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path: root/src/stdio/fopen.c
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2015-06-13remove cancellation points in stdioRich Felker-1/+1
commit 58165923890865a6ac042fafce13f440ee986fd9 added these optional cancellation points on the basis that cancellable stdio could be useful, to unblock threads stuck on stdio operations that will never complete. however, the only way to ensure that cancellation can achieve this is to violate the rules for side effects when cancellation is acted upon, discarding knowledge of any partial data transfer already completed. our implementation exhibited this behavior and was thus non-conforming. in addition to improving correctness, removing these cancellation points moderately reduces code size, and should significantly improve performance on i386, where sysenter/syscall instructions can be used instead of "int $128" for non-cancellable syscalls.
2014-06-06add O_CLOEXEC fallback for open and related functionsRich Felker-0/+2
since there is no easy way to detect whether open honored or ignored the O_CLOEXEC flag, the optimal solution to providing a fallback is simply to make the fcntl syscall to set the close-on-exec flag immediately after open returns.
2014-05-24support kernels with no SYS_open syscall, only SYS_openatRich Felker-1/+1
open is handled specially because it is used from so many places, in so many variants (2 or 3 arguments, setting errno or not, and cancellable or not). trying to do it as a function would not only increase bloat, but would also risk subtle breakage. this is the first step towards supporting "new" archs where linux lacks "old" syscalls.
2012-11-08clean up stdio_impl.hRich Felker-0/+3
this header evolved to facilitate the extremely lazy practice of omitting explicit includes of the necessary headers in individual stdio source files; not only was this sloppy, but it also increased build time. now, stdio_impl.h is only including the headers it needs for its own use; any further headers needed by source files are included directly where needed.
2012-10-24greatly improve freopen behaviorRich Felker-8/+1
1. don't open /dev/null just as a basis to copy flags; use shared __fmodeflags function to get the right file flags for the mode. 2. handle the case (probably invalid, but whatever) case where the original stream's file descriptor was closed; previously, the logic re-closed it. 3. accept the "e" mode flag for close-on-exec; update dup3 to fallback to using dup2 so we can simply call __dup3 instead of putting fallback logic in freopen itself.
2012-09-29add 'e' modifier (close-on-exec) to fopen and fdopenRich Felker-0/+1
this feature will be in the next version of POSIX, and can be used internally immediately. there are many internal uses of fopen where close-on-exec is needed to fix bugs.
2012-09-06use restrict everywhere it's required by c99 and/or posix 2008Rich Felker-1/+1
to deal with the fact that the public headers may be used with pre-c99 compilers, __restrict is used in place of restrict, and defined appropriately for any supported compiler. we also avoid the form [restrict] since older versions of gcc rejected it due to a bug in the original c99 standard, and instead use the form *restrict.
2012-08-25implement "low hanging fruit" from C11Rich Felker-2/+2
based on Gregor's patch sent to the list. includes: - stdalign.h - removing gets in C11 mode - adding aligned_alloc and adjusting other functions to use it - adding 'x' flag to fopen for exclusive mode
2012-02-02make stdio open, read, and write operations cancellation pointsRich Felker-1/+1
it should be noted that only the actual underlying buffer flush and fill operations are cancellable, not reads from or writes to the buffer. this behavior is compatible with POSIX, which makes all cancellation points in stdio optional, and it achieves the goal of allowing cancellation of a thread that's "stuck" on IO (due to a non-responsive socket/pipe peer, slow/stuck hardware, etc.) without imposing any measurable performance cost.
2011-04-17debloat: use __syscall instead of syscall where possibleRich Felker-1/+1
don't waste time (and significant code size due to function call overhead!) setting errno when the result of a syscall does not matter or when it can't fail.
2011-03-20global cleanup to use the new syscall interfaceRich Felker-2/+2
2011-02-12initial check-in, version 0.5.0v0.5.0Rich Felker-0/+34