| Commit message (Expand) | Author | Age | Files | Lines |
|---|
| * | use a local temp buffer for unbuffered streams in vfprintf•••this change makes it so most calls to fprintf(stderr, ...) will result
in a single writev syscall, as opposed to roughly 2*N syscalls (and
possibly more) where N is the number of format specifiers. in
principle we could use a much larger buffer, but it's best not to
increase the stack requirements too much. most messages are under 80
chars.
| Rich Felker | 2011-04-04 | 2 | -0/+14 |
| * | fix nl_langinfo to actually use the existing, correct internal version | Rich Felker | 2011-04-03 | 2 | -15/+5 |
| * | make ualarm actually work (obsolete function removed from SUS) | Rich Felker | 2011-04-03 | 1 | -4/+9 |
| * | fix various bugs in strtold:•••0e10000000000000000000000000000000 was setting ERANGE
exponent char e/p was considered part of the match even if not
followed by a valid decimal value
"1e +10" was parsed as "1e+10"
hex digits were misinterpreted as 0..5 instead of 10..15
| Rich Felker | 2011-04-03 | 1 | -10/+13 |
| * | fix serious bug in strchr - char signedness•••search for bytes with high bit set was giving (potentially dangerous)
wrong results. i've tested, cleaned up, and hopefully sped up this
function now.
| Rich Felker | 2011-04-03 | 1 | -9/+11 |
| * | add setresuid/setresgid functions (nonstandard) | Rich Felker | 2011-04-03 | 2 | -0/+20 |
| * | pthread_create need not set errno | Rich Felker | 2011-04-03 | 1 | -1/+1 |
| * | fix statvfs syscalls (missing size argument) | Rich Felker | 2011-04-03 | 2 | -2/+2 |
| * | block all signals during rsyscall•••otherwise a signal handler could see an inconsistent and nonconformant
program state where different threads have different uids/gids.
| Rich Felker | 2011-04-03 | 1 | -4/+9 |
| * | fix race condition in rsyscall handler•••the problem: there is a (single-instruction) race condition window
between a thread flagging itself dead and decrementing itself from the
thread count. if it receives the rsyscall signal at this exact moment,
the rsyscall caller will never succeed in signalling enough flags to
succeed, and will deadlock forever. in previous versions of musl, the
about-to-terminate thread masked all signals prior to decrementing
the thread count, but this cost a whole syscall just to account for
extremely rare races.
the solution is a huge hack: rather than blocking in the signal
handler if the thread is dead, modify the signal mask of the saved
context and return in order to prevent further signal handling by the
dead thread. this allows the dead thread to continue decrementing the
thread count (if it had not yet done so) and exiting, even while the
live part of the program blocks for rsyscall.
| Rich Felker | 2011-04-03 | 1 | -1/+1 |
| * | don't trust siginfo in rsyscall handler•••for some inexplicable reason, linux allows the sender of realtime
signals to spoof its identity. permission checks for sending signals
should limit the impact to same-user processes, but just to be safe,
we avoid trusting the siginfo structure and instead simply examine the
program state to see if we're in the middle of a legitimate rsyscall.
| Rich Felker | 2011-04-03 | 1 | -3/+2 |
| * | timer threads should sleep and stay asleep... a long time | Rich Felker | 2011-04-03 | 1 | -1/+1 |
| * | revert to deleting kernel-level timer from cancellation handler•••this is necessary in order to avoid breaking timer_getoverrun in the
last run of the timer event handler, if it has not yet finished.
| Rich Felker | 2011-04-03 | 2 | -7/+11 |
| * | simplify calling of timer signal handler | Rich Felker | 2011-04-03 | 3 | -12/+6 |
| * | simplify pthread tsd key handling | Rich Felker | 2011-04-03 | 3 | -10/+7 |
| * | omit pthread tsd dtor code if tsd is not used | Rich Felker | 2011-04-03 | 2 | -14/+24 |
| * | don't disable seeking after first seek failure•••this could cause problems if the application uses dup2(fd,fileno(f))
to redirect, and the old fd was not seekable but the new fd is.
| Rich Felker | 2011-04-02 | 1 | -8/+0 |
| * | apparently fseek should not set the error flag on failed seek | Rich Felker | 2011-04-02 | 1 | -4/+1 |
| * | avoid over-allocation of brk on first malloc•••if init_malloc returns positive (successful first init), malloc will
retry getting a chunk from the free bins rather than expanding the
heap again. also pass init_malloc a hint for the size of the initial
allocation.
