These functions allow to read from and write to a file in one atomic
action from multiple threads, avoiding the race between the seek and the
read.
The functions are named `{read,write}_at` on non-Windows (which don't
change the file cursor), and `seek_{read,write}` on Windows (which
change the file cursor).
When getaddrinfo returns EAI_SYSTEM retrieve actual error from errno.
Fixes issue #36546. This change also updates libc to earliest version
that includes EAI_SYSTEM constant.
Previously, in cases where `EAI_SYSTEM` has been returned from getaddrinfo, the
resulting `io::Error` would be broadly described as "System error":
Error { repr: Custom(Custom { kind: Other, error: StringError("failed to lookup address information: System error") }) }
After change a more detailed error is crated based on particular value of
errno, for example:
Error { repr: Os { code: 64, message: "Machine is not on the network" } }
The only downside is that the prefix "failed to lookup address information" is
no longer included in the error message.
This adds support for building the Rust compiler and standard
library for s390x-linux, allowing a full cross-bootstrap sequence
to complete. This includes:
- Makefile/configure changes to allow native s390x builds
- Full Rust compiler support for the s390x C ABI
(only the non-vector ABI is supported at this point)
- Port of the standard library to s390x
- Update the liblibc submodule to a version including s390x support
- Testsuite fixes to allow clean "make check" on s390x
Caveats:
- Resets base cpu to "z10" to bring support in sync with the default
behaviour of other compilers on the platforms. (Usually, upstream
supports all older processors; a distribution build may then chose
to require a more recent base version.) (Also, using zEC12 causes
failures in the valgrind tests since valgrind doesn't fully support
this CPU yet.)
- z13 vector ABI is not yet supported. To ensure compatible code
generation, the -vector feature is passed to LLVM. Note that this
means that even when compiling for z13, no vector instructions
will be used. In the future, support for the vector ABI should be
added (this will require common code support for different ABIs
that need different data_layout strings on the same platform).
- Two test cases are (temporarily) ignored on s390x to allow passing
the test suite. The underlying issues still need to be fixed:
* debuginfo/simd.rs fails because of incorrect debug information.
This seems to be a LLVM bug (also seen with C code).
* run-pass/union/union-basic.rs simply seems to be incorrect for
all big-endian platforms.
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Fix argument to FIONBIO ioctl
The FIONBIO ioctl takes as argument a pointer to an integer, which
should be either 0 or 1 to indicate whether nonblocking mode is to
be switched off or on. The type of the pointed-to variable is "int".
However, the set_nonblocking routine in libstd/sys/unix/net.rs passes
a pointer to a libc::c_ulong variable. This doesn't matter on all
32-bit platforms and on all litte-endian platforms, but it will
break on big-endian 64-bit platforms.
Found while porting Rust to s390x (a big-endian 64-bit platform).
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
The FIONBIO ioctl takes as argument a pointer to an integer, which
should be either 0 or 1 to indicate whether nonblocking mode is to
be switched off or on. The type of the pointed-to variable is "int".
However, the set_nonblocking routine in libstd/sys/unix/net.rs passes
a pointer to a libc::c_ulong variable. This doesn't matter on all
32-bit platforms and on all litte-endian platforms, but it will
break on big-endian 64-bit platforms.
Found while porting Rust to s390x (a big-endian 64-bit platform).
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Use monotonic time in condition variables.
Configure condition variables to use monotonic time using
pthread_condattr_setclock on systems where this is possible.
This fixes the issue when thread waiting on condition variable is
woken up too late when system time is moved backwards.
Use arc4rand(9) on FreeBSD
From rust-lang-nursery/rand#112:
>After reading through #30691 it seems that there's general agreement that using OS-provided facilities for seeding rust userland processes is fine as long as it doesn't use too much from libc. FreeBSD's `arc4random_buf(3)` is not only a whole lot of libc code, but also not even currently exposed in the libc crate. Fortunately, the mechanism `arc4random_buf(3)` et al. use for getting entropy from the kernel ([`arc4rand(9)`](https://www.freebsd.org/cgi/man.cgi?query=arc4random&apropos=0&sektion=9&manpath=FreeBSD+10.3-RELEASE&arch=default&format=html)) is exposed via `sysctl(3)` with constants that are already in the libc crate.
>I haven't found too much documentation on `KERN_ARND`—it's missing or only briefly described in most of the places that cover sysctl mibs. But, from digging through the kernel source, it appears that the sysctl used in this PR is very close to just calling `arc4rand(9)` directly (with `reseed` set to 0 and no way to change it).
I expected [rand](/rust-lang-nursery/rand) to reply quicker, so I tried submitting it there first. It's been a few weeks with no comment, so I don't know the state of it, but maybe someone will see it here and have an opinion. This is basically the same patch. It pains me to duplicate the code but I guess it hasn't been factored out into just one place yet.
Emscripten test fixes
This picks up parts of #31623 to disable certain tests that emscripten can't run, as threads/processes are not supported.
I re-applied @tomaka's changes manually, I can rebase those commits with his credentials if he wants.
It also disables jemalloc for emscripten (at least in Rustbuild, I have to check if there is another setting for the same thing in the old makefile approach).
This should not impact anything for normal builds.
Fix build on DragonFly (unused function errno_location)
Function errno_location() is not used on DragonFly. As warnings are
errors, this breaks the build.
Handle RwLock reader count overflow
`pthread_rwlock_rdlock` may return `EAGAIN` if the maximum reader count overflows. We shouldn't return a successful lock in that case.
