#include <lttng-ust-comm.h>
#include <ust/usterr-signal-safe.h>
#include <pthread.h>
+#include <semaphore.h>
+#include <time.h>
#include <assert.h>
/*
/* Should the ust comm thread quit ? */
static int lttng_ust_comm_should_quit;
+/*
+ * Wait for either of these before continuing to the main
+ * program:
+ * - the register_done message from sessiond daemon
+ * (will let the sessiond daemon enable sessions before main
+ * starts.)
+ * - sessiond daemon is not reachable.
+ * - timeout (ensuring applications are resilient to session
+ * daemon problems).
+ */
+static sem_t constructor_wait;
+
/*
* Info about socket and associated listener thread.
*/
struct sock_info {
+ const char *name;
char sock_path[PATH_MAX];
int socket;
pthread_t ust_listener; /* listener thread */
+ int root_handle;
};
/* Socket from app (connect) to session daemon (listen) for communication */
struct sock_info global_apps = {
+ .name = "global",
.sock_path = DEFAULT_GLOBAL_APPS_UNIX_SOCK,
.socket = -1,
+ .root_handle = -1,
};
/* TODO: allow global_apps_sock_path override */
struct sock_info local_apps = {
+ .name = "local",
.socket = -1,
+ .root_handle = -1,
};
static
{
ssize_t len;
- len = lttcomm_send_unix_sock(sock, &lur, sizeof(lur));
+ len = lttcomm_send_unix_sock(sock, lur, sizeof(*lur));
switch (len) {
- case sizeof(lur):
+ case sizeof(*lur):
DBG("message successfully sent");
return 0;
case -1:
}
static
-int handle_message(int sock, struct lttcomm_ust_msg *lum)
+int handle_register_done(void)
+{
+ int ret;
+
+ ret = sem_post(&constructor_wait);
+ assert(!ret);
+ return 0;
+}
+
+static
+int handle_message(struct sock_info *sock_info,
+ int sock, struct lttcomm_ust_msg *lum)
{
int ret = 0;
+ const struct objd_ops *ops;
+ struct lttcomm_ust_reply lur;
pthread_mutex_lock(<tng_ust_comm_mutex);
+ memset(&lur, 0, sizeof(lur));
+
if (lttng_ust_comm_should_quit) {
- ret = 0;
+ ret = -EPERM;
goto end;
}
- switch (lum->cmd_type) {
- case UST_CREATE_SESSION:
- {
- struct lttcomm_ust_reply lur;
-
- DBG("Handling create session message");
- memset(&lur, 0, sizeof(lur));
- lur.cmd_type = UST_CREATE_SESSION;
- ret = lttng_abi_create_session();
- if (ret >= 0) {
- lur.ret_val = ret;
- lur.ret_code = LTTCOMM_OK;
- } else {
- lur.ret_code = LTTCOMM_SESSION_FAIL;
- }
- ret = send_reply(sock, &lur);
- break;
+ ops = objd_ops(lum->handle);
+ if (!ops) {
+ ret = -ENOENT;
+ goto end;
}
- case UST_RELEASE:
- {
- struct lttcomm_ust_reply lur;
-
- DBG("Handling release message, handle: %d",
- lum->handle);
- memset(&lur, 0, sizeof(lur));
- lur.cmd_type = UST_RELEASE;
- ret = objd_unref(lum->handle);
- if (!ret) {
- lur.ret_code = LTTCOMM_OK;
- } else {
- lur.ret_code = LTTCOMM_ERR;
- }
- ret = send_reply(sock, &lur);
+
+ switch (lum->cmd) {
+ case LTTNG_UST_REGISTER_DONE:
+ if (lum->handle == LTTNG_UST_ROOT_HANDLE)
+ ret = handle_register_done();
+ else
+ ret = -EINVAL;
+ break;
+ case LTTNG_UST_RELEASE:
+ if (lum->handle == LTTNG_UST_ROOT_HANDLE)
+ ret = -EPERM;
+ else
+ ret = objd_unref(lum->handle);
break;
- }
default:
- ERR("Unimplemented command %d", (int) lum->cmd_type);
- ret = -1;
- goto end;
+ if (ops->cmd)
+ ret = ops->cmd(lum->handle, lum->cmd,
+ (unsigned long) &lum->u);
+ else
+ ret = -ENOSYS;
+ break;
}
+
end:
+ lur.handle = lum->handle;
+ lur.cmd = lum->cmd;