| Rich Felker | 2011-04-01 | 1 | -4/+4 |
| * | reorganize the __libc structure for threaded performance issues•••we want to keep atomically updated fields (locks and thread count) and
really anything writable far away from frequently-needed function
pointers. stuff some rarely-needed function pointers in between to
pad, hopefully up to a cache line boundary.
| Rich Felker | 2011-04-01 | 1 | -6/+6 |
| * | simplify setting result on thread cancellation | Rich Felker | 2011-04-01 | 1 | -1/+1 |
| * | use bss instead of mmap for main thread's pthread thread-specific data•••this simplifies code and removes a failure case
| Rich Felker | 2011-04-01 | 2 | -9/+4 |
| * | remove obsolete and useless useconds_t type | Rich Felker | 2011-04-01 | 2 | -2/+2 |
| * | fix misspelled PTHREAD_CANCELED constant | Rich Felker | 2011-04-01 | 1 | -1/+1 |
| * | use a_store to set cancel flag in pthread_cancel, to ensure a barrier | Rich Felker | 2011-04-01 | 1 | -1/+1 |
| * | simplify pthread_key_delete•••calling this function on an uninitialized key value is UB, so there is
no need to check that the table pointer was initialized.
| Rich Felker | 2011-03-31 | 1 | -1/+1 |
| * | greatly simplify pthread_key_create (~20% size reduction) | Rich Felker | 2011-03-31 | 1 | -10/+9 |
| * | avoid all malloc/free in timer creation/destruction•••instead of allocating a userspace structure for signal-based timers,
simply use the kernel timer id. we use the fact that thread pointers
will always be zero in the low bit (actually more) to encode integer
timerid values as pointers.
also, this change ensures that the timer_destroy syscall has completed
before the library timer_destroy function returns, in case it matters.
| Rich Felker | 2011-03-30 | 5 | -29/+20 |
| * | optimize timer creation and possibly protect against some minor races•••the major idea of this patch is not to depend on having the timer
pointer delivered to the signal handler, and instead use the thread
pointer to get the callback function address and argument. this way,
the parent thread can make the timer_create syscall while the child
thread is starting, and it should never have to block waiting for the
barrier.
| Rich Felker | 2011-03-30 | 2 | -16/+19 |
| * | avoid crash on stupid but allowable usage of pthread_mutex_unlock•••unlocking an unlocked mutex is not UB for robust or error-checking
mutexes, so we must avoid calling __pthread_self (which might crash
due to lack of thread-register initialization) until after checking
that the mutex is locked.
| Rich Felker | 2011-03-30 | 1 | -1/+3 |
| * | rename __simple_malloc.c to lite_malloc.c - yes this affects behavior!•••why does this affect behavior? well, the linker seems to traverse
archive files starting from its current position when resolving
symbols. since calloc.c comes alphabetically (and thus in sequence in
the archive file) between __simple_malloc.c and malloc.c, attempts to
resolve the "malloc" symbol for use by calloc.c were pulling in the
full malloc.c implementation rather than the __simple_malloc.c
implementation.
as of now, lite_malloc.c and malloc.c are adjacent in the archive and
in the correct order, so malloc.c should never be used to resolve
"malloc" unless it's already needed to resolve another symbol ("free"
or "realloc").
| Rich Felker | 2011-03-30 | 1 | -0/+0 |
| * | streamline mutex unlock to remove a useless branch, use a_store to unlock•••this roughly halves the cost of pthread_mutex_unlock, at least for
non-robust, normal-type mutexes.
the a_store change is in preparation for future support of archs which
require a memory barrier or special atomic store operation, and also
should prevent the possibility of the compiler misordering writes.
| Rich Felker | 2011-03-30 | 1 | -2/+6 |
| * | cheap special-case optimization for normal mutexes•••cycle-level benchmark on atom cpu showed typical pthread_mutex_lock
call dropping from ~120 cycles to ~90 cycles with this change. benefit
may vary with compiler options and version, but this optimization is
very cheap to make and should always help some.
| Rich Felker | 2011-03-30 | 1 | -0/+4 |
| * | reorder timer initialization so that timer_create does not depend on free•••this allows small programs which only create times, but never delete
them, to use simple_malloc instead of the full malloc.
