//  - (1 << kMaxBytesCachedLog) is the maximal number of bytes per size class.
+//
+// Part of output of SizeClassMap::Print():
+// c00 => s: 0 diff: +0 00% l 0 cached: 0 0; id 0
+// c01 => s: 16 diff: +16 00% l 4 cached: 256 4096; id 1
+// c02 => s: 32 diff: +16 100% l 5 cached: 256 8192; id 2
+// c03 => s: 48 diff: +16 50% l 5 cached: 256 12288; id 3
+// c04 => s: 64 diff: +16 33% l 6 cached: 256 16384; id 4
+// c05 => s: 80 diff: +16 25% l 6 cached: 256 20480; id 5
+// c06 => s: 96 diff: +16 20% l 6 cached: 256 24576; id 6
+// c07 => s: 112 diff: +16 16% l 6 cached: 256 28672; id 7
+//
+// c08 => s: 128 diff: +16 14% l 7 cached: 256 32768; id 8
+// c09 => s: 144 diff: +16 12% l 7 cached: 256 36864; id 9
+// c10 => s: 160 diff: +16 11% l 7 cached: 256 40960; id 10
+// c11 => s: 176 diff: +16 10% l 7 cached: 256 45056; id 11
+// c12 => s: 192 diff: +16 09% l 7 cached: 256 49152; id 12
+// c13 => s: 208 diff: +16 08% l 7 cached: 256 53248; id 13
+// c14 => s: 224 diff: +16 07% l 7 cached: 256 57344; id 14
+// c15 => s: 240 diff: +16 07% l 7 cached: 256 61440; id 15
+//
+// c16 => s: 256 diff: +16 06% l 8 cached: 256 65536; id 16
+// c17 => s: 320 diff: +64 25% l 8 cached: 204 65280; id 17
+// c18 => s: 384 diff: +64 20% l 8 cached: 170 65280; id 18
+// c19 => s: 448 diff: +64 16% l 8 cached: 146 65408; id 19
+//
+// c20 => s: 512 diff: +64 14% l 9 cached: 128 65536; id 20
+// c21 => s: 640 diff: +128 25% l 9 cached: 102 65280; id 21
+// c22 => s: 768 diff: +128 20% l 9 cached: 85 65280; id 22
+// c23 => s: 896 diff: +128 16% l 9 cached: 73 65408; id 23
+//
+// c24 => s: 1024 diff: +128 14% l 10 cached: 64 65536; id 24
+// c25 => s: 1280 diff: +256 25% l 10 cached: 51 65280; id 25
+// c26 => s: 1536 diff: +256 20% l 10 cached: 42 64512; id 26
+// c27 => s: 1792 diff: +256 16% l 10 cached: 36 64512; id 27
+//
+// ...
+//
+// c48 => s: 65536 diff: +8192 14% l 16 cached: 1 65536; id 48
+// c49 => s: 81920 diff: +16384 25% l 16 cached: 1 81920; id 49
+// c50 => s: 98304 diff: +16384 20% l 16 cached: 1 98304; id 50
+// c51 => s: 114688 diff: +16384 16% l 16 cached: 1 114688; id 51
+//
+// c52 => s: 131072 diff: +16384 14% l 17 cached: 1 131072; id 52
+
+template <uptr kMaxSizeLog, uptr kMaxNumCachedT, uptr kMaxBytesCachedLog>
+class SizeClassMap {
+  static const uptr kMinSizeLog = 4;
+  static const uptr kMidSizeLog = kMinSizeLog + 4;
+  static const uptr kMinSize = 1 << kMinSizeLog;
+  static const uptr kMidSize = 1 << kMidSizeLog;
+  static const uptr kMidClass = kMidSize / kMinSize;
+  static const uptr S = 2;
+  static const uptr M = (1 << S) - 1;
+
+ public:
+  static const uptr kMaxNumCached = kMaxNumCachedT;
+  // We transfer chunks between central and thread-local free lists in batches.
+  // For small size classes we allocate batches separately.
+  // For large size classes we use one of the chunks to store the batch.
