manoj 99/05/09 01:39:32
Modified: pthreads/src/include acceptlock.h
pthreads/src/main acceptlock.c http_accept.c
Log:
Partial solution for the graceful restart during accept locking problem.
Make sure that each thread checks the shutdown flag before attempting to
get the cross-process accept lock, so that if one thread notices that
it's time to die, the rest will soon after.
Revision Changes Path
1.5 +7 -2 apache-apr/pthreads/src/include/acceptlock.h
Index: acceptlock.h
===================================================================
RCS file: /home/cvs/apache-apr/pthreads/src/include/acceptlock.h,v
retrieving revision 1.4
retrieving revision 1.5
diff -u -u -r1.4 -r1.5
--- acceptlock.h 1999/04/17 03:35:53 1.4
+++ acceptlock.h 1999/05/09 08:39:29 1.5
@@ -62,6 +62,11 @@
extern "C" {
#endif
+/* Prototypes for the intraprocess accept mutex functions */
+void intra_mutex_init(pool *p, int);
+void intra_mutex_on(int);
+void intra_mutex_off(int);
+
/* Prototyps for the accept mutex functions. */
#if defined (USE_USLOCK_SERIALIZED_ACCEPT)
#define accept_mutex_child_init(x)
@@ -79,13 +84,13 @@
#elif defined (USE_SYSVSEM_SERIALIZED_ACCEPT)
void accept_mutex_cleanup(void *);
-void accept_mutex_child_init(pool *);
+#define accept_mutex_child_init(x)
void accept_mutex_init(pool *, int);
void accept_mutex_on(int);
void accept_mutex_off(int);
#elif defined(USE_FCNTL_SERIALIZED_ACCEPT)
-void accept_mutex_child_init(pool *);
+#define accept_mutex_child_init(x)
void accept_mutex_init(pool *, int);
void accept_mutex_on(int);
void accept_mutex_off(int);
1.9 +10 -29 apache-apr/pthreads/src/main/acceptlock.c
Index: acceptlock.c
===================================================================
RCS file: /home/cvs/apache-apr/pthreads/src/main/acceptlock.c,v
retrieving revision 1.8
retrieving revision 1.9
diff -u -u -r1.8 -r1.9
--- acceptlock.c 1999/04/22 19:09:01 1.8
+++ acceptlock.c 1999/05/09 08:39:30 1.9
@@ -83,25 +83,28 @@
/* Number of cross-process locks we're managing */
static int lock_count;
+/* Number of intra-process locks we're managing */
+static int intra_lock_count;
+
/* Intraprocess locking used by other serialization techniques */
-#ifdef NEED_INTRAPROCESS_SERIALIZED_ACCEPT
static pthread_mutex_t *intra_mutex = NULL;
static void intra_mutex_cleanup(void *foo)
{
int i;
- for (i = 0; i < lock_count; i++) {
+ for (i = 0; i < intra_lock_count; i++) {
(void) pthread_mutex_destroy(&intra_mutex[i]);
}
}
-static void intra_mutex_init(pool *p)
+void intra_mutex_init(pool *p, int number_of_locks)
{
int i;
- intra_mutex = (pthread_mutex_t *)ap_palloc(p, lock_count *
sizeof(pthread_mutex_t ));
- for (i = 0; i < lock_count; i++) {
+ intra_lock_count = number_of_locks;
+ intra_mutex = (pthread_mutex_t *)ap_palloc(p, intra_lock_count *
sizeof(pthread_mutex_t ));
+ for (i = 0; i < intra_lock_count; i++) {
if (pthread_mutex_init(&intra_mutex[i], NULL) != 0) {
perror("intra_mutex_init");
clean_child_exit(APEXIT_CHILDFATAL);
@@ -110,7 +113,7 @@
ap_register_cleanup(p, NULL, intra_mutex_cleanup, ap_null_cleanup);
}
-static void intra_mutex_on(int locknum)
+void intra_mutex_on(int locknum)
{
if ((errno = pthread_mutex_lock(&intra_mutex[locknum])) != 0) {
ap_log_error(APLOG_MARK, APLOG_EMERG,
@@ -119,7 +122,7 @@
}
}
-static void intra_mutex_off(int locknum)
+void intra_mutex_off(int locknum)
{
if (pthread_mutex_unlock(&intra_mutex[locknum]) != 0) {
ap_log_error(APLOG_MARK, APLOG_EMERG,
@@ -127,11 +130,6 @@
"Error releasing intraprocess lock. Exiting!");
}
}
-#else /* NEED_INTRAPROCESS_SERIALIZED_ACCEPT */
-#define intra_mutex_init(x)
-#define intra_mutex_on(x)
-#define intra_mutex_off(x)
-#endif /* NEED_INTRAPROCESS_SERIALIZED_ACCEPT */
#if defined(USE_FCNTL_SERIALIZED_ACCEPT) ||
defined(USE_FLOCK_SERIALIZED_ACCEPT)
static void init_lock_fname(pool *p)
