Use time.monotonic() for time measumeremts in pytest

For duration measurements, i.e. deadlines and timeouts, it's more
suitable to use monotonic time as it's guaranteed to only go forward,
unlike time.time() which can be affected by local clock settings.

bin/tests/system/doth/tests_gnutls.py

@@ -72,11 +72,11 @@ def test_gnutls_cli_query(gnutls_cli_executable, named_tlsport):
         # upon receiving a DNS response.
         selector = selectors.DefaultSelector()
         selector.register(gnutls_cli.stdout, selectors.EVENT_READ)
-        deadline = time.time() + 10
+        deadline = time.monotonic() + 10
         gnutls_cli_output = b""
         response = b""
         while not response and not gnutls_cli.poll():
-            if not selector.select(timeout=deadline - time.time()):
+            if not selector.select(timeout=deadline - time.monotonic()):
                 break
             gnutls_cli_output += gnutls_cli.stdout.read(512)
             try:

bin/tests/system/isctest/log/watchlog.py

@@ -229,8 +229,8 @@ class WatchLog(abc.ABC):
             raise WatchLogException("No file to watch")
         leftover = ""
         assert timeout, "Do not use this class unless you want to WAIT for something."
-        deadline = time.time() + timeout
-        while time.time() < deadline:
+        deadline = time.monotonic() + timeout
+        while time.monotonic() < deadline:
             for line in self._fd.readlines():
                 if line[-1] != "\n":
                     # Line is not completely written yet, buffer and keep on waiting

bin/tests/system/isctest/run.py

@@ -126,9 +126,9 @@ def perl(script: str, args: Optional[List[str]] = None) -> None:
 
 
 def retry_with_timeout(func, timeout, delay=1, msg=None):
-    start_time = time.time()
+    start_time = time.monotonic()
     exc_msg = None
-    while time.time() < start_time + timeout:
+    while time.monotonic() < start_time + timeout:
         exc_msg = None
         try:
             if func():

bin/tests/system/pipelined/ans5/ans.py

@@ -84,7 +84,7 @@ class TCPDelayer(threading.Thread):
         while self.running:
             curr_timeout = 0.5
             try:
-                curr_timeout = self.queue[0][0] - time.time()
+                curr_timeout = self.queue[0][0] - time.monotonic()
             except StopIteration:
                 pass
             if curr_timeout > 0:
@@ -97,14 +97,14 @@ class TCPDelayer(threading.Thread):
                     data = self.conn.recv(65535)
                     if not data:
                         return
-                    self.queue.append((time.time() + DELAY, data))
+                    self.queue.append((time.monotonic() + DELAY, data))
                 if self.cconn in rfds:
                     data = self.cconn.recv(65535)
                     if not data == 0:
                         return
                     self.conn.send(data)
             try:
-                while self.queue[0][0] - time.time() < 0:
+                while self.queue[0][0] - time.monotonic() < 0:
                     _, data = self.queue.pop(0)
                     self.cconn.send(data)
             except StopIteration:
@@ -133,7 +133,7 @@ class UDPDelayer(threading.Thread):
         while self.running:
             curr_timeout = 0.5
             if self.queue:
-                curr_timeout = self.queue[0][0] - time.time()
+                curr_timeout = self.queue[0][0] - time.monotonic()
             if curr_timeout >= 0:
                 if curr_timeout == 0:
                     curr_timeout = 0.5
@@ -144,7 +144,7 @@ class UDPDelayer(threading.Thread):
                     data, addr = self.sock.recvfrom(65535)
                     if not data:
                         return
-                    self.queue.append((time.time() + DELAY, data))
+                    self.queue.append((time.monotonic() + DELAY, data))
                     qid = struct.unpack(">H", data[:2])[0]
                     log("Received a query from %s, queryid %d" % (str(addr), qid))
                     self.qid_mapping[qid] = addr
@@ -160,7 +160,7 @@ class UDPDelayer(threading.Thread):
                             "Received a response from %s, queryid %d, sending to %s"
                             % (str(addr), qid, str(dst))
                         )
-            while self.queue and self.queue[0][0] - time.time() < 0:
+            while self.queue and self.queue[0][0] - time.monotonic() < 0:
                 _, data = self.queue.pop(0)
                 qid = struct.unpack(">H", data[:2])[0]
                 log("Sending a query to %s, queryid %d" % (str(self.dst), qid))

bin/tests/system/tcp/ans6/ans.py

@@ -71,9 +71,9 @@ def open_connections(active_conns, count, host, port):
         else:
             queued.append(sock)
 
-    start = time.time()
+    start = time.monotonic()
     while queued:
-        now = time.time()
+        now = time.monotonic()
         time_left = OPEN_TIMEOUT - (now - start)
         if time_left <= 0:
             break