Refactoring service_manager in crash_gen to use stronger types

tests/pytest/crash_gen/__init__.py

+# Helpful Ref: https://stackoverflow.com/questions/24100558/how-can-i-split-a-module-into-multiple-files-without-breaking-a-backwards-compa/24100645
+from crash_gen.service_manager import ServiceManager, TdeInstance, TdeSubProcess
+from crash_gen.misc import Logging, Status, CrashGenError, Dice, Helper, Progress
+from crash_gen.db import DbConn, MyTDSql, DbConnNative, DbManager
+from crash_gen.settings import Settings

tests/pytest/crash_gen/crash_gen_main.py

@@ -32,21 +32,22 @@ import getopt
 
 import sys
 import os
+import io
 import signal
 import traceback
 import resource
 # from guppy import hpy
 import gc
 
-from crash_gen.service_manager import ServiceManager, TdeInstance
-from crash_gen.misc import Logging, Status, CrashGenError, Dice, Helper, Progress
-from crash_gen.db import DbConn, MyTDSql, DbConnNative, DbManager
-import crash_gen.settings 
+# from crash_gen import ServiceManager, TdeInstance, TdeSubProcess
+from crash_gen import ServiceManager, Settings, DbConn, DbConnNative, Dice, DbManager, Status, Logging, Helper, \
+    CrashGenError, Progress, MyTDSql, \
+    TdeInstance
 
 import taos
 import requests
 
-crash_gen.settings.init()
+Settings.init()
 
 # Require Python 3
 if sys.version_info[0] < 3:
@@ -89,9 +90,9 @@ class WorkerThread:
                 self._dbConn = DbConn.createRest(tInst.getDbTarget()) 
             elif gConfig.connector_type == 'mixed':
                 if Dice.throw(2) == 0: # 1/2 chance
-                    self._dbConn = DbConn.createNative() 
+                    self._dbConn = DbConn.createNative(tInst.getDbTarget()) 
                 else:
-                    self._dbConn = DbConn.createRest() 
+                    self._dbConn = DbConn.createRest(tInst.getDbTarget()) 
             else:
                 raise RuntimeError("Unexpected connector type: {}".format(gConfig.connector_type))
 
@@ -1370,13 +1371,13 @@ class Task():
             self._err = e
             self._aborted = True
             traceback.print_exc()
-        except BaseException as e:
+        except BaseException as e2:
             self.logInfo("Python base exception encountered")
-            self._err = e
+            # self._err = e2 # Exception/BaseException incompatible!
             self._aborted = True
             traceback.print_exc()
-        except BaseException: # TODO: what is this again??!!
-            raise RuntimeError("Punt")
+        # except BaseException: # TODO: what is this again??!!
+        #     raise RuntimeError("Punt")
             # self.logDebug(
             #     "[=] Unexpected exception, SQL: {}".format(
             #         wt.getDbConn().getLastSql()))
@@ -1980,8 +1981,8 @@ class TaskAddData(StateTransitionTask):
     activeTable: Set[int] = set()
 
     # We use these two files to record operations to DB, useful for power-off tests
-    fAddLogReady = None # type: TextIOWrapper
-    fAddLogDone  = None # type: TextIOWrapper
+    fAddLogReady = None # type: io.TextIOWrapper
+    fAddLogDone  = None # type: io.TextIOWrapper
 
     @classmethod
     def prepToRecordOps(cls):
@@ -2025,7 +2026,7 @@ class TaskAddData(StateTransitionTask):
                 self.prepToRecordOps()
                 self.fAddLogReady.write("Ready to write {} to {}\n".format(nextInt, regTableName))
                 self.fAddLogReady.flush()
-                os.fsync(self.fAddLogReady)
+                os.fsync(self.fAddLogReady.fileno())
                 
             # TODO: too ugly trying to lock the table reliably, refactor...
             fullTableName = db.getName() + '.' + regTableName
@@ -2088,7 +2089,7 @@ class TaskAddData(StateTransitionTask):
             if gConfig.record_ops:
                 self.fAddLogDone.write("Wrote {} to {}\n".format(nextInt, regTableName))
                 self.fAddLogDone.flush()
-                os.fsync(self.fAddLogDone)
+                os.fsync(self.fAddLogDone.fileno())
 
     def _executeInternal(self, te: TaskExecutor, wt: WorkerThread):
         # ds = self._dbManager # Quite DANGEROUS here, may result in multi-thread client access
@@ -2468,7 +2469,7 @@ class MainExec:
 
         global gConfig
         gConfig = parser.parse_args()
-        crash_gen.settings.gConfig = gConfig # TODO: fix this hack, consolidate this global var
+        Settings.setConfig(gConfig) # TODO: fix this hack, consolidate this global var
 
