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+//===-- sanitizer_allocator_primary64.h -------------------------*- C++ -*-===//
+//
+// 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
+
+template<class SizeClassAllocator> struct SizeClassAllocator64LocalCache;
+
+// SizeClassAllocator64 -- allocator for 64-bit address space.
+// The template parameter Params is a class containing the actual parameters.
+//
+// Space: a portion of address space of kSpaceSize bytes starting at SpaceBeg.
+// If kSpaceBeg is ~0 then SpaceBeg is chosen dynamically my mmap.
+// Otherwise SpaceBeg=kSpaceBeg (fixed address).
+// kSpaceSize is a power of two.
+// At the beginning the entire space is mprotect-ed, then small parts of it
+// are mapped on demand.
+//
+// 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.
+
+// FreeArray is an array free-d chunks (stored as 4-byte offsets)
+//
+// A Region looks like this:
+// UserChunk1 ... UserChunkN <gap> MetaChunkN ... MetaChunk1 FreeArray
+
+struct SizeClassAllocator64FlagMasks { // Bit masks.
+ enum {
+ kRandomShuffleChunks = 1,
+ };
+};
+
+template <class Params>
+class SizeClassAllocator64 {
+ public:
+ static const uptr kSpaceBeg = Params::kSpaceBeg;
+ static const uptr kSpaceSize = Params::kSpaceSize;
+ static const uptr kMetadataSize = Params::kMetadataSize;
+ typedef typename Params::SizeClassMap SizeClassMap;
+ typedef typename Params::MapUnmapCallback MapUnmapCallback;
+
+ static const bool kRandomShuffleChunks =
+ Params::kFlags & SizeClassAllocator64FlagMasks::kRandomShuffleChunks;
+
+ typedef SizeClassAllocator64<Params> ThisT;
+ typedef SizeClassAllocator64LocalCache<ThisT> AllocatorCache;
+
+ // When we know the size class (the region base) we can represent a pointer
+ // as a 4-byte integer (offset from the region start shifted right by 4).
+ typedef u32 CompactPtrT;
+ static const uptr kCompactPtrScale = 4;
+ CompactPtrT PointerToCompactPtr(uptr base, uptr ptr) {
+ return static_cast<CompactPtrT>((ptr - base) >> kCompactPtrScale);
+ }
+ uptr CompactPtrToPointer(uptr base, CompactPtrT ptr32) {
+ return base + (static_cast<uptr>(ptr32) << kCompactPtrScale);
+ }
+
+ void Init() {
+ uptr TotalSpaceSize = kSpaceSize + AdditionalSize();
+ if (kUsingConstantSpaceBeg) {
+ CHECK_EQ(kSpaceBeg, reinterpret_cast<uptr>(
+ MmapFixedNoAccess(kSpaceBeg, TotalSpaceSize)));
+ } else {
+ NonConstSpaceBeg =
+ reinterpret_cast<uptr>(MmapNoAccess(TotalSpaceSize));
+ CHECK_NE(NonConstSpaceBeg, ~(uptr)0);
+ }
+ MapWithCallback(SpaceEnd(), AdditionalSize());
+ }
+
+ void MapWithCallback(uptr beg, uptr size) {
+ CHECK_EQ(beg, reinterpret_cast<uptr>(MmapFixedOrDie(beg, size)));
+ MapUnmapCallback().OnMap(beg, size);
+ }
+
+ void UnmapWithCallback(uptr beg, uptr size) {
+ MapUnmapCallback().OnUnmap(beg, size);
+ UnmapOrDie(reinterpret_cast<void *>(beg), size);
+ }
+
+ static bool CanAllocate(uptr size, uptr alignment) {
+ return size <= SizeClassMap::kMaxSize &&
+ alignment <= SizeClassMap::kMaxSize;
+ }
+
+ NOINLINE void ReturnToAllocator(AllocatorStats *stat, uptr class_id,
+ const CompactPtrT *chunks, uptr n_chunks) {
+ RegionInfo *region = GetRegionInfo(class_id);
+ uptr region_beg = GetRegionBeginBySizeClass(class_id);
