This removes the feature where newtype structs can be dereferenced like pointers, and likewise where certain enums can be dereferenced (which I imagine nobody realized still existed). This ad-hoc behavior is to be replaced by a more general overloadable dereference trait in the future.
I've been nursing this patch for two months and think it's about rebased up to master.
@nikomatsakis this makes a bunch of your type checking code noticeably uglier.
If there is a lot of data in thread-local storage some implementations
of pthreads (e.g. glibc) fail if you don't request a stack large enough
-- by adjusting for the minimum size we guarantee that our stacks are
always large enough. Issue #6233.
Previously this was an `rtabort!`, indicating a runtime bug. Promote
this to a more intentional abort and print a (slightly) more
informative error message.
Can't test this sense our test suite can't handle an abort exit.
I consider this to close#910, and that we should open another issue about implementing less conservative semantics here.
After writing some benchmarks for ebml::reader::vuint_at() I noticed that LLVM doesn't seem to inline the from_be32 function even though it only does a call to the bswap32 intrinsic in the x86_64 case. Marking the functions with #[inline(always)] fixes that and seems to me a reasonable thing to do. I got the following measurements in my vuint_at() benchmarks:
- Before
test ebml::bench::vuint_at_A_aligned ... bench: 1075 ns/iter (+/- 58)
test ebml::bench::vuint_at_A_unaligned ... bench: 1073 ns/iter (+/- 5)
test ebml::bench::vuint_at_D_aligned ... bench: 1150 ns/iter (+/- 5)
test ebml::bench::vuint_at_D_unaligned ... bench: 1151 ns/iter (+/- 6)
- Inline from_be32
test ebml::bench::vuint_at_A_aligned ... bench: 769 ns/iter (+/- 9)
test ebml::bench::vuint_at_A_unaligned ... bench: 795 ns/iter (+/- 6)
test ebml::bench::vuint_at_D_aligned ... bench: 758 ns/iter (+/- 8)
test ebml::bench::vuint_at_D_unaligned ... bench: 759 ns/iter (+/- 8)
- Using vuint_at_slow()
test ebml::bench::vuint_at_A_aligned ... bench: 646 ns/iter (+/- 7)
test ebml::bench::vuint_at_A_unaligned ... bench: 645 ns/iter (+/- 3)
test ebml::bench::vuint_at_D_aligned ... bench: 907 ns/iter (+/- 4)
test ebml::bench::vuint_at_D_unaligned ... bench: 1085 ns/iter (+/- 16)
As expected inlining from_be32() gave a considerable speedup.
I also tried how the "slow" version fared against the optimized version and noticed that it's
actually a bit faster for small A class integers (using only two bytes) but slower for big D class integers (using four bytes)
If there is a lot of data in thread-local storage some implementations
of pthreads (e.g. glibc) fail if you don't request a stack large enough
-- by adjusting for the minimum size we guarantee that our stacks are
always large enough. Issue #6233.
These methods are sorely needed on readers and writers, and I believe that the
encoding story should be solved with composition. This commit adds back the
missed functions when reading/writing strings onto generic Readers/Writers.
These methods are sorely needed on readers and writers, and I believe that the
encoding story should be solved with composition. This commit adds back the
missed functions when reading/writing strings onto generic Readers/Writers.
Previously this was an rtabort!, indicating a runtime bug. Promote
this to a more intentional abort and print a (slightly) more
informative error message.
Can't test this sense our test suite can't handle an abort exit.
This patchset adds intrinsics similar to the to_[be|le][16|32|64] intrinsics but for going in the reverse direction, e.g. from big/little endian to host endian. Implementation wise they do exactly the same as the corresponding to_* functions but I think it anyway make sense to have them since using the to_* functions in the reverse direction is not entirely intuitive.
The first patch adds the intrinsics and the two following changes instances of bswap* to use the [to|from]_* intrinsics instead.
For libgreen, bookeeping should not be global but rather on a per-pool basis.
Inside libnative, it's known that there must be a global counter with a
mutex/cvar.
The benefit of taking this strategy is to remove this functionality from libstd
to allow fine-grained control of it through libnative/libgreen. Notably, helper
threads in libnative can manually decrement the global count so they don't count
towards the global count of threads. Also, the shutdown process of *all* sched
pools is now dependent on the number of tasks in the pool being 0 rather than
this only being a hardcoded solution for the initial sched pool in libgreen.
This involved adding a Local::try_take() method on the Local trait in order for
the channel wakeup to work inside of libgreen. The channel send was happening
from a SchedTask when there is no Task available in TLS, and now this is
possible to work (remote wakeups are always possible, just a little slower).
For libgreen, bookeeping should not be global but rather on a per-pool basis.
Inside libnative, it's known that there must be a global counter with a
mutex/cvar.
The benefit of taking this strategy is to remove this functionality from libstd
to allow fine-grained control of it through libnative/libgreen. Notably, helper
threads in libnative can manually decrement the global count so they don't count
towards the global count of threads. Also, the shutdown process of *all* sched
pools is now dependent on the number of tasks in the pool being 0 rather than
this only being a hardcoded solution for the initial sched pool in libgreen.
This involved adding a Local::try_take() method on the Local trait in order for
the channel wakeup to work inside of libgreen. The channel send was happening
from a SchedTask when there is no Task available in TLS, and now this is
possible to work (remote wakeups are always possible, just a little slower).
I personally do not have huge amounts of experience in this area, so there's likely a thing or two wrong around the edges. I tried to just copy what libuv is doing as closely as possible with a few tweaks in a few places, but all of the `std::io::net::udp` tests are now run in both native and green settings so the published functionality is all being tested.
This PR adds `std::unsafe::intrinsics::{volatile_load,volatile_store}`, which map to LLVM's `load volatile` and `store volatile` operations correspondingly.
This would fix#11172.
I have addressed several uncertainties with this PR in the line comments.
The comments have more information as to why this is done, but the basic idea is
that finding an exported trait is actually a fairly difficult problem. The true
answer lies in whether a trait is ever referenced from another exported method,
and right now this kind of analysis doesn't exist, so the conservative answer of
"yes" is always returned to answer whether a trait is exported.
Closes#11224Closes#11225
Right now on linux, an empty executable with LTO still depends on librt becaues
of the clock_gettime function in rust_builtin.o, but this commit moves this
dependency into a rust function which is subject to elimination via LTO.
At the same time, this also drops libstd's dependency on librt on unices that
are not OSX because the library is only used by extra::time (and now the
dependency is listed in that module instead).
