llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_allocator.h

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//===-- sanitizer_allocator.h -----------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Specialized memory allocator for ThreadSanitizer, MemorySanitizer, etc.
//
//===----------------------------------------------------------------------===//
#ifndef SANITIZER_ALLOCATOR_H
#define SANITIZER_ALLOCATOR_H
#include "sanitizer_internal_defs.h"
#include "sanitizer_common.h"
#include "sanitizer_libc.h"
#include "sanitizer_list.h"
#include "sanitizer_mutex.h"
#include "sanitizer_lfstack.h"
#include "sanitizer_procmaps.h"
namespace __sanitizer {
// Allows the tools to name their allocations appropriately.
extern const char *PrimaryAllocatorName;
extern const char *SecondaryAllocatorName;
// Since flags are immutable and allocator behavior can be changed at runtime
// (unit tests or ASan on Android are some examples), allocator_may_return_null
// flag value is cached here and can be altered later.
bool AllocatorMayReturnNull();
void SetAllocatorMayReturnNull(bool may_return_null);
// Returns true if allocator detected OOM condition. Can be used to avoid memory
// hungry operations.
bool IsAllocatorOutOfMemory();
// Should be called by a particular allocator when OOM is detected.
void SetAllocatorOutOfMemory();
void PrintHintAllocatorCannotReturnNull();
// Allocators call these callbacks on mmap/munmap.
struct NoOpMapUnmapCallback {
void OnMap(uptr p, uptr size) const { }
void OnUnmap(uptr p, uptr size) const { }
};
// Callback type for iterating over chunks.
typedef void (*ForEachChunkCallback)(uptr chunk, void *arg);
[sanitizer] Random shuffling of chunks for the 32-bit Primary Allocator Summary: The 64-bit primary has had random shuffling of chunks for a while, this implements it for the 32-bit primary. Scudo is currently the only user of `kRandomShuffleChunks`. This change consists of a few modifications: - move the random shuffling functions out of the 64-bit primary to `sanitizer_common.h`. Alternatively I could move them to `sanitizer_allocator.h` as they are only used in the allocator, I don't feel strongly either way; - small change in the 64-bit primary to make the `rand_state` initialization `UNLIKELY`; - addition of a `rand_state` in the 32-bit primary's `SizeClassInfo` and shuffling of chunks when populating the free list. - enabling the `random_shuffle.cpp` test on platforms using the 32-bit primary for Scudo. Some comments on why the shuffling is done that way. Initially I just implemented a `Shuffle` function in the `TransferBatch` which was simpler but I came to realize this wasn't good enough: for chunks of 10000 bytes for example, with a `CompactSizeClassMap`, a batch holds only 1 chunk, meaning shuffling the batch has no effect, while a region is usually 1MB, eg: 104 chunks of that size. So I decided to "stage" the newly gathered chunks in a temporary array that would be shuffled prior to placing the chunks in batches. The result is looping twice through n_chunks even if shuffling is not enabled, but I didn't notice any significant significant performance impact. Reviewers: alekseyshl Reviewed By: alekseyshl Subscribers: srhines, llvm-commits, kubamracek Differential Revision: https://reviews.llvm.org/D39244 llvm-svn: 316596
2017-10-26 01:24:56 +08:00
INLINE u32 Rand(u32 *state) { // ANSI C linear congruential PRNG.
return (*state = *state * 1103515245 + 12345) >> 16;
}
INLINE u32 RandN(u32 *state, u32 n) { return Rand(state) % n; } // [0, n)
template<typename T>
INLINE void RandomShuffle(T *a, u32 n, u32 *rand_state) {
if (n <= 1) return;
u32 state = *rand_state;
[sanitizer] Random shuffling of chunks for the 32-bit Primary Allocator Summary: The 64-bit primary has had random shuffling of chunks for a while, this implements it for the 32-bit primary. Scudo is currently the only user of `kRandomShuffleChunks`. This change consists of a few modifications: - move the random shuffling functions out of the 64-bit primary to `sanitizer_common.h`. Alternatively I could move them to `sanitizer_allocator.h` as they are only used in the allocator, I don't feel strongly either way; - small change in the 64-bit primary to make the `rand_state` initialization `UNLIKELY`; - addition of a `rand_state` in the 32-bit primary's `SizeClassInfo` and shuffling of chunks when populating the free list. - enabling the `random_shuffle.cpp` test on platforms using the 32-bit primary for Scudo. Some comments on why the shuffling is done that way. Initially I just implemented a `Shuffle` function in the `TransferBatch` which was simpler but I came to realize this wasn't good enough: for chunks of 10000 bytes for example, with a `CompactSizeClassMap`, a batch holds only 1 chunk, meaning shuffling the batch has no effect, while a region is usually 1MB, eg: 104 chunks of that size. So I decided to "stage" the newly gathered chunks in a temporary array that would be shuffled prior to placing the chunks in batches. The result is looping twice through n_chunks even if shuffling is not enabled, but I didn't notice any significant significant performance impact. Reviewers: alekseyshl Reviewed By: alekseyshl Subscribers: srhines, llvm-commits, kubamracek Differential Revision: https://reviews.llvm.org/D39244 llvm-svn: 316596
2017-10-26 01:24:56 +08:00
for (u32 i = n - 1; i > 0; i--)
Swap(a[i], a[RandN(&state, i + 1)]);
*rand_state = state;
[sanitizer] Random shuffling of chunks for the 32-bit Primary Allocator Summary: The 64-bit primary has had random shuffling of chunks for a while, this implements it for the 32-bit primary. Scudo is currently the only user of `kRandomShuffleChunks`. This change consists of a few modifications: - move the random shuffling functions out of the 64-bit primary to `sanitizer_common.h`. Alternatively I could move them to `sanitizer_allocator.h` as they are only used in the allocator, I don't feel strongly either way; - small change in the 64-bit primary to make the `rand_state` initialization `UNLIKELY`; - addition of a `rand_state` in the 32-bit primary's `SizeClassInfo` and shuffling of chunks when populating the free list. - enabling the `random_shuffle.cpp` test on platforms using the 32-bit primary for Scudo. Some comments on why the shuffling is done that way. Initially I just implemented a `Shuffle` function in the `TransferBatch` which was simpler but I came to realize this wasn't good enough: for chunks of 10000 bytes for example, with a `CompactSizeClassMap`, a batch holds only 1 chunk, meaning shuffling the batch has no effect, while a region is usually 1MB, eg: 104 chunks of that size. So I decided to "stage" the newly gathered chunks in a temporary array that would be shuffled prior to placing the chunks in batches. The result is looping twice through n_chunks even if shuffling is not enabled, but I didn't notice any significant significant performance impact. Reviewers: alekseyshl Reviewed By: alekseyshl Subscribers: srhines, llvm-commits, kubamracek Differential Revision: https://reviews.llvm.org/D39244 llvm-svn: 316596
2017-10-26 01:24:56 +08:00
}
#include "sanitizer_allocator_size_class_map.h"
#include "sanitizer_allocator_stats.h"
#include "sanitizer_allocator_primary64.h"
#include "sanitizer_allocator_bytemap.h"
#include "sanitizer_allocator_primary32.h"
#include "sanitizer_allocator_local_cache.h"
#include "sanitizer_allocator_secondary.h"
#include "sanitizer_allocator_combined.h"
} // namespace __sanitizer
#endif // SANITIZER_ALLOCATOR_H