From: Francis Deslauriers <francis.deslauriers@efficios.com>
Date: Mon, 12 Jun 2017 16:13:23 +0000 (-0400)
Subject: Tests: rework select_poll_epoll test to improve verbosity on failure
X-Git-Tag: v2.11.0-rc1~498
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=4c4634e336d05a3078a685de72df22b9edf5f429;p=lttng-tools.git

Tests: rework select_poll_epoll test to improve verbosity on failure

Prints the tested values that caused a test failure to ease the
troubleshooting of unreliable tests.
Also, clean-up unused variables in multiple testcases.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/tests/regression/kernel/validate_select_poll_epoll.py b/tests/regression/kernel/validate_select_poll_epoll.py
index 613cec3ab..e4d0ebaf2 100755
--- a/tests/regression/kernel/validate_select_poll_epoll.py
+++ b/tests/regression/kernel/validate_select_poll_epoll.py
@@ -1,8 +1,11 @@
 #!/usr/bin/env python3
 
+import argparse
+import pprint
 import sys
 import time
-import argparse
+
+from collections import defaultdict
 
 NSEC_PER_SEC = 1000000000
 
@@ -19,7 +22,22 @@ class TraceParser:
     def __init__(self, trace, pid):
         self.trace = trace
         self.pid = pid
-        self.expect = {}
+
+        # This dictionnary holds the results of each testcases of a test.
+        # Its layout is the following:
+        #       self.expect={
+        #                       'event_name_1': {'check_1': 0, 'check_2: 1},
+        #                       'event_name_2': {'check_1': 1}
+        #                   }
+        # Each test classes checks the payload of different events. Each of
+        # those checks are stored in a event_name specific dictionnary in this
+        # data structure.
+        self.expect = defaultdict(lambda : defaultdict(int))
+
+        # This dictionnary holds the value recorded in the trace that are
+        # tested. Its content is use to print the values that caused a test to
+        # fail.
+        self.recorded_values = {}
 
     def ns_to_hour_nsec(self, ns):
         d = time.localtime(ns/NSEC_PER_SEC)
@@ -40,10 +58,15 @@ class TraceParser:
                 func(self, event)
 
         ret = 0
-        for i in self.expect.keys():
-            if self.expect[i] == 0:
-                print("%s not validated" % i)
-                ret = 1
+        # For each event of the test case, check all entries for failed
+        for event_name, event_results in self.expect.items():
+            for val in event_results.keys():
+                if self.expect[event_name][val] == 0:
+                    print("%s not validated" % val)
+                    print("Values of the local variables of this test:")
+                    # using pprint for pretty printing the dictionnary
+                    pprint.pprint(self.recorded_values[event_name])
+                    ret = 1
 
         return ret
 
@@ -194,94 +217,94 @@ class TraceParser:
 class Test1(TraceParser):
     def __init__(self, trace, pid):
         super().__init__(trace, pid)
-        self.expect["select_in_fd0"] = 0
-        self.expect["select_in_fd1023"] = 0
-        self.expect["select_out_fd0"] = 0
-        self.expect["select_out_fd1023"] = 0
-        self.expect["poll_in_nfds1"] = 0
-        self.expect["poll_out_nfds1"] = 0
-        self.expect["epoll_ctl_in_add"] = 0
-        self.expect["epoll_ctl_out_ok"] = 0
-        self.expect["epoll_wait_in_ok"] = 0
-        self.expect["epoll_wait_out_fd0"] = 0
+        self.expect["select_entry"]["select_in_fd0"] = 0
+        self.expect["select_entry"]["select_in_fd1023"] = 0
+        self.expect["select_exit"]["select_out_fd0"] = 0
+        self.expect["select_exit"]["select_out_fd1023"] = 0
+        self.expect["poll_entry"]["poll_in_nfds1"] = 0
+        self.expect["poll_exit"]["poll_out_nfds1"] = 0
+        self.expect["epoll_ctl_entry"]["epoll_ctl_in_add"] = 0
+        self.expect["epoll_ctl_exit"]["epoll_ctl_out_ok"] = 0
+        self.expect["epoll_wait_entry"]["epoll_wait_in_ok"] = 0
+        self.expect["epoll_wait_exit"]["epoll_wait_out_fd0"] = 0
 
