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2012-04-24add another example option to dist/config.makRich Felker-0/+3
2012-04-24ditch the priority inheritance locks; use malloc's version of lockRich Felker-77/+54
i did some testing trying to switch malloc to use the new internal lock with priority inheritance, and my malloc contention test got 20-100 times slower. if priority inheritance futexes are this slow, it's simply too high a price to pay for avoiding priority inversion. maybe we can consider them somewhere down the road once the kernel folks get their act together on this (and perferably don't link it to glibc's inefficient lock API)... as such, i've switch __lock to use malloc's implementation of lightweight locks, and updated all the users of the code to use an array with a waiter count for their locks. this should give optimal performance in the vast majority of cases, and it's simple. malloc is still using its own internal copy of the lock code because it seems to yield measurably better performance with -O3 when it's inlined (20% or more difference in the contention stress test).
2012-04-24internal locks: new owner of contended lock must set waiters flagRich Felker-1/+1
this bug probably would have gone unnoticed since it's only used in the fallback code for systems where priority-inheritance locking fails. unfortunately this approach results in one spurious wake syscall on the final unlock, when there are no waiters remaining. the alternative (possibly better) would be to use broadcast wakes instead of reflagging the waiter unconditionally, and let each waiter reflag itself; this saves one syscall at the expense of invoking the "thundering herd" effect (worse performance degredation) when there are many waiters. ideally we would be able to update all of our locks to use an array of two ints rather than a single int, and use a separate counter system like proper mutexes use; then we could avoid all spurious wake calls without resorting to broadcasts. however, it's not clear to me that priority inheritance futexes support this usage. the kernel sets the waiters flag for them (just like we're doing now) and i can't tell if it's safe to bypass the kernel when unlocking just because we know (from private data, the waiter count) that there are no waiters. this is something that could be explored in the future.
2012-04-24new internal locking primitive; drop spinlocksRich Felker-7/+29
we use priority inheritance futexes if possible so that the library cannot hit internal priority inversion deadlocks in the presence of realtime priority scheduling (full support to be added later).
2012-04-24new wcwidth implementation (fast table-based)Rich Felker-179/+125
i tried to go with improving the old binary-search-based algorithm, but between growth in the number of ranges, bad performance, and lack of confidence in the binary search code's stability under changes in the table, i decided it was worth the extra 1.8k to have something clean and maintainable. also note that, like the alpha and punct tables, there's definitely room to optimize the nonspacing/wide tables by overlapping subtables. this is not a high priority, but i've begun looking into how to do it, and i suspect the table sizes can be roughly halved. if that turns out to be true, the new, fast, table-based implementation will be roughly the same size as if i had just extended the old binary search one.
2012-04-23sync case mappings with unicode 6.1Rich Felker-8/+30
also special-case ß (U+00DF) as lowercase even though it does not have a mapping to uppercase. unicode added an uppercase version of this character but does not map it, presumably because the uppercase version is not actually used except for some obscure purpose...
2012-04-23optimize iswprintRich Felker-3/+12
2012-04-23fix spurious punct class for some surrogate codepoints (invalid)Rich Felker-59/+56
this happened due to their entries in UnicodeData.txt
2012-04-23destubify iswalpha and update iswpunct to unicode 6.1Rich Felker-135/+252
alpha is defined as unicode property "Alphabetic" plus category Nd minus ASCII digits minus 2 special-cased Thai punctuation marks supposedly misclassified by Unicode as letters. punct is defined as all of unicode except control, alphanumeric, and space characters. the tables were generated by a simple tool based on the code posted previously to the mailing list. in the future, this and other code used for maintaining locale/iconv/i18n data will be published either in the main source repository or in a separate locale data generation repository.
2012-04-23make dlerror produce informative resultsRich Felker-4/+15
note that dlerror is specified to be non-thread-safe, so no locking is performed on the error flag or message aside from the rwlock already held by dlopen or dlsym. if 2 invocations of dlsym are generating errors at the same time, they could clobber each other's results, but the resulting string, albeit corrupt, will still be null-terminated. any use of dlerror in such a situation could not be expected to give meaningful results anyway.
2012-04-22implement getusershell, etc. legacy functionsRich Felker-0/+36
I actually wrote these a month ago but forgot to integrate them. ugly, probably-harmful-to-use functions, but some legacy apps want them...
2012-04-22getdtablesize is not standard; move it to its correct spot in unistd.hRich Felker-1/+1
2012-04-22new gcc wrapper, entirely specfile basedRich Felker-63/+47
the _concept_ of this wrapper has been tested extensively, but the integration with the build/install system, and using a persistent specfile rather than one generated at build-time, have not been heavily tested and may need minor tweaks. this approach should be a lot more robust (and easier to improve) than writing a shell script that's responsible for trying to mimic gcc's logic about whether it's compiling or linking, building shared libs or executable files, etc. it's also lighter weight and should result in mildly faster builds when using the wrapper.
2012-04-22remove redundant (unmaintained) check in floatscanRich Felker-3/+3
also be extra careful to avoid wrapping the circular buffer early
2012-04-22fix breakage in endian.hRich Felker-1/+1
2012-04-22add some ugly byte swapping cruft in endian.hRich Felker-0/+59
2012-04-22add getresuid and getresgid syscall wrappersRich Felker-0/+18
2012-04-21fix major breakage in iconv, bogus rejecting of dest charsetsRich Felker-1/+1
2012-04-21make floatscan correctly set errno for overflow/underflowRich Felker-4/+16
care is taken that the setting of errno correctly reflects underflow condition. scanning exact denormal values does not result in ERANGE, nor does scanning values (such as the usual string definition of FLT_MIN) which are actually less than the smallest normal number but which round to a normal result. only the decimal case is handled so far; hex float require a separate fix to come later.
