make signal-handler less shit;

previously: threading.Condition to wakeup the actual handler;
exciting chance of heisenbugs / deadlocks (theoretically)

almost went with os.pipe on unix and socketpairs on windows,
but turns out SimpleQueue is perfect and safe for this purpose

SimpleQueue is 3.7+ so use a regular queue on <3.7
(same problems as original approach)

also need dedicated thread for popping the queue on <3.7
to avoid deadlock on most platforms (--sig-thr)

new features:

--logrot-sig sets a signal for immediate log-rotate

--stack-sig sets a signal to dump stack to log/stdout

--reload-sig sets a signal to initiates config-reload
   (was hardcoded to USR1 previously)

copyparty/__main__.py

@@ -1234,6 +1234,7 @@ def add_general(ap, nc, srvname):
     ap2.add_argument("--mimes", action="store_true", help="list default mimetype mapping and exit")
     ap2.add_argument("--rmagic", action="store_true", help="do expensive analysis to improve accuracy of returned mimetypes; will make file-downloads, rss, and webdav slower (volflag=rmagic)")
     ap2.add_argument("-j", metavar="CORES", type=int, default=1, help="num cpu-cores for uploads/downloads (0=all); keeping the default is almost always best")
+    ap2.add_argument("--reload-sig", metavar="S", type=u, default=("" if ANYWIN else "USR1"), help="reload server config when unix-signal \033[33mS\033[0m is received; examples: [\033[32mSIGUSR1\033[0m], [\033[32mUSR1\033[0m], [\033[32m10\033[0m]")
     ap2.add_argument("--vc-url", metavar="URL", type=u, default="", help="URL to check for vulnerable versions (default-disabled)")
     ap2.add_argument("--vc-age", metavar="HOURS", type=int, default=3, help="how many hours to wait between vulnerability checks")
     ap2.add_argument("--vc-exit", action="store_true", help="panic and exit if current version is vulnerable")
@@ -1706,6 +1707,7 @@ def add_logging(ap):
     ap2.add_argument("-lo", metavar="PATH", type=u, default="", help="logfile; use .txt for plaintext or .xz for compressed. Example: \033[32mcpp-%%Y-%%m%%d-%%H%%M%%S.txt.xz\033[0m (NB: some errors may appear on STDOUT only)")
     ap2.add_argument("--flo", metavar="N", type=int, default=1, help="log format for \033[33m-lo\033[0m; [\033[32m1\033[0m]=classic/colors, [\033[32m2\033[0m]=no-color")
     ap2.add_argument("--rlo", metavar="TXT", type=u, default=".1", help="logrotate counter format; see \033[33m--help-rlo\033[0m")
+    ap2.add_argument("--logrot-sig", metavar="S", type=u, default="", help="immediately logrotate when unix-signal \033[33mS\033[0m is received; examples: [\033[32mSIGHUP\033[0m], [\033[32mHUP\033[0m], [\033[32m1\033[0m]")
     ap2.add_argument("--no-ansi", action="store_true", default=not VT100, help="disable colors; same as environment-variable NO_COLOR")
     ap2.add_argument("--ansi", action="store_true", help="force colors; overrides environment-variable NO_COLOR")
     ap2.add_argument("--no-logflush", action="store_true", help="don't flush the logfile after each write; tiny bit faster")
@@ -1980,10 +1982,15 @@ def add_debug(ap):
     ap2.add_argument("--no-scandir", action="store_true", help="kernel-bug workaround: disable scandir; do a listdir + stat on each file instead")
     ap2.add_argument("--no-fastboot", action="store_true", help="wait for initial filesystem indexing before accepting client requests")
     ap2.add_argument("--no-htp", action="store_true", help="disable httpserver threadpool, create threads as-needed instead")
+    if ANYWIN or sys.version_info < (3, 7):
+        ap2.add_argument("--sig-thr", action="store_true", default=True, help=argparse.SUPPRESS)
+    else:
+        ap2.add_argument("--sig-thr", action="store_true", help="start separate thread for OS-signals (try this if CTRL-C is busted)")
     ap2.add_argument("--rm-sck", action="store_true", help="when listening on unix-sockets, do a basic delete+bind instead of the default atomic bind")
     ap2.add_argument("--srch-dbg", action="store_true", help="explain search processing, and do some extra expensive sanity checks")
     ap2.add_argument("--rclone-mdns", action="store_true", help="use mdns-domain instead of server-ip on /?hc")
     ap2.add_argument("--stackmon", metavar="P,S", type=u, default="", help="write stacktrace to \033[33mP\033[0math every \033[33mS\033[0m second, for example --stackmon=\033[32m./st/%%Y-%%m/%%d/%%H%%M.xz,60")
+    ap2.add_argument("--stack-sig", metavar="S", type=u, default="", help="show stacktrace when unix-signal \033[33mS\033[0m is received; examples: [\033[32mSIGUSR2\033[0m], [\033[32mUSR2\033[0m], [\033[32m12\033[0m]")
     ap2.add_argument("--log-thrs", metavar="SEC", type=float, default=0.0, help="list active threads every \033[33mSEC\033[0m")
     ap2.add_argument("--log-fk", metavar="REGEX", type=u, default="", help="log filekey params for files where path matches \033[33mREGEX\033[0m; [\033[32m.\033[0m] (a single dot) = all files")
     ap2.add_argument("--bak-flips", action="store_true", help="[up2k] if a client uploads a bitflipped/corrupted chunk, store a copy according to \033[33m--bf-nc\033[0m and \033[33m--bf-dir\033[0m")

