StableIO

Stable IO is a interrupt aware IO module.

The basic functionality of the contained routines is to provide IO that is not interrupted by a casual interrupt; i.e. they will retry several times before giving up.

Index:

The StableIOMaxRetries variable
The read function
The write function

The StableIOMaxRetries variable

As said in the begining, the StableIO functions are used to retry several times before giving up. How many times they will retry is specified in the StableIOMaxRetries variable.

To access this variable, the module gives you the following routines:

int StableIOGetMaxRetries(): Returns the current value of StableIOMaxRetries.
int StableIOSetMaxRetries(int newStableIOMaxRetries): Set the value of StableIOMaxRetries if newStableIOMaxRetries is valid.
Returns the new value of StableIOMaxRetries.

Note that the two routines are not thread_safe, so they should be used only in the main thread!

The read function

The read function, with the syntax:
int StableIORead(int stream_id,char *buf,int len)
is an extension of the read function defined in the unistd.h.

The main differences are:

StableIORead returns only if the specified number of bytes are read or in case of error
i.e. if the return value is not len, the call to the function should be considered failed
EINTR must be returned by read StableIOMaxRetries times before it is catched by StableIORead

The write function

The write function, with the syntax:
int StableIOWrite(int stream_id,char *buf,int len)
is an extension of the write function defined in the unistd.h.

The main differences are:

StableIOWrite returns only if the specified number of bytes are writen or in case of error
i.e. if the return value is not len, the call to the function should be considered failed
EINTR must be returned by write StableIOMaxRetries times before it is catched by StableIOWrite

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Send comments to: Igor Sfiligoi

Created	:	10.11.1999
Last modified	:	10.11.1999