mirror of
https://github.com/ziglang/zig.git
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1409 lines
58 KiB
Zig
1409 lines
58 KiB
Zig
//! An allocator that is intended to be used in Debug mode.
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//!
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//! ## Features
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//!
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//! * Captures stack traces on allocation, free, and optionally resize.
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//! * Double free detection, which prints all three traces (first alloc, first
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//! free, second free).
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//! * Leak detection, with stack traces.
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//! * Never reuses memory addresses, making it easier for Zig to detect branch
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//! on undefined values in case of dangling pointers. This relies on
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//! the backing allocator to also not reuse addresses.
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//! * Uses a minimum backing allocation size to avoid operating system errors
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//! from having too many active memory mappings.
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//! * When a page of memory is no longer needed, give it back to resident
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//! memory as soon as possible, so that it causes page faults when used.
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//! * Cross platform. Operates based on a backing allocator which makes it work
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//! everywhere, even freestanding.
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//! * Compile-time configuration.
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//!
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//! These features require the allocator to be quite slow and wasteful. For
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//! example, when allocating a single byte, the efficiency is less than 1%;
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//! it requires more than 100 bytes of overhead to manage the allocation for
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//! one byte. The efficiency gets better with larger allocations.
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//!
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//! ## Basic Design
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//!
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//! Allocations are divided into two categories, small and large.
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//!
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//! Small allocations are divided into buckets based on `page_size`:
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//!
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//! ```
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//! index obj_size
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//! 0 1
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//! 1 2
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//! 2 4
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//! 3 8
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//! 4 16
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//! 5 32
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//! 6 64
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//! 7 128
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//! 8 256
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//! 9 512
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//! 10 1024
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//! 11 2048
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//! ...
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//! ```
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//!
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//! This goes on for `small_bucket_count` indexes.
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//!
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//! Allocations are grouped into an object size based on max(len, alignment),
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//! rounded up to the next power of two.
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//!
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//! The main allocator state has an array of all the "current" buckets for each
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//! size class. Each slot in the array can be null, meaning the bucket for that
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//! size class is not allocated. When the first object is allocated for a given
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//! size class, it makes one `page_size` allocation from the backing allocator.
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//! This allocation is divided into "slots" - one per allocated object, leaving
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//! room for the allocation metadata (starting with `BucketHeader`), which is
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//! located at the very end of the "page".
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//!
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//! The allocation metadata includes "used bits" - 1 bit per slot representing
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//! whether the slot is used. Allocations always take the next available slot
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//! from the current bucket, setting the corresponding used bit, as well as
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//! incrementing `allocated_count`.
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//!
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//! Frees recover the allocation metadata based on the address, length, and
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//! alignment, relying on the backing allocation's large alignment, combined
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//! with the fact that allocations are never moved from small to large, or vice
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//! versa.
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//!
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//! When a bucket is full, a new one is allocated, containing a pointer to the
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//! previous one. This singly-linked list is iterated during leak detection.
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//!
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//! Resizing and remapping work the same on small allocations: if the size
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//! class would not change, then the operation succeeds, and the address is
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//! unchanged. Otherwise, the request is rejected.
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//!
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//! Large objects are allocated directly using the backing allocator. Metadata
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//! is stored separately in a `std.HashMap` using the backing allocator.
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//!
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//! Resizing and remapping are forwarded directly to the backing allocator,
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//! except where such operations would change the category from large to small.
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const std = @import("std");
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const builtin = @import("builtin");
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const log = std.log.scoped(.gpa);
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const math = std.math;
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const assert = std.debug.assert;
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const mem = std.mem;
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const Allocator = std.mem.Allocator;
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const StackTrace = std.builtin.StackTrace;
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const default_page_size: usize = @max(std.heap.page_size_max, switch (builtin.os.tag) {
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.windows => 64 * 1024, // Makes `std.heap.PageAllocator` take the happy path.
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.wasi => 64 * 1024, // Max alignment supported by `std.heap.WasmAllocator`.
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else => 128 * 1024, // Avoids too many active mappings when `page_size_max` is low.
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});
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const Log2USize = std.math.Log2Int(usize);
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const default_sys_stack_trace_frames: usize = if (std.debug.sys_can_stack_trace) 6 else 0;
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const default_stack_trace_frames: usize = switch (builtin.mode) {
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.Debug => default_sys_stack_trace_frames,
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else => 0,
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};
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pub const Config = struct {
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/// Number of stack frames to capture.
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stack_trace_frames: usize = default_stack_trace_frames,
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/// If true, the allocator will have two fields:
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/// * `total_requested_bytes` which tracks the total allocated bytes of memory requested.
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/// * `requested_memory_limit` which causes allocations to return `error.OutOfMemory`
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/// when the `total_requested_bytes` exceeds this limit.
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/// If false, these fields will be `void`.
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enable_memory_limit: bool = false,
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/// Whether to enable safety checks.
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safety: bool = std.debug.runtime_safety,
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/// Whether the allocator may be used simultaneously from multiple threads.
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thread_safe: bool = !builtin.single_threaded,
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/// What type of mutex you'd like to use, for thread safety.
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/// when specified, the mutex type must have the same shape as `std.Thread.Mutex` and
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/// `DummyMutex`, and have no required fields. Specifying this field causes
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/// the `thread_safe` field to be ignored.
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///
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/// when null (default):
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/// * the mutex type defaults to `std.Thread.Mutex` when thread_safe is enabled.
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/// * the mutex type defaults to `DummyMutex` otherwise.
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MutexType: ?type = null,
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/// This is a temporary debugging trick you can use to turn segfaults into more helpful
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/// logged error messages with stack trace details. The downside is that every allocation
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/// will be leaked, unless used with retain_metadata!
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never_unmap: bool = false,
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/// This is a temporary debugging aid that retains metadata about allocations indefinitely.
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/// This allows a greater range of double frees to be reported. All metadata is freed when
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/// deinit is called. When used with never_unmap, deliberately leaked memory is also freed
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/// during deinit. Currently should be used with never_unmap to avoid segfaults.
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/// TODO https://github.com/ziglang/zig/issues/4298 will allow use without never_unmap
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retain_metadata: bool = false,
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/// Enables emitting info messages with the size and address of every allocation.
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verbose_log: bool = false,
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/// Tell whether the backing allocator returns already-zeroed memory.
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backing_allocator_zeroes: bool = true,
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/// When resizing an allocation, refresh the stack trace with the resize
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/// callsite. Comes with a performance penalty.
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resize_stack_traces: bool = false,
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/// Magic value that distinguishes allocations owned by this allocator from
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/// other regions of memory.
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canary: usize = @truncate(0x9232a6ff85dff10f),
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/// The size of allocations requested from the backing allocator for
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/// subdividing into slots for small allocations.
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///
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/// Must be a power of two.
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page_size: usize = default_page_size,
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};
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/// Default initialization of this struct is deprecated; use `.init` instead.
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pub fn DebugAllocator(comptime config: Config) type {
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return struct {
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backing_allocator: Allocator = std.heap.page_allocator,
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/// Tracks the active bucket, which is the one that has free slots in it.
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buckets: [small_bucket_count]?*BucketHeader = [1]?*BucketHeader{null} ** small_bucket_count,
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large_allocations: LargeAllocTable = .empty,
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total_requested_bytes: @TypeOf(total_requested_bytes_init) = total_requested_bytes_init,
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requested_memory_limit: @TypeOf(requested_memory_limit_init) = requested_memory_limit_init,
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mutex: @TypeOf(mutex_init) = mutex_init,
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const Self = @This();
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pub const init: Self = .{};
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/// These can be derived from size_class_index but the calculation is nontrivial.
