diff options
| -rw-r--r-- | wsm.go | 28 |
1 files changed, 15 insertions, 13 deletions
@@ -86,6 +86,15 @@ func messageChooseCourse(ctx context.Context, c *websocket.Conn, reportError rep return reportError("nil course") } + thisCourseGroup := course.Group + + if (*userCourseGroups)[thisCourseGroup] { + return reportError("inconsistent user course groups") + /* + * TODO: reportError terminates the connection which is not necessary + */ + } + err = func() (returnedError error) { /* Named returns so I could modify them in defer */ tx, err := db.Begin(ctx) if err != nil { @@ -138,20 +147,13 @@ func messageChooseCourse(ctx context.Context, c *websocket.Conn, reportError rep } return reportError("Database error while committing transaction") } - var thisCourseGroup courseGroupT - func() { - coursesLock.RLock() - defer coursesLock.RUnlock() - thisCourseGroup = courses[courseID].Group - }() - if (*userCourseGroups)[thisCourseGroup] { - err := course.decrementSelectedAndPropagate(ctx, c) - if err != nil { - return fmt.Errorf("error decrementing and notifying: %w", err) - } - return reportError("inconsistent user course groups") - } + + /* + * This would race if message handlers could run + * concurrently for one connection. + */ (*userCourseGroups)[thisCourseGroup] = true + err = writeText(ctx, c, "Y "+mar[1]) if err != nil { return fmt.Errorf("error affirming course choice: %w", err) |