+ CompactPtrT *free_array = GetFreeArray(region_beg);
+
+ BlockingMutexLock l(&region->mutex);
+ uptr old_num_chunks = region->num_freed_chunks;
+ uptr new_num_freed_chunks = old_num_chunks + n_chunks;
+ EnsureFreeArraySpace(region, region_beg, new_num_freed_chunks);
+ for (uptr i = 0; i < n_chunks; i++)
+ free_array[old_num_chunks + i] = chunks[i];
+ region->num_freed_chunks = new_num_freed_chunks;
+ region->n_freed += n_chunks;
+ }
+
+ NOINLINE void GetFromAllocator(AllocatorStats *stat, uptr class_id,
+ CompactPtrT *chunks, uptr n_chunks) {
+ RegionInfo *region = GetRegionInfo(class_id);
+ uptr region_beg = GetRegionBeginBySizeClass(class_id);
+ CompactPtrT *free_array = GetFreeArray(region_beg);
+
+ BlockingMutexLock l(&region->mutex);
+ if (UNLIKELY(region->num_freed_chunks < n_chunks)) {
+ PopulateFreeArray(stat, class_id, region,
+ n_chunks - region->num_freed_chunks);
+ CHECK_GE(region->num_freed_chunks, n_chunks);
+ }
+ region->num_freed_chunks -= n_chunks;
+ uptr base_idx = region->num_freed_chunks;
+ for (uptr i = 0; i < n_chunks; i++)
+ chunks[i] = free_array[base_idx + i];
+ region->n_allocated += n_chunks;
+ }
+
+
+ bool PointerIsMine(const void *p) {
+ uptr P = reinterpret_cast<uptr>(p);
+ if (kUsingConstantSpaceBeg && (kSpaceBeg % kSpaceSize) == 0)
+ return P / kSpaceSize == kSpaceBeg / kSpaceSize;
+ return P >= SpaceBeg() && P < SpaceEnd();
+ }
+
+ uptr GetRegionBegin(const void *p) {
+ if (kUsingConstantSpaceBeg)
+ return reinterpret_cast<uptr>(p) & ~(kRegionSize - 1);
+ uptr space_beg = SpaceBeg();
+ return ((reinterpret_cast<uptr>(p) - space_beg) & ~(kRegionSize - 1)) +
+ space_beg;
+ }
+
+ uptr GetRegionBeginBySizeClass(uptr class_id) {
+ return SpaceBeg() + kRegionSize * class_id;
+ }
+
+ uptr GetSizeClass(const void *p) {
+ if (kUsingConstantSpaceBeg && (kSpaceBeg % kSpaceSize) == 0)
+ return ((reinterpret_cast<uptr>(p)) / kRegionSize) % kNumClassesRounded;
+ return ((reinterpret_cast<uptr>(p) - SpaceBeg()) / kRegionSize) %
+ kNumClassesRounded;
+ }
+
+ void *GetBlockBegin(const void *p) {
+ uptr class_id = GetSizeClass(p);
+ uptr size = ClassIdToSize(class_id);
+ if (!size) return nullptr;
+ uptr chunk_idx = GetChunkIdx((uptr)p, size);
+ uptr reg_beg = GetRegionBegin(p);
+ uptr beg = chunk_idx * size;
+ uptr next_beg = beg + size;
+ if (class_id >= kNumClasses) return nullptr;
+ RegionInfo *region = GetRegionInfo(class_id);
+ if (region->mapped_user >= next_beg)
+ return reinterpret_cast<void*>(reg_beg + beg);
+ return nullptr;
+ }
+
+ uptr GetActuallyAllocatedSize(void *p) {
+ CHECK(PointerIsMine(p));
+ return ClassIdToSize(GetSizeClass(p));
+ }
+
+ uptr ClassID(uptr size) { return SizeClassMap::ClassID(size); }
+
+ void *GetMetaData(const void *p) {
+ uptr class_id = GetSizeClass(p);
+ uptr size = ClassIdToSize(class_id);
+ uptr chunk_idx = GetChunkIdx(reinterpret_cast<uptr>(p), size);
+ uptr region_beg = GetRegionBeginBySizeClass(class_id);
+ return reinterpret_cast<void *>(GetMetadataEnd(region_beg) -
+ (1 + chunk_idx) * kMetadataSize);
+ }
+
+ uptr TotalMemoryUsed() {
+ uptr res = 0;
+ for (uptr i = 0; i < kNumClasses; i++)
+ res += GetRegionInfo(i)->allocated_user;
+ return res;
+ }
+
+ // Test-only.
