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testAllocatorLargeAlignment

heap.testAllocatorLargeAlignment

pub fn testAllocatorLargeAlignment(base_allocator: mem.Allocator) !void

File

lib/std/heap.zig:506

Code

pub fn testAllocatorLargeAlignment(base_allocator: mem.Allocator) !void {
    var validationAllocator = mem.validationWrap(base_allocator);
    const allocator = validationAllocator.allocator();

    const large_align: usize = page_size_min / 2;

    var align_mask: usize = undefined;
    align_mask = @shlWithOverflow(~@as(usize, 0), @as(Allocator.Log2Align, @ctz(large_align)))[0];

    var slice = try allocator.alignedAlloc(u8, .fromByteUnits(large_align), 500);
    try testing.expect(@intFromPtr(slice.ptr) & align_mask == @intFromPtr(slice.ptr));

    if (allocator.resize(slice, 100)) {
        slice = slice[0..100];
    }

    slice = try allocator.realloc(slice, 5000);
    try testing.expect(@intFromPtr(slice.ptr) & align_mask == @intFromPtr(slice.ptr));

    if (allocator.resize(slice, 10)) {
        slice = slice[0..10];
    }

    slice = try allocator.realloc(slice, 20000);
    try testing.expect(@intFromPtr(slice.ptr) & align_mask == @intFromPtr(slice.ptr));

    allocator.free(slice);
}