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const slot_counts: [small_bucket_count]SlotIndex = init: {
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@setEvalBranchQuota(10000);
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var result: [small_bucket_count]SlotIndex = undefined;
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for (&result, 0..) |*elem, i| elem.* = calculateSlotCount(i);
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break :init result;
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};
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comptime {
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assert(math.isPowerOfTwo(page_size));
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}
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const page_size = config.page_size;
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const page_align: mem.Alignment = .fromByteUnits(page_size);
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/// Integer type for pointing to slots in a small allocation
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const SlotIndex = std.meta.Int(.unsigned, math.log2(page_size) + 1);
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const total_requested_bytes_init = if (config.enable_memory_limit) @as(usize, 0) else {};
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const requested_memory_limit_init = if (config.enable_memory_limit) @as(usize, math.maxInt(usize)) else {};
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const mutex_init = if (config.MutexType) |T|
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T{}
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else if (config.thread_safe)
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std.Thread.Mutex{}
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else
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DummyMutex{};
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const DummyMutex = struct {
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inline fn lock(_: *DummyMutex) void {}
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inline fn unlock(_: *DummyMutex) void {}
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};
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const stack_n = config.stack_trace_frames;
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const one_trace_size = @sizeOf(usize) * stack_n;
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const traces_per_slot = 2;
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pub const Error = mem.Allocator.Error;
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/// Avoids creating buckets that would only be able to store a small
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/// number of slots. Value of 1 means 2 is the minimum slot count.
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const minimum_slots_per_bucket_log2 = 1;
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const small_bucket_count = math.log2(page_size) - minimum_slots_per_bucket_log2;
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const largest_bucket_object_size = 1 << (small_bucket_count - 1);
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const LargestSizeClassInt = std.math.IntFittingRange(0, largest_bucket_object_size);
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const bucketCompare = struct {
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fn compare(a: *BucketHeader, b: *BucketHeader) std.math.Order {
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return std.math.order(@intFromPtr(a.page), @intFromPtr(b.page));
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}
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}.compare;
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const LargeAlloc = struct {
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bytes: []u8,
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requested_size: if (config.enable_memory_limit) usize else void,
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stack_addresses: [trace_n][stack_n]usize,
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freed: if (config.retain_metadata) bool else void,
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alignment: if (config.never_unmap and config.retain_metadata) mem.Alignment else void,
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const trace_n = if (config.retain_metadata) traces_per_slot else 1;
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fn dumpStackTrace(self: *LargeAlloc, trace_kind: TraceKind) void {
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std.debug.dumpStackTrace(self.getStackTrace(trace_kind));
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}
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fn getStackTrace(self: *LargeAlloc, trace_kind: TraceKind) std.builtin.StackTrace {
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assert(@intFromEnum(trace_kind) < trace_n);
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const stack_addresses = &self.stack_addresses[@intFromEnum(trace_kind)];
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var len: usize = 0;
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while (len < stack_n and stack_addresses[len] != 0) {
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len += 1;
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}
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return .{
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.instruction_addresses = stack_addresses,
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.index = len,
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};
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}
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fn captureStackTrace(self: *LargeAlloc, ret_addr: usize, trace_kind: TraceKind) void {
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assert(@intFromEnum(trace_kind) < trace_n);
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const stack_addresses = &self.stack_addresses[@intFromEnum(trace_kind)];
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collectStackTrace(ret_addr, stack_addresses);
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}
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};
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const LargeAllocTable = std.AutoHashMapUnmanaged(usize, LargeAlloc);
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/// Bucket: In memory, in order:
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/// * BucketHeader
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/// * bucket_used_bits: [N]usize, // 1 bit for every slot
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/// -- below only exists when config.safety is true --
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/// * requested_sizes: [N]LargestSizeClassInt // 1 int for every slot
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/// * log2_ptr_aligns: [N]u8 // 1 byte for every slot
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/// -- above only exists when config.safety is true --
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/// * stack_trace_addresses: [N]usize, // traces_per_slot for every allocation
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const BucketHeader = struct {
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allocated_count: SlotIndex,
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freed_count: SlotIndex,
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prev: ?*BucketHeader,
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canary: usize = config.canary,
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fn fromPage(page_addr: usize, slot_count: usize) *BucketHeader {
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const unaligned = page_addr + page_size - bucketSize(slot_count);
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return @ptrFromInt(unaligned & ~(@as(usize, @alignOf(BucketHeader)) - 1));
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}
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fn usedBits(bucket: *BucketHeader, index: usize) *usize {
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const ptr: [*]u8 = @ptrCast(bucket);
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const bits: [*]usize = @alignCast(@ptrCast(ptr + @sizeOf(BucketHeader)));
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return &bits[index];
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}
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fn requestedSizes(bucket: *BucketHeader, slot_count: usize) []LargestSizeClassInt {
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if (!config.safety) @compileError("requested size is only stored when safety is enabled");
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const start_ptr = @as([*]u8, @ptrCast(bucket)) + bucketRequestedSizesStart(slot_count);
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const sizes = @as([*]LargestSizeClassInt, @ptrCast(@alignCast(start_ptr)));
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return sizes[0..slot_count];
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}
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fn log2PtrAligns(bucket: *BucketHeader, slot_count: usize) []mem.Alignment {
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if (!config.safety) @compileError("requested size is only stored when safety is enabled");
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const aligns_ptr = @as([*]u8, @ptrCast(bucket)) + bucketAlignsStart(slot_count);
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return @ptrCast(aligns_ptr[0..slot_count]);
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}
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fn stackTracePtr(
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bucket: *BucketHeader,
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slot_count: usize,
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slot_index: SlotIndex,
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trace_kind: TraceKind,
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) *[stack_n]usize {
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const start_ptr = @as([*]u8, @ptrCast(bucket)) + bucketStackFramesStart(slot_count);
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const addr = start_ptr + one_trace_size * traces_per_slot * slot_index +
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@intFromEnum(trace_kind) * @as(usize, one_trace_size);
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return @ptrCast(@alignCast(addr));
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}
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fn captureStackTrace(
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bucket: *BucketHeader,
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ret_addr: usize,
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slot_count: usize,
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slot_index: SlotIndex,
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trace_kind: TraceKind,
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) void {
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// Initialize them to 0. When determining the count we must look
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// for non zero addresses.
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const stack_addresses = bucket.stackTracePtr(slot_count, slot_index, trace_kind);
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collectStackTrace(ret_addr, stack_addresses);
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}
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};
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pub fn allocator(self: *Self) Allocator {
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return .{
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.ptr = self,
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.vtable = &.{
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.alloc = alloc,
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.resize = resize,
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.remap = remap,
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.free = free,
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},
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};
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}
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fn bucketStackTrace(
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bucket: *BucketHeader,
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slot_count: usize,
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slot_index: SlotIndex,
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trace_kind: TraceKind,
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) StackTrace {
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const stack_addresses = bucket.stackTracePtr(slot_count, slot_index, trace_kind);
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var len: usize = 0;
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while (len < stack_n and stack_addresses[len] != 0) {
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len += 1;
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}
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return .{
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.instruction_addresses = stack_addresses,
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.index = len,
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};
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}
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fn bucketRequestedSizesStart(slot_count: usize) usize {
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if (!config.safety) @compileError("requested sizes are not stored unless safety is enabled");
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return mem.alignForward(
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usize,
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@sizeOf(BucketHeader) + usedBitsSize(slot_count),
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@alignOf(LargestSizeClassInt),
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);
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}
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fn bucketAlignsStart(slot_count: usize) usize {
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if (!config.safety) @compileError("requested sizes are not stored unless safety is enabled");
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return bucketRequestedSizesStart(slot_count) + (@sizeOf(LargestSizeClassInt) * slot_count);
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}
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fn bucketStackFramesStart(slot_count: usize) usize {
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const unaligned_start = if (config.safety)
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bucketAlignsStart(slot_count) + slot_count
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else
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@sizeOf(BucketHeader) + usedBitsSize(slot_count);
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return mem.alignForward(usize, unaligned_start, @alignOf(usize));
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}
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fn bucketSize(slot_count: usize) usize {
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return bucketStackFramesStart(slot_count) + one_trace_size * traces_per_slot * slot_count;
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}
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/// This is executed only at compile-time to prepopulate a lookup table.