copyparty/svchub.py

@@ -82,6 +82,7 @@ from .util import (
     odfusion,
     pybin,
     read_utf8,
+    signame2int,
     start_log_thrs,
     start_stackmon,
     termsize,
@@ -107,6 +108,12 @@ if PY2:
 else:
     from urllib.request import Request, urlopen
 
+try:
+    from queue import SimpleQueue
+except:
+    # yuul b. alwright
+    from queue import Queue as SimpleQueue
+
 
 VER_IDP_DB = 1
 VER_SESSION_DB = 1
@@ -140,13 +147,9 @@ class SvcHub(object):
         self.logf: Optional[typing.TextIO] = None
         self.logf_base_fn = ""
         self.is_dut = False  # running in unittest; always False
-        self.stop_req = False
         self.stopping = False
         self.stopped = False
-        self.reload_req = False
         self.reload_mutex = threading.Lock()
-        self.stop_cond = threading.Condition()
-        self.nsigs = 3
         self.retcode = 0
         self.httpsrv_up = 0
         self.qr_tsz = None
@@ -156,6 +159,12 @@ class SvcHub(object):
         self.cmon = 0
         self.tstack = 0.0
 
+        self.sig_logrot = -999
+        self.sig_reload = -999
+        self.sig_stack = -999
+        self.nsigs = 7
+        self.sig = SimpleQueue()
+
         self.iphash = HMaccas(os.path.join(self.E.cfg, "iphash"), 8)
 
         if args.sss or args.s >= 3:
@@ -1451,31 +1460,37 @@ class SvcHub(object):
 
         sigs = [signal.SIGINT, signal.SIGTERM]
         if not ANYWIN:
-            sigs.append(signal.SIGUSR1)
+            sigs.append(signal.SIGHUP)
+
+        for (opt, mem) in (
+            ("logrot_sig", "sig_logrot"),
+            ("reload_sig", "sig_reload"),
+            ("stack_sig", "sig_stack"),
+        ):
+            zs = getattr(self.args, opt)
+            if not zs:
+                continue
+            zi = signame2int(zs)
+            setattr(self, mem, zi)
+            sigs.append(zi)
 
         for sig in sigs:
             signal.signal(sig, self.signal_handler)
 
