* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
#include <assert.h>
#include <common/common.h>
#include "fd-limit.h"
#include "agent-thread.h"
+#include "agent.h"
#include "lttng-sessiond.h"
#include "session.h"
#include "utils.h"
+#include "thread.h"
+
+struct thread_notifiers {
+ struct lttng_pipe *quit_pipe;
+ sem_t ready;
+};
+
+static int agent_tracing_enabled = -1;
/*
* Note that there is not port here. It's set after this URI is parsed so we
session_lock_list();
cds_list_for_each_entry_safe(session, stmp, &list->head, list) {
+ if (!session_get(session)) {
+ continue;
+ }
+
session_lock(session);
if (session->ust_session) {
struct agent *agt;
+ rcu_read_lock();
agt = trace_ust_find_agent(session->ust_session, app->domain);
if (agt) {
agent_update(agt, app->sock->fd);
}
+ rcu_read_unlock();
}
session_unlock(session);
+ session_put(session);
}
session_unlock_list();
}
-/*
- * Destroy a agent application by socket.
- */
-static void destroy_agent_app(int sock)
-{
- struct agent_app *app;
-
- assert(sock >= 0);
-
- /*
- * Not finding an application is a very important error that should NEVER
- * happen. The hash table deletion is ONLY done through this call even on
- * thread cleanup.
- */
- rcu_read_lock();
- app = agent_find_app_by_sock(sock);
- assert(app);
- rcu_read_unlock();
-
- /* RCU read side lock is taken in this function call. */
- agent_delete_app(app);
-
- /* The application is freed in a RCU call but the socket is closed here. */
- agent_destroy_app(app);
-}
-
-/*
- * Cleanup remaining agent apps in the hash table. This should only be called in
- * the exit path of the thread.
- */
-static void clean_agent_apps_ht(void)
-{
- struct lttng_ht_node_ulong *node;
- struct lttng_ht_iter iter;
-
- DBG3("[agent-thread] Cleaning agent apps ht");
-
- rcu_read_lock();
- cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, node, node) {
- struct agent_app *app;
-
- app = caa_container_of(node, struct agent_app, node);
- destroy_agent_app(app->sock->fd);
- }
- rcu_read_unlock();
-}
-
/*
* Create and init socket from uri.
*/
int ret;
struct lttng_uri *uri = NULL;
struct lttcomm_sock *sock = NULL;
+ unsigned int port;
+ bool bind_succeeded = false;
/*
* This should never fail since the URI is hardcoded and the port is set
*/
ret = uri_parse(default_reg_uri, &uri);
assert(ret);
- assert(agent_tcp_port);
- uri->port = agent_tcp_port;
+ assert(config.agent_tcp_port.begin > 0);
+ uri->port = config.agent_tcp_port.begin;
sock = lttcomm_alloc_sock_from_uri(uri);
uri_free(uri);
goto error;
}
- ret = sock->ops->bind(sock);
- if (ret < 0) {
- WARN("Another session daemon is using this agent port. Agent support "
- "will be deactivated to prevent interfering with the tracing.");
- goto error;
+ for (port = config.agent_tcp_port.begin;
+ port <= config.agent_tcp_port.end; port++) {
+ ret = lttcomm_sock_set_port(sock, (uint16_t) port);
+ if (ret) {
+ ERR("[agent-thread] Failed to set port %u on socket",
+ port);
+ goto error;
+ }
+ DBG3("[agent-thread] Trying to bind on port %u", port);
+ ret = sock->ops->bind(sock);
+ if (!ret) {
+ bind_succeeded = true;
+ break;
+ }
+
+ if (errno == EADDRINUSE) {
+ DBG("Failed to bind to port %u since it is already in use",
+ port);
+ } else {
+ PERROR("Failed to bind to port %u", port);
+ goto error;
+ }
+ }
+
+ if (!bind_succeeded) {
+ if (config.agent_tcp_port.begin == config.agent_tcp_port.end) {
+ WARN("Another process is already using the agent port %i. "
+ "Agent support will be deactivated.",
+ config.agent_tcp_port.begin);
+ goto error;
+ } else {
+ WARN("All ports in the range [%i, %i] are already in use. "
+ "Agent support will be deactivated.",
+ config.agent_tcp_port.begin,
+ config.agent_tcp_port.end);
+ goto error;
+ }
}
ret = sock->ops->listen(sock, -1);