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fn calculateSlotCount(size_class_index: usize) SlotIndex {
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const size_class = @as(usize, 1) << @as(Log2USize, @intCast(size_class_index));
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var lower: usize = 1 << minimum_slots_per_bucket_log2;
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var upper: usize = (page_size - bucketSize(lower)) / size_class;
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while (upper > lower) {
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const proposed: usize = lower + (upper - lower) / 2;
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if (proposed == lower) return lower;
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const slots_end = proposed * size_class;
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const header_begin = mem.alignForward(usize, slots_end, @alignOf(BucketHeader));
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const end = header_begin + bucketSize(proposed);
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if (end > page_size) {
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upper = proposed - 1;
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} else {
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lower = proposed;
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}
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}
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const slots_end = lower * size_class;
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const header_begin = mem.alignForward(usize, slots_end, @alignOf(BucketHeader));
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const end = header_begin + bucketSize(lower);
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assert(end <= page_size);
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return lower;
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}
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fn usedBitsCount(slot_count: usize) usize {
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return (slot_count + (@bitSizeOf(usize) - 1)) / @bitSizeOf(usize);
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}
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fn usedBitsSize(slot_count: usize) usize {
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return usedBitsCount(slot_count) * @sizeOf(usize);
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}
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fn detectLeaksInBucket(bucket: *BucketHeader, size_class_index: usize, used_bits_count: usize) bool {
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const size_class = @as(usize, 1) << @as(Log2USize, @intCast(size_class_index));
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const slot_count = slot_counts[size_class_index];
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var leaks = false;
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for (0..used_bits_count) |used_bits_byte| {
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const used_int = bucket.usedBits(used_bits_byte).*;
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if (used_int != 0) {
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for (0..@bitSizeOf(usize)) |bit_index_usize| {
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const bit_index: Log2USize = @intCast(bit_index_usize);
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const is_used = @as(u1, @truncate(used_int >> bit_index)) != 0;
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if (is_used) {
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const slot_index: SlotIndex = @intCast(used_bits_byte * @bitSizeOf(usize) + bit_index);
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const stack_trace = bucketStackTrace(bucket, slot_count, slot_index, .alloc);
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const page_addr = @intFromPtr(bucket) & ~(page_size - 1);
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const addr = page_addr + slot_index * size_class;
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log.err("memory address 0x{x} leaked: {}", .{ addr, stack_trace });
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leaks = true;
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}
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}
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}
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}
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return leaks;
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}
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/// Emits log messages for leaks and then returns whether there were any leaks.
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pub fn detectLeaks(self: *Self) bool {
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var leaks = false;
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for (self.buckets, 0..) |init_optional_bucket, size_class_index| {
|
|
var optional_bucket = init_optional_bucket;
|
|
const slot_count = slot_counts[size_class_index];
|
|
const used_bits_count = usedBitsCount(slot_count);
|
|
while (optional_bucket) |bucket| {
|
|
leaks = detectLeaksInBucket(bucket, size_class_index, used_bits_count) or leaks;
|
|
optional_bucket = bucket.prev;
|
|
}
|
|
}
|
|
|
|
var it = self.large_allocations.valueIterator();
|
|
while (it.next()) |large_alloc| {
|
|
if (config.retain_metadata and large_alloc.freed) continue;
|
|
const stack_trace = large_alloc.getStackTrace(.alloc);
|
|
log.err("memory address 0x{x} leaked: {}", .{
|
|
@intFromPtr(large_alloc.bytes.ptr), stack_trace,
|
|
});
|
|
leaks = true;
|
|
}
|
|
return leaks;
|
|
}
|
|
|
|
fn freeRetainedMetadata(self: *Self) void {
|
|
comptime assert(config.retain_metadata);
|
|
if (config.never_unmap) {
|
|
// free large allocations that were intentionally leaked by never_unmap
|
|
var it = self.large_allocations.iterator();
|
|
while (it.next()) |large| {
|
|
if (large.value_ptr.freed) {
|
|
self.backing_allocator.rawFree(large.value_ptr.bytes, large.value_ptr.alignment, @returnAddress());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn flushRetainedMetadata(self: *Self) void {
|
|
comptime assert(config.retain_metadata);
|
|
self.freeRetainedMetadata();
|
|
// also remove entries from large_allocations
|
|
var it = self.large_allocations.iterator();
|
|
while (it.next()) |large| {
|
|
if (large.value_ptr.freed) {
|
|
_ = self.large_allocations.remove(@intFromPtr(large.value_ptr.bytes.ptr));
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Returns `std.heap.Check.leak` if there were leaks; `std.heap.Check.ok` otherwise.
|
|
pub fn deinit(self: *Self) std.heap.Check {
|
|
const leaks = if (config.safety) self.detectLeaks() else false;
|
|
if (config.retain_metadata) self.freeRetainedMetadata();
|
|
self.large_allocations.deinit(self.backing_allocator);
|
|
self.* = undefined;
|
|
return if (leaks) .leak else .ok;
|
|
}
|
|
|
|
fn collectStackTrace(first_trace_addr: usize, addresses: *[stack_n]usize) void {
|
|
if (stack_n == 0) return;
|
|
@memset(addresses, 0);
|
|
var stack_trace: StackTrace = .{
|
|
.instruction_addresses = addresses,
|
|
.index = 0,
|
|
};
|
|
std.debug.captureStackTrace(first_trace_addr, &stack_trace);
|
|
}
|
|
|
|
fn reportDoubleFree(ret_addr: usize, alloc_stack_trace: StackTrace, free_stack_trace: StackTrace) void {
|
|
var addresses: [stack_n]usize = @splat(0);
|
|
var second_free_stack_trace: StackTrace = .{
|
|
.instruction_addresses = &addresses,
|
|
.index = 0,
|
|
};
|
|
std.debug.captureStackTrace(ret_addr, &second_free_stack_trace);
|
|
log.err("Double free detected. Allocation: {} First free: {} Second free: {}", .{
|
|
alloc_stack_trace, free_stack_trace, second_free_stack_trace,
|
|
});
|
|
}
|
|
|
|
/// This function assumes the object is in the large object storage regardless
|
|
/// of the parameters.
|
|
fn resizeLarge(
|
|
self: *Self,
|
|
old_mem: []u8,
|
|
alignment: mem.Alignment,
|
|
new_size: usize,
|
|
ret_addr: usize,
|
|
may_move: bool,
|
|
) ?[*]u8 {
|
|
if (config.retain_metadata and may_move) {
|
|
// Before looking up the entry (since this could invalidate
|
|
// it), we must reserve space for the new entry in case the
|
|
// allocation is relocated.
