11-13-2015
Linux lock problem
Hi Team,
I have a requirement to access a shared resource from the user and interrupt context. What type of locking mechanism I have to use for this. Can any body give advice on this.
Thanks in advance.
-Shiva
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LEARN ABOUT HPUX
posix_fadvise
posix_fadvise(2) System Calls Manual posix_fadvise(2)
NAME
posix_fadvise(), posix_fadvise64() - file advisory information
SYNOPSIS
Parameters
fd The open file descriptor to which the fadvise operation applies.
offset The begining of the specified range as a positive, byte offset.
len The length of the specified range in bytes.
advice Specifies advice to be applied to range.
DESCRIPTION
The function is used to advise the system about the expected behavior of the application with respect to the data in the file associated
with the open file descriptor, fd, starting at offset and continuing for len bytes. The specified range need not currently exist in the
file. If len is zero, all data following offset is specified.
It should be noted that the effect of all hints is cumulative for a given file object. All hints will be removed on processing the last
close of the file object.
The function may be used for large file access by a 32-bit application built with set to 64.
The advice parameter is used to convey the hint to be applied to the data and may be one of the following values:
Specifies that the application has no advice to give on its behavior with respect to the specified data. It is the default characteristic
if no advice is given for an open file.
Specifies that the application expects to access the specified range of data
sequentially from the lower offsets to higher offsets.
Specifies that the application will expect to access the specified
specified range of data in a random order.
Specifies that the application will expect to access the specified
range of data in the near future.
Specifies that the application will expect that it will not
access the specified range of data in the near future.
Specifies that the application will expect to access the specified range
of data once and then not reuse it thereafter.
These values will be defined in
RETURN VALUE
Successful completion.
Failure.
is set to indicate the error.
ERRORS
If the service fails, is set to one of the following values:
The fd argument is not a valid file descriptor.
The fd argument is associated with a pipe or FIFO.
The posix_fadvise operation is not supported by the underlying file system.
The value of advice or one of the other input values has been found to be invalid.
A designated hint is not supported by the underlying file object.
EXAMPLES
AUTHOR
was derived by HP from the IEEE POSIX 1003.1-2001 Standard.
SEE ALSO
fadvise(2), fcntl(2), fadvise(5), fcntl(5).
STANDARDS CONFORMANCE
posix_fadvise(2)