* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#define _GNU_SOURCE
#define _LGPL_SOURCE
#include <assert.h>
#include "fd-limit.h"
#include "agent-thread.h"
+#include "agent.h"
#include "lttng-sessiond.h"
#include "session.h"
#include "utils.h"
+static int agent_tracing_enabled = -1;
+
/*
* Note that there is not port here. It's set after this URI is parsed so we
* can let the user define a custom one. However, localhost is ALWAYS the
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);
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);
+}
+
/*
* This thread manage application notify communication.
*/
}
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. */
+ sessiond_notify_ready();
+ goto error;
+ }
+ } else {
+ /* Don't prevent the launch of the sessiond on error. */
+ sessiond_notify_ready();
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);
+ sessiond_notify_ready();
+
+ /* 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.
revents = LTTNG_POLL_GETEV(&events, i);
pollfd = LTTNG_POLL_GETFD(&events, i);
+ if (!revents) {
+ /* No activity for this FD (poll implementation). */
+ continue;
+ }
+
/* Thread quit pipe has been closed. Killing thread. */
ret = sessiond_check_thread_quit_pipe(pollfd, revents);
if (ret) {
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:
+ uatomic_set(&agent_tracing_enabled, 0);
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);
- }
-
rcu_thread_offline();
rcu_unregister_thread();
return NULL;
projects / lttng-tools.git / blobdiff