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42 lines
1.7 KiB
Text
42 lines
1.7 KiB
Text
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Copyright (c) 1993, 1994 Chris Provenzano. All rights reserved.
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This is a threadsafe stdio based on the BSD stdio written by Chris Torek.
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This product includes software developed by the Univeristy of California,
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Berkeley and its contributors.
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INCLUDE FILES AND PORTING
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To continue to make this package portable, some basic rules on includes
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files must be followed.
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pthread.h should be included first (if it is to be included).
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stdio.h should be included.
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INTERNAL LOCKING
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1. All functions that can be called by the user must have flockfile() at the
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begining and a funlockfile() at the end. The routine flockfile() is a
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counting mutex, The thread that owns the lock can call flockfile() as
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many times as it wants, but must call an equal number of funlockfile()
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before the lock will be released.
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2. All functions starting with __ shouldn't need addtional locking.
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3. Anything that writes the variable __sglue should lock __sfp_mutex,
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check __sfp_state, and do a condion wait if it is set.
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4. Anything that checks fp->_flag for valididity should also lock
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__sfp_mutex.
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5. Anything that reads the variable __sglue should lock __sfp_mutex, increment
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__sfp_state, and then unlock the mutex. At function return it should
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lock the mutex again decrement __sfp_state and check if zero. If so
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do a cond_signal, and unlock the mutex.
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6. The functions fopen, fdopen, and freopen are the only functions that
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will change a fp->_file
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7. fdopen and fopen both allocate the next fp by locking __sfp_mutex
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checking fp->_flags and then setting it if free.
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8. freopen tries to preserve fp->_file. It sets __sfp_mutex, then it
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tries to lock fp->_file and close it.
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9. __sinit is done with a pthread_once routine.
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Things to do.
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Fix printf so it uses the ininf function.
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