From ed81a111d1999a6b62f2cfea21c241e557b800da Mon Sep 17 00:00:00 2001 From: Marijn Schouten Date: Thu, 19 Jun 2025 15:56:32 +0000 Subject: [PATCH] wasm: rm static mut --- library/std/src/sys/alloc/wasm.rs | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/library/std/src/sys/alloc/wasm.rs b/library/std/src/sys/alloc/wasm.rs index c8fab992a88a7..48e2fdd4eccec 100644 --- a/library/std/src/sys/alloc/wasm.rs +++ b/library/std/src/sys/alloc/wasm.rs @@ -16,12 +16,15 @@ //! The crate itself provides a global allocator which on wasm has no //! synchronization as there are no threads! -// FIXME(static_mut_refs): Do not allow `static_mut_refs` lint -#![allow(static_mut_refs)] +use core::cell::SyncUnsafeCell; use crate::alloc::{GlobalAlloc, Layout, System}; -static mut DLMALLOC: dlmalloc::Dlmalloc = dlmalloc::Dlmalloc::new(); +struct SyncDlmalloc(dlmalloc::Dlmalloc); +unsafe impl Sync for SyncDlmalloc {} + +static DLMALLOC: SyncUnsafeCell = + SyncUnsafeCell::new(SyncDlmalloc(dlmalloc::Dlmalloc::new())); #[stable(feature = "alloc_system_type", since = "1.28.0")] unsafe impl GlobalAlloc for System { @@ -30,7 +33,7 @@ unsafe impl GlobalAlloc for System { // SAFETY: DLMALLOC access is guaranteed to be safe because the lock gives us unique and non-reentrant access. // Calling malloc() is safe because preconditions on this function match the trait method preconditions. let _lock = lock::lock(); - unsafe { DLMALLOC.malloc(layout.size(), layout.align()) } + unsafe { (*DLMALLOC.get()).0.malloc(layout.size(), layout.align()) } } #[inline] @@ -38,7 +41,7 @@ unsafe impl GlobalAlloc for System { // SAFETY: DLMALLOC access is guaranteed to be safe because the lock gives us unique and non-reentrant access. // Calling calloc() is safe because preconditions on this function match the trait method preconditions. let _lock = lock::lock(); - unsafe { DLMALLOC.calloc(layout.size(), layout.align()) } + unsafe { (*DLMALLOC.get()).0.calloc(layout.size(), layout.align()) } } #[inline] @@ -46,7 +49,7 @@ unsafe impl GlobalAlloc for System { // SAFETY: DLMALLOC access is guaranteed to be safe because the lock gives us unique and non-reentrant access. // Calling free() is safe because preconditions on this function match the trait method preconditions. let _lock = lock::lock(); - unsafe { DLMALLOC.free(ptr, layout.size(), layout.align()) } + unsafe { (*DLMALLOC.get()).0.free(ptr, layout.size(), layout.align()) } } #[inline] @@ -54,7 +57,7 @@ unsafe impl GlobalAlloc for System { // SAFETY: DLMALLOC access is guaranteed to be safe because the lock gives us unique and non-reentrant access. // Calling realloc() is safe because preconditions on this function match the trait method preconditions. let _lock = lock::lock(); - unsafe { DLMALLOC.realloc(ptr, layout.size(), layout.align(), new_size) } + unsafe { (*DLMALLOC.get()).0.realloc(ptr, layout.size(), layout.align(), new_size) } } }