Save/load: pid_tracker feature.

[lttng-tools.git] / src / bin / lttng-sessiond / save.c

diff --git a/src/bin/lttng-sessiond/save.c b/src/bin/lttng-sessiond/save.c
index d6316ef971145211afcf74cee0bc2d7527c5e19c..0a1393a4bd90267bb9d5d041af3f6b40e007595b 100644 (file)
--- a/src/bin/lttng-sessiond/save.c
+++ b/src/bin/lttng-sessiond/save.c
@@ -30,6 +30,7 @@
 #include <common/runas.h>
 #include <lttng/save-internal.h>
 
+#include "kernel.h"
 #include "save.h"
 #include "session.h"
 #include "syscall.h"
@@ -722,8 +723,6 @@ end:
        return ret;
 }
 
-/* TODO: save/restore tracker pid */
-
 static
 int save_kernel_context(struct config_writer *writer,
        struct lttng_kernel_context *ctx)
@@ -1192,6 +1191,99 @@ end:
        return ret;
 }
 
+static
+int save_pid_tracker(struct config_writer *writer,
+       struct ltt_session *sess, int domain)
+{
+       int ret = 0;
+       ssize_t nr_pids = 0, i;
+       int32_t *pids = NULL;
+
+       switch (domain) {
+       case LTTNG_DOMAIN_KERNEL:
+       {
+               nr_pids = kernel_list_tracker_pids(sess->kernel_session, &pids);
+               if (nr_pids < 0) {
+                       ret = LTTNG_ERR_KERN_LIST_FAIL;
+                       goto end;
+               }
+               break;
+       }
+       case LTTNG_DOMAIN_UST:
+       {
+               nr_pids = trace_ust_list_tracker_pids(sess->ust_session, &pids);
+               if (nr_pids < 0) {
+                       ret = LTTNG_ERR_UST_LIST_FAIL;
+                       goto end;
+               }
+               break;
+       }
+       case LTTNG_DOMAIN_JUL:
+       case LTTNG_DOMAIN_LOG4J:
+       case LTTNG_DOMAIN_PYTHON:
+       default:
+               ret = LTTNG_ERR_UNKNOWN_DOMAIN;
+               goto end;
+       }
+
+       /* Only create a pid_tracker if enabled or untrack all */
+       if (nr_pids != 1 || (nr_pids == 1 && pids[0] != -1)) {
+               ret = config_writer_open_element(writer,
+                               config_element_pid_tracker);
+               if (ret) {
+                       ret = LTTNG_ERR_SAVE_IO_FAIL;
+                       goto end;
+               }
+
+               ret = config_writer_open_element(writer,
+                               config_element_targets);
+               if (ret) {
+                       ret = LTTNG_ERR_SAVE_IO_FAIL;
+                       goto end;
+               }
+
+               for (i = 0; i < nr_pids; i++) {
+                       ret = config_writer_open_element(writer,
+                                       config_element_target_pid);
+                       if (ret) {
+                               ret = LTTNG_ERR_SAVE_IO_FAIL;
+                               goto end;
+                       }
+
+                       ret = config_writer_write_element_unsigned_int(writer,
+                                       config_element_pid, pids[i]);
+                       if (ret) {
+                               ret = LTTNG_ERR_SAVE_IO_FAIL;
+                               goto end;
+                       }
+
+                       /* /pid_target */
+                       ret = config_writer_close_element(writer);
+                       if (ret) {
+                               ret = LTTNG_ERR_SAVE_IO_FAIL;
+                               goto end;
+                       }
+               }
+
+               /* /targets */
+               ret = config_writer_close_element(writer);
+               if (ret) {
+                       ret = LTTNG_ERR_SAVE_IO_FAIL;
+                       goto end;
+               }
+
+               /* /pid_tracker */
+               ret = config_writer_close_element(writer);
+               if (ret) {
+                       ret = LTTNG_ERR_SAVE_IO_FAIL;
+                       goto end;
+               }
+       }
+end:
+       free(pids);
+       return ret;
+}
+
 static
 int save_domains(struct config_writer *writer, struct ltt_session *session)
 {
@@ -1224,6 +1316,24 @@ int save_domains(struct config_writer *writer, struct ltt_session *session)
                        goto end;
                }
 
+               ret = config_writer_open_element(writer,
+                       config_element_trackers);
+               if (ret) {
+                       ret = LTTNG_ERR_SAVE_IO_FAIL;
+                       goto end;
+               }
+
+               ret = save_pid_tracker(writer, session, LTTNG_DOMAIN_KERNEL);
+               if (ret) {
+                       goto end;
+               }
+
+               /* /trackers */
+               ret = config_writer_close_element(writer);
+               if (ret) {
+                       ret = LTTNG_ERR_SAVE_IO_FAIL;
+                       goto end;
+               }
                /* /domain */
                ret = config_writer_close_element(writer);
                if (ret) {
@@ -1247,6 +1357,24 @@ int save_domains(struct config_writer *writer, struct ltt_session *session)
                        goto end;
                }
 
+               ret = config_writer_open_element(writer,
+                       config_element_trackers);
+               if (ret) {
+                       ret = LTTNG_ERR_SAVE_IO_FAIL;
+                       goto end;
+               }
+
+               ret = save_pid_tracker(writer, session, LTTNG_DOMAIN_UST);
+               if (ret) {
+                       goto end;
+               }
+
+               /* /trackers */
+               ret = config_writer_close_element(writer);
+               if (ret) {
+                       ret = LTTNG_ERR_SAVE_IO_FAIL;
+                       goto end;
+               }
                /* /domain */
                ret = config_writer_close_element(writer);
                if (ret) {