Files
swift-mirror/unittests/runtime/StackAllocator.cpp
Mike Ash a62f08e050 [Concurrency] Add environment variable for disabling async stack slab allocator.
Add SWIFT_DEBUG_ENABLE_TASK_SLAB_ALLOCATOR, which is on by default. When turned off, async stack allocations call through to malloc/free. This allows memory debugging tools to be used on async stack allocations.
2025-11-07 22:48:41 -05:00

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4.1 KiB
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//===--- StackAllocator.cpp - Unit tests for the StackAllocator -----------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
#include "../../stdlib/public/runtime/StackAllocator.h"
#include "swift/ABI/Metadata.h"
#include "gtest/gtest.h"
using namespace swift;
static constexpr size_t slabCapacity = 256;
static constexpr size_t firstSlabBufferCapacity = 140;
static constexpr size_t fitsIntoFirstSlab = 16;
static constexpr size_t fitsIntoSlab = slabCapacity - 16;
static constexpr size_t twoFitIntoSlab = slabCapacity / 2 - 32;
static constexpr size_t exceedsSlab = slabCapacity + 16;
static Metadata SlabMetadata;
struct SlabAllocatorConfiguration {
bool enableSlabAllocator() { return true; }
};
TEST(StackAllocatorTest, withPreallocatedSlab) {
char firstSlab[firstSlabBufferCapacity];
StackAllocator<slabCapacity, &SlabMetadata, SlabAllocatorConfiguration>
allocator(firstSlab, firstSlabBufferCapacity);
char *mem1 = (char *)allocator.alloc(fitsIntoFirstSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 0);
char *mem1a = (char *)allocator.alloc(fitsIntoFirstSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 0);
char *mem2 = (char *)allocator.alloc(exceedsSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 1);
char *mem3 = (char *)allocator.alloc(fitsIntoSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 2);
char *mem4 = (char *)allocator.alloc(fitsIntoSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 3);
allocator.dealloc(mem4);
allocator.dealloc(mem3);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 3);
char *mem5 = (char *)allocator.alloc(twoFitIntoSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 3);
char *mem6 = (char *)allocator.alloc(twoFitIntoSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 3);
char *mem7 = (char *)allocator.alloc(twoFitIntoSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 3);
allocator.dealloc(mem7);
allocator.dealloc(mem6);
allocator.dealloc(mem5);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 3);
char *mem8 = (char *)allocator.alloc(exceedsSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 2);
allocator.dealloc(mem8);
allocator.dealloc(mem2);
allocator.dealloc(mem1a);
allocator.dealloc(mem1);
}
TEST(StackAllocatorTest, withoutPreallocatedSlab) {
constexpr size_t slabCapacity = 256;
StackAllocator<slabCapacity, &SlabMetadata, SlabAllocatorConfiguration>
allocator;
size_t fitsIntoSlab = slabCapacity - 16;
size_t twoFitIntoSlab = slabCapacity / 2 - 32;
size_t exceedsSlab = slabCapacity + 16;
char *mem1 = (char *)allocator.alloc(twoFitIntoSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 1);
char *mem1a = (char *)allocator.alloc(twoFitIntoSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 1);
char *mem2 = (char *)allocator.alloc(exceedsSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 2);
char *mem3 = (char *)allocator.alloc(fitsIntoSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 3);
char *mem4 = (char *)allocator.alloc(fitsIntoSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 4);
allocator.dealloc(mem4);
allocator.dealloc(mem3);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 4);
char *mem5 = (char *)allocator.alloc(twoFitIntoSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 4);
char *mem6 = (char *)allocator.alloc(twoFitIntoSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 4);
char *mem7 = (char *)allocator.alloc(twoFitIntoSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 4);
allocator.dealloc(mem7);
allocator.dealloc(mem6);
allocator.dealloc(mem5);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 4);
char *mem8 = (char *)allocator.alloc(exceedsSlab);
EXPECT_EQ(allocator.getNumAllocatedSlabs(), 3);
allocator.dealloc(mem8);
allocator.dealloc(mem2);
allocator.dealloc(mem1a);
allocator.dealloc(mem1);
}