From: Sebastian Harl Date: Fri, 8 Dec 2006 14:12:42 +0000 (+0100) Subject: email plugin: Use a thread pool. X-Git-Tag: collectd-3.11.0~21 X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=f058adfa20f3a17eba344d1613c634c137980875;p=collectd.git email plugin: Use a thread pool. Up to now the email plugin created a thread for each connection. This thread was destroyed after the connection has been closed. Now, a pool containing MaxConns threads is created and a new connection is assigned to a free thread. Signed-off-by: Sebastian Harl --- diff --git a/src/email.c b/src/email.c index c1e139ea..401ac928 100644 --- a/src/email.c +++ b/src/email.c @@ -100,24 +100,30 @@ typedef struct { type_t *tail; } type_list_t; -/* linked list of collector thread control information */ +/* collector thread control information */ typedef struct collector { pthread_t thread; + /* socket descriptor of the current/last connection */ + int socket; +} collector_t; + +/* linked list of pending connections */ +typedef struct conn { /* socket to read data from */ int socket; /* buffer to read data to */ - char buffer[BUFSIZE]; + char *buffer; int idx; /* current position in buffer */ - struct collector *next; -} collector_t; + struct conn *next; +} conn_t; typedef struct { - collector_t *head; - collector_t *tail; -} collector_list_t; + conn_t *head; + conn_t *tail; +} conn_list_t; #endif /* EMAIL_HAVE_READ */ /* @@ -146,16 +152,21 @@ static int disabled = 0; static pthread_t connector; static int connector_socket; +/* tell the collector threads that a new connection is available */ +static pthread_cond_t conn_available = PTHREAD_COND_INITIALIZER; + +/* connections that are waiting to be processed */ +static pthread_mutex_t conns_mutex = PTHREAD_MUTEX_INITIALIZER; +static conn_list_t conns; + /* tell the connector thread that a collector is available */ static pthread_cond_t collector_available = PTHREAD_COND_INITIALIZER; -/* collector threads that are in use */ -static pthread_mutex_t active_mutex = PTHREAD_MUTEX_INITIALIZER; -static collector_list_t active; +/* collector threads */ +static collector_t **collectors; -/* collector threads that are available for use */ static pthread_mutex_t available_mutex = PTHREAD_MUTEX_INITIALIZER; -static collector_list_t available; +static int available_collectors; static pthread_mutex_t count_mutex = PTHREAD_MUTEX_INITIALIZER; static type_list_t count; @@ -275,7 +286,7 @@ static void type_list_incr (type_list_t *list, char *name, int incr) /* Read a single character from the socket. If an error occurs or end-of-file * is reached return '\0'. */ -char read_char (collector_t *src) +char read_char (conn_t *src) { char ret = '\0'; @@ -306,7 +317,7 @@ char read_char (collector_t *src) return '\0'; } while (EINTR == errno); return ret; -} /* char read_char (collector_t *) */ +} /* char read_char (conn_t *) */ /* Read a single line (terminated by '\n') from the the socket. * @@ -320,7 +331,7 @@ char read_char (collector_t *src) * characters of the input stream, the line will will be ignored! By * definition we should not get any longer input lines, thus this is * acceptable in this case ;-) */ -char *read_line (collector_t *src) +char *read_line (conn_t *src) { int i = 0; char *ret; @@ -334,7 +345,7 @@ char *read_line (collector_t *src) if (i == src->idx) { fd_set fdset; - + ssize_t len = 0; FD_ZERO (&fdset); @@ -350,7 +361,7 @@ char *read_line (collector_t *src) do { errno = 0; if (0 > (len = read (src->socket, - (void *)(&(src->buffer[0]) + src->idx), + (void *)(src->buffer + src->idx), BUFSIZE - src->idx))) { if (EINTR != errno) { syslog (LOG_ERR, "read() failed: %s", strerror (errno)); @@ -385,7 +396,7 @@ char *read_line (collector_t *src) } ret = (char *)smalloc (i + 1); - memcpy (ret, &(src->buffer[0]), i + 1); + memcpy (ret, src->buffer, i + 1); ret[i] = '\0'; src->idx -= (i + 1); @@ -393,142 +404,134 @@ char *read_line (collector_t *src) if (0 == src->idx) src->buffer[0] = '\0'; else - memmove (&(src->buffer[0]), &(src->buffer[i + 1]), src->idx); + memmove (src->buffer, src->buffer + i + 1, src->idx); return ret; -} /* char *read_line (collector_t *) */ +} /* char *read_line (conn_t *) */ static void *collect (void *arg) { collector_t *this = (collector_t *)arg; - - int loop = 1; - { /* put the socket in non-blocking mode */ - int flags = 0; + char *buffer = (char *)smalloc (BUFSIZE); - errno = 0; - if (-1 == fcntl (this->socket, F_GETFL, &flags)) { - syslog (LOG_ERR, "fcntl() failed: %s", strerror (errno)); - loop = 0; - } + while (1) { + int