+ void TestOnlyUnmap() {
+ UnmapWithCallback(SpaceBeg(), kSpaceSize + AdditionalSize());
+ }
+
+ static void FillMemoryProfile(uptr start, uptr rss, bool file, uptr *stats,
+ uptr stats_size) {
+ for (uptr class_id = 0; class_id < stats_size; class_id++)
+ if (stats[class_id] == start)
+ stats[class_id] = rss;
+ }
+
+ void PrintStats(uptr class_id, uptr rss) {
+ RegionInfo *region = GetRegionInfo(class_id);
+ if (region->mapped_user == 0) return;
+ uptr in_use = region->n_allocated - region->n_freed;
+ uptr avail_chunks = region->allocated_user / ClassIdToSize(class_id);
+ Printf(
+ " %02zd (%zd): mapped: %zdK allocs: %zd frees: %zd inuse: %zd "
+ "num_freed_chunks %zd"
+ " avail: %zd rss: %zdK releases: %zd\n",
+ class_id, ClassIdToSize(class_id), region->mapped_user >> 10,
+ region->n_allocated, region->n_freed, in_use,
+ region->num_freed_chunks, avail_chunks, rss >> 10,
+ region->rtoi.num_releases);
+ }
+
+ void PrintStats() {
+ uptr total_mapped = 0;
+ uptr n_allocated = 0;
+ uptr n_freed = 0;
+ for (uptr class_id = 1; class_id < kNumClasses; class_id++) {
+ RegionInfo *region = GetRegionInfo(class_id);
+ total_mapped += region->mapped_user;
+ n_allocated += region->n_allocated;
+ n_freed += region->n_freed;
+ }
+ Printf("Stats: SizeClassAllocator64: %zdM mapped in %zd allocations; "
+ "remains %zd\n",
+ total_mapped >> 20, n_allocated, n_allocated - n_freed);
+ uptr rss_stats[kNumClasses];
+ for (uptr class_id = 0; class_id < kNumClasses; class_id++)
+ rss_stats[class_id] = SpaceBeg() + kRegionSize * class_id;
+ GetMemoryProfile(FillMemoryProfile, rss_stats, kNumClasses);
+ for (uptr class_id = 1; class_id < kNumClasses; class_id++)
+ PrintStats(class_id, rss_stats[class_id]);
+ }
+
+ // ForceLock() and ForceUnlock() are needed to implement Darwin malloc zone
+ // introspection API.
+ void ForceLock() {
+ for (uptr i = 0; i < kNumClasses; i++) {
+ GetRegionInfo(i)->mutex.Lock();
+ }
+ }
+
+ void ForceUnlock() {
+ for (int i = (int)kNumClasses - 1; i >= 0; i--) {
+ GetRegionInfo(i)->mutex.Unlock();
+ }
+ }
+
+ // Iterate over all existing chunks.
+ // The allocator must be locked when calling this function.
