DESCRIPTION
The module
aem-core provides the
basic AEM functionalities. It must be loaded before any other AEM modules.
As such, it doesn't provide some specific event interface but implements a
de/multiplexing and management interface towards these event modules.
DEFINITIONS
/* Event/Job
operations */
#define EVJOBPRIO 1
#define EVTBLINIT 2
#define EVJOBSHTDN 3
#define EVJOBSTART 4
#define EVJOBSTOP 5
/* VMTABLE */
#define TBL_UZONE 0
#define TBL_VZONE 1
/* Runtime control flags */
#define EVF_EXCL (1<<17) /* not used */
#define EVF_ONESHOT (1<<18)
#define EVF_CLONE (1<<19) /* not used */
#define EVF_FORK (1<<20)
#define EVF_NOCLDWAIT (1<<21)
#define EVF_CAPSULE (1<<22)
#define EVF_KEEPALIVE (1<<23)
INTERFACES
aem_evkeepalive
- endless-loop to keep a process running so that it can continue to receive event notifications.
void aem_evkeepalive (void);
aem_keepalive exits when being
sent a signal.
aem_evctl - event control entry point.
int aem_evctl (unsigned int eid, unsigned long
opt, unsigned long args);
aem_evctl is the control function towards events. The opt and args parameters represents the operation
and its arguments to apply to the event specified by eid. This identifier is obtained during
event registration using aem_entry.
aem_entry - event registration function
int aem_entry (int sys_nr, void * args);
aem_entry is the control
fuction used to register an event of type sys_nr with the options specified by args. These two parameters are event specific.
It returns an system unique identifier in case of succes or a negative value
in case of error.
The integer sys_nr is a reference for one of the specific
event registration methods implemented by event modules. sys_nrrepresents
one specific event and is unique in the system. It is obtained by reading
the number from the module using ioctlt:
fd = open ("/dev/aem-my_module", O_RDONLY);
sys_nr = ioctl (fd, GET_SYSNR);
close (fd);
The GET_SYSNR value is the event reference for the module and is unique for
the module only.
The structure arg defines the event specific information
part:
struct my_aem_struct {
some_type1_t specific_field1;
some_type2_t specific_field2;
some_type3_t specific_field3;
int flags;
unsigned long handler;
} args;
args.specific_field1 = ...;
args.specific_field2 = ...;
args.specific_field3 = ...;
args.flags = (Runtime control flag1 | flag2 | ...);
args.handler = (unsigned long)
handler;