     def select_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         n = event["n"]
         overflow = event["overflow"]
-        tvp = event["tvp"]
-        _readfds_length = event["_readfds_length"]
-        readfds = event["readfds"]
-        _writefds_length = event["_writefds_length"]
-        writefds = event["writefds"]
-        _exceptfds_length = event["_exceptfds_length"]
-        exceptfds = event["exceptfds"]
+        readfd_0 = event["readfds"][0]
 
         # check that the FD 0 is actually set in the readfds
-        if n == 1 and readfds[0] == 1:
-            self.expect["select_in_fd0"] = 1
+        if n == 1 and readfd_0 == 1:
+            self.expect["select_entry"]["select_in_fd0"] = 1
         if n == 1023:
+            readfd_127 = event["readfds"][127]
+            writefd_127 = event["writefds"][127]
+            exceptfd_127 = event["exceptfds"][127]
+
             # check that the FD 1023 is actually set in the readfds
-            if readfds[127] == 0x40 and writefds[127] == 0 and \
-                    exceptfds[127] == 0 and overflow == 0:
-                self.expect["select_in_fd1023"] = 1
+            if readfd_127 == 0x40 and writefd_127 == 0 and \
+                    exceptfd_127 == 0 and overflow == 0:
+                self.expect["select_entry"]["select_in_fd1023"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["select_entry"] = locals()
 
     def select_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
-        overflow = event["overflow"]
         tvp = event["tvp"]
+        overflow = event["overflow"]
         _readfds_length = event["_readfds_length"]
-        readfds = event["readfds"]
-        _writefds_length = event["_writefds_length"]
-        writefds = event["writefds"]
-        _exceptfds_length = event["_exceptfds_length"]
-        exceptfds = event["exceptfds"]
 
         if ret == 1:
             # check that the FD 0 is actually set in the readfds
-            if readfds[0] == 1:
-                self.expect["select_out_fd0"] = 1
+            readfd_0 = event["readfds"][0]
+
+            if readfd_0 == 1:
+                self.expect["select_exit"]["select_out_fd0"] = 1
             # check that the FD 1023 is actually set in the readfds
-            if _readfds_length == 128 and readfds[127] == 0x40 and \
-                    writefds[127] == 0 and exceptfds[127] == 0 and tvp == 0:
-                self.expect["select_out_fd1023"] = 1
+            if _readfds_length == 128:
+                readfd_127 = event["readfds"][127]
+                writefd_127 = event["writefds"][127]
+                exceptfd_127 = event["exceptfds"][127]
+                if readfd_127 == 0x40 and writefd_127 == 0 and \
+                        exceptfd_127 == 0 and tvp == 0:
+                    self.expect["select_exit"]["select_out_fd1023"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["select_exit"] = locals()
 
     def poll_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         nfds = event["nfds"]
         fds_length = event["fds_length"]
         overflow = event["overflow"]
-        fds = event["fds"]
 
         # check that only one FD is set, that it has the POLLIN flag and that
         # the raw value matches the events bit field.
-        if nfds == 1 and fds_length == 1 and fds[0]["raw_events"] == 0x3 \
-                and fds[0]["events"]["POLLIN"] == 1 and \
-                fds[0]["events"]["padding"] == 0:
-            self.expect["poll_in_nfds1"] = 1
+        if nfds == 1 and fds_length == 1:
+            fd_0 = event["fds"][0]
+            if fd_0["raw_events"] == 0x3 and fd_0["events"]["POLLIN"] == 1 and \
+                    fd_0["events"]["padding"] == 0:
+                self.expect["poll_entry"]["poll_in_nfds1"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["poll_entry"] = locals()
 
     def poll_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
-        nfds = event["nfds"]
         fds_length = event["fds_length"]
-        fds = event["fds"]
 