@@ -454,14 +452,8 @@
}
}
-void accept_mutex_child_init(pool *p)
-{
- intra_mutex_init(p);
-}
-
void accept_mutex_on(int locknum)
{
- intra_mutex_on(locknum);
if (semop(sem_id[locknum], &op_on, 1) < 0) {
perror("accept_mutex_on");
clean_child_exit(APEXIT_CHILDFATAL);
@@ -474,7 +466,6 @@
perror("accept_mutex_off");
clean_child_exit(APEXIT_CHILDFATAL);
}
- intra_mutex_off(locknum);
}
#elif defined(USE_FCNTL_SERIALIZED_ACCEPT)
@@ -519,16 +510,10 @@
}
}
-void accept_mutex_child_init(pool *p)
-{
- intra_mutex_init(p);
-}
-
void accept_mutex_on(int locknum)
{
int ret;
- intra_mutex_on(locknum);
while ((ret = fcntl(lock_fd[locknum], F_SETLKW, &lock_it)) < 0 &&
errno == EINTR) {
/* nop */
@@ -558,7 +543,6 @@
"your lock file on a local disk!");
clean_child_exit(APEXIT_CHILDFATAL);
}
- intra_mutex_off(locknum);
}
#elif defined(USE_FLOCK_SERIALIZED_ACCEPT)
@@ -584,7 +568,6 @@
{
int i;
- intra_mutex_init(p);
for (i = 0; i < lock_count; i++) {
char *lock_fname = expand_lock_fname(p, i);
@@ -629,7 +612,6 @@
{
int ret;
- intra_mutex_on(locknum);
while ((ret = flock(lock_fd[locknum], LOCK_EX)) < 0 && errno == EINTR)
continue;
@@ -649,7 +631,6 @@
"flock: LOCK_UN: Error freeing accept lock. Exiting!");
clean_child_exit(APEXIT_CHILDFATAL);
}
- intra_mutex_off(locknum);
}
#elif defined(USE_OS2SEM_SERIALIZED_ACCEPT)
1.12 +16 -0 apache-apr/pthreads/src/main/http_accept.c
Index: http_accept.c
===================================================================
RCS file: /home/cvs/apache-apr/pthreads/src/main/http_accept.c,v
retrieving revision 1.11
retrieving revision 1.12
diff -u -u -r1.11 -r1.12
--- http_accept.c 1999/04/29 19:34:20 1.11
+++ http_accept.c 1999/05/09 08:39:31 1.12
@@ -109,9 +109,15 @@
(void) ap_update_child_status(my_pid, my_tid, SERVER_ACCEPTING,
(request_rec *) NULL);
/* lock around the accept if necessary */
+ SAFE_ACCEPT(intra_mutex_on(my_tid - ap_threads_per_child));
+ if (workers_may_exit) {
+ SAFE_ACCEPT(intra_mutex_off(my_tid - ap_threads_per_child));
+ break;
+ }
SAFE_ACCEPT(accept_mutex_on(my_tid - ap_threads_per_child));
if (queue_full(&csd_queue)) {
SAFE_ACCEPT(accept_mutex_off(my_tid - ap_threads_per_child));
+ SAFE_ACCEPT(intra_mutex_off(my_tid - ap_threads_per_child));
block_on_queue(&csd_queue);
csd = -1;
}
@@ -119,6 +125,7 @@
csd = accept(sd, &sa_client, &len);
requests_this_child--;
SAFE_ACCEPT(accept_mutex_off(my_tid - ap_threads_per_child));
+ SAFE_ACCEPT(intra_mutex_off(my_tid - ap_threads_per_child));
}
(void) ap_update_child_status(my_pid, my_tid, SERVER_QUEUEING,
(request_rec *) NULL);
@@ -211,6 +218,7 @@
int worker_threads_per_child)
{
int queue_capacity = worker_threads_per_child + ap_acceptors_per_child;
+ SAFE_ACCEPT(intra_mutex_init(pchild, ap_acceptors_per_child));
SAFE_ACCEPT(accept_mutex_child_init(pchild));
requests_this_child = ap_max_requests_per_child;
queue_init(&csd_queue, queue_capacity, pchild);
@@ -338,6 +346,7 @@
int pipe_pair_of_death[2];
listen_rec *lr;
+ SAFE_ACCEPT(intra_mutex_init(pchild, 1));
SAFE_ACCEPT(accept_mutex_child_init(pchild));
requests_this_child = ap_max_requests_per_child;
head_listener = ap_listeners;
@@ -377,6 +386,11 @@
while ((ap_max_requests_per_child != 0 && requests_this_child > 0) ||
(ap_max_requests_per_child == 0)) {
+ SAFE_ACCEPT(intra_mutex_on(0));
+ if (workers_may_exit) {
+ SAFE_ACCEPT(intra_mutex_off(0));
+ return -1;
+ }
SAFE_ACCEPT(accept_mutex_on(0));
for (;;) {
@@ -398,6 +412,7 @@
continue;
}
SAFE_ACCEPT(accept_mutex_off(0));
+ SAFE_ACCEPT(intra_mutex_off(0));
/* Single Unix documents select as returning errnos
* EBADF, EINTR, and EINVAL... and in none of those
* cases does it make sense to continue. In fact
@@ -459,6 +474,7 @@
SAFE_ACCEPT(accept_mutex_off(0));
+ SAFE_ACCEPT(intra_mutex_off(0));
if (csd >= 0) {
return csd;