         # Sanity check for arguments
         if gConfig.use_shadow_db and gConfig.max_dbs>1 :

tests/pytest/crash_gen/service_manager.py

+from __future__ import annotations
+
 import os
 import io
 import sys
@@ -5,9 +7,9 @@ import threading
 import signal
 import logging
 import time
-import subprocess
+from subprocess import PIPE, Popen, TimeoutExpired
 
-from typing import IO, List
+from typing import IO, List, NewType, Optional
 
 try:
     import psutil
@@ -170,6 +172,7 @@ quorum 2
         if crash_gen.settings.gConfig.track_memory_leaks:
             Logging.info("Invoking VALGRIND on service...")
             cmdLine = ['valgrind', '--leak-check=yes']
+        # TODO: move "exec -c" into Popen(), we can both "use shell" and NOT fork so ask to lose kill control
         cmdLine += ["exec " + self.getExecFile(), '-c', self.getCfgDir()] # used in subproce.Popen()        
         return cmdLine
     
@@ -225,41 +228,46 @@ class TdeSubProcess:
 
     It takes a TdeInstance object as its parameter, with the rationale being
     "a sub process runs an instance".
+
+    We aim to ensure that this object has exactly the same life-cycle as the 
+    underlying sub process.
     """
 
     # RET_ALREADY_STOPPED = -1
     # RET_TIME_OUT = -3
     # RET_SUCCESS = -4
 
-    def __init__(self):
-        self.subProcess = None # type: subprocess.Popen
+    def __init__(self, po: Popen):
+        self._popen = po # type: Popen
         # if tInst is None:
         #     raise CrashGenError("Empty instance not allowed in TdeSubProcess")
         # self._tInst = tInst # Default create at ServiceManagerThread
 
     def __repr__(self):
-        if self.subProcess is None:
-            return '[TdeSubProc: Empty]'
+        # if self.subProcess is None:
+        #     return '[TdeSubProc: Empty]'
         return '[TdeSubProc: pid = {}]'.format(self.getPid())
 
     def getStdOut(self):
-        return self.subProcess.stdout
+        return self._popen.stdout
 
     def getStdErr(self):
-        return self.subProcess.stderr
+        return self._popen.stderr
 
-    def isRunning(self):
-        return self.subProcess is not None
+    # Now it's always running, since we matched the life cycle
+    # def isRunning(self):
+    #     return self.subProcess is not None
 
     def getPid(self):
-        return self.subProcess.pid
+        return self._popen.pid
 
-    def start(self, cmdLine):
+    @classmethod
+    def start(cls, cmdLine):
         ON_POSIX = 'posix' in sys.builtin_module_names
 
         # Sanity check
-        if self.subProcess:  # already there
-            raise RuntimeError("Corrupt process state")
+        # if self.subProcess:  # already there
+        #     raise RuntimeError("Corrupt process state")
 
         # Prepare environment variables for coverage information
         # Ref: https://stackoverflow.com/questions/2231227/python-subprocess-popen-with-a-modified-environment
@@ -270,23 +278,22 @@ class TdeSubProcess:
         # print("Starting TDengine with env: ", myEnv.items())
         # print("Starting TDengine via Shell: {}".format(cmdLineStr))
 
-        useShell = True # Needed to pass environments into it
-        self.subProcess = subprocess.Popen(
-            # ' '.join(cmdLine) if useShell else cmdLine,
-            # shell=useShell,
-            ' '.join(cmdLine),
-            shell=True,
-            stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE,
-            # bufsize=1, # not supported in binary mode
+        # useShell = True # Needed to pass environments into it
+        popen = Popen(            
+            ' '.join(cmdLine), # ' '.join(cmdLine) if useShell else cmdLine,
+            shell=True, # Always use shell, since we need to pass ENV vars
+            stdout=PIPE,
+            stderr=PIPE,
             close_fds=ON_POSIX,
             env=myEnv
             )  # had text=True, which interferred with reading EOF
+        return cls(popen)
 
     STOP_SIGNAL = signal.SIGINT # signal.SIGKILL/SIGINT # What signal to use (in kill) to stop a taosd process?
     SIG_KILL_RETCODE = 137 # ref: https://stackoverflow.com/questions/43268156/process-finished-with-exit-code-137-in-pycharm
 
-    def stop(self):
+    @classmethod
+    def stop(cls, tsp: TdeSubProcess):
         """
         Stop a sub process, DO NOT return anything, process all conditions INSIDE
 
@@ -306,29 +313,30 @@ class TdeSubProcess:
         SIGSEGV         11
         SIGUSR2         12
         """
-        if not self.subProcess:
-            Logging.error("Sub process already stopped")
-            return
+        # self._popen should always be valid.
+
+        # if not self.subProcess:
+        #     Logging.error("Sub process already stopped")
+        #     return
 