+ lur.ret_val = ret;
+ if (ret >= 0) {
+ lur.ret_code = LTTCOMM_OK;
+ } else {
+ lur.ret_code = LTTCOMM_SESSION_FAIL;
+ }
+ ret = send_reply(sock, &lur);
+
pthread_mutex_unlock(<tng_ust_comm_mutex);
return ret;
}
+static
+void cleanup_sock_info(struct sock_info *sock_info)
+{
+ int ret;
+
+ if (sock_info->socket != -1) {
+ ret = close(sock_info->socket);
+ if (ret) {
+ ERR("Error closing local apps socket");
+ }
+ sock_info->socket = -1;
+ }
+ if (sock_info->root_handle != -1) {
+ ret = objd_unref(sock_info->root_handle);
+ if (ret) {
+ ERR("Error unref root handle");
+ }
+ sock_info->root_handle = -1;
+ }
+}
+
/*
* This thread does not allocate any resource, except within
* handle_message, within mutex protection. This mutex protects against
if (sock_info->socket != -1) {
ret = close(sock_info->socket);
if (ret) {
- ERR("Error closing local apps socket");
+ ERR("Error closing %s apps socket", sock_info->name);
}
sock_info->socket = -1;
}
+
/* Check for sessiond availability with pipe TODO */
/* Register */
ret = lttcomm_connect_unix_sock(sock_info->sock_path);
if (ret < 0) {
- ERR("Error connecting to global apps socket");
+ ERR("Error connecting to %s apps socket", sock_info->name);
+ /*
+ * If we cannot find the sessiond daemon, don't delay
+ * constructor execution.
+ */
+ ret = handle_register_done();
+ assert(!ret);
pthread_mutex_unlock(<tng_ust_comm_mutex);
+ sleep(5);
goto restart;
- } else {
- sock_info->socket = sock = ret;
- pthread_mutex_unlock(<tng_ust_comm_mutex);
+ }
+
+ sock_info->socket = sock = ret;
+
+ /*
+ * Create only one root handle per listener thread for the whole
+ * process lifetime.
+ */
+ if (sock_info->root_handle == -1) {
+ ret = lttng_abi_create_root_handle();
+ if (ret) {
+ ERR("Error creating root handle");
+ pthread_mutex_unlock(<tng_ust_comm_mutex);
+ goto quit;
+ }
+ sock_info->root_handle = ret;
}
ret = register_app_to_sessiond(sock);
if (ret < 0) {
- ERR("Error registering app to local apps socket");
+ ERR("Error registering to %s apps socket", sock_info->name);
+ /*
+ * If we cannot register to the sessiond daemon, don't
+ * delay constructor execution.
+ */
+ ret = handle_register_done();
+ assert(!ret);
+ pthread_mutex_unlock(<tng_ust_comm_mutex);
sleep(5);
goto restart;
}
+ pthread_mutex_unlock(<tng_ust_comm_mutex);
+
for (;;) {
ssize_t len;
struct lttcomm_ust_msg lum;
- /* Receive session handle */
len = lttcomm_recv_unix_sock(sock, &lum, sizeof(lum));
switch (len) {
case 0: /* orderly shutdown */
- DBG("ltt-sessiond has performed an orderly shutdown\n");
+ DBG("%s ltt-sessiond has performed an orderly shutdown\n", sock_info->name);
goto end;
case sizeof(lum):
DBG("message received\n");
- ret = handle_message(sock, &lum);
+ ret = handle_message(sock_info, sock, &lum);
if (ret < 0) {
- ERR("Error handling message\n");
+ ERR("Error handling message for %s socket", sock_info->name);
}
continue;
case -1:
if (errno == ECONNRESET) {
- ERR("remote end closed connection\n");
+ ERR("%s remote end closed connection\n", sock_info->name);
goto end;
}
goto end;
default:
- ERR("incorrect message size: %zd\n", len);
+ ERR("incorrect message size (%s socket): %zd\n", sock_info->name, len);
continue;
}
return NULL;
}
+/*
+ * Return values: -1: don't wait. 0: wait forever. 1: timeout wait.