|
|
self.large_allocations.ensureUnusedCapacity(self.backing_allocator, 1) catch return null;
|
|
}
|
|
|
|
const entry = self.large_allocations.getEntry(@intFromPtr(old_mem.ptr)) orelse {
|
|
if (config.safety) {
|
|
@panic("Invalid free");
|
|
} else {
|
|
unreachable;
|
|
}
|
|
};
|
|
|
|
if (config.retain_metadata and entry.value_ptr.freed) {
|
|
if (config.safety) {
|
|
reportDoubleFree(ret_addr, entry.value_ptr.getStackTrace(.alloc), entry.value_ptr.getStackTrace(.free));
|
|
@panic("Unrecoverable double free");
|
|
} else {
|
|
unreachable;
|
|
}
|
|
}
|
|
|
|
if (config.safety and old_mem.len != entry.value_ptr.bytes.len) {
|
|
var addresses: [stack_n]usize = [1]usize{0} ** stack_n;
|
|
var free_stack_trace: StackTrace = .{
|
|
.instruction_addresses = &addresses,
|
|
.index = 0,
|
|
};
|
|
std.debug.captureStackTrace(ret_addr, &free_stack_trace);
|
|
log.err("Allocation size {d} bytes does not match free size {d}. Allocation: {} Free: {}", .{
|
|
entry.value_ptr.bytes.len,
|
|
old_mem.len,
|
|
entry.value_ptr.getStackTrace(.alloc),
|
|
free_stack_trace,
|
|
});
|
|
}
|
|
|
|
// If this would move the allocation into a small size class,
|
|
// refuse the request, because it would require creating small
|
|
// allocation metadata.
|
|
const new_size_class_index: usize = @max(@bitSizeOf(usize) - @clz(new_size - 1), @intFromEnum(alignment));
|
|
if (new_size_class_index < self.buckets.len) return null;
|
|
|
|
// Do memory limit accounting with requested sizes rather than what
|
|
// backing_allocator returns because if we want to return
|
|
// error.OutOfMemory, we have to leave allocation untouched, and
|
|
// that is impossible to guarantee after calling
|
|
// backing_allocator.rawResize.
|
|
const prev_req_bytes = self.total_requested_bytes;
|
|
if (config.enable_memory_limit) {
|
|
const new_req_bytes = prev_req_bytes + new_size - entry.value_ptr.requested_size;
|
|
if (new_req_bytes > prev_req_bytes and new_req_bytes > self.requested_memory_limit) {
|
|
return null;
|
|
}
|
|
self.total_requested_bytes = new_req_bytes;
|
|
}
|
|
|
|
const opt_resized_ptr = if (may_move)
|
|
self.backing_allocator.rawRemap(old_mem, alignment, new_size, ret_addr)
|
|
else if (self.backing_allocator.rawResize(old_mem, alignment, new_size, ret_addr))
|
|
old_mem.ptr
|
|
else
|
|
null;
|
|
|
|
const resized_ptr = opt_resized_ptr orelse {
|
|
if (config.enable_memory_limit) {
|
|
self.total_requested_bytes = prev_req_bytes;
|
|
}
|
|
return null;
|
|
};
|
|
|
|
if (config.enable_memory_limit) {
|
|
entry.value_ptr.requested_size = new_size;
|
|
}
|
|
|
|
if (config.verbose_log) {
|
|
log.info("large resize {d} bytes at {*} to {d} at {*}", .{
|
|
old_mem.len, old_mem.ptr, new_size, resized_ptr,
|
|
});
|
|
}
|
|
entry.value_ptr.bytes = resized_ptr[0..new_size];
|
|
if (config.resize_stack_traces)
|
|
entry.value_ptr.captureStackTrace(ret_addr, .alloc);
|
|
|
|
// Update the key of the hash map if the memory was relocated.
|
|
if (resized_ptr != old_mem.ptr) {
|
|
const large_alloc = entry.value_ptr.*;
|
|
if (config.retain_metadata) {
|
|
entry.value_ptr.freed = true;
|
|
entry.value_ptr.captureStackTrace(ret_addr, .free);
|
|
} else {
|
|
self.large_allocations.removeByPtr(entry.key_ptr);
|
|
}
|
|
|
|
const gop = self.large_allocations.getOrPutAssumeCapacity(@intFromPtr(resized_ptr));
|
|
if (config.retain_metadata and !config.never_unmap) {
|
|
// Backing allocator may be reusing memory that we're retaining metadata for
|
|
assert(!gop.found_existing or gop.value_ptr.freed);
|
|
} else {
|
|
assert(!gop.found_existing); // This would mean the kernel double-mapped pages.
|
|
}
|
|
gop.value_ptr.* = large_alloc;
|
|
}
|
|
|
|
return resized_ptr;
|
|
}
|
|
|
|
/// This function assumes the object is in the large object storage regardless
|
|
/// of the parameters.
|
|
fn freeLarge(
|
|
self: *Self,
|
|
old_mem: []u8,
|
|
alignment: mem.Alignment,
|
|
ret_addr: usize,
|
|
) void {
|
|
const entry = self.large_allocations.getEntry(@intFromPtr(old_mem.ptr)) orelse {
|
|
if (config.safety) {
|
|
@panic("Invalid free");
|
|
} else {
|
|
unreachable;
|
|
}
|
|
};
|
|
|
|
if (config.retain_metadata and entry.value_ptr.freed) {
|
|
if (config.safety) {
|
|
reportDoubleFree(ret_addr, entry.value_ptr.getStackTrace(.alloc), entry.value_ptr.getStackTrace(.free));
|
|
return;
|
|
} else {
|
|
unreachable;
|
|
}
|
|
}
|
|
|
|
if (config.safety and old_mem.len != entry.value_ptr.bytes.len) {
|
|
var addresses: [stack_n]usize = [1]usize{0} ** stack_n;
|
|
var free_stack_trace = StackTrace{
|
|
.instruction_addresses = &addresses,
|
|
.index = 0,
|
|
};
|
|
std.debug.captureStackTrace(ret_addr, &free_stack_trace);
|
|
log.err("Allocation size {d} bytes does not match free size {d}. Allocation: {} Free: {}", .{
|
|
entry.value_ptr.bytes.len,
|
|
old_mem.len,
|
|
entry.value_ptr.getStackTrace(.alloc),
|
|
free_stack_trace,
|
|
});
|
|
}
|
|
|
|
if (!config.never_unmap) {
|
|
self.backing_allocator.rawFree(old_mem, alignment, ret_addr);
|
|
}
|
|
|
|
if (config.enable_memory_limit) {
|
|
self.total_requested_bytes -= entry.value_ptr.requested_size;
|
|
}
|
|
|
|
if (config.verbose_log) {
|
|
log.info("large free {d} bytes at {*}", .{ old_mem.len, old_mem.ptr });
|
|
}
|
|
|
|
if (!config.retain_metadata) {
|
|
assert(self.large_allocations.remove(@intFromPtr(old_mem.ptr)));
|
|
} else {
|
|
entry.value_ptr.freed = true;
|
|
entry.value_ptr.captureStackTrace(ret_addr, .free);
|
|
}
|
|
}
|
|
|
|
fn alloc(context: *anyopaque, len: usize, alignment: mem.Alignment, ret_addr: usize) ?[*]u8 {
|
|
const self: *Self = @ptrCast(@alignCast(context));
|
|
self.mutex.lock();
|
|
defer self.mutex.unlock();
|
|
|
|
if (config.enable_memory_limit) {
|
|
const new_req_bytes = self.total_requested_bytes + len;
|
|
if (new_req_bytes > self.requested_memory_limit) return null;
|
|
self.total_requested_bytes = new_req_bytes;
|
|
}
|
|
|
|
const size_class_index: usize = @max(@bitSizeOf(usize) - @clz(len - 1), @intFromEnum(alignment));
|
|
if (size_class_index >= self.buckets.len) {
|
|
@branchHint(.unlikely);
|
|
self.large_allocations.ensureUnusedCapacity(self.backing_allocator, 1) catch return null;
|
|
const ptr = self.backing_allocator.rawAlloc(len, alignment, ret_addr) orelse return null;
|
|
const slice = ptr[0..len];
|
|
|
|
const gop = self.large_allocations.getOrPutAssumeCapacity(@intFromPtr(slice.ptr));
|
|
if (config.retain_metadata and !config.never_unmap) {
|
|
// Backing allocator may be reusing memory that we're retaining metadata for
|
|
assert(!gop.found_existing or gop.value_ptr.freed);
|
|
} else {
|
|
assert(!gop.found_existing); // This would mean the kernel double-mapped pages.