-        retCode = self.subProcess.poll() # ret -N means killed with signal N, otherwise it's from exit(N)
+        retCode = tsp._popen.poll() # ret -N means killed with signal N, otherwise it's from exit(N)
         if retCode:  # valid return code, process ended
             # retCode = -retCode # only if valid
             Logging.warning("TSP.stop(): process ended itself")
-            self.subProcess = None
+            # self.subProcess = None
             return
 
         # process still alive, let's interrupt it
-        self._stopForSure(self.subProcess, self.STOP_SIGNAL) # success if no exception
-        self.subProcess = None
+        cls._stopForSure(tsp._popen, cls.STOP_SIGNAL) # success if no exception
 
         # sub process should end, then IPC queue should end, causing IO thread to end        
 
     @classmethod
-    def _stopForSure(cls, proc: subprocess.Popen, sig: int):
+    def _stopForSure(cls, proc: Popen, sig: int):
         ''' 
         Stop a process and all sub processes with a singal, and SIGKILL if necessary
         '''
-        def doKillTdService(proc: subprocess.Popen, sig: int):
+        def doKillTdService(proc: Popen, sig: int):
             Logging.info("Killing sub-sub process {} with signal {}".format(proc.pid, sig))
             proc.send_signal(sig)
             try:            
@@ -340,7 +348,7 @@ class TdeSubProcess:
                 else:
                     Logging.warning("TD service terminated, EXPECTING ret code {}, got {}".format(sig, -retCode))
                 return True # terminated successfully
-            except subprocess.TimeoutExpired as err:
+            except TimeoutExpired as err:
                 Logging.warning("Failed to kill sub-sub process {} with signal {}".format(proc.pid, sig))
             return False # failed to terminate
 
@@ -361,10 +369,10 @@ class TdeSubProcess:
                 Logging.warning("Failed to kill sub-sub process {} with signal {}".format(child.pid, sig))
             return False # did not terminate
 
-        def doKill(proc: subprocess.Popen, sig: int):
+        def doKill(proc: Popen, sig: int):
             pid = proc.pid
             try:
-                topSubProc = psutil.Process(pid)
+                topSubProc = psutil.Process(pid) # Now that we are doing "exec -c", should not have children any more
                 for child in topSubProc.children(recursive=True):  # or parent.children() for recursive=False
                     Logging.warning("Unexpected child to be killed")
                     doKillChild(child, sig)
@@ -389,17 +397,15 @@ class TdeSubProcess:
             return doKill(proc, sig)
 
         def hardKill(proc):
-            return doKill(proc, signal.SIGKILL)
-
-        
+            return doKill(proc, signal.SIGKILL) 
 
         pid = proc.pid
         Logging.info("Terminate running processes under {}, with SIG #{} and wait...".format(pid, sig))
         if softKill(proc, sig):            
-            return# success
+            return # success
         if sig != signal.SIGKILL: # really was soft above            
             if hardKill(proc):
-                return
+                return 
         raise CrashGenError("Failed to stop process, pid={}".format(pid))
 
 class ServiceManager:
@@ -657,10 +663,9 @@ class ServiceManagerThread:
         Logging.info("Attempting to start TAOS service: {}".format(self))
 
         self._status.set(Status.STATUS_STARTING)
-        self._tdeSubProcess = TdeSubProcess()
-        self._tdeSubProcess.start(cmdLine) # TODO: verify process is running
+        self._tdeSubProcess = TdeSubProcess.start(cmdLine) # TODO: verify process is running
 
-        self._ipcQueue = Queue()
+        self._ipcQueue = Queue() # type: Queue
         self._thread = threading.Thread( # First thread captures server OUTPUT
             target=self.svcOutputReader,
             args=(self._tdeSubProcess.getStdOut(), self._ipcQueue, logDir))
@@ -738,21 +743,15 @@ class ServiceManagerThread:
             raise RuntimeError("sub process object missing")
 
         self._status.set(Status.STATUS_STOPPING)
-        # retCode = self._tdeSubProcess.stop()
-        # try:
-        #     retCode = self._tdeSubProcess.stop()
-        #     # print("Attempted to stop sub process, got return code: {}".format(retCode))
-        #     if retCode == signal.SIGSEGV : # SGV
-        #         Logging.error("[[--ERROR--]]: TDengine service SEGV fault (check core file!)")
-        # except subprocess.TimeoutExpired as err:
-        #     Logging.info("Time out waiting for TDengine service process to exit")
-        if not self._tdeSubProcess.stop(): # everything withing
-            if self._tdeSubProcess.isRunning():  # still running, should now never happen
-                Logging.error("FAILED to stop sub process, it is still running... pid = {}".format(
-                    self._tdeSubProcess.getPid()))
-            else:
-                self._tdeSubProcess = None  # not running any more
-                self.join()  # stop the thread, change the status, etc.
+        TdeSubProcess.stop(self._tdeSubProcess) # must stop, no matter what
+        self._tdeSubProcess = None
+        # if not self._tdeSubProcess.stop(): # everything withing
+        #     if self._tdeSubProcess.isRunning():  # still running, should now never happen
+        #         Logging.error("FAILED to stop sub process, it is still running... pid = {}".format(
+        #             self._tdeSubProcess.getPid()))
+        #     else:
+        #         self._tdeSubProcess = None  # not running any more
+        self.join()  # stop the thread, change the status, etc.
 
