Which call to the operating system (any operating system is fine) returns a read lock? I did locking, but it has been some time back, and there were only write locks. You could open a file in shared MODE or not, which write locked the file, or failed to write lock the file.
My understanding was that a "shared lock" is a metaphor, and IMHO, a fairly stupid one. If you lock a room, nobody else can get in, it's not a mechanism for sharing, it's a mechanism for preventing sharing. The absense of black does not imply white. On 1/21/07, John Stanton <[EMAIL PROTECTED]> wrote:
POSIX defines read and write locks. A write lock is exclusive and a read lock inhibits a write lock from occurring. Any number of processes/threads can have a read lock but as long as one read lock is in place a write lock cannot be established. When a write lock is set no read or write locks can complete.