}
DBG("[agent-thread] Listening on TCP port %u and socket %d",
- agent_tcp_port, sock->fd);
+ port, sock->fd);
return sock;
*/
static void destroy_tcp_socket(struct lttcomm_sock *sock)
{
+ int ret;
+ uint16_t port;
+
assert(sock);
- DBG3("[agent-thread] Destroy TCP socket on port %u", agent_tcp_port);
+ ret = lttcomm_sock_get_port(sock, &port);
+ if (ret) {
+ ERR("[agent-thread] Failed to get port of agent TCP socket");
+ port = 0;
+ }
+
+ DBG3("[agent-thread] Destroy TCP socket on port %" PRIu16,
+ port);
/* This will return gracefully if fd is invalid. */
sock->ops->close(sock);
{
int ret;
pid_t pid;
+ uint32_t major_version, minor_version;
ssize_t size;
enum lttng_domain_type domain;
struct agent_app *app;
size = new_sock->ops->recvmsg(new_sock, &msg, sizeof(msg), 0);
if (size < sizeof(msg)) {
- ret = -errno;
+ ret = -EINVAL;
goto error_socket;
}
domain = be32toh(msg.domain);
pid = be32toh(msg.pid);
+ major_version = be32toh(msg.major_version);
+ minor_version = be32toh(msg.minor_version);
+
+ /* Test communication protocol version of the registring agent. */
+ if (major_version != AGENT_MAJOR_VERSION) {
+ ret = -EINVAL;
+ goto error_socket;
+ }
+ if (minor_version != AGENT_MINOR_VERSION) {
+ ret = -EINVAL;
+ goto error_socket;
+ }
DBG2("[agent-thread] New registration for pid %d domain %d on socket %d",
pid, domain, new_sock->fd);
return ret;
}
+bool agent_tracing_is_enabled(void)
+{
+ int enabled;
+
+ enabled = uatomic_read(&agent_tracing_enabled);
+ assert(enabled != -1);
+ return enabled == 1;
+}
+
+/*
+ * Write agent TCP port using the rundir.
+ */
+static int write_agent_port(uint16_t port)
+{
+ return utils_create_pid_file((pid_t) port,
+ config.agent_port_file_path.value);
+}
+
+static
+void mark_thread_as_ready(struct thread_notifiers *notifiers)
+{
+ DBG("Marking agent management thread as ready");
+ sem_post(¬ifiers->ready);
+}
+
+static
+void wait_until_thread_is_ready(struct thread_notifiers *notifiers)
+{
+ DBG("Waiting for agent management thread to be ready");
+ sem_wait(¬ifiers->ready);
+ DBG("Agent management thread is ready");
+}
+
/*
* This thread manage application notify communication.
*/
-void *agent_thread_manage_registration(void *data)
+static void *thread_agent_management(void *data)
{
int i, ret, pollfd;
uint32_t revents, nb_fd;
struct lttng_poll_event events;
struct lttcomm_sock *reg_sock;
+ struct thread_notifiers *notifiers = data;
+ const int quit_pipe_read_fd = lttng_pipe_get_readfd(
+ notifiers->quit_pipe);
DBG("[agent-thread] Manage agent application registration.");
/* Agent initialization call MUST be called before starting the thread. */
assert(agent_apps_ht_by_sock);
- /* Create pollset with size 2, quit pipe and socket. */
- ret = sessiond_set_thread_pollset(&events, 2);
+ /* Create pollset with size 2, quit pipe and registration socket. */
+ ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
if (ret < 0) {
goto error_poll_create;
}
+ ret = lttng_poll_add(&events, quit_pipe_read_fd,
+ LPOLLIN | LPOLLERR);
+ if (ret < 0) {
+ goto error_tcp_socket;
+ }
+
reg_sock = init_tcp_socket();
- if (!reg_sock) {
+ if (reg_sock) {
+ uint16_t port;
+
+ assert(lttcomm_sock_get_port(reg_sock, &port) == 0);
+
+ ret = write_agent_port(port);
+ if (ret) {
+ ERR("[agent-thread] Failed to create agent port file: agent tracing will be unavailable");
+ /* Don't prevent the launch of the sessiond on error. */
+ mark_thread_as_ready(notifiers);
+ goto error;
+ }
+ } else {
+ /* Don't prevent the launch of the sessiond on error. */
+ mark_thread_as_ready(notifiers);
goto error_tcp_socket;
}
- /* Add create valid TCP socket to poll set. */
+ /*
+ * Signal that the agent thread is ready. The command thread
+ * may start to query whether or not agent tracing is enabled.