| Rich Felker | 2011-03-29 | 2 | -9/+17 |
| * | revert mutex "optimization" that turned out to be worse | Rich Felker | 2011-03-29 | 1 | -1/+1 |
| * | implement POSIX timers•••this implementation is superior to the glibc/nptl implementation, in
that it gives true realtime behavior. there is no risk of timer
expiration events being lost due to failed thread creation or failed
malloc, because the thread is created as time creation time, and
reused until the timer is deleted.
| Rich Felker | 2011-03-29 | 5 | -0/+143 |
| * | major improvements to cancellation handling•••- there is no longer any risk of spoofing cancellation requests, since
the cancel flag is set in pthread_cancel rather than in the signal
handler.
- cancellation signal is no longer unblocked when running the
cancellation handlers. instead, pthread_create will cause any new
threads created from a cancellation handler to unblock their own
cancellation signal.
- various tweaks in preparation for POSIX timer support.
| Rich Felker | 2011-03-29 | 4 | -8/+19 |
| * | some preliminaries for adding POSIX timers | Rich Felker | 2011-03-29 | 1 | -0/+4 |
| * | fix tempnam name generation, and a small bug in tmpnam on retry limit | Rich Felker | 2011-03-29 | 2 | -21/+20 |
| * | make tmpfile fail after exceeding max tries. | Rich Felker | 2011-03-29 | 1 | -2/+6 |
| * | fix tmpnam to generate better names, not depend on non-ISO-C symbols | Rich Felker | 2011-03-29 | 1 | -25/+17 |
| * | fix messed-up errno if remove fails for a non-EISDIR reason | Rich Felker | 2011-03-29 | 1 | -2/+2 |
| * | learned something new - remove is supposed to support directories on POSIX | Rich Felker | 2011-03-29 | 1 | -1/+3 |
| * | revert some more spin optimizations that turned out to be pessimizations | Rich Felker | 2011-03-28 | 3 | -4/+3 |
| * | fix broken spinlock due to miscompilation•••actually this trick also seems to have made the uncontended case slower.
| Rich Felker | 2011-03-28 | 1 | -1/+1 |
| * | remove useless field in pthread struct (wasted a good bit of space) | Rich Felker | 2011-03-28 | 1 | -1/+0 |
| * | fix getc - the classic error of trying to store EOF+0-255 in a char type.. | Rich Felker | 2011-03-28 | 1 | -3/+3 |
| * | major stdio overhaul, using readv/writev, plus other changes•••the biggest change in this commit is that stdio now uses readv to fill
the caller's buffer and the FILE buffer with a single syscall, and
likewise writev to flush the FILE buffer and write out the caller's
buffer in a single syscall.
making this change required fundamental architectural changes to
stdio, so i also made a number of other improvements in the process:
- the implementation no longer assumes that further io will fail
following errors, and no longer blocks io when the error flag is set
(though the latter could easily be changed back if desired)
- unbuffered mode is no longer implemented as a one-byte buffer. as a
consequence, scanf unreading has to use ungetc, to the unget buffer
has been enlarged to hold at least 2 wide characters.
- the FILE structure has been rearranged to maintain the locations of
the fields that might be used in glibc getc/putc type macros, while
shrinking the structure to save some space.
- error cases for fflush, fseek, etc. should be more correct.
- library-internal macros are used for getc_unlocked and putc_unlocked
now, eliminating some ugly code duplication. __uflow and __overflow
are no longer used anywhere but these macros. switch to read or
write mode is also separated so the code can be better shared, e.g.
with ungetc.
- lots of other small things.
| Rich Felker | 2011-03-28 | 37 | -281/+258 |
| * | match glibc/lsb cancellation abi on i386•••glibc made the ridiculous choice to use pass-by-register calling
convention for these functions, which is impossible to duplicate
directly on non-gcc compilers. instead, we use ugly asm to wrap and
convert the calling convention. presumably this works with every
compiler anyone could potentially want to use.
| Rich Felker | 2011-03-25 | 6 | -0/+36 |
| * | fix all implicit conversion between signed/unsigned pointers•••sadly the C language does not specify any such implicit conversion, so
this is not a matter of just fixing warnings (as gcc treats it) but
actual errors. i would like to revisit a number of these changes and
possibly revise the types used to reduce the number of casts required.
| Rich Felker | 2011-03-25 | 19 | -48/+44 |