+  struct TransferBatch {
+    TransferBatch *next;
+    uptr count;
+    void *batch[kMaxNumCached];
+  };
+
+  static const uptr kMaxSize = 1UL << kMaxSizeLog;
+  static const uptr kNumClasses =
+      kMidClass + ((kMaxSizeLog - kMidSizeLog) << S) + 1;
+  COMPILER_CHECK(kNumClasses >= 32 && kNumClasses <= 256);
+  static const uptr kNumClassesRounded =
+      kNumClasses == 32  ? 32 :
+      kNumClasses <= 64  ? 64 :
+      kNumClasses <= 128 ? 128 : 256;
+
+  static uptr Size(uptr class_id) {
+    if (class_id <= kMidClass)
+      return kMinSize * class_id;
+    class_id -= kMidClass;
+    uptr t = kMidSize << (class_id >> S);
+    return t + (t >> S) * (class_id & M);
+  }
+
+  static uptr ClassID(uptr size) {
+    if (size <= kMidSize)
+      return (size + kMinSize - 1) >> kMinSizeLog;
+    if (size > kMaxSize) return 0;
+    uptr l = MostSignificantSetBitIndex(size);
+    uptr hbits = (size >> (l - S)) & M;
+    uptr lbits = size & ((1 << (l - S)) - 1);
+    uptr l1 = l - kMidSizeLog;
+    return kMidClass + (l1 << S) + hbits + (lbits > 0);
+  }
+
+  static uptr MaxCached(uptr class_id) {
+    if (class_id == 0) return 0;
+    uptr n = (1UL << kMaxBytesCachedLog) / Size(class_id);
+    return Max<uptr>(1, Min(kMaxNumCached, n));
+  }
+
+  static void Print() {
+    uptr prev_s = 0;
+    uptr total_cached = 0;
+    for (uptr i = 0; i < kNumClasses; i++) {
+      uptr s = Size(i);
+      if (s >= kMidSize / 2 && (s & (s - 1)) == 0)
+        Printf("\n");
+      uptr d = s - prev_s;
+      uptr p = prev_s ? (d * 100 / prev_s) : 0;
+      uptr l = s ? MostSignificantSetBitIndex(s) : 0;
+      uptr cached = MaxCached(i) * s;
+      Printf("c%02zd => s: %zd diff: +%zd %02zd%% l %zd "
+             "cached: %zd %zd; id %zd\n",
+             i, Size(i), d, p, l, MaxCached(i), cached, ClassID(s));
+      total_cached += cached;
+      prev_s = s;
+    }
+    Printf("Total cached: %zd\n", total_cached);
+  }
+
+  static bool SizeClassRequiresSeparateTransferBatch(uptr class_id) {
+    return Size(class_id) < sizeof(TransferBatch) -
+        sizeof(uptr) * (kMaxNumCached - MaxCached(class_id));
+  }
+
+  static void Validate() {
+    for (uptr c = 1; c < kNumClasses; c++) {
+      // Printf("Validate: c%zd\n", c);
+      uptr s = Size(c);
+      CHECK_NE(s, 0U);
+      CHECK_EQ(ClassID(s), c);
+      if (c != kNumClasses - 1)
+        CHECK_EQ(ClassID(s + 1), c + 1);
+      CHECK_EQ(ClassID(s - 1), c);
+      if (c)
+        CHECK_GT(Size(c), Size(c-1));
+    }
+    CHECK_EQ(ClassID(kMaxSize + 1), 0);
+
+    for (uptr s = 1; s <= kMaxSize; s++) {
+      uptr c = ClassID(s);
+      // Printf("s%zd => c%zd\n", s, c);
+      CHECK_LT(c, kNumClasses);
+      CHECK_GE(Size(c), s);
+      if (c > 0)
+        CHECK_LT(Size(c-1), s);
+    }
+  }
+};
+
+typedef SizeClassMap<17, 128, 16> DefaultSizeClassMap;
+typedef SizeClassMap<17, 64,  14> CompactSizeClassMap;
+template<class SizeClassAllocator> struct SizeClassAllocatorLocalCache;
+