From: Andrew Bays Date: Thu, 18 Oct 2018 23:11:27 +0000 (-0400) Subject: Additional mutex + styling changes X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=110fac0df246ee4d18b0c074b5ba57a542215a58;p=collectd.git Additional mutex + styling changes --- diff --git a/src/procevent.c b/src/procevent.c index fc8e4302..4c8d024b 100644 --- a/src/procevent.c +++ b/src/procevent.c @@ -130,9 +130,9 @@ static pthread_t procevent_netlink_thread_id; static int procevent_dequeue_thread_loop = 0; static int procevent_dequeue_thread_error = 0; static pthread_t procevent_dequeue_thread_id; -static pthread_mutex_t procevent_lock = PTHREAD_MUTEX_INITIALIZER; +static pthread_mutex_t procevent_thread_lock = PTHREAD_MUTEX_INITIALIZER; +static pthread_mutex_t procevent_data_lock = PTHREAD_MUTEX_INITIALIZER; static pthread_cond_t procevent_cond = PTHREAD_COND_INITIALIZER; -static pthread_mutex_t procevent_list_lock = PTHREAD_MUTEX_INITIALIZER; static int nl_sock = -1; static int buffer_length; static circbuf_t ring; @@ -435,17 +435,14 @@ static int gen_message_payload(int state, long pid, char *process, if (yajl_gen_get_buf(g, &buf2, &len) != yajl_gen_status_ok) goto err; - *buf = malloc(strlen((char *)buf2) + 1); + *buf = strdup((char *)buf2); if (*buf == NULL) { - char errbuf[1024]; - ERROR("procevent plugin: malloc failed during gen_message_payload: %s", - sstrerror(errno, errbuf, sizeof(errbuf))); + ERROR("procevent plugin: strdup failed during gen_message_payload: %s", + STRERRNO); goto err; } - sstrncpy(*buf, (char *)buf2, strlen((char *)buf2) + 1); - yajl_gen_free(g); return 0; @@ -457,13 +454,13 @@ err: } // Does /proc//comm contain a process name we are interested in? +// NOTE: Caller MUST hold procevent_data_lock when calling this function static processlist_t *process_check(long pid) { - int len, is_match, retval; char file[BUFSIZE]; FILE *fh; char buffer[BUFSIZE]; - len = snprintf(file, sizeof(file), PROCDIR "/%ld/comm", pid); + int len = snprintf(file, sizeof(file), PROCDIR "/%ld/comm", pid); if ((len < 0) || (len >= BUFSIZE)) { WARNING("procevent process_check: process name too large"); @@ -476,7 +473,7 @@ static processlist_t *process_check(long pid) { return NULL; } - retval = fscanf(fh, "%[^\n]", buffer); + int retval = fscanf(fh, "%[^\n]", buffer); if (retval < 0) { WARNING("procevent process_check: unable to read comm file for pid %ld", @@ -508,14 +505,11 @@ static processlist_t *process_check(long pid) { // associate with it (with the same process name as the existing). // - pthread_mutex_lock(&procevent_list_lock); - - processlist_t *pl; processlist_t *match = NULL; - for (pl = processlist_head; pl != NULL; pl = pl->next) { + for (processlist_t *pl = processlist_head; pl != NULL; pl = pl->next) { - is_match = (strcmp(buffer, pl->process) == 0 ? 1 : 0); + int is_match = (strcmp(buffer, pl->process) == 0 ? 1 : 0); if (is_match == 1) { DEBUG("procevent plugin: process %ld name match for %s", pid, buffer); @@ -560,25 +554,18 @@ static processlist_t *process_check(long pid) { "(%s)", pid, buffer); - processlist_t *pl2; - char *process; - - pl2 = malloc(sizeof(*pl2)); + processlist_t *pl2 = calloc(1, sizeof(*pl2)); if (pl2 == NULL) { - char errbuf[1024]; - ERROR("procevent plugin: malloc failed during process_check: %s", - sstrerror(errno, errbuf, sizeof(errbuf))); - pthread_mutex_unlock(&procevent_list_lock); + ERROR("procevent plugin: calloc failed during process_check: %s", + STRERRNO); return NULL; } - process = strdup(buffer); + char *process = strdup(buffer); if (process == NULL) { - char errbuf[1024]; sfree(pl2); ERROR("procevent plugin: strdup failed during process_check: %s", - sstrerror(errno, errbuf, sizeof(errbuf))); - pthread_mutex_unlock(&procevent_list_lock); + STRERRNO); return NULL; } @@ -590,18 +577,13 @@ static processlist_t *process_check(long pid) { match = pl2; } - pthread_mutex_unlock(&procevent_list_lock); - return match; } // Does our map have this PID or name? +// NOTE: Caller MUST hold procevent_data_lock when calling this function static processlist_t *process_map_check(long pid, char *process) { - processlist_t *pl; - - pthread_mutex_lock(&procevent_list_lock); - - for (pl = processlist_head; pl != NULL; pl = pl->next) { + for (processlist_t *pl = processlist_head; pl != NULL; pl = pl->next) { int match_pid = 0; int match_process = 0; int match = 0; @@ -624,47 +606,35 @@ static processlist_t *process_map_check(long pid, char *process) { match = 1; if (match == 1) { - pthread_mutex_unlock(&procevent_list_lock); return pl; } } - pthread_mutex_unlock(&procevent_list_lock); - return NULL; } static int process_map_refresh(void) { - DIR *proc; - errno = 0; - proc = opendir(PROCDIR); + DIR *proc = opendir(PROCDIR); + if (proc == NULL) { - char errbuf[1024]; - ERROR("procevent plugin: fopen (%s): %s", PROCDIR, - sstrerror(errno, errbuf, sizeof(errbuf))); + ERROR("procevent plugin: fopen (%s): %s", PROCDIR, STRERRNO); return -1; } while (42) { - struct dirent *dent; - int len; char file[BUFSIZE]; struct stat statbuf; - int status; - errno = 0; - dent = readdir(proc); + struct dirent *dent = readdir(proc); if (dent == NULL) { - char errbuf[4096]; - if (errno == 0) /* end of directory */ break; ERROR("procevent plugin: failed to read directory %s: %s", PROCDIR, - sstrerror(errno, errbuf, sizeof(errbuf))); + STRERRNO); closedir(proc); return -1; } @@ -672,15 +642,13 @@ static int process_map_refresh(void) { if (dent->d_name[0] == '.') continue; - len = snprintf(file, sizeof(file), PROCDIR "/%s", dent->d_name); + int len = snprintf(file, sizeof(file), PROCDIR "/%s", dent->d_name); if ((len < 0) || (len >= BUFSIZE)) continue; - status = stat(file, &statbuf); + int status = stat(file, &statbuf); if (status != 0) { - char errbuf[4096]; - WARNING("procevent plugin: stat (%s) failed: %s", file, - sstrerror(errno, errbuf, sizeof(errbuf))); + WARNING("procevent plugin: stat (%s) failed: %s", file, STRERRNO); continue; } @@ -706,7 +674,9 @@ static int process_map_refresh(void) { // Check if we need to store this pid/name combo in our processlist_t linked // list int this_pid = atoi(dent->d_name); + pthread_mutex_lock(&procevent_data_lock); processlist_t *pl = process_check(this_pid); + pthread_mutex_unlock(&procevent_data_lock); if (pl != NULL) DEBUG("procevent plugin: process map refreshed for PID %d and name %s", @@ -719,8 +689,9 @@ static int process_map_refresh(void) { } static int nl_connect() { - int rc; - struct sockaddr_nl sa_nl; + struct sockaddr_nl sa_nl = { + .nl_family = AF_NETLINK, .nl_groups = CN_IDX_PROC, .nl_pid = getpid(), + }; nl_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR); if (nl_sock == -1) { @@ -728,11 +699,7 @@ static int nl_connect() { return -1; } - sa_nl.nl_family = AF_NETLINK; - sa_nl.nl_groups = CN_IDX_PROC; - sa_nl.nl_pid = getpid(); - - rc = bind(nl_sock, (struct sockaddr *)&sa_nl, sizeof(sa_nl)); + int rc = bind(nl_sock, (struct sockaddr *)&sa_nl, sizeof(sa_nl)); if (rc == -1) { ERROR("procevent plugin: socket bind failed: %d", errno); close(nl_sock); @@ -743,7 +710,6 @@ static int nl_connect() { } static int set_proc_ev_listen(bool enable) { - int rc; struct __attribute__((aligned(NLMSG_ALIGNTO))) { struct nlmsghdr nl_hdr; struct __attribute__((__packed__)) { @@ -763,7 +729,7 @@ static int set_proc_ev_listen(bool enable) { nlcn_msg.cn_mcast = enable ? PROC_CN_MCAST_LISTEN : PROC_CN_MCAST_IGNORE; - rc = send(nl_sock, &nlcn_msg, sizeof(nlcn_msg), 0); + int rc = send(nl_sock, &nlcn_msg, sizeof(nlcn_msg), 0); if (rc == -1) { ERROR("procevent plugin: subscribing to netlink process events failed: %d", errno); @@ -775,11 +741,6 @@ static int set_proc_ev_listen(bool enable) { // Read from netlink socket and write to ring buffer static int read_event() { - int status; - int ret = 0; - int proc_id = -1; - int proc_status = -1; - int proc_extra = -1; int recv_flags = MSG_DONTWAIT; struct __attribute__((aligned(NLMSG_ALIGNTO))) { struct nlmsghdr nl_hdr; @@ -790,26 +751,29 @@ static int read_event() { } nlcn_msg; if (nl_sock == -1) - return ret; + return 0; while (42) { + int proc_id = -1; + int proc_status = -1; + int proc_extra = -1; - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_thread_lock); if (procevent_netlink_thread_loop <= 0) { - pthread_mutex_unlock(&procevent_lock); - return ret; + pthread_mutex_unlock(&procevent_thread_lock); + return 0; } - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); - status = recv(nl_sock, &nlcn_msg, sizeof(nlcn_msg), recv_flags); + int status = recv(nl_sock, &nlcn_msg, sizeof(nlcn_msg), recv_flags); if (status == 0) { return 0; } else if (status < 0) { if (errno == EAGAIN || errno == EWOULDBLOCK) { - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_data_lock); // There was nothing more to receive for now, so... // If ring head does not equal ring tail, there is data @@ -818,7 +782,7 @@ static int read_event() { if (ring.head != ring.tail) pthread_cond_signal(&procevent_cond); - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_data_lock); // Since there was nothing to receive, set recv to block and // try again @@ -859,7 +823,7 @@ static int read_event() { // in the ring buffer for consumption by the main polling thread. if (proc_status != -1) { - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_data_lock); int next = ring.head + 1; if (next >= ring.maxLen) @@ -871,7 +835,7 @@ static int read_event() { WARNING("procevent plugin: ring buffer full"); pthread_cond_signal(&procevent_cond); - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_data_lock); usleep(1000); continue; @@ -897,21 +861,21 @@ static int read_event() { ring.head = next; } - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_data_lock); } } - return ret; + return 0; } // Read from ring buffer and dispatch to write plugins static int read_ring_buffer() { - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_data_lock); // If there's currently nothing to read from the buffer, // then wait if (ring.head == ring.tail) - pthread_cond_wait(&procevent_cond, &procevent_lock); + pthread_cond_wait(&procevent_cond, &procevent_data_lock); while (ring.head != ring.tail) { int next = ring.tail + 1; @@ -959,7 +923,7 @@ static int read_ring_buffer() { ring.tail = next; } - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_data_lock); return 0; } @@ -968,29 +932,22 @@ static int read_ring_buffer() { // to netlink socket and writing data to ring buffer static void *procevent_netlink_thread(void *arg) /* {{{ */ { - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_thread_lock); while (procevent_netlink_thread_loop > 0) { - int status; - - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); - usleep(1000); + int status = read_event(); - status = read_event(); - - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_thread_lock); if (status < 0) { procevent_netlink_thread_error = 1; break; } - - if (procevent_netlink_thread_loop <= 0) - break; } /* while (procevent_netlink_thread_loop > 0) */ - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); return ((void *)0); } /* }}} void *procevent_netlink_thread */ @@ -999,27 +956,22 @@ static void *procevent_netlink_thread(void *arg) /* {{{ */ // ring buffer and dispatching notifications static void *procevent_dequeue_thread(void *arg) /* {{{ */ { - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_thread_lock); while (procevent_dequeue_thread_loop > 0) { - int status; - - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); - status = read_ring_buffer(); + int status = read_ring_buffer(); - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_thread_lock); if (status < 0) { procevent_dequeue_thread_error = 1; break; } - - if (procevent_dequeue_thread_loop <= 0) - break; } /* while (procevent_dequeue_thread_loop > 0) */ - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); return ((void *)0); } /* }}} void *procevent_dequeue_thread */ @@ -1028,22 +980,26 @@ static int start_netlink_thread(void) /* {{{ */ { int status; - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_thread_lock); if (procevent_netlink_thread_loop != 0) { - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); return (0); } if (nl_sock == -1) { status = nl_connect(); - if (status != 0) + if (status != 0) { + pthread_mutex_unlock(&procevent_thread_lock); return status; + } status = set_proc_ev_listen(true); - if (status == -1) + if (status == -1) { + pthread_mutex_unlock(&procevent_thread_lock); return status; + } } DEBUG("procevent plugin: socket created and bound"); @@ -1057,11 +1013,20 @@ static