19 lines
940 B
Rust
19 lines
940 B
Rust
// This is the amount of bytes that need to be left on the stack before increasing the size.
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// It must be at least as large as the stack required by any code that does not call
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// `ensure_sufficient_stack`.
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const RED_ZONE: usize = 100 * 1024; // 100k
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// Only the first stack that is pushed, grows exponentially (2^n * STACK_PER_RECURSION) from then
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// on. This flag has performance relevant characteristics. Don't set it too high.
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#[allow(clippy::identity_op)]
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const STACK_PER_RECURSION: usize = 1 * 1024 * 1024; // 1MB
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/// Grows the stack on demand to prevent stack overflow. Call this in strategic locations
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/// to "break up" recursive calls. E.g. almost any call to `visit_expr` or equivalent can benefit
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/// from this.
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///
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/// Should not be sprinkled around carelessly, as it causes a little bit of overhead.
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pub fn ensure_sufficient_stack<R>(f: impl FnOnce() -> R) -> R {
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stacker::maybe_grow(RED_ZONE, STACK_PER_RECURSION, f)
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}
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