+ void ForEachChunk(ForEachChunkCallback callback, void *arg) {
+ for (uptr class_id = 1; class_id < kNumClasses; class_id++) {
+ RegionInfo *region = GetRegionInfo(class_id);
+ uptr chunk_size = ClassIdToSize(class_id);
+ uptr region_beg = SpaceBeg() + class_id * kRegionSize;
+ for (uptr chunk = region_beg;
+ chunk < region_beg + region->allocated_user;
+ chunk += chunk_size) {
+ // Too slow: CHECK_EQ((void *)chunk, GetBlockBegin((void *)chunk));
+ callback(chunk, arg);
+ }
+ }
+ }
+
+ static uptr ClassIdToSize(uptr class_id) {
+ return SizeClassMap::Size(class_id);
+ }
+
+ static uptr AdditionalSize() {
+ return RoundUpTo(sizeof(RegionInfo) * kNumClassesRounded,
+ GetPageSizeCached());
+ }
+
+ void ReleaseToOS() {
+ for (uptr class_id = 1; class_id < kNumClasses; class_id++)
+ ReleaseToOS(class_id);
+ }
+
+ typedef SizeClassMap SizeClassMapT;
+ static const uptr kNumClasses = SizeClassMap::kNumClasses;
+ static const uptr kNumClassesRounded = SizeClassMap::kNumClassesRounded;
+
+ private:
+ static const uptr kRegionSize = kSpaceSize / kNumClassesRounded;
+ // FreeArray is the array of free-d chunks (stored as 4-byte offsets).
+ // In the worst case it may reguire kRegionSize/SizeClassMap::kMinSize
+ // elements, but in reality this will not happen. For simplicity we
+ // dedicate 1/8 of the region's virtual space to FreeArray.
+ static const uptr kFreeArraySize = kRegionSize / 8;
+
+ static const bool kUsingConstantSpaceBeg = kSpaceBeg != ~(uptr)0;
+ uptr NonConstSpaceBeg;
+ uptr SpaceBeg() const {
+ return kUsingConstantSpaceBeg ? kSpaceBeg : NonConstSpaceBeg;
+ }
+ uptr SpaceEnd() const { return SpaceBeg() + kSpaceSize; }
+ // kRegionSize must be >= 2^32.
+ COMPILER_CHECK((kRegionSize) >= (1ULL << (SANITIZER_WORDSIZE / 2)));
+ // kRegionSize must be <= 2^36, see CompactPtrT.
+ COMPILER_CHECK((kRegionSize) <= (1ULL << (SANITIZER_WORDSIZE / 2 + 4)));
+ // Call mmap for user memory with at least this size.
+ static const uptr kUserMapSize = 1 << 16;
+ // Call mmap for metadata memory with at least this size.
+ static const uptr kMetaMapSize = 1 << 16;
+ // Call mmap for free array memory with at least this size.
+ static const uptr kFreeArrayMapSize = 1 << 16;
+ // Granularity of ReleaseToOs (aka madvise).
+ static const uptr kReleaseToOsGranularity = 1 << 12;
+
+ struct ReleaseToOsInfo {
+ uptr n_freed_at_last_release;
+ uptr num_releases;
+ };
+
+ struct RegionInfo {
+ BlockingMutex mutex;
+ uptr num_freed_chunks; // Number of elements in the freearray.
+ uptr mapped_free_array; // Bytes mapped for freearray.
+ uptr allocated_user; // Bytes allocated for user memory.
+ uptr allocated_meta; // Bytes allocated for metadata.
+ uptr mapped_user; // Bytes mapped for user memory.
+ uptr mapped_meta; // Bytes mapped for metadata.
+ u32 rand_state; // Seed for random shuffle, used if kRandomShuffleChunks.
+ uptr n_allocated, n_freed; // Just stats.
+ ReleaseToOsInfo rtoi;
+ };
+ COMPILER_CHECK(sizeof(RegionInfo) >= kCacheLineSize);
+
+ u32 Rand(u32 *state) { // ANSI C linear congruential PRNG.