         # check that only one FD is set, that it has the POLLIN flag and that
         # the raw value matches the events bit field.
-        if ret == 1 and fds_length == 1 and fds[0]["raw_events"] == 0x1 \
-                and fds[0]["events"]["POLLIN"] == 1 and \
-                fds[0]["events"]["padding"] == 0:
-            self.expect["poll_out_nfds1"] = 1
+        if ret == 1 and fds_length == 1:
+            fd_0 = event["fds"][0]
+            if fd_0["raw_events"] == 0x1 and fd_0["events"]["POLLIN"] == 1 and \
+                fd_0["events"]["padding"] == 0:
+                self.expect["poll_exit"]["poll_out_nfds1"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["poll_exit"] = locals()
 
     def epoll_ctl_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         epfd = event["epfd"]
         op_enum = event["op_enum"]
         fd = event["fd"]
@@ -293,358 +316,333 @@ class Test1(TraceParser):
                 _event["data_union"]["fd"] == 0 and \
                 _event["events"]["EPOLLIN"] == 1 and \
                 _event["events"]["EPOLLPRI"] == 1:
-            self.expect["epoll_ctl_in_add"] = 1
+            self.expect["epoll_ctl_entry"]["epoll_ctl_in_add"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["epoll_ctl_entry"] = locals()
 
     def epoll_ctl_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
 
         if ret == 0:
-            self.expect["epoll_ctl_out_ok"] = 1
+            self.expect["epoll_ctl_exit"]["epoll_ctl_out_ok"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["epoll_ctl_exit"] = locals()
 
     def epoll_wait_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         epfd = event["epfd"]
         maxevents = event["maxevents"]
         timeout = event["timeout"]
 
         if epfd == 3 and maxevents == 1 and timeout == -1:
-            self.expect["epoll_wait_in_ok"] = 1
+            self.expect["epoll_wait_entry"]["epoll_wait_in_ok"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["epoll_wait_entry"] = locals()
 
     def epoll_wait_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
         fds_length = event["fds_length"]
         overflow = event["overflow"]
-        fds = event["fds"]
 
         # check that FD 0 returned with EPOLLIN and the right data.fd
-        if ret == 1 and fds_length == 1 and overflow == 0 and \
-                fds[0]["data_union"]["fd"] == 0 and \
-                fds[0]["events"]["EPOLLIN"] == 1:
-            self.expect["epoll_wait_out_fd0"] = 1
+        if ret == 1 and fds_length == 1:
+            fd_0 = event["fds"][0]
+            if overflow == 0 and  fd_0["data_union"]["fd"] == 0 and \
+                fd_0["events"]["EPOLLIN"] == 1:
+                self.expect["epoll_wait_exit"]["epoll_wait_out_fd0"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["epoll_wait_exit"] = locals()
 
 
 class Test2(TraceParser):
     def __init__(self, trace, pid):
         super().__init__(trace, pid)
-        self.expect["select_timeout_in_fd0"] = 0
-        self.expect["select_timeout_in_fd1023"] = 0
-        self.expect["select_timeout_out"] = 0
-        self.expect["poll_timeout_in"] = 0
-        self.expect["poll_timeout_out"] = 0
-        self.expect["epoll_ctl_timeout_in_add"] = 0
-        self.expect["epoll_ctl_timeout_out_ok"] = 0
-        self.expect["epoll_wait_timeout_in"] = 0
-        self.expect["epoll_wait_timeout_out"] = 0
+        self.expect["select_entry"]["select_timeout_in_fd0"] = 0
+        self.expect["select_entry"]["select_timeout_in_fd1023"] = 0
+        self.expect["select_exit"]["select_timeout_out"] = 0
+        self.expect["poll_entry"]["poll_timeout_in"] = 0
+        self.expect["poll_exit"]["poll_timeout_out"] = 0
+        self.expect["epoll_ctl_entry"]["epoll_ctl_timeout_in_add"] = 0
+        self.expect["epoll_ctl_exit"]["epoll_ctl_timeout_out_ok"] = 0
+        self.expect["epoll_wait_entry"]["epoll_wait_timeout_in"] = 0
+        self.expect["epoll_wait_exit"]["epoll_wait_timeout_out"] = 0
 