-        # macos hangs after shutdown on sigterm with while-sleep,
+        if self.args.sig_thr:
-        # windows cannot ^c stop_cond (and win10 does the macos thing but winxp is fine??)
+            Daemon(self._signal_thr, "svchub-sig")
-        # linux is fine with both,
-        # never lucky
-        if ANYWIN:
-            # msys-python probably fine but >msys-python
-            Daemon(self.stop_thr, "svchub-sig")
 
             try:
-                while not self.stop_req:
+                while not self.stopping:
                     time.sleep(1)
             except:
                 pass
 
-            self.shutdown()
             # cant join; eats signals on win10
             while not self.stopped:
                 time.sleep(0.1)
         else:
-            self.stop_thr()
+            self._signal_thr()
 
     def start_zeroconf(self) -> None:
         self.zc_ngen += 1
@@ -1533,17 +1548,6 @@ class SvcHub(object):
             self.asrv.load_sessions(True)
         self.broker.reload_sessions()
 
-    def stop_thr(self) -> None:
-        while not self.stop_req:
-            with self.stop_cond:
-                self.stop_cond.wait(9001)
-
-            if self.reload_req:
-                self.reload_req = False
-                self.reload(True, True)
-
-        self.shutdown()
-
     def kill9(self, delay: float = 0.0) -> None:
         if delay > 0.01:
             time.sleep(delay)
@@ -1556,26 +1560,42 @@ class SvcHub(object):
             os.kill(os.getpid(), signal.SIGKILL)
 
     def signal_handler(self, sig: int, frame: Optional[FrameType]) -> None:
-        if self.stopping:
+        if sig in (signal.SIGINT, signal.SIGTERM):
-            if self.nsigs <= 0:
+            self.nsigs -= 1
+
+            if self.nsigs == 0:
                 try:
                     threading.Thread(target=self.pr, args=("OMBO BREAKER",)).start()
                     time.sleep(0.1)
                 except:
                     pass
 
+            if self.nsigs <= 0:
                 self.kill9()
-            else:
-                self.nsigs -= 1
-                return
 
-        if not ANYWIN and sig == signal.SIGUSR1:
+        self.sig.put(sig)
-            self.reload_req = True
+
+    def _signal_thr(self) -> None:
+        while not self.stopping:
+            sig = self.sig.get()
+            self._signal_handler(sig)
+
+    def _signal_handler(self, sig: int) -> None:
+        if sig == self.sig_logrot:
+            self.log("root", "signal: logrotate")
+            dt = datetime.now(self.tz)
+            self.logf_base_fn = "\t"
+            self._set_next_day(dt)
+
+        elif sig == self.sig_reload:
+            self.log("root", "signal: reload")
+            self.reload(True, True)
+
+        elif sig == self.sig_stack:
+            self.log("root", "signal: stack%s" % (alltrace(),))
+
         else:
-            self.stop_req = True
+            self.shutdown()
-
-        with self.stop_cond:
-            self.stop_cond.notify_all()
 
     def shutdown(self) -> None:
         if self.stopping:
@@ -1583,10 +1603,8 @@ class SvcHub(object):
 
         # start_log_thrs(print, 0.1, 1)
 
+        self.nsigs = 3
         self.stopping = True
-        self.stop_req = True
-        with self.stop_cond:
-            self.stop_cond.notify_all()
 
         ret = 1
         try:

copyparty/util.py

@@ -1635,6 +1635,16 @@ def expand_osenv_cs(txt) -> str:
     raise Exception(t)
 
 
+def signame2int(txt: str) -> int:
+    try:
+        return int(txt)
+    except:
+        txt = txt.upper()
+        if not txt.startswith("SIG"):
+            txt = "SIG" + txt
+        return int(getattr(signal, txt))
+
+
 def rice_tid() -> str:
     tid = threading.current_thread().ident
     c = sunpack(b"B" * 5, spack(b">Q", tid)[-5:])