diff options
Diffstat (limited to 'library/std/src/sys/pal/unix/alloc.rs')
| -rw-r--r-- | library/std/src/sys/pal/unix/alloc.rs | 88 |
1 files changed, 0 insertions, 88 deletions
diff --git a/library/std/src/sys/pal/unix/alloc.rs b/library/std/src/sys/pal/unix/alloc.rs deleted file mode 100644 index 625ba5247f1..00000000000 --- a/library/std/src/sys/pal/unix/alloc.rs +++ /dev/null @@ -1,88 +0,0 @@ -use crate::alloc::{GlobalAlloc, Layout, System}; -use crate::ptr; -use crate::sys::common::alloc::{realloc_fallback, MIN_ALIGN}; - -#[stable(feature = "alloc_system_type", since = "1.28.0")] -unsafe impl GlobalAlloc for System { - #[inline] - unsafe fn alloc(&self, layout: Layout) -> *mut u8 { - // jemalloc provides alignment less than MIN_ALIGN for small allocations. - // So only rely on MIN_ALIGN if size >= align. - // Also see <https://github.com/rust-lang/rust/issues/45955> and - // <https://github.com/rust-lang/rust/issues/62251#issuecomment-507580914>. - if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() { - libc::malloc(layout.size()) as *mut u8 - } else { - // `posix_memalign` returns a non-aligned value if supplied a very - // large alignment on older versions of Apple's platforms (unknown - // exactly which version range, but the issue is definitely - // present in macOS 10.14 and iOS 13.3). - // - // <https://github.com/rust-lang/rust/issues/30170> - #[cfg(target_vendor = "apple")] - { - if layout.align() > (1 << 31) { - return ptr::null_mut(); - } - } - aligned_malloc(&layout) - } - } - - #[inline] - unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 { - // See the comment above in `alloc` for why this check looks the way it does. - if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() { - libc::calloc(layout.size(), 1) as *mut u8 - } else { - let ptr = self.alloc(layout); - if !ptr.is_null() { - ptr::write_bytes(ptr, 0, layout.size()); - } - ptr - } - } - - #[inline] - unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) { - libc::free(ptr as *mut libc::c_void) - } - - #[inline] - unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 { - if layout.align() <= MIN_ALIGN && layout.align() <= new_size { - libc::realloc(ptr as *mut libc::c_void, new_size) as *mut u8 - } else { - realloc_fallback(self, ptr, layout, new_size) - } - } -} - -cfg_if::cfg_if! { - // We use posix_memalign wherever possible, but some targets have very incomplete POSIX coverage - // so we need a fallback for those. - if #[cfg(any( - target_os = "horizon", - target_os = "vita", - ))] { - #[inline] - unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 { - unsafe { libc::memalign(layout.align(), layout.size()) as *mut u8 } - } - } else { - #[inline] - unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 { - let mut out = ptr::null_mut(); - // We prefer posix_memalign over aligned_alloc since it is more widely available, and - // since with aligned_alloc, implementations are making almost arbitrary choices for - // which alignments are "supported", making it hard to use. For instance, some - // implementations require the size to be a multiple of the alignment (wasi emmalloc), - // while others require the alignment to be at least the pointer size (Illumos, macOS). - // posix_memalign only has one, clear requirement: that the alignment be a multiple of - // `sizeof(void*)`. Since these are all powers of 2, we can just use max. - let align = layout.align().max(crate::mem::size_of::<usize>()); - let ret = libc::posix_memalign(&mut out, align, layout.size()); - if ret != 0 { ptr::null_mut() } else { out as *mut u8 } - } - } -} |