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path: root/src/stdio/open_memstream.c
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2015-10-08fix open_[w]memstream behavior when no writes take placeRich Felker-2/+9
the specification for these functions requires that the buffer/size exposed to the caller be valid after any successful call to fflush or fclose on the stream. the implementation's approach is to update them only at flush time, but that misses the case where fflush or fclose is called without any writes having taken place, in which case the write flushing callback will not be called. to fix both the observable bug and the desired invariant, setup empty buffers at open time and fail the open operation if no memory is available.
2015-06-16refactor stdio open file list handling, move it out of global libc structRich Felker-7/+1
functions which open in-memory FILE stream variants all shared a tail with __fdopen, adding the FILE structure to stdio's open file list. replacing this common tail with a function call reduces code size and duplication of logic. the list is also partially encapsulated now. function signatures were chosen to facilitate tail call optimization and reduce the need for additional accessor functions. with these changes, static linked programs that do not use stdio no longer have an open file list at all.
2012-11-09always add memory streams to stdio open file listRich Felker-6/+7
per interpretation for austin group issue #626, fflush(0) and exit() must block waiting for a lock if another thread has locked a memory stream with flockfile. this adds some otherwise-unnecessary synchronization cost to use of memory streams, but there was already a synchronization cost calling malloc anyway. previously the stream was only added to the open file list in single-threaded programs, so that upon subsequent call to pthread_create, locking could be turned on for the stream.
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.
2011-09-04memstreams: fix incorrect handling of file pos > current sizeRich Felker-2/+2
the addition is safe and cannot overflow because both operands are positive when considered as signed quantities.
2011-09-04optimize seek function for memory streamsRich Felker-12/+3
2011-09-04fix twos complement overflow bug in mem streams boundary checkRich Felker-1/+1
the expression -off is not safe in case off is the most-negative value. instead apply - to base which is known to be non-negative and bounded within sanity.
2011-09-03fix some length calculations in memory streamsRich Felker-1/+1
2011-09-03implement open_memstreamRich Felker-0/+94
this is the first attempt, and may have bugs. only minimal testing has been performed.