d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Make the EVENTHANDLER mechanism MP-safe. Events can now be invoked

Browse Source 
without holding the Giant lock.
This commit is contained in:
Mike Smith 2000-09-22 03:17:35 +00:00
parent 8456e16e24
commit 6595c331f3
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=66205
2 changed files with 67 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
sys/kern/subr_eventhandler.c
View File

@ -58,9 +58,13 @@ eventhandler_register(struct eventhandler_list *list, char *name,
/* avoid the need for a SYSINIT just to init the list */
if (!eventhandler_lists_initted) {
TAILQ_INIT(&eventhandler_lists);
mtx_init(&eventhandler_mutex, "eventhandler", MTX_DEF);
eventhandler_lists_initted = 1;
}
/* lock the eventhandler lists */
mtx_enter(&eventhandler_mutex, MTX_DEF);
/* Do we need to find/create the (slow) list? */
if (list == NULL) {
/* look for a matching, existing list */
@ -69,8 +73,10 @@ eventhandler_register(struct eventhandler_list *list, char *name,
/* Do we need to create the list? */
if (list == NULL) {
if ((list = malloc(sizeof(struct eventhandler_list) + strlen(name) + 1,
M_EVENTHANDLER, M_NOWAIT)) == NULL)
M_EVENTHANDLER, M_NOWAIT)) == NULL) {
mtx_exit(&eventhandler_mutex, MTX_DEF);
return(NULL);
}
list->el_flags = 0;
list->el_name = (char *)list + sizeof(struct eventhandler_list);
strcpy(list->el_name, name);
@ -79,18 +85,22 @@ eventhandler_register(struct eventhandler_list *list, char *name,
}
if (!(list->el_flags & EHE_INITTED)) {
TAILQ_INIT(&list->el_entries);
mtx_init(&list->el_mutex, name, MTX_DEF);
list->el_flags = EHE_INITTED;
}
/* allocate an entry for this handler, populate it */
if ((eg = malloc(sizeof(struct eventhandler_entry_generic),
M_EVENTHANDLER, M_NOWAIT)) == NULL)
M_EVENTHANDLER, M_NOWAIT)) == NULL) {
mtx_exit(&eventhandler_mutex, MTX_DEF);
return(NULL);
}
eg->func = func;
eg->ee.ee_arg = arg;
eg->ee.ee_priority = priority;
/* sort it into the list */
mtx_enter(&list->el_mutex, MTX_DEF);
for (ep = TAILQ_FIRST(&list->el_entries);
ep != NULL;
ep = TAILQ_NEXT(ep, ee_link)) {
@ -101,6 +111,8 @@ eventhandler_register(struct eventhandler_list *list, char *name,
}
if (ep == NULL)
TAILQ_INSERT_TAIL(&list->el_entries, &eg->ee, ee_link);
mtx_exit(&list->el_mutex, MTX_DEF);
mtx_exit(&eventhandler_mutex, MTX_DEF);
return(&eg->ee);
}
@ -110,6 +122,7 @@ eventhandler_deregister(struct eventhandler_list *list, eventhandler_tag tag)
struct eventhandler_entry *ep = tag;
/* XXX insert diagnostic check here? */
mtx_enter(&list->el_mutex, MTX_DEF);
if (ep != NULL) {
/* remove just this entry */
TAILQ_REMOVE(&list->el_entries, ep, ee_link);
@ -122,19 +135,24 @@ eventhandler_deregister(struct eventhandler_list *list, eventhandler_tag tag)
free(ep, M_EVENTHANDLER);
}
}
mtx_exit(&list->el_mutex, MTX_DEF);
}
struct eventhandler_list *
eventhandler_find_list(char *name)
{
struct eventhandler_list *list;
/* scan looking for the requested list */
mtx_enter(&eventhandler_mutex, MTX_DEF);
for (list = TAILQ_FIRST(&eventhandler_lists);
list != NULL;
list = TAILQ_NEXT(list, el_link)) {
if (!strcmp(name, list->el_name))
break;
}
mtx_exit(&eventhandler_mutex, MTX_DEF);
return(list);
}

