Allow command retries in case of process launch failures. This recovery

mechanism seems to work fine on my MacBook Pro in some limited test cases.

The default maxLaunchCount and timeWait variables used in the scheme can be
overridden by the env variables LLDB_MAX_LAUNCH_COUNT and LLDB_TIME_WAIT.

llvm-svn: 112071

lldb/test/lldbtest.py

@@ -107,6 +107,7 @@ $
 
 import os
 import sys
+import time
 import unittest2
 import lldb
 
@@ -150,6 +151,14 @@ class TestBase(unittest2.TestCase):
     # State pertaining to the inferior process, if any.
     runStarted = False
 
+    # Maximum allowed attempts when launching the inferior process.
+    # Can be overridden by the LLDB_MAX_LAUNCH_COUNT environment variable.
+    maxLaunchCount = 3;
+
+    # Time to wait before the next launching attempt in second(s).
+    # Can be overridden by the LLDB_TIME_WAIT environment variable.
+    timeWait = 1.0;
+
     # os.environ["LLDB_COMMAND_TRACE"], if set to "YES", will turn on this flag.
     traceAlways = False;
 
@@ -168,6 +177,12 @@ class TestBase(unittest2.TestCase):
         if ("LLDB_TEST" in os.environ):
             os.chdir(os.path.join(os.environ["LLDB_TEST"], self.mydir));
 
+        if "LLDB_MAX_LAUNCH_COUNT" in os.environ:
+            self.maxLaunchCount = int(os.environ["LLDB_MAX_LAUNCH_COUNT"])
+
+        if "LLDB_TIME_WAIT" in os.environ:
+            self.timeWait = float(os.environ["LLDB_TIME_WAIT"])
+
         if ("LLDB_COMMAND_TRACE" in os.environ and
             os.environ["LLDB_COMMAND_TRACE"] == "YES"):
             self.traceAlways = True
@@ -213,19 +228,25 @@ class TestBase(unittest2.TestCase):
 
         trace = (True if self.traceAlways else trace)
 
-        if trace:
-            print >> sys.stderr, "runCmd:", cmd
+        self.runStarted = (cmd.startswith("run") or
+                           cmd.startswith("process launch"))
 
-        self.ci.HandleCommand(cmd, self.res)
+        for i in range(self.maxLaunchCount if self.runStarted else 1):
+            self.ci.HandleCommand(cmd, self.res)
 
-        if cmd.startswith("run"):
-            self.runStarted = True
+            if trace:
+                print >> sys.stderr, "runCmd:", cmd
+                if self.res.Succeeded():
+                    print >> sys.stderr, "output:", self.res.GetOutput()
+                else:
+                    print >> sys.stderr, self.res.GetError()
 
-        if trace:
             if self.res.Succeeded():
-                print >> sys.stderr, "output:", self.res.GetOutput()
+                break
             else:
-                print >> sys.stderr, self.res.GetError()
+                if self.runStarted:
+                    # Process launch failed, wait some time before the next try.
+                    time.sleep(self.timeWait)
 
         if check:
             self.assertTrue(self.res.Succeeded(),