67de8b490d
The only architecture that actually needs special support for scanning the stack is WebAssembly. All others allow raw access to the stack with a small bit of assembly. Therefore, don't manually keep track of all these objects on the stack manually and instead just use conservative stack scanning. This results in a massive code size decrease in the affected targets (only tested linux/amd64 for code size) - sometimes around 33%. It also allows for future improvements such as using proper stackful goroutines.
40 строки
1,1 КиБ
Go
40 строки
1,1 КиБ
Go
// +build gc.conservative gc.extalloc
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// +build !wasm
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package runtime
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import "internal/task"
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// markStack marks all root pointers found on the stack.
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//
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// This implementation is conservative and relies on the stack top (provided by
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// the linker) and getting the current stack pointer from a register. Also, it
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// assumes a descending stack. Thus, it is not very portable.
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func markStack() {
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// Scan the current stack, and all current registers.
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scanCurrentStack()
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if !task.OnSystemStack() {
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// Mark system stack.
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markRoots(getSystemStackPointer(), stackTop)
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}
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}
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//go:export tinygo_scanCurrentStack
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func scanCurrentStack()
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//go:export tinygo_scanstack
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func scanstack(sp uintptr) {
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// Mark current stack.
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// This function is called by scanCurrentStack, after pushing all registers onto the stack.
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// Callee-saved registers have been pushed onto stack by tinygo_localscan, so this will scan them too.
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if task.OnSystemStack() {
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// This is the system stack.
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// Scan all words on the stack.
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markRoots(sp, stackTop)
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} else {
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// This is a goroutine stack.
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// It is an allocation, so scan it as if it were a value in a global.
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markRoot(0, sp)
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}
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}
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