73
sys/sys/eventhandler.h
View File

@ -27,6 +27,8 @@
*/
#include <sys/queue.h>
#include <sys/proc.h> /* XXX should these be prerequisites? */
#include <machine/mutex.h>
#ifndef SYS_EVENTHANDLER_H
#define SYS_EVENTHANDLER_H
@ -40,14 +42,16 @@ struct eventhandler_entry
struct eventhandler_list
{
TAILQ_ENTRY(eventhandler_list) el_link;
char *el_name;
int el_flags;
#define EHE_INITTED (1<<0)
struct mtx el_mutex;
TAILQ_ENTRY(eventhandler_list) el_link;
TAILQ_HEAD(,eventhandler_entry) el_entries;
};
typedef struct eventhandler_entry *eventhandler_tag;
struct mtx eventhandler_mutex;
/*
* Fast handler lists require the eventhandler list be present
@ -72,29 +76,33 @@ struct __hack
struct eventhandler_list Xeventhandler_list_ ## name = { #name }; \
struct __hack
#define EVENTHANDLER_FAST_INVOKE(name, args...) \
do { \
struct eventhandler_list *_el = &Xeventhandler_list_ ## name ; \
struct eventhandler_entry *_ep = TAILQ_FIRST(&(_el->el_entries)); \
\
while (_ep != NULL) { \
((struct eventhandler_entry_ ## name *)_ep)->eh_func(_ep->ee_arg , ## args); \
_ep = TAILQ_NEXT(_ep, ee_link); \
} \
#define EVENTHANDLER_FAST_INVOKE(name, args...) \
do { \
struct eventhandler_list *_el = &Xeventhandler_list_ ## name ; \
struct eventhandler_entry *_ep = TAILQ_FIRST(&(_el->el_entries)); \
\
if (_el->el_flags & EHE_INITTED) { \
mtx_enter(&_el->el_mutex, MTX_DEF); \
while (_ep != NULL) { \
((struct eventhandler_entry_ ## name *)_ep)->eh_func(_ep->ee_arg , \
## args); \
_ep = TAILQ_NEXT(_ep, ee_link); \
} \
mtx_exit(&_el->el_mutex, MTX_DEF); \
} \
} while (0)
#define EVENTHANDLER_FAST_REGISTER(name, func, arg, priority) \
eventhandler_register(Xeventhandler_list_ ## name, #name, func, arg, priority)
eventhandler_register(&Xeventhandler_list_ ## name, #name, func, arg, priority)
#define EVENTHANDLER_FAST_DEREGISTER(name, tag) \
eventhandler_deregister(Xeventhandler_list ## name, tag)
eventhandler_deregister(&Xeventhandler_list ## name, tag)
/*
* Slow handlerss are entirely dynamic; lists are created
* Slow handlers are entirely dynamic; lists are created
* when entries are added to them, and thus have no concept of "owner",
*
* Slow handlerss need to be declared, but do not need to be defined. The
* Slow handlers need to be declared, but do not need to be defined. The
* declaration must be in scope wherever the handler is to be invoked.
*/
#define EVENTHANDLER_DECLARE(name, type) \
@ -105,18 +113,22 @@ struct eventhandler_entry_ ## name \
}; \
struct __hack
#define EVENTHANDLER_INVOKE(name, args...) \
do { \
struct eventhandler_list *_el; \
struct eventhandler_entry *_ep; \
\
if ((_el = eventhandler_find_list(#name)) != NULL) { \
for (_ep = TAILQ_FIRST(&(_el->el_entries)); \
_ep != NULL; \
_ep = TAILQ_NEXT(_ep, ee_link)) { \
((struct eventhandler_entry_ ## name *)_ep)->eh_func(_ep->ee_arg , ## args); \
} \
} \
#define EVENTHANDLER_INVOKE(name, args...) \
do { \
struct eventhandler_list *_el; \
struct eventhandler_entry *_ep; \
\
if (((_el = eventhandler_find_list(#name)) != NULL) && \
(_el->el_flags & EHE_INITTED)) { \
mtx_enter(&_el->el_mutex, MTX_DEF); \
for (_ep = TAILQ_FIRST(&(_el->el_entries)); \
_ep != NULL; \
_ep = TAILQ_NEXT(_ep, ee_link)) { \
((struct eventhandler_entry_ ## name *)_ep)->eh_func(_ep->ee_arg , \
## args); \
} \
mtx_exit(&_el->el_mutex, MTX_DEF); \
} \
} while (0)
#define EVENTHANDLER_REGISTER(name, func, arg, priority) \
@ -155,4 +167,11 @@ EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn); /* before fs sync */
EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn); /* after fs sync */
EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
/* Idle process event */
typedef void (*idle_eventhandler_t) __P((void *, int));
#define IDLE_PRI_LAST 20000
EVENTHANDLER_FAST_DECLARE(idle_event, idle_eventhandler_t);
#endif /* SYS_EVENTHANDLER_H */