puffs_flush(3) [netbsd man page]

PUFFS_FLUSH(3)						   BSD Library Functions Manual 					    PUFFS_FLUSH(3)

NAME

     puffs_flush -- puffs kernel cache flushing and invalidation routines

LIBRARY

     puffs Convenience Library (libpuffs, -lpuffs)

SYNOPSIS

     #include <puffs.h>

     int
     puffs_inval_namecache_dir(struct puffs_usermount *pu, puffs_cookie_t cookie);

     int
     puffs_inval_namecache_all(struct puffs_usermount *pu);

     int
     puffs_inval_pagecache_node(struct puffs_usermount *pu, puffs_cookie_t cookie);

     int
     puffs_inval_pagecache_node_range(struct puffs_usermount *pu, puffs_cookie_t cookie, off_t start, off_t end);

     int
     puffs_flush_pagecache_node(struct puffs_usermount *pu, puffs_cookie_t cookie);

     int
     puffs_flush_pagecache_node_range(struct puffs_usermount *pu, puffs_cookie_t cookie, off_t start, off_t end);

DESCRIPTION

     These routines are used inform the kernel that any information it might have cached is no longer valid.  puffs_inval_namecache_dir() invali-
     dates the name cache for a given directory.  The argument cookie should describe an existing and valid directory cookie for the file system.
     Similarly, puffs_inval_namecache_all() invalidates the name cache for the entire file system (this routine might go away).

     The cached pages (file contents) for a regular file described by cookie are invalidated using puffs_inval_pagecache_node().  A specific range
     can be invalidated using puffs_inval_pagecache_node_range() for a platform specific page level granularity.  The offset start will be
     truncated to a page boundary while end will be rounded up to the next page boundary.  As a special case, specifying 0 as end will invalidate
     all contents from start to the end of the file.

     It is especially important to note that these routines will not only invalidate data in the "read cache", but also data in the "write back"
     cache (conceptually speaking; in reality they are the same cache), which has not yet been flushed to the file server.  Therefore any
     unflushed data will be lost.

     The counterparts of the invalidation routines are the flushing routines puffs_flush_pagecache_node() and puffs_flush_pagecache_node_range(),
     which force unwritten data from the kernel page cache to be written.  For the flush range version, the same range rules as with the invalida-
     tion routine apply.  The data is flushed asynchronously, i.e. if the routine returns successfully, all the caller knows is that the data has
     been queued for writing.

SEE ALSO

     puffs(3)

BSD
								   April 7, 2007							       BSD

Check Out this Related Man Page

XGetEventData(3)						  XLIB FUNCTIONS						  XGetEventData(3)

NAME

       XGetEventData, XFreeEventData, XGenericEventCookie - retrieve and free additional event data through cookies.

SYNTAX

       Bool XGetEventData(Display *display, XGenericEventCookie *cookie);

       void XFreeEventData(Display *display, XGenericEventCookie *cookie);

ARGUMENTS

       display	 Specifies the connection to the X server.

       cookie	 Specifies the cookie to free or retrieve the data for.

STRUCTURES

       typedef struct {
	    int type;
	    unsigned long serial;
	    Bool send_event;
	    Display *display;
	    int extension;
	    int evtype;
	    unsigned int cookie;
	    void *data;
       } XGenericEventCookie;

DESCRIPTION

       Some extension XGenericEvents require additional memory to store information.  For these events, the library returns a XGenericEventCookie
       with a token ('cookie') unique to this event. The XGenericEventCookie's data pointer is undefined until XGetEventData is called.

       The XGetEventData function retrieves this extra data for the given cookie. No round-trip to the server is required. If the cookie is
       invalid or the event is not an event handled by cookie handlers, False is returned. If XGetEventData returns True, the cookie's data
       pointer points to the memory containing the event information. A client must call XFreeEventData to free this memory.  XGetEventData
       returns False for multiple calls for the same event cookie.

       The XFreeEventData function frees the data associated with a cookie. A client must call XFreeEventData for each cookie claimed with
       XGetEventData.

EXAMPLE CODE

       XEvent event;
       XGenericEventCookie *cookie = &ev;

       XNextEvent(display, &event);
       if (XGetEventData(display, cookie)) {
	   handle_cookie_event(cookie->data);
       } else
	   handle_event(&event);
       }
       XFreeEventData(display, cookie);

NOTES

       A cookie is defined as unclaimed if it has been returned to the client through XNextEvent but its data has not been retrieved via
       XGetEventData.  Subsequent calls to XNextEvent may free memory associated with unclaimed cookies.  Multi-threaded X clients must ensure
       that XGetEventData is called before the next call to XNextEvent.

SEE ALSO

       XNextEvent(3),
       Xlib - C Language X Interface

X Version 11							   libX11 1.5.0 						  XGetEventData(3)

Linux and UNIX Man Pages

puffs_flush(3) [netbsd man page]

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