|
|
}
|
|
gop.value_ptr.bytes = slice;
|
|
if (config.enable_memory_limit)
|
|
gop.value_ptr.requested_size = len;
|
|
gop.value_ptr.captureStackTrace(ret_addr, .alloc);
|
|
if (config.retain_metadata) {
|
|
gop.value_ptr.freed = false;
|
|
if (config.never_unmap) {
|
|
gop.value_ptr.alignment = alignment;
|
|
}
|
|
}
|
|
|
|
if (config.verbose_log) {
|
|
log.info("large alloc {d} bytes at {*}", .{ slice.len, slice.ptr });
|
|
}
|
|
return slice.ptr;
|
|
}
|
|
|
|
const slot_count = slot_counts[size_class_index];
|
|
|
|
if (self.buckets[size_class_index]) |bucket| {
|
|
@branchHint(.likely);
|
|
const slot_index = bucket.allocated_count;
|
|
if (slot_index < slot_count) {
|
|
@branchHint(.likely);
|
|
bucket.allocated_count = slot_index + 1;
|
|
const used_bits_byte = bucket.usedBits(slot_index / @bitSizeOf(usize));
|
|
const used_bit_index: Log2USize = @intCast(slot_index % @bitSizeOf(usize));
|
|
used_bits_byte.* |= (@as(usize, 1) << used_bit_index);
|
|
const size_class = @as(usize, 1) << @as(Log2USize, @intCast(size_class_index));
|
|
if (config.stack_trace_frames > 0) {
|
|
bucket.captureStackTrace(ret_addr, slot_count, slot_index, .alloc);
|
|
}
|
|
if (config.safety) {
|
|
bucket.requestedSizes(slot_count)[slot_index] = @intCast(len);
|
|
bucket.log2PtrAligns(slot_count)[slot_index] = alignment;
|
|
}
|
|
const page_addr = @intFromPtr(bucket) & ~(page_size - 1);
|
|
const addr = page_addr + slot_index * size_class;
|
|
if (config.verbose_log) {
|
|
log.info("small alloc {d} bytes at 0x{x}", .{ len, addr });
|
|
}
|
|
return @ptrFromInt(addr);
|
|
}
|
|
}
|
|
|
|
const page = self.backing_allocator.rawAlloc(page_size, page_align, @returnAddress()) orelse
|
|
return null;
|
|
const bucket: *BucketHeader = .fromPage(@intFromPtr(page), slot_count);
|
|
bucket.* = .{
|
|
.allocated_count = 1,
|
|
.freed_count = 0,
|
|
.prev = self.buckets[size_class_index],
|
|
};
|
|
self.buckets[size_class_index] = bucket;
|
|
|
|
if (!config.backing_allocator_zeroes) {
|
|
@memset(@as([*]usize, @as(*[1]usize, bucket.usedBits(0)))[0..usedBitsCount(slot_count)], 0);
|
|
if (config.safety) @memset(bucket.requestedSizes(slot_count), 0);
|
|
}
|
|
|
|
bucket.usedBits(0).* = 0b1;
|
|
|
|
if (config.stack_trace_frames > 0) {
|
|
bucket.captureStackTrace(ret_addr, slot_count, 0, .alloc);
|
|
}
|
|
|
|
if (config.safety) {
|
|
bucket.requestedSizes(slot_count)[0] = @intCast(len);
|
|
bucket.log2PtrAligns(slot_count)[0] = alignment;
|
|
}
|
|
|
|
if (config.verbose_log) {
|
|
log.info("small alloc {d} bytes at 0x{x}", .{ len, @intFromPtr(page) });
|
|
}
|
|
|
|
return page;
|
|
}
|
|
|
|
fn resize(
|
|
context: *anyopaque,
|
|
memory: []u8,
|
|
alignment: mem.Alignment,
|
|
new_len: usize,
|
|
return_address: usize,
|
|
) bool {
|
|
const self: *Self = @ptrCast(@alignCast(context));
|
|
self.mutex.lock();
|
|
defer self.mutex.unlock();
|
|
|
|
const size_class_index: usize = @max(@bitSizeOf(usize) - @clz(memory.len - 1), @intFromEnum(alignment));
|
|
if (size_class_index >= self.buckets.len) {
|
|
return self.resizeLarge(memory, alignment, new_len, return_address, false) != null;
|
|
} else {
|
|
return resizeSmall(self, memory, alignment, new_len, return_address, size_class_index);
|
|
}
|
|
}
|
|
|
|
fn remap(
|
|
context: *anyopaque,
|
|
memory: []u8,
|
|
alignment: mem.Alignment,
|
|
new_len: usize,
|
|
return_address: usize,
|
|
) ?[*]u8 {
|
|
const self: *Self = @ptrCast(@alignCast(context));
|
|
self.mutex.lock();
|
|
defer self.mutex.unlock();
|
|
|
|
const size_class_index: usize = @max(@bitSizeOf(usize) - @clz(memory.len - 1), @intFromEnum(alignment));
|
|
if (size_class_index >= self.buckets.len) {
|
|
return self.resizeLarge(memory, alignment, new_len, return_address, true);
|
|
} else {
|
|
return if (resizeSmall(self, memory, alignment, new_len, return_address, size_class_index)) memory.ptr else null;
|
|
}
|
|
}
|
|
|
|
fn free(
|
|
context: *anyopaque,
|
|
old_memory: []u8,
|
|
alignment: mem.Alignment,
|
|
return_address: usize,
|
|
) void {
|
|
const self: *Self = @ptrCast(@alignCast(context));
|
|
self.mutex.lock();
|
|
defer self.mutex.unlock();
|
|
|
|
const size_class_index: usize = @max(@bitSizeOf(usize) - @clz(old_memory.len - 1), @intFromEnum(alignment));
|
|
if (size_class_index >= self.buckets.len) {
|
|
@branchHint(.unlikely);
|
|
self.freeLarge(old_memory, alignment, return_address);
|
|
return;
|
|
}
|
|
|
|
const slot_count = slot_counts[size_class_index];
|
|
const freed_addr = @intFromPtr(old_memory.ptr);
|
|
const page_addr = freed_addr & ~(page_size - 1);
|
|
const bucket: *BucketHeader = .fromPage(page_addr, slot_count);
|
|
if (bucket.canary != config.canary) @panic("Invalid free");
|
|
const page_offset = freed_addr - page_addr;
|
|
const size_class = @as(usize, 1) << @as(Log2USize, @intCast(size_class_index));
|
|
const slot_index: SlotIndex = @intCast(page_offset / size_class);
|
|
const used_byte_index = slot_index / @bitSizeOf(usize);
|
|
const used_bit_index: Log2USize = @intCast(slot_index % @bitSizeOf(usize));
|
|
const used_byte = bucket.usedBits(used_byte_index);
|
|
const is_used = @as(u1, @truncate(used_byte.* >> used_bit_index)) != 0;
|
|
if (!is_used) {
|
|
if (config.safety) {
|
|
reportDoubleFree(
|
|
return_address,
|
|
bucketStackTrace(bucket, slot_count, slot_index, .alloc),
|
|
bucketStackTrace(bucket, slot_count, slot_index, .free),
|
|
);
|
|
// Recoverable since this is a free.
