manoj 99/07/23 16:35:23
Modified: mpm/src/modules/mpm/dexter dexter.c
Log:
Add a MaxThreadsPerChild directive
Revision Changes Path
1.7 +62 -15 apache-2.0/mpm/src/modules/mpm/dexter/dexter.c
Index: dexter.c
===================================================================
RCS file: /home/cvs/apache-2.0/mpm/src/modules/mpm/dexter/dexter.c,v
retrieving revision 1.6
retrieving revision 1.7
diff -u -d -u -r1.6 -r1.7
--- dexter.c 1999/07/23 22:43:47 1.6
+++ dexter.c 1999/07/23 23:35:20 1.7
@@ -81,6 +81,7 @@
static int threads_to_start = 0; /* Worker threads per child */
static int min_spare_threads = 0;
static int max_spare_threads = 0;
+static int max_threads = 0;
static int max_requests_per_child = 0;
static char *ap_pid_fname=NULL;
static int num_daemons=0;
@@ -842,19 +843,42 @@
static void *worker_thread(void *);
-static void start_thread(worker_thread_info *thread_info)
+/* Starts a thread as long as we're below max_threads */
+static int start_thread(worker_thread_info *thread_info)
{
pthread_t thread;
- if (pthread_create(&thread, &(thread_info->attr), worker_thread,
thread_info)) {
- ap_log_error(APLOG_MARK, APLOG_ALERT, server_conf,
- "pthread_create: unable to create worker thread");
- /* In case system resources are maxxed out, we don't want
- Apache running away with the CPU trying to fork over and
- over and over again if we exit. */
- sleep(10);
- workers_may_exit = 1;
+ pthread_mutex_lock(&worker_thread_count_mutex);
+ if (worker_thread_count < max_threads) {
+ worker_thread_count++;
+ if (pthread_create(&thread, &(thread_info->attr), worker_thread,
thread_info)) {
+ ap_log_error(APLOG_MARK, APLOG_ALERT, server_conf,
+ "pthread_create: unable to create worker thread");
+ /* In case system resources are maxxed out, we don't want
+ Apache running away with the CPU trying to fork over and
+ over and over again if we exit. */
+ sleep(10);
+ worker_thread_count--;
+ workers_may_exit = 1;
+ pthread_mutex_unlock(&worker_thread_count_mutex);
+ return 0;
+ }
+ }
+ else {
+ static int reported = 0;
+
+ if (!reported) {
+ ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, server_conf,
+ "server reached MaxThreadsPerChild setting,
consider raising the"
+ " MaxThreadsPerChild or NumServers settings");
+ reported = 1;
+ }
+ pthread_mutex_unlock(&worker_thread_count_mutex);
+ return 0;
}
+ pthread_mutex_unlock(&worker_thread_count_mutex);
+ return 1;
+
}
/* idle_thread_count should be incremented before starting a worker_thread */
@@ -879,10 +903,6 @@
pthread_mutex_unlock(&thread_info->mutex);
ptrans = ap_make_sub_pool(tpool);
- pthread_mutex_lock(&worker_thread_count_mutex);
- worker_thread_count++;
- pthread_mutex_unlock(&worker_thread_count_mutex);
-
/* TODO: Switch to a system where threads reuse the results from earlier
poll calls - manoj */
while (!workers_may_exit) {
@@ -978,7 +998,9 @@
idle_thread_count--;
}
else {
- start_thread(thread_info);
+ if (!start_thread(thread_info)) {
+ idle_thread_count--;
+ }
}
pthread_mutex_unlock(&idle_thread_count_mutex);
} else {
@@ -1053,6 +1075,9 @@
/* Setup worker threads */
+ if (threads_to_start > max_threads) {
+ threads_to_start = max_threads;
+ }
idle_thread_count = threads_to_start;
worker_thread_count = 0;
thread_info.pool = ap_make_sub_pool(pconf);
@@ -1065,7 +1090,10 @@
/* We are creating worker threads right now */
for (i=0; i < threads_to_start; i++) {
- start_thread(&thread_info);
+ /* start_thread shouldn't fail here */
+ if (!start_thread(&thread_info)) {
+ break;
+ }
}
/* This thread will be the one responsible for handling signals */
@@ -1444,6 +1472,7 @@
threads_to_start = DEFAULT_START_THREAD;
min_spare_threads = DEFAULT_MIN_SPARE_THREAD;
max_spare_threads = DEFAULT_MAX_SPARE_THREAD;
+ max_threads = HARD_THREAD_LIMIT;
ap_pid_fname = DEFAULT_PIDLOG;
ap_lock_fname = DEFAULT_LOCKFILE;
max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;
@@ -1556,6 +1585,22 @@
return NULL;
}
+static const char *set_max_threads(cmd_parms *cmd, void *dummy, char *arg)
+{
+ const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+ if (err != NULL) {
+ return err;
+ }
+
+ max_threads = atoi(arg);
+ if (max_threads >= HARD_THREAD_LIMIT) {
+ fprintf(stderr, "WARNING: detected MaxThreadsPerChild set higher
than\n");
+ fprintf(stderr, "HARD_THREAD_LIMIT. Resetting to %d\n",
HARD_THREAD_LIMIT);
+ max_threads = HARD_THREAD_LIMIT;
+ }
+ return NULL;
+}
+
static const char *set_max_requests(cmd_parms *cmd, void *dummy, char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
@@ -1635,6 +1680,8 @@
"Minimum number of idle threads per child, to handle request spikes" },
{ "MaxSpareThreads", set_max_spare_threads, NULL, RSRC_CONF, TAKE1,
"Maximum number of idle threads per child" },
+{ "MaxThreadsPerChild", set_max_threads, NULL, RSRC_CONF, TAKE1,
+ "Maximum number of threads per child" },
{ "MaxRequestsPerChild", set_max_requests, NULL, RSRC_CONF, TAKE1,
"Maximum number of requests a particular child serves before dying." },
{ "CoreDumpDirectory", set_coredumpdir, NULL, RSRC_CONF, TAKE1,
