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author | Justin Erenkrantz <jerenkrantz@apache.org> | 2004-12-04 06:25:57 +0100 |
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committer | Justin Erenkrantz <jerenkrantz@apache.org> | 2004-12-04 06:25:57 +0100 |
commit | 779e530a5cbe21e8956725729932947e6057f0a7 (patch) | |
tree | cf647d550e3a69c1315ae6a7c0cd546319cc55c5 | |
parent | update transformation (diff) | |
download | apache2-779e530a5cbe21e8956725729932947e6057f0a7.tar.xz apache2-779e530a5cbe21e8956725729932947e6057f0a7.zip |
* server/mpm/experimental/event/event.c: Go through and reformat and correct
comments to be more appropriate.
*no functional changes*
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@109773 13f79535-47bb-0310-9956-ffa450edef68
-rw-r--r-- | server/mpm/experimental/event/event.c | 111 |
1 files changed, 58 insertions, 53 deletions
diff --git a/server/mpm/experimental/event/event.c b/server/mpm/experimental/event/event.c index 80efb43757..ac2a4fc5f2 100644 --- a/server/mpm/experimental/event/event.c +++ b/server/mpm/experimental/event/event.c @@ -16,28 +16,29 @@ /** * This MPM tries to fix the 'keep alive problem' in HTTP. * - * After a client completes the first request, it can keep it open to send more - * requests with the same socket. This can save signifigant overhead in - * creating TCP connections. However, the major disadvantage is that Apache - * traditionally keeps an entire child process/thread waiting for data from - * the client. This MPM has a dedicated thread for handling both the - * Listenting sockets, and all sockets that are in a Keep Alive status. - * - * The MPM assumes the underlying apr_pollset implmentation is somewhat threadsafe. - * This currently is only comptaible with KQueue and EPoll. This enables the - * MPM to avoid extra high level locking or having to wake up the listener - * thread when a keep-alive socket needs to be sent to it. - * - * This MPM not preform well on older platforms that do not have very good - * threading, like Linux with a 2.4 kernel, but this does not matter, since we + * After a client completes the first request, the client can keep the + * connection open to send more requests with the same socket. This can save + * signifigant overhead in creating TCP connections. However, the major + * disadvantage is that Apache traditionally keeps an entire child + * process/thread waiting for data from the client. To solve this problem, + * this MPM has a dedicated thread for handling both the Listenting sockets, + * and all sockets that are in a Keep Alive status. + * + * The MPM assumes the underlying apr_pollset implmentation is somewhat + * threadsafe. This currently is only compatible with KQueue and EPoll. This + * enables the MPM to avoid extra high level locking or having to wake up the + * listener thread when a keep-alive socket needs to be sent to it. + * + * This MPM not preform well on older platforms that do not have very good + * threading, like Linux with a 2.4 kernel, but this does not matter, since we * require EPoll or KQueue. * - * For FreeBSD, use 5.3. It is possible to run this MPM - * on FreeBSD 5.2.1, if you use libkse (see `man libmap.conf`). + * For FreeBSD, use 5.3. It is possible to run this MPM on FreeBSD 5.2.1, if + * you use libkse (see `man libmap.conf`). * * For NetBSD, use at least 2.0. * - * For Linux, you should use a2.6 kernel, and make sure your glibc has epoll + * For Linux, you should use a 2.6 kernel, and make sure your glibc has epoll * support compiled in. * */ @@ -111,8 +112,8 @@ /* Admin can't tune ServerLimit beyond MAX_SERVER_LIMIT. We want * some sort of compile-time limit to help catch typos. - */ -#ifndef MAX_SERVER_LIMIT + */ +#ifndef MAX_SERVER_LIMIT #define MAX_SERVER_LIMIT 20000 #endif @@ -249,7 +250,8 @@ static apr_os_thread_t *listener_os_thread; #define LISTENER_SIGNAL SIGHUP /* An array of socket descriptors in use by each thread used to - * perform a non-graceful (forced) shutdown of the server. */ + * perform a non-graceful (forced) shutdown of the server. + */ static apr_socket_t **worker_sockets; static void close_worker_sockets(void) @@ -636,13 +638,13 @@ static int process_socket(apr_pool_t * p, apr_socket_t * sock, apr_status_t rc; listener_poll_type *pt = (listener_poll_type *) cs->pfd.client_data; - /* It greatly simplifies the logic to use a single timeout value here - * because the new element can just be added to the end of the list - * and it will stay sorted in expiration time sequence. If brand new - * sockets are sent to the event thread for a readability check, this - * will be a slight behavior change - they use the non-keepalive timeout - * today. With a normal client, the socket will be readable in a few - * milliseconds anyway. + /* It greatly simplifies the logic to use a single timeout value here + * because the new element can just be added to the end of the list and + * it will stay sorted in expiration time sequence. If brand new + * sockets are sent to the event thread for a readability check, this + * will be a slight behavior change - they use the non-keepalive + * timeout today. With a normal client, the socket will be readable in + * a few milliseconds anyway. */ cs->expiration_time = ap_server_conf->keep_alive_timeout + time_now; apr_thread_mutex_lock(timeout_mutex); @@ -674,11 +676,11 @@ static void check_infinite_requests(void) else { /* wow! if you're executing this code, you may have set a record. * either this child process has served over 2 billion requests, or - * you're running a