int start_netlink_thread(void) /* {{{ */ if (status != 0) { procevent_netlink_thread_loop = 0; ERROR("procevent plugin: Starting netlink thread failed."); - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); + + int status2 = close(nl_sock); + + if (status2 != 0) { + ERROR("procevent plugin: failed to close socket %d: %d (%s)", nl_sock, + status2, STRERRNO); + } else + nl_sock = -1; + return (-1); } - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); return status; } /* }}} int start_netlink_thread */ @@ -1070,10 +1035,10 @@ static int start_dequeue_thread(void) /* {{{ */ { int status; - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_thread_lock); if (procevent_dequeue_thread_loop != 0) { - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); return (0); } @@ -1086,23 +1051,21 @@ static int start_dequeue_thread(void) /* {{{ */ if (status != 0) { procevent_dequeue_thread_loop = 0; ERROR("procevent plugin: Starting dequeue thread failed."); - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); return (-1); } - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); return status; } /* }}} int start_dequeue_thread */ static int start_threads(void) /* {{{ */ { - int status, status2; + int status = start_netlink_thread(); + int status2 = start_dequeue_thread(); - status = start_netlink_thread(); - status2 = start_dequeue_thread(); - - if (status < 0) + if (status != 0) return status; else return status2; @@ -1110,28 +1073,30 @@ static int start_threads(void) /* {{{ */ static int stop_netlink_thread(int shutdown) /* {{{ */ { - int status; + int socket_status, thread_status; if (nl_sock != -1) { - status = close(nl_sock); - if (status != 0) { + socket_status = close(nl_sock); + if (socket_status != 0) { ERROR("procevent plugin: failed to close socket %d: %d (%s)", nl_sock, - status, strerror(errno)); + socket_status, strerror(errno)); return (-1); } else nl_sock = -1; - } + } else + socket_status = 0; - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_thread_lock); if (procevent_netlink_thread_loop == 0) { - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); return (-1); } procevent_netlink_thread_loop = 0; + pthread_mutex_unlock(&procevent_thread_lock); + pthread_cond_broadcast(&procevent_cond); - pthread_mutex_unlock(&procevent_lock); if (shutdown == 1) { // Calling pthread_cancel here in @@ -1140,46 +1105,52 @@ static int stop_netlink_thread(int shutdown) /* {{{ */ DEBUG("procevent plugin: Canceling netlink thread for process shutdown"); - status = pthread_cancel(procevent_netlink_thread_id); + thread_status = pthread_cancel(procevent_netlink_thread_id); - if (status != 0 && status != ESRCH) { - ERROR("procevent plugin: Unable to cancel netlink thread: %d", status); - status = -1; + if (thread_status != 0 && thread_status != ESRCH) { + ERROR("procevent plugin: Unable to cancel netlink thread: %d", + thread_status); + thread_status = -1; } else - status = 0; + thread_status = 0; } else { - status = pthread_join(procevent_netlink_thread_id, /* return = */ NULL); - if (status != 0 && status != ESRCH) { + thread_status = + pthread_join(procevent_netlink_thread_id, /* return = */ NULL); + if (thread_status != 0 && thread_status != ESRCH) { ERROR("procevent plugin: Stopping netlink thread failed."); - status = -1; + thread_status = -1; } else - status = 0; + thread_status = 0; } - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_thread_lock); memset(&procevent_netlink_thread_id, 0, sizeof(procevent_netlink_thread_id)); procevent_netlink_thread_error = 0; - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); DEBUG("procevent plugin: Finished requesting stop of netlink thread"); - return (status); + if (socket_status != 0) + return socket_status; + else + return thread_status; } /* }}} int stop_netlink_thread */ static int stop_dequeue_thread(int shutdown) /* {{{ */ { int status; - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_thread_lock); if (procevent_dequeue_thread_loop == 0) { - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); return (-1); } procevent_dequeue_thread_loop = 0; + pthread_mutex_unlock(&procevent_thread_lock); + pthread_cond_broadcast(&procevent_cond); - pthread_mutex_unlock(&procevent_lock); if (shutdown == 1) { // Calling pthread_cancel here in @@ -1204,10 +1175,10 @@ static int stop_dequeue_thread(int shutdown) /* {{{ */ status = 0; } - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_thread_lock); memset(&procevent_dequeue_thread_id, 0, sizeof(procevent_dequeue_thread_id)); procevent_dequeue_thread_error = 0; - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); DEBUG("procevent plugin: Finished requesting stop of dequeue thread"); @@ -1216,10 +1187,8 @@ static int stop_dequeue_thread(int shutdown) /* {{{ */ static int stop_threads(int shutdown) /* {{{ */ { - int status, status2; - - status = stop_netlink_thread(shutdown); - status2 = stop_dequeue_thread(shutdown); + int status = stop_netlink_thread(shutdown); + int status2 = stop_dequeue_thread(shutdown); if (status < 0) return status; @@ -1229,20 +1198,18 @@ static int stop_threads(int shutdown) /* {{{ */ static int procevent_init(void) /* {{{ */ { - int status; - ring.head = 0; ring.tail = 0; ring.maxLen = buffer_length; - ring.buffer = (long long unsigned int **)malloc( - buffer_length * sizeof(long long unsigned int *)); + ring.buffer = (long long unsigned int **)calloc( + buffer_length, sizeof(long long unsigned int *)); for (int i = 0; i < buffer_length; i++) { - ring.buffer[i] = (long long unsigned int *)malloc( - PROCEVENT_FIELDS * sizeof(long long unsigned int)); + ring.buffer[i] = (long long unsigned int *)calloc( + PROCEVENT_FIELDS, sizeof(long long unsigned int)); } - status = process_map_refresh(); + int status = process_map_refresh(); if (status == -1) { ERROR("procevent plugin: Initial process mapping failed."); @@ -1259,8 +1226,6 @@ static int procevent_init(void) /* {{{ */ static int procevent_config(const char *key, const char *value) /* {{{ */ { - int status; - if (ignorelist == NULL) ignorelist = ignorelist_create(/* invert = */ 1); @@ -1270,7 +1235,7 @@ static int procevent_config(const char *key, const char *value) /* {{{ */ ignorelist_add(ignorelist, value); } else if (strcasecmp(key, "ProcessRegex") == 0) { #if HAVE_REGEX_H - status = ignorelist_add(ignorelist, value); + int status = ignorelist_add(ignorelist, value); if (status != 0) { ERROR("procevent plugin: invalid regular expression: %s", value); @@ -1308,10 +1273,8 @@ static void procevent_dispatch_notification(long pid, notification_meta_t *m = calloc(1, sizeof(*m)); if (m == NULL) { - char errbuf[1024]; sfree(buf); - ERROR("procevent plugin: unable to allocate metadata: %s", - sstrerror(errno, errbuf, sizeof(errbuf))); + ERROR("procevent plugin: unable to allocate metadata: %s", STRERRNO); return; } @@ -1329,18 +1292,18 @@ static void procevent_dispatch_notification(long pid, plugin_dispatch_notification(&n); plugin_notification_meta_free(n.meta); - // malloc'd in gen_message_payload + // strdup'd in gen_message_payload if (buf != NULL) sfree(buf); } static int procevent_read(void) /* {{{ */ { - pthread_mutex_lock(&procevent_lock); + pthread_mutex_lock(&procevent_thread_lock); if (procevent_netlink_thread_error != 0) { - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); ERROR("procevent plugin: The netlink thread had a problem. Restarting it."); @@ -1353,7 +1316,7 @@ static int procevent_read(void) /* {{{ */ if (procevent_dequeue_thread_error != 0) { - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); ERROR("procevent plugin: The dequeue thread had a problem. Restarting it."); @@ -1364,19 +1327,16 @@ static int procevent_read(void) /* {{{ */ return (-1); } /* if (procevent_dequeue_thread_error != 0) */ - pthread_mutex_unlock(&procevent_lock); + pthread_mutex_unlock(&procevent_thread_lock); return (0); } /* }}} int procevent_read */ static int procevent_shutdown(void) /* {{{ */ { - int status; - processlist_t *pl; - DEBUG("procevent plugin: Shutting down threads."); - status = stop_threads(1); + int status = stop_threads(1); for (int i = 0; i < buffer_length; i++) { free(ring.buffer[i]); @@ -1384,7 +1344,7 @@ static int procevent_shutdown(void) /* {{{ */ free(ring.buffer); - pl = processlist_head; + processlist_t *pl = processlist_head; while (pl != NULL) { processlist_t *pl_next;