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std: Add cfg(test) to UnsafeArc assertions

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This is a ubiquitous type in concurrent code, and the assertions are causing
significant code bloat for simple operations such as reading the pointer
(injecting a failure point, etc).

I am testing executable sizes with no I/O implementations (everything stubbed
out to return nothing), and this took the size of a libnative executable from
328K to 207K (37% reduction in size), so I think that this is one assertion
that's well worth configuring off for now.
This commit is contained in:
Alex Crichton 2014-02-27 19:53:03 -08:00
parent f01a9a8d02
commit d5aa795aa5
1 changed files with 8 additions and 4 deletions
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12
src/libstd/sync/arc.rs
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@ -80,7 +80,8 @@ impl<T: Send> UnsafeArc<T> {
#[inline]
pub fn get(&self) -> *mut T {
unsafe {
assert!((*self.data).count.load(Relaxed) > 0);
// FIXME(#12049): this needs some sort of debug assertion
if cfg!(test) { assert!((*self.data).count.load(Relaxed) > 0); }
return &mut (*self.data).data as *mut T;
}
}
@ -90,7 +91,8 @@ impl<T: Send> UnsafeArc<T> {
#[inline]
pub fn get_immut(&self) -> *T {
unsafe {
assert!((*self.data).count.load(Relaxed) > 0);
// FIXME(#12049): this needs some sort of debug assertion
if cfg!(test) { assert!((*self.data).count.load(Relaxed) > 0); }
return &(*self.data).data as *T;
}
}
@ -109,7 +111,8 @@ impl<T: Send> Clone for UnsafeArc<T> {
unsafe {
// This barrier might be unnecessary, but I'm not sure...
let old_count = (*self.data).count.fetch_add(1, Acquire);
assert!(old_count >= 1);
// FIXME(#12049): this needs some sort of debug assertion
if cfg!(test) { assert!(old_count >= 1); }
return UnsafeArc { data: self.data };
}
}
@ -127,7 +130,8 @@ impl<T> Drop for UnsafeArc<T>{
// Must be acquire+release, not just release, to make sure this
// doesn't get reordered to after the unwrapper pointer load.
let old_count = (*self.data).count.fetch_sub(1, SeqCst);
assert!(old_count >= 1);
// FIXME(#12049): this needs some sort of debug assertion
if cfg!(test) { assert!(old_count >= 1); }
if old_count == 1 {
let _: ~ArcData<T> = cast::transmute(self.data);
}