|
|
return;
|
|
} else {
|
|
unreachable;
|
|
}
|
|
}
|
|
|
|
// Definitely an in-use small alloc now.
|
|
if (config.safety) {
|
|
const requested_size = bucket.requestedSizes(slot_count)[slot_index];
|
|
if (requested_size == 0) @panic("Invalid free");
|
|
const slot_alignment = bucket.log2PtrAligns(slot_count)[slot_index];
|
|
if (old_memory.len != requested_size or alignment != slot_alignment) {
|
|
var addresses: [stack_n]usize = [1]usize{0} ** stack_n;
|
|
var free_stack_trace: StackTrace = .{
|
|
.instruction_addresses = &addresses,
|
|
.index = 0,
|
|
};
|
|
std.debug.captureStackTrace(return_address, &free_stack_trace);
|
|
if (old_memory.len != requested_size) {
|
|
log.err("Allocation size {d} bytes does not match free size {d}. Allocation: {} Free: {}", .{
|
|
requested_size,
|
|
old_memory.len,
|
|
bucketStackTrace(bucket, slot_count, slot_index, .alloc),
|
|
free_stack_trace,
|
|
});
|
|
}
|
|
if (alignment != slot_alignment) {
|
|
log.err("Allocation alignment {d} does not match free alignment {d}. Allocation: {} Free: {}", .{
|
|
slot_alignment.toByteUnits(),
|
|
alignment.toByteUnits(),
|
|
bucketStackTrace(bucket, slot_count, slot_index, .alloc),
|
|
free_stack_trace,
|
|
});
|
|
}
|
|
}
|
|
}
|
|
|
|
if (config.enable_memory_limit) {
|
|
self.total_requested_bytes -= old_memory.len;
|
|
}
|
|
|
|
if (config.stack_trace_frames > 0) {
|
|
// Capture stack trace to be the "first free", in case a double free happens.
|
|
bucket.captureStackTrace(return_address, slot_count, slot_index, .free);
|
|
}
|
|
|
|
used_byte.* &= ~(@as(usize, 1) << used_bit_index);
|
|
if (config.safety) {
|
|
bucket.requestedSizes(slot_count)[slot_index] = 0;
|
|
}
|
|
bucket.freed_count += 1;
|
|
if (bucket.freed_count == bucket.allocated_count) {
|
|
if (self.buckets[size_class_index] == bucket) {
|
|
self.buckets[size_class_index] = null;
|
|
}
|
|
if (!config.never_unmap) {
|
|
const page: [*]align(page_size) u8 = @ptrFromInt(page_addr);
|
|
self.backing_allocator.rawFree(page[0..page_size], page_align, @returnAddress());
|
|
}
|
|
}
|
|
if (config.verbose_log) {
|
|
log.info("small free {d} bytes at {*}", .{ old_memory.len, old_memory.ptr });
|
|
}
|
|
}
|
|
|
|
fn resizeSmall(
|
|
self: *Self,
|
|
memory: []u8,
|
|
alignment: mem.Alignment,
|
|
new_len: usize,
|
|
return_address: usize,
|
|
size_class_index: usize,
|
|
) bool {
|
|
const new_size_class_index: usize = @max(@bitSizeOf(usize) - @clz(new_len - 1), @intFromEnum(alignment));
|
|
if (!config.safety) return new_size_class_index == size_class_index;
|
|
const slot_count = slot_counts[size_class_index];
|
|
const memory_addr = @intFromPtr(memory.ptr);
|
|
const page_addr = memory_addr & ~(page_size - 1);
|
|
const bucket: *BucketHeader = .fromPage(page_addr, slot_count);
|
|
if (bucket.canary != config.canary) @panic("Invalid free");
|
|
const page_offset = memory_addr - page_addr;
|
|
const size_class = @as(usize, 1) << @as(Log2USize, @intCast(size_class_index));
|
|
const slot_index: SlotIndex = @intCast(page_offset / size_class);
|
|
const used_byte_index = slot_index / @bitSizeOf(usize);
|
|
const used_bit_index: Log2USize = @intCast(slot_index % @bitSizeOf(usize));
|
|
const used_byte = bucket.usedBits(used_byte_index);
|
|
const is_used = @as(u1, @truncate(used_byte.* >> used_bit_index)) != 0;
|
|
if (!is_used) {
|
|
reportDoubleFree(
|
|
return_address,
|
|
bucketStackTrace(bucket, slot_count, slot_index, .alloc),
|
|
bucketStackTrace(bucket, slot_count, slot_index, .free),
|
|
);
|
|
// Recoverable since this is a free.
|
|
return false;
|
|
}
|
|
|
|
// Definitely an in-use small alloc now.