     def select_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         n = event["n"]
-        overflow = event["overflow"]
         tvp = event["tvp"]
-        _readfds_length = event["_readfds_length"]
-        readfds = event["readfds"]
-        _writefds_length = event["_writefds_length"]
-        writefds = event["writefds"]
-        _exceptfds_length = event["_exceptfds_length"]
-        exceptfds = event["exceptfds"]
 
         if n == 1 and tvp != 0:
-            self.expect["select_timeout_in_fd0"] = 1
+            self.expect["select_entry"]["select_timeout_in_fd0"] = 1
         if n == 1023:
-            if readfds[127] == 0x40 and writefds[127] == 0 and \
-                    exceptfds[127] == 0 and tvp != 0:
-                self.expect["select_timeout_in_fd1023"] = 1
+            readfd_127 = event["readfds"][127]
+            writefd_127 = event["writefds"][127]
+            exceptfd_127 = event["exceptfds"][127]
+
+            if readfd_127 == 0x40 and writefd_127 == 0 and \
+                    exceptfd_127 == 0 and tvp != 0:
+                self.expect["select_entry"]["select_timeout_in_fd1023"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["select_entry"] = locals()
 
     def select_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
-        overflow = event["overflow"]
         tvp = event["tvp"]
-        _readfds_length = event["_readfds_length"]
-        readfds = event["readfds"]
-        _writefds_length = event["_writefds_length"]
-        writefds = event["writefds"]
-        _exceptfds_length = event["_exceptfds_length"]
-        exceptfds = event["exceptfds"]
 
         if ret == 0 and tvp != 0:
-            self.expect["select_timeout_out"] = 1
+            self.expect["select_exit"]["select_timeout_out"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["select_exit"] = locals()
 
     def poll_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         nfds = event["nfds"]
         fds_length = event["fds_length"]
-        overflow = event["overflow"]
-        fds = event["fds"]
 
         # check that we wait on FD 0 for POLLIN and that the raw_events
         # field matches the value of POLLIN
-        if nfds == 1 and fds_length == 1 and fds[0]["raw_events"] == 0x3 \
-                and fds[0]["events"]["POLLIN"] == 1 and \
-                fds[0]["events"]["padding"] == 0:
-            self.expect["poll_timeout_in"] = 1
+        if nfds == 1 and fds_length == 1:
+            fd_0 = event["fds"][0]
+            if fd_0["raw_events"] == 0x3 and \
+                    fd_0["events"]["POLLIN"] == 1 and \
+                    fd_0["events"]["padding"] == 0:
+                self.expect["poll_entry"]["poll_timeout_in"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["poll_entry"] = locals()
 
     def poll_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
         nfds = event["nfds"]
         fds_length = event["fds_length"]
-        fds = event["fds"]
 
         if ret == 0 and nfds == 1 and fds_length == 0:
-            self.expect["poll_timeout_out"] = 1
+            self.expect["poll_exit"]["poll_timeout_out"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["poll_exit"] = locals()
 
     def epoll_ctl_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
-        epfd = event["epfd"]
         op_enum = event["op_enum"]
-        fd = event["fd"]
         _event = event["event"]
 
         # make sure we see a EPOLLIN|EPOLLPRI
         if op_enum == "EPOLL_CTL_ADD" and \
                 _event["events"]["EPOLLIN"] == 1 and \
                 _event["events"]["EPOLLPRI"] == 1:
-            self.expect["epoll_ctl_timeout_in_add"] = 1
+            self.expect["epoll_ctl_entry"]["epoll_ctl_timeout_in_add"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["epoll_ctl_entry"] = locals()
 
     def epoll_ctl_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
 
         if ret == 0:
-            self.expect["epoll_ctl_timeout_out_ok"] = 1
+            self.expect["epoll_ctl_exit"]["epoll_ctl_timeout_out_ok"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["epoll_ctl_exit"] = locals()
 
     def epoll_wait_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
-        epfd = event["epfd"]
         maxevents = event["maxevents"]
         timeout = event["timeout"]
 