2012-04-21skip leading zeros even after decimal point in floatscanRich Felker-4/+9
in principle this should just be an optimization, but it happens to also fix a nasty bug where values like 0.00000000001 were getting caught by the early zero detection path and wrongly scanned as zero.
2012-04-21fix overread (consuming an extra byte) scanning NANRich Felker-1/+1
bug detected by glib test suite
2012-04-21fix broken sysconf when correct value is -1Rich Felker-1/+1
this caused glib to try to allocate >2gb for getpwnam_r, and probably numerous other problems.
2012-04-19release notes for 0.8.9 (bugfix release)v0.8.9Rich Felker-0/+11
2012-04-19further fixes to leading space issue (forgot the wide versions)Rich Felker-5/+9
2012-04-19fix really bad breakage in strtol, etc.: failure to accept leading spacesRich Felker-10/+9
2012-04-18fix header typoRich Felker-1/+1
2012-04-18legacy junk compatibility grab-bagRich Felker-7/+36
- add the rest of the junk traditionally in sys/param.h - add prototypes for some nonstandard functions - add _GNU_SOURCE to their source files so the compiler can check proto
2012-04-18fix incorrect macro name for MATH_ERREXCEPT in math.hRich Felker-1/+1
2012-04-18release notes for 0.8.8v0.8.8Rich Felker-0/+34
2012-04-18fix typo in exponent reading code or floatsRich Felker-1/+1
this was basically harmless, but could have resulted in misreading inputs with more than a few gigabytes worth of digits..
2012-04-17fix wide scanf's handling of input failure on %c, and simplify %[Rich Felker-5/+6
2012-04-17fix failure to distinguish input/match failure in wide %[ scanfRich Felker-2/+4
this also includes a related fix for vswscanf's read function, which was returning a spurious (uninitialized) character for empty strings.
2012-04-17fix over-read in %ls with non-wide scanfRich Felker-0/+1
2012-04-17fix broken %s and %[ with no width specifier in wide scanfRich Felker-3/+7
2012-04-17fix failure to read infinity in scanfRich Felker-3/+4
this code worked in strtod, but not in scanf. more evidence that i should design a better interface for discarding multiple tail characters than just calling unget repeatedly...
2012-04-17fix failure of int parser to unget an initial mismatching characterRich Felker-0/+1
2012-04-17make wide scanf %[ respect widthRich Felker-2/+3
2012-04-17fix wide scanf to respect field width for stringsRich Felker-4/+7
2012-04-17fix some bugs in scanf %[ handling detected while writing the wide versionRich Felker-4/+4
2012-04-17introduce new wide scanf code and remove the last remnants of old scanfRich Felker-524/+312
at this point, strto* and all scanf family functions are using the new unified integer and floating point parser/converter code. the wide scanf is largely a wrapper for ordinary byte-based scanf; since numbers can only contain ascii characters, only strings need to be handled specially.
2012-04-17avoid depending on POSIX symbol in code used from plain C functionsRich Felker-1/+3
2012-04-17avoid null pointer dereference on %*p fields in scanfRich Felker-1/+1
2012-04-17also ensure that write buffer is bounded when __stdio_write returnsRich Felker-0/+1
assuming other code is correct, this should be a no-op, but better to be safe...
2012-04-17fix buffer overflow in vfprintf on long writes to unbuffered filesRich Felker-1/+2
vfprintf temporarily swaps in a local buffer (for the duration of the operation) when the target stream is unbuffered; this both simplifies the implementation of functions like dprintf (they don't need their own buffers) and eliminates the pathologically bad performance of writing the formatted output with one or more write syscalls per formatting field. in cases like dprintf where we are dealing with a virgin FILE structure, everything worked correctly. however for long-lived files (like stderr), it's possible that the buffer bounds were already set for the internal zero-size buffer. on the next write, __stdio_write would pick up and use the new buffer provided by vfprintf, but the bound (wend) field was still pointing at the internal zero-size buffer's end. this in turn allowed unbounded writes to the temporary buffer.
2012-04-16fix %lf, etc. with printfRich Felker-0/+2
the l prefix is redundant/no-op with printf, since default promotions always promote floats to double; however, it is valid, and printf was wrongly rejecting it.
2012-04-16better description for errno==0Rich Felker-1/+1
2012-04-16implement wcstod and familyRich Felker-0/+61
not heavily tested but these functions appear to work correctly
2012-04-16avoid hitting eof in wcstolRich Felker-2/+3
shunget cannot unget eof status, causing wcstol to leave endptr pointing to the wrong place when scanning, for example, L"0x". cheap fix is to make the read function provide an infinite stream of bogus characters rather than eof. really this is something of a design flaw in how the shgetc system is used for strto* and wcsto*; in the long term, I believe multi-character unget should be scrapped and replaced with a function that can subtract from the f->shcnt counter.
2012-04-16use the new integer parser (FILE/shgetc based) for strtol, wcstol, etc.Rich Felker-405/+120
2012-04-16new scanf implementation and corresponding integer parser/converterRich Felker-30/+450
advantages over the old code: - correct results for floating point (old code was bogus) - wide/regular scanf separated so scanf does not pull in wide code - well-defined behavior on integers that overflow dest type - support for %[a-b] ranges with %[ (impl-defined by widely used) - no intermediate conversion of fmt string to wide string - cleaner, easier to share code with strto* functions - better standards conformance for corner cases the old code remains in the source tree, as the wide versions of the scanf-family functions are still using it. it will be removed when no longer needed.