|
|
const requested_size = bucket.requestedSizes(slot_count)[slot_index];
|
|
if (requested_size == 0) @panic("Invalid free");
|
|
const slot_alignment = bucket.log2PtrAligns(slot_count)[slot_index];
|
|
if (memory.len != requested_size or alignment != slot_alignment) {
|
|
var addresses: [stack_n]usize = [1]usize{0} ** stack_n;
|
|
var free_stack_trace: StackTrace = .{
|
|
.instruction_addresses = &addresses,
|
|
.index = 0,
|
|
};
|
|
std.debug.captureStackTrace(return_address, &free_stack_trace);
|
|
if (memory.len != requested_size) {
|
|
log.err("Allocation size {d} bytes does not match free size {d}. Allocation: {} Free: {}", .{
|
|
requested_size,
|
|
memory.len,
|
|
bucketStackTrace(bucket, slot_count, slot_index, .alloc),
|
|
free_stack_trace,
|
|
});
|
|
}
|
|
if (alignment != slot_alignment) {
|
|
log.err("Allocation alignment {d} does not match free alignment {d}. Allocation: {} Free: {}", .{
|
|
slot_alignment.toByteUnits(),
|
|
alignment.toByteUnits(),
|
|
bucketStackTrace(bucket, slot_count, slot_index, .alloc),
|
|
free_stack_trace,
|
|
});
|
|
}
|
|
}
|
|
|
|
if (new_size_class_index != size_class_index) return false;
|
|
|
|
const prev_req_bytes = self.total_requested_bytes;
|
|
if (config.enable_memory_limit) {
|
|
const new_req_bytes = prev_req_bytes - memory.len + new_len;
|
|
if (new_req_bytes > prev_req_bytes and new_req_bytes > self.requested_memory_limit) {
|
|
return false;
|
|
}
|
|
self.total_requested_bytes = new_req_bytes;
|
|
}
|
|
|
|
if (memory.len > new_len) @memset(memory[new_len..], undefined);
|
|
if (config.verbose_log)
|
|
log.info("small resize {d} bytes at {*} to {d}", .{ memory.len, memory.ptr, new_len });
|
|
|
|
if (config.safety)
|
|
bucket.requestedSizes(slot_count)[slot_index] = @intCast(new_len);
|
|
|
|
if (config.resize_stack_traces)
|
|
bucket.captureStackTrace(return_address, slot_count, slot_index, .alloc);
|
|
|
|
return true;
|
|
}
|
|
};
|
|
}
|
|
|
|
const TraceKind = enum {
|
|
alloc,
|
|
free,
|
|
};
|
|
|
|
const test_config = Config{};
|
|
|
|
test "small allocations - free in same order" {
|
|
var gpa = DebugAllocator(test_config){};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
var list = std.ArrayList(*u64).init(std.testing.allocator);
|
|
defer list.deinit();
|
|
|
|
var i: usize = 0;
|
|
while (i < 513) : (i += 1) {
|
|
const ptr = try allocator.create(u64);
|
|
try list.append(ptr);
|
|
}
|
|
|
|
for (list.items) |ptr| {
|
|
allocator.destroy(ptr);
|
|
}
|
|
}
|
|
|
|
test "small allocations - free in reverse order" {
|
|
var gpa = DebugAllocator(test_config){};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
var list = std.ArrayList(*u64).init(std.testing.allocator);
|
|
defer list.deinit();
|
|
|
|
var i: usize = 0;
|
|
while (i < 513) : (i += 1) {
|
|
const ptr = try allocator.create(u64);
|
|
try list.append(ptr);
|
|
}
|
|
|
|
while (list.popOrNull()) |ptr| {
|
|
allocator.destroy(ptr);
|
|
}
|
|
}
|
|
|
|
test "large allocations" {
|
|
var gpa = DebugAllocator(test_config){};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
const ptr1 = try allocator.alloc(u64, 42768);
|
|
const ptr2 = try allocator.alloc(u64, 52768);
|
|
allocator.free(ptr1);
|
|
const ptr3 = try allocator.alloc(u64, 62768);
|
|
allocator.free(ptr3);
|
|
allocator.free(ptr2);
|
|
}
|
|
|
|
test "very large allocation" {
|
|
var gpa = DebugAllocator(test_config){};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
try std.testing.expectError(error.OutOfMemory, allocator.alloc(u8, math.maxInt(usize)));
|
|
}
|
|
|
|
test "realloc" {
|
|
var gpa = DebugAllocator(test_config){};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
var slice = try allocator.alignedAlloc(u8, @alignOf(u32), 1);
|
|
defer allocator.free(slice);
|
|
slice[0] = 0x12;
|
|
|
|
// This reallocation should keep its pointer address.
|
|
const old_slice = slice;
|
|
slice = try allocator.realloc(slice, 2);
|
|
try std.testing.expect(old_slice.ptr == slice.ptr);
|
|
try std.testing.expect(slice[0] == 0x12);
|
|
slice[1] = 0x34;
|
|
|
|
// This requires upgrading to a larger size class
|
|
slice = try allocator.realloc(slice, 17);
|
|
try std.testing.expect(slice[0] == 0x12);
|
|
try std.testing.expect(slice[1] == 0x34);
|
|
}
|
|
|
|
test "shrink" {
|
|
var gpa: DebugAllocator(test_config) = .{};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
var slice = try allocator.alloc(u8, 20);
|
|
defer allocator.free(slice);
|
|
|
|
@memset(slice, 0x11);
|
|
|
|
try std.testing.expect(allocator.resize(slice, 17));
|
|
slice = slice[0..17];
|
|
|
|
for (slice) |b| {
|
|
try std.testing.expect(b == 0x11);
|
|
}
|
|
|
|
// Does not cross size class boundaries when shrinking.
|
|
try std.testing.expect(!allocator.resize(slice, 16));
|
|
}
|
|
|
|
test "large object - grow" {
|
|
if (builtin.target.isWasm()) {
|
|
// Not expected to pass on targets that do not have memory mapping.
|
|
return error.SkipZigTest;
|
|
}
|
|
var gpa: DebugAllocator(test_config) = .{};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
var slice1 = try allocator.alloc(u8, default_page_size * 2 - 20);
|
|
defer allocator.free(slice1);
|
|
|
|
const old = slice1;
|
|
slice1 = try allocator.realloc(slice1, default_page_size * 2 - 10);
|
|
try std.testing.expect(slice1.ptr == old.ptr);
|
|
|
|
slice1 = try allocator.realloc(slice1, default_page_size * 2);
|
|
try std.testing.expect(slice1.ptr == old.ptr);
|
|
|
|
slice1 = try allocator.realloc(slice1, default_page_size * 2 + 1);
|
|
}
|
|
|
|
test "realloc small object to large object" {
|
|
var gpa = DebugAllocator(test_config){};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
var slice = try allocator.alloc(u8, 70);
|
|
defer allocator.free(slice);
|
|
slice[0] = 0x12;
|
|
slice[60] = 0x34;
|
|
|
|
// This requires upgrading to a large object
|
|
const large_object_size = default_page_size * 2 + 50;
|
|
slice = try allocator.realloc(slice, large_object_size);
|
|
try std.testing.expect(slice[0] == 0x12);
|
|
try std.testing.expect(slice[60] == 0x34);
|
|
}
|
|
|
|
test "shrink large object to large object" {
|
|
var gpa: DebugAllocator(test_config) = .{};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
var slice = try allocator.alloc(u8, default_page_size * 2 + 50);
|
|
defer allocator.free(slice);
|
|
slice[0] = 0x12;
|
|
slice[60] = 0x34;
|
|
|
|
if (!allocator.resize(slice, default_page_size * 2 + 1)) return;
|
|
slice = slice.ptr[0 .. default_page_size * 2 + 1];
|
|
try std.testing.expect(slice[0] == 0x12);
|
|
try std.testing.expect(slice[60] == 0x34);
|
|
|
|
try std.testing.expect(allocator.resize(slice, default_page_size * 2 + 1));
|
|
slice = slice[0 .. default_page_size * 2 + 1];
|
|
try std.testing.expect(slice[0] == 0x12);
|
|
try std.testing.expect(slice[60] == 0x34);
|
|
|
|
slice = try allocator.realloc(slice, default_page_size * 2);
|
|
try std.testing.expect(slice[0] == 0x12);
|
|
try std.testing.expect(slice[60] == 0x34);
|
|
}
|
|
|
|
test "shrink large object to large object with larger alignment" {
|
|
if (!builtin.link_libc and builtin.os.tag == .wasi) return error.SkipZigTest; // https://github.com/ziglang/zig/issues/22731
|
|
|
|
var gpa = DebugAllocator(test_config){};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
var debug_buffer: [1000]u8 = undefined;
|
|
var fba = std.heap.FixedBufferAllocator.init(&debug_buffer);
|
|
const debug_allocator = fba.allocator();
|
|
|
|
const alloc_size = default_page_size * 2 + 50;
|
|
var slice = try allocator.alignedAlloc(u8, 16, alloc_size);
|
|
defer allocator.free(slice);
|
|
|
|
const big_alignment: usize = default_page_size * 2;
|
|
// This loop allocates until we find a page that is not aligned to the big
|
|
// alignment. Then we shrink the allocation after the loop, but increase the
|
|
// alignment to the higher one, that we know will force it to realloc.