+ */
+ uatomic_set(&agent_tracing_enabled, 1);
+ mark_thread_as_ready(notifiers);
+
+ /* Add TCP socket to poll set. */
ret = lttng_poll_add(&events, reg_sock->fd,
LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP);
if (ret < 0) {
}
while (1) {
- DBG3("[agent-thread] Manage agent polling on %d fds",
- LTTNG_POLL_GETNB(&events));
+ DBG3("[agent-thread] Manage agent polling");
/* Inifinite blocking call, waiting for transmission */
restart:
ret = lttng_poll_wait(&events, -1);
+ DBG3("[agent-thread] Manage agent return from poll on %d fds",
+ LTTNG_POLL_GETNB(&events));
if (ret < 0) {
/*
* Restart interrupted system call.
pollfd = LTTNG_POLL_GETFD(&events, i);
/* Thread quit pipe has been closed. Killing thread. */
- ret = sessiond_check_thread_quit_pipe(pollfd, revents);
- if (ret) {
+ if (pollfd == quit_pipe_read_fd) {
goto exit;
}
- /*
- * Check first if this is a POLLERR since POLLIN is also included
- * in an error value thus checking first.
- */
- if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
- /* Removing from the poll set */
- ret = lttng_poll_del(&events, pollfd);
- if (ret < 0) {
- goto error;
- }
-
- destroy_agent_app(pollfd);
- } else if (revents & (LPOLLIN)) {
+ if (revents & LPOLLIN) {
int new_fd;
struct agent_app *app = NULL;
- /* Pollin event of agent app socket should NEVER happen. */
assert(pollfd == reg_sock->fd);
-
new_fd = handle_registration(reg_sock, &app);
if (new_fd < 0) {
- WARN("[agent-thread] agent registration failed. Ignoring.");
- /* Somehow the communication failed. Just continue. */
continue;
}
/* Should not have a NULL app on success. */
assert(app);
- /* Only add poll error event to only detect shutdown. */
+ /*
+ * Since this is a command socket (write then read),
+ * only add poll error event to only detect shutdown.
+ */
ret = lttng_poll_add(&events, new_fd,
LPOLLERR | LPOLLHUP | LPOLLRDHUP);
if (ret < 0) {
- destroy_agent_app(new_fd);
+ agent_destroy_app_by_sock(new_fd);
continue;
}
update_agent_app(app);
/* On failure, the poll will detect it and clean it up. */
- (void) agent_send_registration_done(app);
+ ret = agent_send_registration_done(app);
+ if (ret < 0) {
+ /* Removing from the poll set */
+ ret = lttng_poll_del(&events, new_fd);
+ if (ret < 0) {
+ goto error;
+ }
+ agent_destroy_app_by_sock(new_fd);
+ continue;
+ }
+ } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ /* Removing from the poll set */
+ ret = lttng_poll_del(&events, pollfd);
+ if (ret < 0) {
+ goto error;
+ }
+ agent_destroy_app_by_sock(pollfd);
} else {
- ERR("Unknown poll events %u for sock %d", revents, pollfd);
- continue;
+ ERR("Unexpected poll events %u for sock %d", revents, pollfd);
+ goto error;
}
}
}
error_tcp_socket:
lttng_poll_clean(&events);
error_poll_create:
- DBG("[agent-thread] is cleaning up and stopping.");
-
- if (agent_apps_ht_by_sock) {
- clean_agent_apps_ht();
- lttng_ht_destroy(agent_apps_ht_by_sock);
- }
-
+ uatomic_set(&agent_tracing_enabled, 0);
+ DBG("[agent-thread] Cleaning up and stopping.");
rcu_thread_offline();
rcu_unregister_thread();
return NULL;
}
+
+static bool shutdown_agent_management_thread(void *data)
+{
+ struct thread_notifiers *notifiers = data;
+ const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe);
+
+ return notify_thread_pipe(write_fd) == 1;
+}
+
+static void cleanup_agent_management_thread(void *data)
+{
+ struct thread_notifiers *notifiers = data;
+
+ lttng_pipe_destroy(notifiers->quit_pipe);
+ sem_destroy(¬ifiers->ready);
+ free(notifiers);
+}
+
+bool launch_agent_management_thread(void)
+{
+ struct thread_notifiers *notifiers;
+ struct lttng_thread *thread;
+
+ notifiers = zmalloc(sizeof(*notifiers));
+ if (!notifiers) {
+ goto error_alloc;
+ }
+
+ sem_init(¬ifiers->ready, 0, 0);
+ notifiers->quit_pipe = lttng_pipe_open(FD_CLOEXEC);
+ if (!notifiers->quit_pipe) {
+ goto error;
+ }
+ thread = lttng_thread_create("Agent management",
+ thread_agent_management,
+ shutdown_agent_management_thread,
+ cleanup_agent_management_thread,
+ notifiers);
+ if (!thread) {
+ goto error;
+ }
+ wait_until_thread_is_ready(notifiers);
+ lttng_thread_put(thread);
+ return true;
+error:
+ cleanup_agent_management_thread(notifiers);
+error_alloc:
+ return false;
+}
projects / lttng-tools.git / blobdiff