lib: unstupidify thread debug information

the library's thread scheduling functions keep track of the thread
function's name, so far so good.  However, copying the compiler-provided
constant into a buffer inside the thread structure is plain useless.
Also, strip_funcname() was trying to support something that never
happens.

Instead, let's use some bytes here to track where threads are scheduled
from.  Another commit will print that information on crashes.

Ripping out useless stuff:  -64 bytes in the thread structure
Re-add as const ptr:         +8 bytes
Extra debug info:           +12 bytes

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
(cherry picked from commit 3493b7731b750cbc62f00be94b624a08ccccf0b2)

1 files changed, 36 insertions, 49 deletions

diff --git a/lib/thread.c b/lib/thread.c
index ca54a44563..b666219ceb 100644
--- a/lib/thread.c
+++ b/lib/thread.c
@@ -264,7 +264,7 @@ cpu_record_hash_alloc (struct cpu_thread_history *a)
   struct cpu_thread_history *new;
   new = XCALLOC (MTYPE_THREAD_STATS, sizeof (struct cpu_thread_history));
   new->func = a->func;
-  strcpy(new->funcname, a->funcname);
+  new->funcname = a->funcname;
   return new;
 }
 
@@ -330,7 +330,7 @@ cpu_record_print(struct vty *vty, thread_type filter)
   void *args[3] = {&tmp, vty, &filter};
 
   memset(&tmp, 0, sizeof tmp);
-  strcpy(tmp.funcname, "TOTAL");
+  tmp.funcname = "TOTAL";
   tmp.types = filter;
 
 #ifdef HAVE_RUSAGE
@@ -634,7 +634,6 @@ thread_add_unuse (struct thread_master *m, struct thread *thread)
   assert (thread->prev == NULL);
   assert (thread->type == THREAD_UNUSED);
   thread_list_add (&m->unuse, thread);
-  /* XXX: Should we deallocate funcname here? */
 }
 
 /* Free all unused thread. */
@@ -739,30 +738,8 @@ thread_timer_remain_second (struct thread *thread)
     return 0;
 }
 
-/* Trim blankspace and "()"s */
-static void
-strip_funcname (char *dest, const char *funcname)
-{
-  char buff[FUNCNAME_LEN];
-  char tmp, *e, *b = buff;
-
-  strncpy(buff, funcname, sizeof(buff));
-  buff[ sizeof(buff) -1] = '\0';
-  e = buff +strlen(buff) -1;
-
-  /* Wont work for funcname ==  "Word (explanation)"  */
-
-  while (*b == ' ' || *b == '(')
-    ++b;
-  while (*e == ' ' || *e == ')')
-    --e;
-  e++;
-
-  tmp = *e;
-  *e = '\0';
-  strcpy (dest, b);
-  *e = tmp;
-}
+#define debugargdef  const char *funcname, const char *schedfrom, int fromln
+#define debugargpass funcname, schedfrom, fromln
 
 struct timeval
 thread_timer_remain(struct thread *thread)
@@ -775,7 +752,7 @@ thread_timer_remain(struct thread *thread)
 /* Get new thread.  */
 static struct thread *
 thread_get (struct thread_master *m, u_char type,
-	    int (*func) (struct thread *), void *arg, const char* funcname)
+	    int (*func) (struct thread *), void *arg, debugargdef)
 {
   struct thread *thread = thread_trim_head (&m->unuse);
 
@@ -792,7 +769,9 @@ thread_get (struct thread_master *m, u_char type,
   thread->index = -1;
   thread->yield = THREAD_YIELD_TIME_SLOT; /* default */
 
-  strip_funcname (thread->funcname, funcname);
+  thread->funcname = funcname;
+  thread->schedfrom = schedfrom;
+  thread->schedfrom_line = fromln;
 
   return thread;
 }
@@ -804,7 +783,7 @@ thread_get (struct thread_master *m, u_char type,
 /* generic add thread function */
 static struct thread *
 generic_thread_add(struct thread_master *m, int (*func) (struct thread *),
-                  void *arg, int fd, const char* funcname, int dir)
+		   void *arg, int fd, int dir, debugargdef)
 {
   struct thread *thread;
 
@@ -834,7 +813,7 @@ generic_thread_add(struct thread_master *m, int (*func) (struct thread *),
   /* is there enough space for a new fd? */
   assert (queuepos < m->handler.pfdsize);
 
-  thread = thread_get (m, type, func, arg, funcname);
+  thread = thread_get (m, type, func, arg, funcname, debugargpass);
   m->handler.pfds[queuepos].fd = fd;
   m->handler.pfds[queuepos].events |= event;
   if (queuepos == m->handler.pfdcount)
@@ -899,7 +878,8 @@ fd_clear_read_write (struct thread *thread)
 /* Add new read thread. */
 struct thread *
 funcname_thread_add_read_write (int dir, struct thread_master *m,
-				int (*func) (struct thread *), void *arg, int fd, const char* funcname)
+				int (*func) (struct thread *), void *arg, int fd,
+				debugargdef)
 {
   struct thread *thread = NULL;
 