+ */
+static
+int get_timeout(struct timespec *constructor_timeout)
+{
+ long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS;
+ char *str_delay;
+ int ret;
+
+ str_delay = getenv("UST_REGISTER_TIMEOUT");
+ if (str_delay) {
+ constructor_delay_ms = strtol(str_delay, NULL, 10);
+ }
+
+ switch (constructor_delay_ms) {
+ case -1:/* fall-through */
+ case 0:
+ return constructor_delay_ms;
+ default:
+ break;
+ }
+
+ /*
+ * If we are unable to find the current time, don't wait.
+ */
+ ret = clock_gettime(CLOCK_REALTIME, constructor_timeout);
+ if (ret) {
+ return -1;
+ }
+
+ constructor_timeout->tv_nsec =
+ constructor_timeout->tv_nsec + (constructor_delay_ms * 1000000UL);
+ if (constructor_timeout->tv_nsec >= 1000000000UL) {
+ constructor_timeout->tv_sec++;
+ constructor_timeout->tv_nsec -= 1000000000UL;
+ }
+ return 1;
+}
/*
* sessiond monitoring thread: monitor presence of global and per-user
void __attribute__((constructor)) lttng_ust_comm_init(void)
{
+ struct timespec constructor_timeout;
+ int timeout_mode;
int ret;
init_usterr();
+ timeout_mode = get_timeout(&constructor_timeout);
+
+ ret = sem_init(&constructor_wait, 0, 2);
+ assert(!ret);
+
ret = setup_local_apps_socket();
if (ret) {
ERR("Error setting up to local apps socket");
}
-#if 0
+
+ /*
+ * Wait for the pthread cond to let us continue to main program
+ * execution. Hold mutex across thread creation, so we start
+ * waiting for the condition before the threads can signal its
+ * completion.
+ */
+ pthread_mutex_lock(<tng_ust_comm_mutex);
ret = pthread_create(&global_apps.ust_listener, NULL,
ust_listener_thread, &global_apps);
-#endif //0
ret = pthread_create(&local_apps.ust_listener, NULL,
ust_listener_thread, &local_apps);
+
+ switch (timeout_mode) {
+ case 1: /* timeout wait */
+ ret = sem_timedwait(&constructor_wait, &constructor_timeout);
+ if (ret < 0 && errno == ETIMEDOUT) {
+ ERR("Timed out waiting for ltt-sessiond");
+ } else {
+ assert(!ret);
+ }
+ break;
+ case 0: /* wait forever */
+ ret = sem_wait(&constructor_wait);
+ assert(!ret);
+ break;
+ case -1:/* no timeout */
+ break;
+ }
+ pthread_mutex_unlock(<tng_ust_comm_mutex);
}
void __attribute__((destructor)) lttng_ust_comm_exit(void)
ERR("Error cancelling global ust listener thread");
}
#endif //0
- if (global_apps.socket != -1) {
- ret = close(global_apps.socket);
- assert(!ret);
- }
+
+ cleanup_sock_info(&global_apps);
ret = pthread_cancel(local_apps.ust_listener);
if (ret) {
ERR("Error cancelling local ust listener thread");
}
- if (local_apps.socket != -1) {
- ret = close(local_apps.socket);
- assert(!ret);
- }
+ cleanup_sock_info(&local_apps);
lttng_ust_abi_exit();
ltt_events_exit();
projects / lttng-ust.git / blobdiff