|
|
var stuff_to_free = std.ArrayList([]align(16) u8).init(debug_allocator);
|
|
while (mem.isAligned(@intFromPtr(slice.ptr), big_alignment)) {
|
|
try stuff_to_free.append(slice);
|
|
slice = try allocator.alignedAlloc(u8, 16, alloc_size);
|
|
}
|
|
while (stuff_to_free.popOrNull()) |item| {
|
|
allocator.free(item);
|
|
}
|
|
slice[0] = 0x12;
|
|
slice[60] = 0x34;
|
|
|
|
slice = try allocator.reallocAdvanced(slice, big_alignment, alloc_size / 2);
|
|
try std.testing.expect(slice[0] == 0x12);
|
|
try std.testing.expect(slice[60] == 0x34);
|
|
}
|
|
|
|
test "realloc large object to small object" {
|
|
var gpa = DebugAllocator(test_config){};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
var slice = try allocator.alloc(u8, default_page_size * 2 + 50);
|
|
defer allocator.free(slice);
|
|
slice[0] = 0x12;
|
|
slice[16] = 0x34;
|
|
|
|
slice = try allocator.realloc(slice, 19);
|
|
try std.testing.expect(slice[0] == 0x12);
|
|
try std.testing.expect(slice[16] == 0x34);
|
|
}
|
|
|
|
test "overridable mutexes" {
|
|
var gpa = DebugAllocator(.{ .MutexType = std.Thread.Mutex }){
|
|
.backing_allocator = std.testing.allocator,
|
|
.mutex = std.Thread.Mutex{},
|
|
};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
const ptr = try allocator.create(i32);
|
|
defer allocator.destroy(ptr);
|
|
}
|
|
|
|
test "non-page-allocator backing allocator" {
|
|
var gpa: DebugAllocator(.{
|
|
.backing_allocator_zeroes = false,
|
|
}) = .{
|
|
.backing_allocator = std.testing.allocator,
|
|
};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
const ptr = try allocator.create(i32);
|
|
defer allocator.destroy(ptr);
|
|
}
|
|
|
|
test "realloc large object to larger alignment" {
|
|
if (!builtin.link_libc and builtin.os.tag == .wasi) return error.SkipZigTest; // https://github.com/ziglang/zig/issues/22731
|
|
|
|
var gpa = DebugAllocator(test_config){};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
var debug_buffer: [1000]u8 = undefined;
|
|
var fba = std.heap.FixedBufferAllocator.init(&debug_buffer);
|
|
const debug_allocator = fba.allocator();
|
|
|
|
var slice = try allocator.alignedAlloc(u8, 16, default_page_size * 2 + 50);
|
|
defer allocator.free(slice);
|
|
|
|
const big_alignment: usize = default_page_size * 2;
|
|
// This loop allocates until we find a page that is not aligned to the big alignment.
|
|
var stuff_to_free = std.ArrayList([]align(16) u8).init(debug_allocator);
|
|
while (mem.isAligned(@intFromPtr(slice.ptr), big_alignment)) {
|
|
try stuff_to_free.append(slice);
|
|
slice = try allocator.alignedAlloc(u8, 16, default_page_size * 2 + 50);
|
|
}
|
|
while (stuff_to_free.popOrNull()) |item| {
|
|
allocator.free(item);
|
|
}
|
|
slice[0] = 0x12;
|
|
slice[16] = 0x34;
|
|
|
|
slice = try allocator.reallocAdvanced(slice, 32, default_page_size * 2 + 100);
|
|
try std.testing.expect(slice[0] == 0x12);
|
|
try std.testing.expect(slice[16] == 0x34);
|
|
|
|
slice = try allocator.reallocAdvanced(slice, 32, default_page_size * 2 + 25);
|
|
try std.testing.expect(slice[0] == 0x12);
|
|
try std.testing.expect(slice[16] == 0x34);
|
|
|
|
slice = try allocator.reallocAdvanced(slice, big_alignment, default_page_size * 2 + 100);
|
|
try std.testing.expect(slice[0] == 0x12);
|
|
try std.testing.expect(slice[16] == 0x34);
|
|
}
|
|
|
|
test "large object rejects shrinking to small" {
|
|
if (builtin.target.isWasm()) {
|
|
// Not expected to pass on targets that do not have memory mapping.
|
|
return error.SkipZigTest;
|
|
}
|
|
|
|
var failing_allocator = std.testing.FailingAllocator.init(std.heap.page_allocator, .{ .fail_index = 3 });
|
|
var gpa: DebugAllocator(.{}) = .{
|
|
.backing_allocator = failing_allocator.allocator(),
|
|
};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
var slice = try allocator.alloc(u8, default_page_size * 2 + 50);
|
|
defer allocator.free(slice);
|
|
slice[0] = 0x12;
|
|
slice[3] = 0x34;
|
|
|
|
try std.testing.expect(!allocator.resize(slice, 4));
|
|
try std.testing.expect(slice[0] == 0x12);
|
|
try std.testing.expect(slice[3] == 0x34);
|
|
}
|
|
|
|
test "objects of size 1024 and 2048" {
|
|
var gpa = DebugAllocator(test_config){};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
const slice = try allocator.alloc(u8, 1025);
|
|
const slice2 = try allocator.alloc(u8, 3000);
|
|
|
|
allocator.free(slice);
|
|
allocator.free(slice2);
|
|
}
|
|
|
|
test "setting a memory cap" {
|
|
var gpa = DebugAllocator(.{ .enable_memory_limit = true }){};
|
|
defer std.testing.expect(gpa.deinit() == .ok) catch @panic("leak");
|
|
const allocator = gpa.allocator();
|
|
|
|
gpa.requested_memory_limit = 1010;
|
|
|
|
const small = try allocator.create(i32);
|
|
try std.testing.expect(gpa.total_requested_bytes == 4);
|
|
|
|
const big = try allocator.alloc(u8, 1000);
|
|
try std.testing.expect(gpa.total_requested_bytes == 1004);
|
|
|
|
try std.testing.expectError(error.OutOfMemory, allocator.create(u64));
|
|
|
|
allocator.destroy(small);
|
|
try std.testing.expect(gpa.total_requested_bytes == 1000);
|
|
|
|
allocator.free(big);
|
|
try std.testing.expect(gpa.total_requested_bytes == 0);
|
|
|
|
const exact = try allocator.alloc(u8, 1010);
|
|
try std.testing.expect(gpa.total_requested_bytes == 1010);
|
|
allocator.free(exact);
|
|
}
|
|
|
|
test "large allocations count requested size not backing size" {
|
|
var gpa: DebugAllocator(.{ .enable_memory_limit = true }) = .{};
|
|
const allocator = gpa.allocator();
|
|
|
|
var buf = try allocator.alignedAlloc(u8, 1, default_page_size + 1);
|
|
try std.testing.expectEqual(default_page_size + 1, gpa.total_requested_bytes);
|
|
buf = try allocator.realloc(buf, 1);
|
|
try std.testing.expectEqual(1, gpa.total_requested_bytes);
|
|
buf = try allocator.realloc(buf, 2);
|
|
try std.testing.expectEqual(2, gpa.total_requested_bytes);
|
|
}
|
|
|
|
test "retain metadata and never unmap" {
|
|
var gpa = std.heap.DebugAllocator(.{
|
|
.safety = true,
|
|
.never_unmap = true,
|
|
.retain_metadata = true,
|
|
}){};
|
|
defer std.debug.assert(gpa.deinit() == .ok);
|
|
const allocator = gpa.allocator();
|
|
|
|
const alloc = try allocator.alloc(u8, 8);
|
|
allocator.free(alloc);
|
|
|
|
const alloc2 = try allocator.alloc(u8, 8);
|
|
allocator.free(alloc2);
|
|
}
|