         # Check if it's really stopped
         outputLines = 10 # for last output
@@ -827,6 +826,19 @@ class ServiceManagerThread:
         print(pBar, end="", flush=True)
         print('\b\b\b\b', end="", flush=True)
 
+    BinaryLine = NewType('BinaryLine', bytes) # line with binary data, directly from STDOUT, etc.
+    TextLine   = NewType('TextLine', str) # properly decoded, suitable for printing, etc.
+    x = TextLine('xyz')
+    
+    @classmethod
+    def _decodeBinLine(cls, bLine: BinaryLine) -> Optional[TextLine] :
+        try:
+            tLine = bLine.decode("utf-8").rstrip()
+            return cls.TextLine(tLine)
+        except UnicodeError:
+            print("\nNon-UTF8 server output: {}\n".format(bLine.decode('cp437')))
+            return None
+
     def svcOutputReader(self, out: IO, queue, logDir: str):
         '''
         The infinite routine that processes the STDOUT stream for the sub process being managed.
@@ -841,32 +853,37 @@ class ServiceManagerThread:
         # Important Reference: https://stackoverflow.com/questions/375427/non-blocking-read-on-a-subprocess-pipe-in-python
         # print("This is the svcOutput Reader...")
         # for line in out :
-        for line in iter(out.readline, b''):
-            fOut.write(line)
+        out.readline()
+        for bLine in iter(out.readline, b''):
+            fOut.write(bLine)
             # print("Finished reading a line: {}".format(line))
             # print("Adding item to queue...")
-            try:
-                line = line.decode("utf-8").rstrip()
-            except UnicodeError:
-                print("\nNon-UTF8 server output: {}\n".format(line))
-
-            # This might block, and then causing "out" buffer to block
-            queue.put(line)
-            self._printProgress("_i")
-
-            if self._status.isStarting():  # we are starting, let's see if we have started
-                if line.find(self.TD_READY_MSG) != -1:  # found
-                    Logging.info("Waiting for the service to become FULLY READY")
-                    time.sleep(1.0) # wait for the server to truly start. TODO: remove this
-                    Logging.info("Service is now FULLY READY") # TODO: more ID info here?
-                    self._status.set(Status.STATUS_RUNNING)
-
-            # Trim the queue if necessary: TODO: try this 1 out of 10 times
-            self._trimQueue(self.MAX_QUEUE_SIZE * 9 // 10)  # trim to 90% size
-
-            if self._status.isStopping():  # TODO: use thread status instead
-                # WAITING for stopping sub process to finish its outptu
-                print("_w", end="", flush=True)
+
+            # Moved to above
+            # try:
+            #     line = line.decode("utf-8").rstrip()
+            # except UnicodeError:
+            #     print("\nNon-UTF8 server output: {}\n".format(line))
+            tLine = self._decodeBinLine(bLine)
+
+            if tLine is not None:
+                # This might block, and then causing "out" buffer to block
+                queue.put(tLine)
+                self._printProgress("_i")
+
+                if self._status.isStarting():  # we are starting, let's see if we have started
+                    if tLine.find(self.TD_READY_MSG) != -1:  # found
+                        Logging.info("Waiting for the service to become FULLY READY")
+                        time.sleep(1.0) # wait for the server to truly start. TODO: remove this
+                        Logging.info("Service is now FULLY READY") # TODO: more ID info here?
+                        self._status.set(Status.STATUS_RUNNING)
+
+                # Trim the queue if necessary: TODO: try this 1 out of 10 times
+                self._trimQueue(self.MAX_QUEUE_SIZE * 9 // 10)  # trim to 90% size
+
+                if self._status.isStopping():  # TODO: use thread status instead
+                    # WAITING for stopping sub process to finish its outptu
+                    print("_w", end="", flush=True)
 
             # queue.put(line)
         # meaning sub process must have died

tests/pytest/crash_gen/settings.py

@@ -3,6 +3,13 @@ import argparse
 
 gConfig:    argparse.Namespace 
 
-def init():
-    global gConfig
-    gConfig = []
\ No newline at end of file
+class Settings:
+    @classmethod    
+    def init(cls):
+        global gConfig
+        gConfig = []
+
+    @classmethod
+    def setConfig(cls, config):
+        global gConfig
+        gConfig = config
\ No newline at end of file