65 строки
1,4 КиБ
Go
65 строки
1,4 КиБ
Go
//go:build tinygo.wasm && !custommalloc
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package runtime
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import "unsafe"
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// The below functions override the default allocator of wasi-libc. This ensures
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// code linked from other languages can allocate memory without colliding with
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// our GC allocations.
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var allocs = make(map[uintptr][]byte)
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//export malloc
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func libc_malloc(size uintptr) unsafe.Pointer {
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if size == 0 {
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return nil
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}
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buf := make([]byte, size)
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ptr := unsafe.Pointer(&buf[0])
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allocs[uintptr(ptr)] = buf
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return ptr
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}
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//export free
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func libc_free(ptr unsafe.Pointer) {
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if ptr == nil {
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return
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}
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if _, ok := allocs[uintptr(ptr)]; ok {
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delete(allocs, uintptr(ptr))
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} else {
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panic("free: invalid pointer")
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}
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}
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//export calloc
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func libc_calloc(nmemb, size uintptr) unsafe.Pointer {
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// No difference between calloc and malloc.
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return libc_malloc(nmemb * size)
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}
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//export realloc
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func libc_realloc(oldPtr unsafe.Pointer, size uintptr) unsafe.Pointer {
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if size == 0 {
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libc_free(oldPtr)
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return nil
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}
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// It's hard to optimize this to expand the current buffer with our GC, but
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// it is theoretically possible. For now, just always allocate fresh.
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buf := make([]byte, size)
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if oldPtr != nil {
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if oldBuf, ok := allocs[uintptr(oldPtr)]; ok {
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copy(buf, oldBuf)
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delete(allocs, uintptr(oldPtr))
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} else {
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panic("realloc: invalid pointer")
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}
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}
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ptr := unsafe.Pointer(&buf[0])
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allocs[uintptr(ptr)] = buf
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return ptr
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}
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