+ return (*state = *state * 1103515245 + 12345) >> 16;
+ }
+
+ u32 RandN(u32 *state, u32 n) { return Rand(state) % n; } // [0, n)
+
+ void RandomShuffle(u32 *a, u32 n, u32 *rand_state) {
+ if (n <= 1) return;
+ for (u32 i = n - 1; i > 0; i--)
+ Swap(a[i], a[RandN(rand_state, i + 1)]);
+ }
+
+ RegionInfo *GetRegionInfo(uptr class_id) {
+ CHECK_LT(class_id, kNumClasses);
+ RegionInfo *regions =
+ reinterpret_cast<RegionInfo *>(SpaceBeg() + kSpaceSize);
+ return &regions[class_id];
+ }
+
+ uptr GetMetadataEnd(uptr region_beg) {
+ return region_beg + kRegionSize - kFreeArraySize;
+ }
+
+ uptr GetChunkIdx(uptr chunk, uptr size) {
+ if (!kUsingConstantSpaceBeg)
+ chunk -= SpaceBeg();
+
+ uptr offset = chunk % kRegionSize;
+ // Here we divide by a non-constant. This is costly.
+ // size always fits into 32-bits. If the offset fits too, use 32-bit div.
+ if (offset >> (SANITIZER_WORDSIZE / 2))
+ return offset / size;
+ return (u32)offset / (u32)size;
+ }
+
+ CompactPtrT *GetFreeArray(uptr region_beg) {
+ return reinterpret_cast<CompactPtrT *>(region_beg + kRegionSize -
+ kFreeArraySize);
+ }
+
+ void EnsureFreeArraySpace(RegionInfo *region, uptr region_beg,
+ uptr num_freed_chunks) {
+ uptr needed_space = num_freed_chunks * sizeof(CompactPtrT);
+ if (region->mapped_free_array < needed_space) {
+ CHECK_LE(needed_space, kFreeArraySize);
+ uptr new_mapped_free_array = RoundUpTo(needed_space, kFreeArrayMapSize);
+ uptr current_map_end = reinterpret_cast<uptr>(GetFreeArray(region_beg)) +
+ region->mapped_free_array;
+ uptr new_map_size = new_mapped_free_array - region->mapped_free_array;
+ MapWithCallback(current_map_end, new_map_size);
+ region->mapped_free_array = new_mapped_free_array;
+ }
+ }
+
+
+ NOINLINE void PopulateFreeArray(AllocatorStats *stat, uptr class_id,
+ RegionInfo *region, uptr requested_count) {
+ // region->mutex is held.
+ uptr size = ClassIdToSize(class_id);
+ uptr beg_idx = region->allocated_user;
+ uptr end_idx = beg_idx + requested_count * size;
+ uptr region_beg = GetRegionBeginBySizeClass(class_id);
+ if (end_idx > region->mapped_user) {
+ if (!kUsingConstantSpaceBeg && region->mapped_user == 0)
+ region->rand_state = static_cast<u32>(region_beg >> 12); // From ASLR.
+ // Do the mmap for the user memory.
+ uptr map_size = kUserMapSize;
+ while (end_idx > region->mapped_user + map_size)
+ map_size += kUserMapSize;
+ CHECK_GE(region->mapped_user + map_size, end_idx);
+ MapWithCallback(region_beg + region->mapped_user, map_size);
+ stat->Add(AllocatorStatMapped, map_size);
+ region->mapped_user += map_size;
+ }
+ CompactPtrT *free_array = GetFreeArray(region_beg);
+ uptr total_count = (region->mapped_user - beg_idx) / size;
+ uptr num_freed_chunks = region->num_freed_chunks;
+ EnsureFreeArraySpace(region, region_beg, num_freed_chunks + total_count);
+ for (uptr i = 0; i < total_count; i++) {
+ uptr chunk = beg_idx + i * size;
+ free_array[num_freed_chunks + total_count - 1 - i] =
+ PointerToCompactPtr(0, chunk);
+ }
+ if (kRandomShuffleChunks)
+ RandomShuffle(&free_array[num_freed_chunks], total_count,
+ &region->rand_state);
+ region->num_freed_chunks += total_count;
+ region->allocated_user += total_count * size;
+ CHECK_LE(region->allocated_user, region->mapped_user);
+
+ region->allocated_meta += total_count * kMetadataSize;
+ if (region->allocated_meta > region->mapped_meta) {
+ uptr map_size = kMetaMapSize;
+ while (region->allocated_meta > region->mapped_meta + map_size)
+ map_size += kMetaMapSize;
+ // Do the mmap for the metadata.