         if maxevents == 1 and timeout == 1:
-            self.expect["epoll_wait_timeout_in"] = 1
+            self.expect["epoll_wait_entry"]["epoll_wait_timeout_in"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["epoll_wait_entry"] = locals()
 
     def epoll_wait_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
         fds_length = event["fds_length"]
         overflow = event["overflow"]
-        fds = event["fds"]
 
         if ret == 0 and fds_length == 0 and overflow == 0:
-            self.expect["epoll_wait_timeout_out"] = 1
+            self.expect["epoll_wait_exit"]["epoll_wait_timeout_out"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["epoll_wait_exit"] = locals()
 
 
 class Test3(TraceParser):
     def __init__(self, trace, pid):
         super().__init__(trace, pid)
-        self.expect["select_invalid_fd_in"] = 0
-        self.expect["select_invalid_fd_out"] = 0
+        self.expect["select_entry"]["select_invalid_fd_in"] = 0
+        self.expect["select_exit"]["select_invalid_fd_out"] = 0
 
     def select_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         n = event["n"]
         overflow = event["overflow"]
-        tvp = event["tvp"]
-        _readfds_length = event["_readfds_length"]
-        readfds = event["readfds"]
-        _writefds_length = event["_writefds_length"]
-        writefds = event["writefds"]
-        _exceptfds_length = event["_exceptfds_length"]
-        exceptfds = event["exceptfds"]
 
         if n > 0 and overflow == 0:
-            self.expect["select_invalid_fd_in"] = 1
+            self.expect["select_entry"]["select_invalid_fd_in"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["select_entry"] = locals()
 
     def select_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
         overflow = event["overflow"]
-        tvp = event["tvp"]
         _readfds_length = event["_readfds_length"]
-        readfds = event["readfds"]
-        _writefds_length = event["_writefds_length"]
-        writefds = event["writefds"]
-        _exceptfds_length = event["_exceptfds_length"]
-        exceptfds = event["exceptfds"]
 
         # make sure the event has a ret field equal to -EBADF
         if ret == -9 and overflow == 0 and _readfds_length == 0:
-            self.expect["select_invalid_fd_out"] = 1
+            self.expect["select_exit"]["select_invalid_fd_out"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["select_exit"] = locals()
 
 
 class Test4(TraceParser):
     def __init__(self, trace, pid):
         super().__init__(trace, pid)
-        self.expect["big_poll_in"] = 0
-        self.expect["big_poll_out"] = 0
+        self.expect["poll_entry"]["big_poll_in"] = 0
+        self.expect["poll_exit"]["big_poll_out"] = 0
 
     def poll_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         nfds = event["nfds"]
         fds_length = event["fds_length"]
         overflow = event["overflow"]
-        fds = event["fds"]
 
         # test of big list of FDs and the behaviour of the overflow
-        if nfds == 2047 and fds_length == 512 and overflow == 1 and \
-                fds[0]["raw_events"] == 0x3 \
-                and fds[0]["events"]["POLLIN"] == 1 and \
-                fds[0]["events"]["padding"] == 0 and \
-                fds[511]["events"]["POLLIN"] == 1 and \
-                fds[511]["events"]["POLLPRI"] == 1:
-            self.expect["big_poll_in"] = 1
+        if nfds == 2047 and fds_length == 512 and overflow == 1:
+            fd_0 = event["fds"][0]
+            fd_511 = event["fds"][511]
+            if fd_0["raw_events"] == 0x3 and fd_0["events"]["POLLIN"] == 1 and \
+                    fd_0["events"]["padding"] == 0 and \
+                    fd_511["events"]["POLLIN"] == 1 and \
+                    fd_511["events"]["POLLPRI"] == 1:
+                self.expect["poll_entry"]["big_poll_in"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["poll_entry"] = locals()
 
     def poll_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
         nfds = event["nfds"]
         fds_length = event["fds_length"]
         overflow = event["overflow"]
-        fds = event["fds"]
 
