Fix: relayd: tracefile rotation: viewer opening missing index file

[lttng-tools.git] / src / bin / lttng-relayd / tracefile-array.c

diff --git a/src/bin/lttng-relayd/tracefile-array.c b/src/bin/lttng-relayd/tracefile-array.c
index 20b760c06893f2387968f3f773dd2cd846675fa1..3d62317ac76d7a6fbe2d731a9991aa788181db78 100644 (file)
--- a/src/bin/lttng-relayd/tracefile-array.c
+++ b/src/bin/lttng-relayd/tracefile-array.c
@@ -62,7 +62,8 @@ void tracefile_array_destroy(struct tracefile_array *tfa)
        free(tfa);
 }
 
-void tracefile_array_file_rotate(struct tracefile_array *tfa)
+void tracefile_array_file_rotate(struct tracefile_array *tfa,
+               enum tracefile_rotate_type type)
 {
        uint64_t *headp, *tailp;
 
@@ -70,24 +71,37 @@ void tracefile_array_file_rotate(struct tracefile_array *tfa)
                /* Not in tracefile rotation mode. */
                return;
        }
-       /* Rotate to next file.  */
-       tfa->file_head = (tfa->file_head + 1) % tfa->count;
-       if (tfa->file_head == tfa->file_tail) {
-               /* Move tail. */
-               tfa->file_tail = (tfa->file_tail + 1) % tfa->count;
-       }
-       headp = &tfa->tf[tfa->file_head].seq_head;
-       tailp = &tfa->tf[tfa->file_head].seq_tail;
-       /*
-        * If we overwrite a file with content, we need to push the tail
-        * to the position following the content we are overwriting.
-        */
-       if (*headp != -1ULL) {
-               tfa->seq_tail = tfa->tf[tfa->file_tail].seq_tail;
+       switch (type) {
+       case TRACEFILE_ROTATE_READ:
+               /*
+                * Rotate read head to write head position, thus allowing
+                * reader to consume the newly rotated head file.
+                */
+               tfa->file_head_read = tfa->file_head_write;
+               break;
+       case TRACEFILE_ROTATE_WRITE:
+               /* Rotate write head to next file, pushing tail if needed.  */
+               tfa->file_head_write = (tfa->file_head_write + 1) % tfa->count;
+               if (tfa->file_head_write == tfa->file_tail) {
+                       /* Move tail. */
+                       tfa->file_tail = (tfa->file_tail + 1) % tfa->count;
+               }
+               headp = &tfa->tf[tfa->file_head_write].seq_head;
+               tailp = &tfa->tf[tfa->file_head_write].seq_tail;
+               /*
+                * If we overwrite a file with content, we need to push the tail
+                * to the position following the content we are overwriting.
+                */
+               if (*headp != -1ULL) {
+                       tfa->seq_tail = tfa->tf[tfa->file_tail].seq_tail;
+               }
+               /* Reset this file head/tail (overwrite). */
+               *headp = -1ULL;
+               *tailp = -1ULL;
+               break;
+       default:
+               abort();
        }
-       /* Reset this file head/tail (overwrite). */
-       *headp = -1ULL;
-       *tailp = -1ULL;
 }
 
 void tracefile_array_commit_seq(struct tracefile_array *tfa)
@@ -104,8 +118,8 @@ void tracefile_array_commit_seq(struct tracefile_array *tfa)
                /* Not in tracefile rotation mode. */
                return;
        }
-       headp = &tfa->tf[tfa->file_head].seq_head;
-       tailp = &tfa->tf[tfa->file_head].seq_tail;
+       headp = &tfa->tf[tfa->file_head_write].seq_head;
+       tailp = &tfa->tf[tfa->file_head_write].seq_tail;
        /* Update head tracefile seq_head. */
        *headp = tfa->seq_head;
        /*
@@ -117,9 +131,9 @@ void tracefile_array_commit_seq(struct tracefile_array *tfa)
        }
 }
 
-uint64_t tracefile_array_get_file_index_head(struct tracefile_array *tfa)
+uint64_t tracefile_array_get_read_file_index_head(struct tracefile_array *tfa)
 {
-       return tfa->file_head;
+       return tfa->file_head_read;
 }
 
 uint64_t tracefile_array_get_seq_head(struct tracefile_array *tfa)