Add test for multicore failure

Specifically, make sure that after resuming all cores, and halting core
0, that OpenOCD's poll() doesn't mess up the currently selected hart to
the point where memory accesses intended for core 0 go to core 1.

2 files changed, 40 insertions, 5 deletions

diff --git a/debug/gdbserver.py b/debug/gdbserver.py
index 8104fed..bf27950 100755
--- a/debug/gdbserver.py
+++ b/debug/gdbserver.py
@@ -574,6 +574,34 @@ class MulticoreRunHaltStepiTest(GdbTest):
                 stepped_pc = self.gdb.p("$pc")
                 assertNotEqual(pc, stepped_pc)
 
+class MulticoreRunAllHaltOne(GdbTest):
+    compile_args = ("programs/multicore.c", "-DMULTICORE")
+
+    def early_applicable(self):
+        return len(self.target.harts) > 1
+
+    def setup(self):
+        self.gdb.select_hart(self.target.harts[0])
+        self.gdb.load()
+        for hart in self.target.harts:
+            self.gdb.select_hart(hart)
+            self.gdb.p("$pc=_start")
+
+    def test(self):
+        if not self.gdb.one_hart_per_gdb():
+            return 'not_applicable'
+
+        # Run harts in reverse order
+        for h in reversed(self.target.harts):
+            self.gdb.select_hart(h)
+            self.gdb.c(wait=False)
+
+        self.gdb.interrupt()
+        # Give OpenOCD time to call poll() on both harts, which is what causes
+        # the bug.
+        time.sleep(1)
+        self.gdb.p("buf", fmt="")
+
 class StepTest(GdbTest):
     compile_args = ("programs/step.S", )
 
diff --git a/debug/testlib.py b/debug/testlib.py
index 94ee83e..c6bf59c 100644
--- a/debug/testlib.py
+++ b/debug/testlib.py
@@ -390,12 +390,18 @@ class Gdb(object):
                         hartid = max(self.harts) + 1
                     else:
                         hartid = 0
-                self.harts[hartid] = (child, t)
+                # solo: True iff this is the only thread on this child
+                self.harts[hartid] = {'child': child,
+                        'thread': t,
+                        'solo': len(threads) == 1}
 
     def __del__(self):
         for child in self.children:
             del child
 
+    def one_hart_per_gdb(self):
+        return all(h['solo'] for h in self.harts.itervalues())
+
     def lognames(self):
         return [logfile.name for logfile in self.logfiles]
 
@@ -403,10 +409,11 @@ class Gdb(object):
         self.active_child = child
 
     def select_hart(self, hart):
-        child, thread = self.harts[hart.id]
-        self.select_child(child)
-        output = self.command("thread %s" % thread.id)
-        assert "Unknown" not in output
+        h = self.harts[hart.id]
+        self.select_child(h['child'])
+        if not h['solo']:
+            output = self.command("thread %s" % h['thread'].id, timeout=10)
+            assert "Unknown" not in output
 
     def push_state(self):
         self.stack.append({