         # test of big list of FDs and the behaviour of the overflow
-        if ret == 2047 and nfds == 2047 and fds_length == 512 and \
-                overflow == 1 and fds[0]["events"]["POLLIN"] == 1 and \
-                fds[511]["events"]["POLLIN"] == 1:
-            self.expect["big_poll_out"] = 1
+        if ret == 2047 and nfds == 2047 and fds_length == 512 and overflow == 1:
+                fd_0 = event["fds"][0]
+                fd_511 = event["fds"][511]
+                if fd_0["events"]["POLLIN"] == 1 and fd_511["events"]["POLLIN"] == 1:
+                    self.expect["poll_exit"]["big_poll_out"] = 1
 
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["poll_exit"] = locals()
 
 class Test5(TraceParser):
     def __init__(self, trace, pid):
         super().__init__(trace, pid)
-        self.expect["poll_overflow_in"] = 0
-        self.expect["poll_overflow_out"] = 0
+        self.expect["poll_entry"]["poll_overflow_in"] = 0
+        self.expect["poll_exit"]["poll_overflow_out"] = 0
 
     def poll_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         nfds = event["nfds"]
         fds_length = event["fds_length"]
         overflow = event["overflow"]
-        fds = event["fds"]
 
         # test that event in valid even though the target buffer is too small
         # and the program segfaults
-        if nfds == 100 and fds_length == 100 and overflow == 0 and \
-                fds[0]["events"]["POLLIN"] == 1:
-            self.expect["poll_overflow_in"] = 1
+        if nfds == 100 and fds_length == 100 and overflow == 0:
+            fd_0 = event["fds"][0]
+            if fd_0["events"]["POLLIN"] == 1:
+                self.expect["poll_entry"]["poll_overflow_in"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["poll_entry"] = locals()
 
     def poll_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
-        ret = event["ret"]
         nfds = event["nfds"]
-        fds_length = event["fds_length"]
         overflow = event["overflow"]
-        fds = event["fds"]
 
         # test that event in valid even though the target buffer is too small
         # and the program segfaults
         if nfds == 100 and overflow == 0:
-            self.expect["poll_overflow_out"] = 1
+            self.expect["poll_exit"]["poll_overflow_out"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["poll_exit"] = locals()
 
 
 class Test6(TraceParser):
     def __init__(self, trace, pid):
         super().__init__(trace, pid)
-        self.expect["pselect_invalid_in"] = 0
-        self.expect["pselect_invalid_out"] = 0
+        self.expect["select_entry"]["pselect_invalid_in"] = 0
+        self.expect["select_exit"]["pselect_invalid_out"] = 0
 
     def select_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         n = event["n"]
         overflow = event["overflow"]
-        tvp = event["tvp"]
         _readfds_length = event["_readfds_length"]
-        readfds = event["readfds"]
-        _writefds_length = event["_writefds_length"]
-        writefds = event["writefds"]
-        _exceptfds_length = event["_exceptfds_length"]
-        exceptfds = event["exceptfds"]
 
         # test that event in valid even though the target buffer pointer is
         # invalid and the program segfaults
         if n == 1 and overflow == 0 and _readfds_length == 0:
-            self.expect["pselect_invalid_in"] = 1
+            self.expect["select_entry"]["pselect_invalid_in"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["select_entry"] = locals()
 
     def select_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
         overflow = event["overflow"]
-        tvp = event["tvp"]
         _readfds_length = event["_readfds_length"]
-        readfds = event["readfds"]
-        _writefds_length = event["_writefds_length"]
-        writefds = event["writefds"]
-        _exceptfds_length = event["_exceptfds_length"]
-        exceptfds = event["exceptfds"]
 
         # test that event in valid even though the target buffer pointer is
         # invalid and the program segfaults
         if ret == -14 and overflow == 0 and _readfds_length == 0:
-            self.expect["pselect_invalid_out"] = 1
+            self.expect["select_exit"]["pselect_invalid_out"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["select_exit"] = locals()
 
 
 class Test7(TraceParser):
     def __init__(self, trace, pid):
         super().__init__(trace, pid)
-        self.expect["poll_max_in"] = 0
-        self.expect["poll_max_out"] = 0
+        self.expect["poll_entry"]["poll_max_in"] = 0
+        self.expect["poll_exit"]["poll_max_out"] = 0
 
     def poll_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         nfds = event["nfds"]
-        fds_length = event["fds_length"]
         overflow = event["overflow"]
-        fds = event["fds"]
 
