gdb/testsuite/

* gdb.python/py-events.exp: Remove pretty printing comment.
	* gdb.python/py-evsignal.exp: New file.
	* gdb.python/py-evthreads.c: Include signal.h.
	(thread3): Remove variable count3.  Remove variable bad and use raise
	instead.
	(thread2): Remove variable count2.  Move thread3 pthread_create here,
	merge pthread_join to a single line.
	(main): Remove variable count1.  Merge pthread_join with pthread_create
	to a single line.
	* gdb.python/py-evthreads.exp: Remove pretty printing comment.  New
	KFAIL python/12966 for gdbserver.  Test return value of
	gdb_compile_pthreads.  Use gdb_run_cmd.  Replace send_gdb and
	gdb_expect by gdb_test and gdb_test_multiple.
	(thread 2, thread 3): New tests.

gdb/testsuite/gdb.python/py-evthreads.c

@@ -19,37 +19,35 @@
 #include <stdio.h>
 #include <pthread.h>
 #include <unistd.h>
+#include <signal.h>
 
 pthread_t thread2_id;
 pthread_t thread3_id;
 
 void* thread3 (void* d)
 {
-  int count3 = 0;
-  count3++;
-
-  int *bad;
-  *bad = 1;
+  raise (SIGUSR1);
 
   return NULL;
 }
 
 void* thread2 (void* d)
 {
-  int count2 = 0;
-  count2++;
+  /* Do not quit thread3 asynchronously wrt thread2 stop - wait first on
+     thread3_id to stop.  It would complicate testcase receiption of the
+     events.  */
+
+  pthread_create (&thread3_id, NULL, thread3, NULL); pthread_join (thread3_id, NULL);
+
   return NULL;
 }
 
-int main (){
+int main (void)
+{
+  /* Use single line to not to race whether `thread2' breakpoint or `next' over
+     pthread_create will stop first.  */
 
-  pthread_create (&thread2_id, NULL, thread2, NULL);
-  pthread_create (&thread3_id, NULL, thread3, NULL);
+  pthread_create (&thread2_id, NULL, thread2, NULL); pthread_join (thread2_id, NULL);
 
-  int count1 = 0; // stop1
-  count1++;
-
-  pthread_join (thread2_id, NULL);
-  pthread_join (thread3_id, NULL);
   return 12;
 }