+ CHECK_GE(region->mapped_meta + map_size, region->allocated_meta);
+ MapWithCallback(GetMetadataEnd(region_beg) -
+ region->mapped_meta - map_size, map_size);
+ region->mapped_meta += map_size;
+ }
+ CHECK_LE(region->allocated_meta, region->mapped_meta);
+ if (region->mapped_user + region->mapped_meta >
+ kRegionSize - kFreeArraySize) {
+ Printf("%s: Out of memory. Dying. ", SanitizerToolName);
+ Printf("The process has exhausted %zuMB for size class %zu.\n",
+ kRegionSize / 1024 / 1024, size);
+ Die();
+ }
+ }
+
+ bool MaybeReleaseChunkRange(uptr region_beg, uptr chunk_size,
+ CompactPtrT first, CompactPtrT last) {
+ uptr beg_ptr = CompactPtrToPointer(region_beg, first);
+ uptr end_ptr = CompactPtrToPointer(region_beg, last) + chunk_size;
+ CHECK_GE(end_ptr - beg_ptr, kReleaseToOsGranularity);
+ beg_ptr = RoundUpTo(beg_ptr, kReleaseToOsGranularity);
+ end_ptr = RoundDownTo(end_ptr, kReleaseToOsGranularity);
+ if (end_ptr == beg_ptr) return false;
+ ReleaseMemoryToOS(beg_ptr, end_ptr - beg_ptr);
+ return true;
+ }
+
+ // Releases some RAM back to OS.
+ // Algorithm:
+ // * Lock the region.
+ // * Sort the chunks.
+ // * Find ranges fully covered by free-d chunks
+ // * Release them to OS with madvise.
+ //
+ // TODO(kcc): make sure we don't do it too frequently.
+ void ReleaseToOS(uptr class_id) {
+ RegionInfo *region = GetRegionInfo(class_id);
+ uptr region_beg = GetRegionBeginBySizeClass(class_id);
+ CompactPtrT *free_array = GetFreeArray(region_beg);
+ uptr chunk_size = ClassIdToSize(class_id);
+ uptr scaled_chunk_size = chunk_size >> kCompactPtrScale;
+ const uptr kScaledGranularity = kReleaseToOsGranularity >> kCompactPtrScale;
+ BlockingMutexLock l(&region->mutex);
+ uptr n = region->num_freed_chunks;
+ if (n * chunk_size < kReleaseToOsGranularity)
+ return; // No chance to release anything.
+ if ((region->rtoi.n_freed_at_last_release - region->n_freed) * chunk_size <
+ kReleaseToOsGranularity)
+ return; // Nothing new to release.
+ SortArray(free_array, n);
+ uptr beg = free_array[0];
+ uptr prev = free_array[0];
+ for (uptr i = 1; i < n; i++) {
+ uptr chunk = free_array[i];
+ CHECK_GT(chunk, prev);
+ if (chunk - prev != scaled_chunk_size) {
+ CHECK_GT(chunk - prev, scaled_chunk_size);
+ if (prev + scaled_chunk_size - beg >= kScaledGranularity) {
+ MaybeReleaseChunkRange(region_beg, chunk_size, beg, prev);
+ region->rtoi.n_freed_at_last_release = region->n_freed;
+ region->rtoi.num_releases++;
+ }
+ beg = chunk;
+ }
+ prev = chunk;
+ }
+ }
+};
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