loop = 1; - errno = 0; - if (-1 == fcntl (this->socket, F_SETFL, flags | O_NONBLOCK)) { - syslog (LOG_ERR, "fcntl() failed: %s", strerror (errno)); - loop = 0; - } - } + conn_t *connection; - while (loop) { - char *line = read_line (this); + pthread_mutex_lock (&conns_mutex); - if (NULL == line) { - loop = 0; - break; + while (NULL == conns.head) { + pthread_cond_wait (&conn_available, &conns_mutex); } - if ('\0' == line[0]) { - free (line); - continue; - } + connection = conns.head; + conns.head = conns.head->next; - if (':' != line[1]) { - syslog (LOG_ERR, "email: syntax error in line '%s'", line); - free (line); - continue; + if (NULL == conns.head) { + conns.tail = NULL; } - if ('e' == line[0]) { /* e:: */ - char *ptr = NULL; - char *type = strtok_r (line + 2, ":", &ptr); - char *tmp = strtok_r (NULL, ":", &ptr); - int bytes = 0; + this->socket = connection->socket; - if (NULL == tmp) { - syslog (LOG_ERR, "email: syntax error in line '%s'", line); - free (line); - continue; - } + pthread_mutex_unlock (&conns_mutex); - bytes = atoi (tmp); + connection->buffer = buffer; + connection->idx = 0; - pthread_mutex_lock (&count_mutex); - type_list_incr (&count, type, 1); - pthread_mutex_unlock (&count_mutex); + { /* put the socket in non-blocking mode */ + int flags = 0; - pthread_mutex_lock (&size_mutex); - type_list_incr (&size, type, bytes); - pthread_mutex_unlock (&size_mutex); - } - else if ('s' == line[0]) { /* s: */ - pthread_mutex_lock (&score_mutex); - score = (score * (double)score_count + atof (line + 2)) - / (double)(score_count + 1); - ++score_count; - pthread_mutex_unlock (&score_mutex); - } - else if ('c' == line[0]) { /* c:[,,...] */ - char *ptr = NULL; - char *type = strtok_r (line + 2, ",", &ptr); - - do { - pthread_mutex_lock (&check_mutex); - type_list_incr (&check, type, 1); - pthread_mutex_unlock (&check_mutex); - } while (NULL != (type = strtok_r (NULL, ",", &ptr))); - } - else { - syslog (LOG_ERR, "email: unknown type '%c'", line[0]); + errno = 0; + if (-1 == fcntl (connection->socket, F_GETFL, &flags)) { + syslog (LOG_ERR, "fcntl() failed: %s", strerror (errno)); + loop = 0; + } + + errno = 0; + if (-1 == fcntl (connection->socket, F_SETFL, flags | O_NONBLOCK)) { + syslog (LOG_ERR, "fcntl() failed: %s", strerror (errno)); + loop = 0; + } } - free (line); - } + while (loop) { + char *line = read_line (connection); + + if (NULL == line) { + loop = 0; + break; + } + + if ('\0' == line[0]) { + free (line); + continue; + } - /* put this thread back into the available list */ - pthread_mutex_lock (&active_mutex); - { - collector_t *last; - collector_t *ptr; + if (':' != line[1]) { + syslog (LOG_ERR, "email: syntax error in line '%s'", line); + free (line); + continue; + } - last = NULL; + if ('e' == line[0]) { /* e:: */ + char *ptr = NULL; + char *type = strtok_r (line + 2, ":", &ptr); + char *tmp = strtok_r (NULL, ":", &ptr); + int bytes = 0; - for (ptr = active.head; NULL != ptr; last = ptr, ptr = ptr->next) { - if (0 != pthread_equal (ptr->thread, this->thread)) - break; - } + if (NULL == tmp) { + syslog (LOG_ERR, "email: syntax error in line '%s'", line); + free (line); + continue; + } - /* the current thread _has_ to be in the active list */ - assert (NULL != ptr); + bytes = atoi (tmp); - if (NULL == last) { - active.head = ptr->next; - } - else { - last->next = ptr->next; + pthread_mutex_lock (&count_mutex); + type_list_incr (&count, type, 1); + pthread_mutex_unlock (&count_mutex); - if (NULL == last->next) { - active.tail = last; + pthread_mutex_lock (&size_mutex); + type_list_incr (&size, type, bytes); + pthread_mutex_unlock (&size_mutex); } - } - } - pthread_mutex_unlock (&active_mutex); + else if ('s' == line[0]) { /* s: */ + pthread_mutex_lock (&score_mutex); + score = (score * (double)score_count + atof (line + 2)) + / (double)(score_count + 1); + ++score_count; + pthread_mutex_unlock (&score_mutex); + } + else if ('c' == line[0]) { /* c:[,,...] */ + char *ptr = NULL; + char *type = strtok_r (line + 2, ",", &ptr); + + do { + pthread_mutex_lock (&check_mutex); + type_list_incr (&check, type, 1); + pthread_mutex_unlock (&check_mutex); + } while (NULL != (type = strtok_r (NULL, ",", &ptr))); + } + else { + syslog (LOG_ERR, "email: unknown type '%c'", line[0]); + } + + free (line); + } /* while (loop) */ - this->next = NULL; + close (connection->socket); - pthread_mutex_lock (&available_mutex); + free (connection); - if (NULL == available.head) { - available.head = this; - available.tail = this; - } - else { - available.tail->next = this; - available.tail = this; - } + pthread_mutex_lock (&available_mutex); + ++available_collectors; + pthread_mutex_unlock (&available_mutex); - pthread_mutex_unlock (&available_mutex); + pthread_cond_signal (&collector_available); + } /* while (1) */ - pthread_cond_signal (&collector_available); + free (buffer); pthread_exit ((void *)0); } /* void *collect (void *) */ @@ -589,40 +592,50 @@ static void *open_connection (void *arg) syslog (LOG_WARNING, "chmod() failed: %s", strerror (errno)); } - { /* initialize queue of available threads */ - int i = 0; + { /* initialize collector threads */ + int i = 0; + int err = 0; - collector_t *last; + pthread_attr_t ptattr; + + conns.head = NULL; + conns.tail = NULL; + + pthread_attr_init (&ptattr); + pthread_attr_setdetachstate (&ptattr, PTHREAD_CREATE_DETACHED); - active.head = NULL; - active.tail = NULL; + available_collectors = max_conns; - available.head = (collector_t *)smalloc (sizeof (collector_t)); - available.tail = available.head; - available.tail->next = NULL; + collectors = + (collector_t **)smalloc (max_conns * sizeof (collector_t *)); - last = available.head; + for (i = 0; i < max_conns; ++i) { + collectors[i] = (collector_t *)smalloc (sizeof (collector_t)); + collectors[i]->socket = 0; - for (i = 1; i < max_conns; ++i) { - last->next = (collector_t *)smalloc (sizeof (collector_t)); - last = last->next; - available.tail = last; - available.tail->next = NULL; + if (0 != (err = pthread_create (&collectors[i]->thread, &ptattr, + collect, collectors[i]))) { + syslog (LOG_ERR, "pthread_create() failed: %s", + strerror (err)); + } } + + pthread_attr_destroy (&ptattr); } while (1) { int remote = 0; - int err = 0; - - collector_t *collector; - pthread_attr_t ptattr; + conn_t *connection; pthread_mutex_lock (&available_mutex); - while (NULL == available.head) { + + while (0 == available_collectors) { pthread_cond_wait (&collector_available, &available_mutex); } + + --available_collectors; + pthread_mutex_unlock (&available_mutex); do { @@ -636,62 +649,25 @@ static void *open_connection (void *arg) } } while (EINTR == errno); - /* assign connection to next available thread */ - pthread_mutex_lock (&available_mutex); - - collector = available.head; - collector->socket = remote; - - if (available.head == available.tail) { - available.head = NULL; - available.tail = NULL; - } - else { - available.head = available.head->next; - } - - pthread_mutex_unlock (&available_mutex); - - collector->idx = 0; - collector->next = NULL; - - pthread_attr_init (&ptattr); - pthread_attr_setdetachstate (&ptattr, PTHREAD_CREATE_DETACHED); + connection = (conn_t *)smalloc (sizeof (conn_t)); - if (0 == (err = pthread_create (&collector->thread, &ptattr, collect, - (void *)collector))) { - pthread_mutex_lock (&active_mutex); + connection->socket = remote; + connection->next = NULL; - if (NULL == active.head) { - active.head = collector; - active.tail = collector; - } - else { - active.tail->next = collector; - active.tail = collector; - } + pthread_mutex_lock (&conns_mutex); - pthread_mutex_unlock (&active_mutex); + if (NULL == conns.head) { + conns.head = connection; + conns.tail = connection; } else { - pthread_mutex_lock (&available_mutex); - - if (NULL == available.head) { - available.head = collector; - available.tail = collector; - } - else { - available.tail->next = collector; - available.tail = collector; - } - - pthread_mutex_unlock (&available_mutex); - - close (remote); - syslog (LOG_ERR, "pthread_create() failed: %s", strerror (err)); + conns.tail->next = connection; + conns.tail = conns.tail->next; } - pthread_attr_destroy (&ptattr); + pthread_mutex_unlock (&conns_mutex); + + pthread_cond_signal (&conn_available); } pthread_exit ((void *)0); } /* void *open_connection (void *) */ @@ -715,7 +691,7 @@ static void email_init (void) #if EMAIL_HAVE_READ static void email_shutdown (void) { - collector_t *ptr; + int i = 0; if (disabled) return; @@ -723,14 +699,15 @@ static void email_shutdown (void) close (connector_socket); pthread_kill (connector, SIGTERM); - pthread_mutex_lock (&active_mutex); + /* don't allow any more connections to be processed */ + pthread_mutex_lock (&conns_mutex); - for (ptr = active.head; NULL != ptr; ptr = ptr->next) { - close (ptr->socket); - pthread_kill (ptr->thread, SIGTERM); + for (i = 0; i < max_conns; ++i) { + close (collectors[i]->socket); + pthread_kill (collectors[i]->thread, SIGTERM); } - pthread_mutex_unlock (&active_mutex); + pthread_mutex_unlock (&conns_mutex); unlink (SOCK_PATH); return;