diff options
Diffstat (limited to 'rust/qemu-api')
| -rw-r--r-- | rust/qemu-api/Cargo.toml | 1 | ||||
| -rw-r--r-- | rust/qemu-api/meson.build | 1 | ||||
| -rw-r--r-- | rust/qemu-api/src/lib.rs | 135 |
3 files changed, 0 insertions, 137 deletions
diff --git a/rust/qemu-api/Cargo.toml b/rust/qemu-api/Cargo.toml index c07a17a28b..c5ed78035b 100644 --- a/rust/qemu-api/Cargo.toml +++ b/rust/qemu-api/Cargo.toml @@ -21,7 +21,6 @@ libc = { workspace = true } [features] default = ["debug_cell"] -allocator = [] debug_cell = [] [lints] diff --git a/rust/qemu-api/meson.build b/rust/qemu-api/meson.build index a090297c45..062009f161 100644 --- a/rust/qemu-api/meson.build +++ b/rust/qemu-api/meson.build @@ -2,7 +2,6 @@ _qemu_api_cfg = run_command(rustc_args, '--config-headers', config_host_h, '--features', files('Cargo.toml'), capture: true, check: true).stdout().strip().splitlines() -# _qemu_api_cfg += ['--cfg', 'feature="allocator"'] if get_option('debug_mutex') _qemu_api_cfg += ['--cfg', 'feature="debug_cell"'] endif diff --git a/rust/qemu-api/src/lib.rs b/rust/qemu-api/src/lib.rs index bcb51c7986..daa2493bb6 100644 --- a/rust/qemu-api/src/lib.rs +++ b/rust/qemu-api/src/lib.rs @@ -36,139 +36,4 @@ pub mod zeroable; // crate). extern crate self as qemu_api; -use std::{ - alloc::{GlobalAlloc, Layout}, - ffi::c_void, -}; - pub use error::{Error, Result}; - -#[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)] -extern "C" { - fn g_aligned_alloc0( - n_blocks: bindings::gsize, - n_block_bytes: bindings::gsize, - alignment: bindings::gsize, - ) -> bindings::gpointer; - fn g_aligned_free(mem: bindings::gpointer); -} - -#[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))] -extern "C" { - fn qemu_memalign(alignment: usize, size: usize) -> *mut c_void; - fn qemu_vfree(ptr: *mut c_void); -} - -extern "C" { - fn g_malloc0(n_bytes: bindings::gsize) -> bindings::gpointer; - fn g_free(mem: bindings::gpointer); -} - -/// An allocator that uses the same allocator as QEMU in C. -/// -/// It is enabled by default with the `allocator` feature. -/// -/// To set it up manually as a global allocator in your crate: -/// -/// ```ignore -/// use qemu_api::QemuAllocator; -/// -/// #[global_allocator] -/// static GLOBAL: QemuAllocator = QemuAllocator::new(); -/// ``` -#[derive(Clone, Copy, Debug)] -#[repr(C)] -pub struct QemuAllocator { - _unused: [u8; 0], -} - -#[cfg_attr(all(feature = "allocator", not(test)), global_allocator)] -pub static GLOBAL: QemuAllocator = QemuAllocator::new(); - -impl QemuAllocator { - // From the glibc documentation, on GNU systems, malloc guarantees 16-byte - // alignment on 64-bit systems and 8-byte alignment on 32-bit systems. See - // https://www.gnu.org/software/libc/manual/html_node/Malloc-Examples.html. - // This alignment guarantee also applies to Windows and Android. On Darwin - // and OpenBSD, the alignment is 16 bytes on both 64-bit and 32-bit systems. - #[cfg(all( - target_pointer_width = "32", - not(any(target_os = "macos", target_os = "openbsd")) - ))] - pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = Some(8); - #[cfg(all( - target_pointer_width = "64", - not(any(target_os = "macos", target_os = "openbsd")) - ))] - pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = Some(16); - #[cfg(all( - any(target_pointer_width = "32", target_pointer_width = "64"), - any(target_os = "macos", target_os = "openbsd") - ))] - pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = Some(16); - #[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))] - pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = None; - - pub const fn new() -> Self { - Self { _unused: [] } - } -} - -impl Default for QemuAllocator { - fn default() -> Self { - Self::new() - } -} - -// Sanity check. -const _: [(); 8] = [(); ::core::mem::size_of::<*mut c_void>()]; - -unsafe impl GlobalAlloc for QemuAllocator { - unsafe fn alloc(&self, layout: Layout) -> *mut u8 { - if matches!(Self::DEFAULT_ALIGNMENT_BYTES, Some(default) if default.checked_rem(layout.align()) == Some(0)) - { - // SAFETY: g_malloc0() is safe to call. - unsafe { g_malloc0(layout.size().try_into().unwrap()).cast::<u8>() } - } else { - #[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)] - { - // SAFETY: g_aligned_alloc0() is safe to call. - unsafe { - g_aligned_alloc0( - layout.size().try_into().unwrap(), - 1, - layout.align().try_into().unwrap(), - ) - .cast::<u8>() - } - } - #[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))] - { - // SAFETY: qemu_memalign() is safe to call. - unsafe { qemu_memalign(layout.align(), layout.size()).cast::<u8>() } - } - } - } - - unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) { - if matches!(Self::DEFAULT_ALIGNMENT_BYTES, Some(default) if default.checked_rem(layout.align()) == Some(0)) - { - // SAFETY: `ptr` must have been allocated by Self::alloc thus a valid - // glib-allocated pointer, so `g_free`ing is safe. - unsafe { g_free(ptr.cast::<_>()) } - } else { - #[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)] - { - // SAFETY: `ptr` must have been allocated by Self::alloc thus a valid aligned - // glib-allocated pointer, so `g_aligned_free`ing is safe. - unsafe { g_aligned_free(ptr.cast::<_>()) } - } - #[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))] - { - // SAFETY: `ptr` must have been allocated by Self::alloc thus a valid aligned - // glib-allocated pointer, so `qemu_vfree`ing is safe. - unsafe { qemu_vfree(ptr.cast::<_>()) } - } - } - } -} |