@@ -912,7 +892,7 @@ funcname_thread_add_read_write (int dir, struct thread_master *m,
 #endif
 
 #if defined (HAVE_POLL)
-  thread = generic_thread_add(m, func, arg, fd, funcname, dir);
+  thread = generic_thread_add(m, func, arg, fd, dir, debugargpass);
 
   if (thread == NULL)
     return NULL;
@@ -924,7 +904,7 @@ funcname_thread_add_read_write (int dir, struct thread_master *m,
     }
 
   FD_SET (fd, fdset);
-  thread = thread_get (m, dir, func, arg, funcname);
+  thread = thread_get (m, dir, func, arg, debugargpass);
 #endif
 
   thread->u.fd = fd;
@@ -941,8 +921,8 @@ funcname_thread_add_timer_timeval (struct thread_master *m,
                                    int (*func) (struct thread *), 
                                   int type,
                                   void *arg, 
-                                  struct timeval *time_relative, 
-                                  const char* funcname)
+                                  struct timeval *time_relative,
+				  debugargdef)
 {
   struct thread *thread;
   struct pqueue *queue;
@@ -954,7 +934,7 @@ funcname_thread_add_timer_timeval (struct thread_master *m,
   assert (time_relative);
   
   queue = ((type == THREAD_TIMER) ? m->timer : m->background);
-  thread = thread_get (m, type, func, arg, funcname);
+  thread = thread_get (m, type, func, arg, debugargpass);
 
   /* Do we need jitter here? */
   quagga_get_relative (NULL);
@@ -971,7 +951,8 @@ funcname_thread_add_timer_timeval (struct thread_master *m,
 struct thread *
 funcname_thread_add_timer (struct thread_master *m,
 		           int (*func) (struct thread *), 
-		           void *arg, long timer, const char* funcname)
+		           void *arg, long timer,
+			   debugargdef)
 {
   struct timeval trel;
 
@@ -981,14 +962,15 @@ funcname_thread_add_timer (struct thread_master *m,
   trel.tv_usec = 0;
 
   return funcname_thread_add_timer_timeval (m, func, THREAD_TIMER, arg, 
-                                            &trel, funcname);
+                                            &trel, debugargpass);
 }
 
 /* Add timer event thread with "millisecond" resolution */
 struct thread *
 funcname_thread_add_timer_msec (struct thread_master *m,
                                 int (*func) (struct thread *), 
-                                void *arg, long timer, const char* funcname)
+                                void *arg, long timer,
+				debugargdef)
 {
   struct timeval trel;
 
@@ -998,15 +980,15 @@ funcname_thread_add_timer_msec (struct thread_master *m,
   trel.tv_usec = 1000*(timer % 1000);
 
   return funcname_thread_add_timer_timeval (m, func, THREAD_TIMER, 
-                                            arg, &trel, funcname);
+                                            arg, &trel, debugargpass);
 }
 
 /* Add a background thread, with an optional millisec delay */
 struct thread *
 funcname_thread_add_background (struct thread_master *m,
                                 int (*func) (struct thread *),
-                                void *arg, long delay, 
-                                const char *funcname)
+                                void *arg, long delay,
+				debugargdef)
 {
   struct timeval trel;
   
@@ -1024,19 +1006,20 @@ funcname_thread_add_background (struct thread_master *m,
     }
 
   return funcname_thread_add_timer_timeval (m, func, THREAD_BACKGROUND,
-                                            arg, &trel, funcname);
+                                            arg, &trel, debugargpass);
 }
 
 /* Add simple event thread. */
 struct thread *
 funcname_thread_add_event (struct thread_master *m,
-		  int (*func) (struct thread *), void *arg, int val, const char* funcname)
+		  int (*func) (struct thread *), void *arg, int val,
+		  debugargdef)
 {
   struct thread *thread;
 
   assert (m != NULL);
 
-  thread = thread_get (m, THREAD_EVENT, func, arg, funcname);
+  thread = thread_get (m, THREAD_EVENT, func, arg, debugargpass);
   thread->u.val = val;
   thread_list_add (&m->event, thread);
 
@@ -1563,7 +1546,7 @@ thread_call (struct thread *thread)
       struct cpu_thread_history tmp;
       
       tmp.func = thread->func;
-      strcpy(tmp.funcname, thread->funcname);
+      tmp.funcname = thread->funcname;
       
       thread->hist = hash_get (cpu_record, &tmp, 
                     (void * (*) (void *))cpu_record_hash_alloc);
@@ -1611,7 +1594,7 @@ funcname_thread_execute (struct thread_master *m,
                 int (*func)(struct thread *), 
                 void *arg,
                 int val,
-		const char* funcname)
+		debugargdef)
 {
   struct thread dummy; 
 
@@ -1623,7 +1606,11 @@ funcname_thread_execute (struct thread_master *m,
   dummy.func = func;
   dummy.arg = arg;
   dummy.u.val = val;
-  strip_funcname (dummy.funcname, funcname);
+
+  dummy.funcname = funcname;
+  dummy.schedfrom = schedfrom;
+  dummy.schedfrom_line = fromln;
+
   thread_call (&dummy);
 
   return NULL;