X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=ltt-sessiond%2Fsession.c;h=1ffe1d8e7ec05a47a2c0e1d372025eca764cc61a;hp=a4101d2ee8fed3076364b8283504345669c78681;hb=050349bbb362ea993533591532643022efeab864;hpb=f3ed775ef4842019b396f06095b053c3a70bc3c8 diff --git a/ltt-sessiond/session.c b/ltt-sessiond/session.c index a4101d2ee..1ffe1d8e7 100644 --- a/ltt-sessiond/session.c +++ b/ltt-sessiond/session.c @@ -3,12 +3,12 @@ * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version 2 - * of the License, or (at your option) any later version. + * as published by the Free Software Foundation; only version 2 + * of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License @@ -17,117 +17,119 @@ */ #define _GNU_SOURCE +#include +#include #include #include #include +#include #include #include "lttngerr.h" #include "session.h" -/* Variables */ -static unsigned int session_count; - -/* Static internal function */ -static void add_session_list(struct ltt_session *ls); -static void del_session_list(struct ltt_session *ls); - -/* Init global session list */ -struct ltt_session_list ltt_session_list = { - .head = CDS_LIST_HEAD_INIT(ltt_session_list.head), -}; - /* - * get_session_list + * NOTES: * - * Return a pointer to the session list. + * No ltt_session.lock is taken here because those data structure are widely + * spread across the lttng-tools code base so before caling functions below + * that can read/write a session, the caller MUST acquire the session lock + * using lock_session() and unlock_session(). */ -struct ltt_session_list *get_session_list(void) -{ - return <t_session_list; -} /* - * get_session_count + * Init tracing session list. * - * Return session_count + * Please see session.h for more explanation and correct usage of the list. */ -unsigned int get_session_count(void) -{ - return session_count; -} +static struct ltt_session_list ltt_session_list = { + .head = CDS_LIST_HEAD_INIT(ltt_session_list.head), + .lock = PTHREAD_MUTEX_INITIALIZER, + .count = 0, +}; /* - * add_session_list + * Add a ltt_session structure to the global list. * - * Add a ltt_session structure to the global list. + * The caller MUST acquire the session list lock before. */ static void add_session_list(struct ltt_session *ls) { cds_list_add(&ls->list, <t_session_list.head); - session_count++; + ltt_session_list.count++; } /* - * del_session_list + * Delete a ltt_session structure to the global list. * - * Delete a ltt_session structure to the global list. + * The caller MUST acquire the session list lock before. */ static void del_session_list(struct ltt_session *ls) { cds_list_del(&ls->list); /* Sanity check */ - if (session_count != 0) { - session_count--; + if (ltt_session_list.count > 0) { + ltt_session_list.count--; } } /* - * find_session_by_uuid - * - * Return a ltt_session structure ptr that matches the uuid. + * Return a pointer to the session list. */ -struct ltt_session *find_session_by_uuid(uuid_t session_id) +struct ltt_session_list *get_session_list(void) { - int found = 0; - struct ltt_session *iter; + return <t_session_list; +} - /* Sanity check for NULL session_id */ - if (uuid_is_null(session_id)) { - goto end; - } +/* + * Acquire session list lock + */ +void lock_session_list(void) +{ + pthread_mutex_lock(<t_session_list.lock); +} - cds_list_for_each_entry(iter, <t_session_list.head, list) { - if (uuid_compare(iter->uuid, session_id) == 0) { - found = 1; - break; - } - } +/* + * Release session list lock + */ +void unlock_session_list(void) +{ + pthread_mutex_unlock(<t_session_list.lock); +} -end: - if (!found) { - iter = NULL; - } - return iter; +/* + * Acquire session lock + */ +void lock_session(struct ltt_session *session) +{ + pthread_mutex_lock(&session->lock); } /* - * find_session_by_name - * - * Return a ltt_session structure ptr that matches name. - * If no session found, NULL is returned. + * Release session lock + */ +void unlock_session(struct ltt_session *session) +{ + pthread_mutex_unlock(&session->lock); +} + +/* + * Return a ltt_session structure ptr that matches name. + * If no session found, NULL is returned. */ struct ltt_session *find_session_by_name(char *name) { int found = 0; struct ltt_session *iter; + lock_session_list(); cds_list_for_each_entry(iter, <t_session_list.head, list) { - if (strncmp(iter->name, name, strlen(name)) == 0) { + if (strncmp(iter->name, name, NAME_MAX) == 0) { found = 1; break; } } + unlock_session_list(); if (!found) { iter = NULL; @@ -137,44 +139,41 @@ struct ltt_session *find_session_by_name(char *name) } /* - * destroy_session - * - * Delete session from the global session list - * and free the memory. + * Delete session from the session list and free the memory. * - * Return -1 if no session is found. - * On success, return 1; + * Return -1 if no session is found. On success, return 1; */ int destroy_session(char *name) { int found = -1; - struct ltt_session *iter; + struct ltt_session *iter, *tmp; - cds_list_for_each_entry(iter, <t_session_list.head, list) { + lock_session_list(); + cds_list_for_each_entry_safe(iter, tmp, <t_session_list.head, list) { if (strcmp(iter->name, name) == 0) { DBG("Destroying session %s", iter->name); del_session_list(iter); + free(iter->name); + free(iter->path); + pthread_mutex_destroy(&iter->lock); free(iter); found = 1; break; } } + unlock_session_list(); return found; } /* - * create_session - * - * Create a brand new session and add it to the global session list. + * Create a brand new session and add it to the session list. */ int create_session(char *name, char *path) { int ret; struct ltt_session *new_session; - DBG("Creating session %s at %s", name, path); - new_session = find_session_by_name(name); if (new_session != NULL) { ret = -EEXIST; @@ -213,18 +212,8 @@ int create_session(char *name, char *path) goto error; } - /* UUID generation */ - uuid_generate(new_session->uuid); - - /* - * Set consumer (identifier) to 0. This means that there is - * NO consumer attach to that session yet. - */ - new_session->ust_consumer = 0; - /* Init kernel session */ new_session->kernel_session = NULL; - new_session->kern_session_count = 0; /* Init list */ CDS_INIT_LIST_HEAD(&new_session->ust_traces); @@ -232,8 +221,15 @@ int create_session(char *name, char *path) /* Set trace list counter */ new_session->ust_trace_count = 0; - /* Add new session to the global session list */ + /* Add new session to the session list */ + lock_session_list(); add_session_list(new_session); + unlock_session_list(); + + /* Init lock */ + pthread_mutex_init(&new_session->lock, NULL); + + DBG("Tracing session %s created in %s", new_session->name, new_session->path); return 0; @@ -247,32 +243,3 @@ error_exist: error_malloc: return ret; } - -/* - * get_lttng_session - * - * Iterate over the global session list and fill the lttng_session array. - */ -void get_lttng_session(struct lttng_session *sessions) -{ - int i = 0; - struct ltt_session *iter; - struct lttng_session lsess; - - DBG("Getting all available session"); - - /* Iterate over session list and append data after - * the control struct in the buffer. - */ - cds_list_for_each_entry(iter, <t_session_list.head, list) { - strncpy(lsess.path, iter->path, sizeof(lsess.path)); - lsess.path[sizeof(lsess.path) - 1] = '\0'; - strncpy(lsess.name, iter->name, sizeof(lsess.name)); - lsess.name[sizeof(lsess.name) - 1] = '\0'; - memcpy(&sessions[i], &lsess, sizeof(lsess)); - i++; - /* Reset struct for next pass */ - memset(&lsess, 0, sizeof(lsess)); - } -} -