         # check the proper working of INT_MAX maxevent value
         if nfds == 4294967295 and overflow == 1:
-            self.expect["poll_max_in"] = 1
+            self.expect["poll_entry"]["poll_max_in"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["poll_entry"] = locals()
+
 
     def poll_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
         nfds = event["nfds"]
-        fds_length = event["fds_length"]
         overflow = event["overflow"]
-        fds = event["fds"]
 
         # check the proper working of UINT_MAX maxevent value
         if ret == -22 and nfds == 4294967295 and overflow == 0:
-            self.expect["poll_max_out"] = 1
+            self.expect["poll_exit"]["poll_max_out"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["poll_exit"] = locals()
 
 
 class Test8(TraceParser):
     def __init__(self, trace, pid):
         super().__init__(trace, pid)
-        self.expect["epoll_wait_invalid_in"] = 0
-        self.expect["epoll_wait_invalid_out"] = 0
+        self.expect["epoll_wait_entry"]["epoll_wait_invalid_in"] = 0
+        self.expect["epoll_wait_exit"]["epoll_wait_invalid_out"] = 0
 
     def epoll_wait_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         epfd = event["epfd"]
         maxevents = event["maxevents"]
         timeout = event["timeout"]
@@ -652,50 +650,54 @@ class Test8(TraceParser):
         # test that event in valid even though the target buffer pointer is
         # invalid and the program segfaults
         if epfd == 3 and maxevents == 1 and timeout == -1:
-            self.expect["epoll_wait_invalid_in"] = 1
+            self.expect["epoll_wait_entry"]["epoll_wait_invalid_in"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["epoll_wait_entry"] = locals()
 
     def epoll_wait_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
         fds_length = event["fds_length"]
         overflow = event["overflow"]
-        fds = event["fds"]
 
         # test that event in valid even though the target buffer pointer is
         # invalid and the program segfaults
         if ret == -14 and fds_length == 0 and overflow == 0:
-            self.expect["epoll_wait_invalid_out"] = 1
+            self.expect["epoll_wait_exit"]["epoll_wait_invalid_out"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["epoll_wait_exit"] = locals()
 
 
 class Test9(TraceParser):
     def __init__(self, trace, pid):
         super().__init__(trace, pid)
-        self.expect["epoll_wait_max_in"] = 0
-        self.expect["epoll_wait_max_out"] = 0
+        self.expect["epoll_wait_entry"]["epoll_wait_max_in"] = 0
+        self.expect["epoll_wait_exit"]["epoll_wait_max_out"] = 0
 
     def epoll_wait_entry(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         epfd = event["epfd"]
         maxevents = event["maxevents"]
         timeout = event["timeout"]
 
         # check the proper working of INT_MAX maxevent value
         if epfd == 3 and maxevents == 2147483647 and timeout == -1:
-            self.expect["epoll_wait_max_in"] = 1
+            self.expect["epoll_wait_entry"]["epoll_wait_max_in"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["epoll_wait_entry"] = locals()
 
     def epoll_wait_exit(self, event):
-        timestamp = event.timestamp
-        cpu_id = event["cpu_id"]
         ret = event["ret"]
         fds_length = event["fds_length"]
         overflow = event["overflow"]
-        fds = event["fds"]
 
         # check the proper working of INT_MAX maxevent value
         if ret == -22 and fds_length == 0 and overflow == 0:
-            self.expect["epoll_wait_max_out"] = 1
+            self.expect["epoll_wait_exit"]["epoll_wait_max_out"] = 1
+
+        # Save values of local variables to print in case of test failure
+        self.recorded_values["epoll_wait_exit"] = locals()
 
 
 if __name__ == "__main__":