Workaround thread-unsafeness of cli_echo().

sysdep/unix/log.c

@@ -39,14 +39,21 @@ static const int rate_limit_count = 5;
 #ifdef USE_PTHREADS
 
 #include <pthread.h>
+
 static pthread_mutex_t log_mutex;
 static inline void log_lock(void) { pthread_mutex_lock(&log_mutex); }
 static inline void log_unlock(void) { pthread_mutex_unlock(&log_mutex); }
 
+static pthread_t main_thread;
+void main_thread_init(void) { main_thread = pthread_self(); }
+static int main_thread_self(void) { return pthread_equal(pthread_self(), main_thread); }
+
 #else
 
 static inline void log_lock(void) {  }
 static inline void log_unlock(void) {  }
+void main_thread_init(void) { }
+static int main_thread_self(void) { return 1; }
 
 #endif
 
@@ -128,7 +135,8 @@ log_commit(int class, buffer *buf)
     }
   log_unlock();
 
-  /* FIXME: cli_echo is not thread-safe */
+  /* cli_echo is not thread-safe, so call it just from the main thread */
+  if (main_thread_self())
     cli_echo(class, buf->start);
 
   buf->pos = buf->start;

sysdep/unix/main.c

@@ -797,6 +797,8 @@ main(int argc, char **argv)
       dup2(0, 2);
     }
 
+  main_thread_init();
+
   write_pid_file();
 
   signal_init();

sysdep/unix/unix.h

@@ -67,6 +67,7 @@ void krt_io_init(void);
 
 /* log.c */
 
+void main_thread_init(void);
 void log_init_debug(char *);		/* Initialize debug dump to given file (NULL=stderr, ""=off) */
 void log_switch(int debug, list *l, char *); /* Use l=NULL for initial switch */