minix/servers/vfs/dmap.h
Thomas Veerman aba392e630 Clean up and fix multiple bugs in select:
- Remove redundant code.
 - Always wait for the initial reply from an asynchronous select request,
   even if the select has been satisfied on another file descriptor or
   was canceled due to a serious error.
 - Restart asynchronous selects if upon reply from the driver turns out
   that there are deferred operations (and do not forget we're still
   interested in the results of the deferred operations).
 - Do not hang a non-blocking select when another blocking select on
   the same filp is still blocking.
 - Split blocking operations in read, write, and exceptions (i.e.,
   blocking on read does not imply the write will block as well).
 - Some loops would iterate over OPEN_MAX file descriptors instead of
   the "highest" file descriptor.
 - Use proper internal error return values.
 - A secondary reply from a synchronous driver is essentially the same
   as from an asynchronous driver (the only difference being how the 
   answer is received). Merge.
 - Return proper error code after a driver failure.
 - Auto-detect whether a driver is synchronous or asynchronous.
 - Remove some code duplication.
 - Clean up code (coding style, add missing comments, put all select
   related code together).
2011-04-13 13:25:34 +00:00

28 lines
856 B
C

#ifndef __VFS_DMAP_H__
#define __VFS_DMAP_H__
/*
dmap.h
*/
/*===========================================================================*
* Device <-> Driver Table *
*===========================================================================*/
/* Device table. This table is indexed by major device number. It provides
* the link between major device numbers and the routines that process them.
* The table can be update dynamically. The field 'dmap_flags' describe an
* entry's current status and determines what control options are possible.
*/
extern struct dmap {
int _PROTOTYPE ((*dmap_opcl), (int, dev_t, int, int) );
int _PROTOTYPE ((*dmap_io), (int, message *) );
endpoint_t dmap_driver;
char dmap_label[LABEL_MAX];
int dmap_flags;
int dmap_style;
struct filp *dmap_sel_filp;
} dmap[];
#endif