page_allocator

On operating systems that support memory mapping, this allocator makes a syscall directly for every allocation and free.

Otherwise, it falls back to the preferred singleton for the target.

Thread-safe.

Source

Implementation

pub const page_allocator: Allocator = if (@hasDecl(root, "os") and
    @hasDecl(root.os, "heap") and
    @hasDecl(root.os.heap, "page_allocator"))
    root.os.heap.page_allocator
else if (builtin.target.cpu.arch.isWasm()) .{
    .ptr = undefined,
    .vtable = &WasmAllocator.vtable,
} else if (builtin.target.os.tag == .plan9) .{
    .ptr = undefined,
    .vtable = &SbrkAllocator(std.os.plan9.sbrk).vtable,
} else .{
    .ptr = undefined,
    .vtable = &PageAllocator.vtable,
}