threaded 2.0 on a 16 bit machine. + * you're running a threaded 2.0 on a 16 bit machine. * * I'll buy pizza and beers at Apachecon for the first person to do * the former without cheating (dorking with INT_MAX, or running with - * uncommitted performance patches, for example). + * uncommitted performance patches, for example). * * for the latter case, you probably deserve a beer too. Greg Ames */ @@ -752,8 +754,7 @@ static apr_status_t push2worker(const apr_pollfd_t * pfd, * reserve a worker thread, block if all are currently busy. * this prevents the worker queue from overflowing and lets * other processes accept new connections in the mean time. - */ - + */ static int get_worker(int *have_idle_worker_p) { apr_status_t rc; @@ -768,7 +769,7 @@ static int get_worker(int *have_idle_worker_p) else { if (!APR_STATUS_IS_EOF(rc)) { ap_log_error(APLOG_MARK, APLOG_ERR, rc, ap_server_conf, - "ap_queue_info_wait_for_idler failed. " + "ap_queue_info_wait_for_idler failed. " "Attempting to shutdown process gracefully"); signal_threads(ST_GRACEFUL); } @@ -778,10 +779,10 @@ static int get_worker(int *have_idle_worker_p) else { /* already reserved a worker thread - must have hit a * transient error on a previous pass - */ - return 1; + */ + return 1; } -} +} static void *listener_thread(apr_thread_t * thd, void *dummy) { @@ -806,14 +807,14 @@ static void *listener_thread(apr_thread_t * thd, void *dummy) /* We set this to force apr_pollset to wakeup if there hasn't been any IO * on any of its sockets. This allows sockets to have been added * when no other keepalive operations where going on. - * + * * current value is 1 second */ timeout_interval = 1000000; /* the following times out events that are really close in the future * to prevent extra poll calls - * + * * current value is .1 second */ #define TIMEOUT_FUDGE_FACTOR 100000 @@ -821,7 +822,7 @@ static void *listener_thread(apr_thread_t * thd, void *dummy) /* POLLSET_SCALE_FACTOR * ap_threads_per_child sets the size of * the pollset. I've seen 15 connections per active worker thread * running SPECweb99. - * + * * However, with the newer apr_pollset, this is the number of sockets that * we will return to any *one* call to poll(). Therefore, there is no * reason to make it more than ap_threads_per_child. @@ -846,8 +847,8 @@ static void *listener_thread(apr_thread_t * thd, void *dummy) tpool, APR_POLLSET_THREADSAFE); if (rc != APR_SUCCESS) { ap_log_error(APLOG_MARK, APLOG_ERR, rc, ap_server_conf, - "apr_pollset_create with Thread Safety failed. Attempting to " - "shutdown process gracefully"); + "apr_pollset_create with Thread Safety failed. " + "Attempting to shutdown process gracefully"); signal_threads(ST_GRACEFUL); return NULL; } @@ -961,8 +962,9 @@ static void *listener_thread(apr_thread_t * thd, void *dummy) rc = lr->accept_func(&csd, lr, ptrans); - /* later we trash rv and rely on csd to indicate success/failure */ - + /* later we trash rv and rely on csd to indicate + * success/failure + */ AP_DEBUG_ASSERT(rc == APR_SUCCESS || !csd); if (rc == APR_EGENERAL) { @@ -1088,8 +1090,8 @@ static void *APR_THREAD_FUNC worker_thread(apr_thread_t * thd, void *dummy) rv = ap_queue_pop(worker_queue, &csd, &cs, &ptrans); if (rv != APR_SUCCESS) { - /* We get APR_EOF during a graceful shutdown once all the connections - * accepted by this server process have been handled. + /* We get APR_EOF during a graceful shutdown once all the + * connections accepted by this server process have been handled. */ if (APR_STATUS_IS_EOF(rv)) { break; @@ -1464,10 +1466,12 @@ static void child_main(int child_num_arg) * shutdown this child */ join_start_thread(start_thread_id); - signal_threads(ST_UNGRACEFUL); /* helps us terminate a little more - * quickly than the dispatch of the signal thread - * beats the Pipe of Death and the browsers - */ + + /* helps us terminate a little more quickly than the dispatch of the + * signal thread; beats the Pipe of Death and the browsers + */ + signal_threads(ST_UNGRACEFUL); + /* A terminating signal was received. Now join each of the * workers to clean them up. * If the worker already exited, then the join frees @@ -2007,7 +2011,8 @@ static int worker_pre_config(apr_pool_t * pconf, apr_pool_t * plog, for (pdir = ap_conftree; pdir != NULL; pdir = pdir->next) { if (strncasecmp(pdir->directive, "ThreadsPerChild", 15) == 0) { if (!max_clients) { - break; /* we're in the clear, got ThreadsPerChild first */ + /* we're in the clear, got ThreadsPerChild first */ + break; } else { /* now to swap the data */ @@ -2119,7 +2124,7 @@ static const char *set_daemons_to_start(cmd_parms *cmd, void *dummy, if (err != NULL) { return err; } - + ap_daemons_to_start = atoi(arg); return NULL; } @@ -2231,8 +2236,8 @@ static const char *set_threads_per_child(cmd_parms * cmd, void *dummy, "WARNING: ThreadsPerChild of %d exceeds ThreadLimit " "value of %d", ap_threads_per_child, thread_limit); ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, - "threads, lowering ThreadsPerChild to %d. To increase, please" - " see the", thread_limit); + "threads, lowering ThreadsPerChild to %d. To increase, " + "please see the", thread_limit); ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, " ThreadLimit directive."); ap_threads_per_child = thread_limit; @@ -2267,7 +2272,7 @@ static const char *set_server_limit (cmd_parms *cmd, void *dummy, const char *ar return NULL; } server_limit = tmp_server_limit; - + if (server_limit > MAX_SERVER_LIMIT) { ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, "WARNING: ServerLimit of %d exceeds compile time limit " |