63 lines
1.4 KiB
Plaintext
63 lines
1.4 KiB
Plaintext
c :: import "@ffi/c"
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Allocator :: struct {
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context ?*mut anyopaque
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alloc @func(context ?*mut anyopaque, size usize, alignment usize) ?*mut u8
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free @func(context ?*mut anyopaque, memory ?*mut u8, size usize, alignment usize) void
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}
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_malloc_alignment usize :: 16 # ponytail: aarch64-macos libc malloc alignment assumption.
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_power_of_two func(value usize) bool {
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if value == 0 {
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return false
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}
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current usize = value
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while current > 1 {
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half usize = current / 2
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if half * 2 != current {
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return false
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}
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current = half
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}
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return true
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}
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_c_alloc func(_ ?*mut anyopaque, size usize, alignment usize) ?*mut u8 {
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if _power_of_two(alignment) == false {
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return none
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}
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if alignment <= _malloc_alignment {
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return ptr_cast(u8, c.malloc(c_ulong(size)))
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}
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memory [1]mut ?*mut anyopaque = [none]
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status c_int = c.posix_memalign((&memory).ptr, c_ulong(alignment), c_ulong(size))
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if status != 0 {
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return none
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}
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return ptr_cast(u8, memory[0])
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}
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_c_free func(_ ?*mut anyopaque, memory ?*mut u8, _ usize, _ usize) void {
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c.free(memory)
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}
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c_allocator Allocator :: Allocator {
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context = none,
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alloc = _c_alloc,
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free = _c_free,
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}
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alloc func(allocator Allocator, size usize, alignment usize) ?*mut u8 {
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return allocator.alloc(allocator.context, size, alignment)
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}
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free func(allocator Allocator, memory ?*mut u8, size usize, alignment usize) void {
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allocator.free(allocator.context, memory, size, alignment)
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}
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