Merge pull request #50 from ferus-web/graceful-exits

Graceful exit support

Author: xTrayambak

ferus.nimble

@@ -13,12 +13,12 @@ bin = @["ferus", "ferus_process"]
 requires "nim >= 2.0.2"
 requires "ferusgfx >= 1.2.1"
 requires "colored_logger >= 0.1.0"
-requires "stylus#master"
+requires "stylus >= 0.1.3"
 requires "https://github.com/ferus-web/sanchar >= 2.0.2"
 requires "https://git.sr.ht/~bptato/chame >= 1.0.1"
 requires "seccomp >= 0.2.1"
 requires "simdutf >= 5.5.0"
-requires "https://github.com/ferus-web/bali >= 0.6.3"
+requires "https://github.com/ferus-web/bali#master"
 requires "results >= 0.5.0"
 requires "pretty >= 0.1.0"
 requires "jsony >= 1.1.5"

src/bindings/yoga.nim

@@ -18,7 +18,7 @@ static:
   echo pwd
 
 {.passC: "-I" & gorge("pwd") & "/install/include".}
-{.passL: "-L" & gorge("pwd") & "/install/lib64 -lyogacore".}
+{.passL: "-L" & gorge("pwd") & "/install/lib -lyogacore".}
 
 {.push header: "<yoga/Yoga.h>".}
 type

src/components/ipc/shared.nim

@@ -395,6 +395,8 @@ proc magicFromStr*(s: string): Option[FerusMagic] =
     return some feJSTakeDocument
   of "feRendererExit":
     return some feRendererExit
+  of "feGoodbye":
+    return some feGoodbye
   else:
     warn "magicFromStr(" & s & "): no such magic string found."
 

src/components/js/process.nim

@@ -15,6 +15,7 @@ type JSProcess* = object
   ipc*: IPCClient
   parser*: Parser
   runtime*: Runtime
+  running*: bool = true
 
   document*: HTMLDocument
 
@@ -72,6 +73,14 @@ proc talk(js: var JSProcess, process: FerusProcess) =
 
     debug "Got document for this tab - passing it to JS land."
     js.document = packet.document
+  of feGoodbye:
+    info "js: got goodbye packet, cleaning up."
+    # TODO: make it so that we always respond to goodbye(s), even when in an unreachable/expensive VM loop
+    # there's two ways to do this:
+    # a) either add a way for a hook function to constantly monitor for this packet (bad performance)
+    # b) shift the VM to another thread (good performance but harder to work with)
+    js.runtime.vm.halt = true
+    js.running = false
   else:
     discard
 
@@ -87,5 +96,5 @@ proc jsProcessLogic*(client: var IPCClient, process: FerusProcess) {.inline.} =
   else:
     setLogFilter(lvlNone)
 
-  while true:
+  while js.running:
     js.talk(process)

src/components/master/master.nim

@@ -1,3 +1,7 @@
+## The IPC "master". This is just an abstraction over the IPC server.
+## It essentially allows you to do anything with your own group of processes (renderer, JS runtime, CSS/HTML parsers, etc.)
+## This includes summoning them, telling them to do a task, telling them to exit, et cetera.
+
 import
   std/
     [os, logging, osproc, strutils, options, base64, net, sets, terminal, posix, tables]
@@ -25,6 +29,8 @@ type MasterProcess* = ref object
   server*: IPCServer
   urls*: Table[uint, URL]
 
+  alive*: bool = true
+
 proc initialize*(master: MasterProcess) {.inline.} =
   master.server.add(FerusGroup())
     # TODO: multi-tab support, although we could just keep adding more FerusGroup(s) and it should *theoretically* scale
@@ -515,8 +521,20 @@ proc packetHandler*(
       master.server.reportBadMessage(
         process, "Non-renderer process sent `feRendererExit` opcode", High
       )
+      return
+
+    info "The renderer has shut down. Beginning cleanup."
+
+    # Here, we start sending "goodbye" packets to all processes.
+    # We're essentially telling them, "Hey, start cleaning up and die."
+    for i, group in master.server.groups:
+      for process in group:
+        debug "Telling PID " & $process.pid & " (group " & $i & "'s " & $process.kind &
+          ") to exit"
+        master.server.send(process.socket, GoodbyePacket())
 
-    debug "The renderer has shut down."
+    info "Cleanup completed. Adios!"
+    master.alive = false
   else:
     warn "Unhandled IPC protocol magic: " & $kind
     return

src/components/network/process.nim

@@ -162,6 +162,17 @@ proc talk(client: FerusNetworkClient, process: FerusProcess) {.inline.} =
     info "network: Created WebSocket connection to address " & $openReq.address &
       " successfully!"
     client.ipc.send(NetworkWebSocketCreationResult(error: none(string)))
+  of feGoodbye:
+    info "network: received goodbye packet."
+
+    info "network: closing all websockets"
+    for ws in client.websockets:
+      ws.handle.close()
+
+    info "network: closing cURL handle"
+    curl.close()
+
+    client.running = false
   else:
     discard
 
@@ -170,6 +181,6 @@ proc networkProcessLogic*(client: var IPCClient, process: FerusProcess) {.inline
   var client = FerusNetworkClient(ipc: client)
   client.ipc.setState(Idling)
 
-  while true:
+  while client.running:
     client.talk(process)
     client.tickAllConnections()

src/components/network/types.nim

@@ -10,3 +10,4 @@ type
   FerusNetworkClient* = ref object
     ipc*: IPCClient
     websockets*: seq[WebSocketConnection] ## All open WebSocket instances
+    running*: bool = true

src/components/parsers/html/process.nim

@@ -24,7 +24,13 @@ proc htmlParse*(oparsingData: Option[ParseHTMLPacket]): HTMLParseResult =
 
   HTMLParseResult(document: some(document.parseHTMLDocument()))
 
-proc talk(client: var IPCClient, process: FerusProcess) {.inline.} =
+type HTMLParserData* = object
+  running*: bool = true
+  documentsParsed*: uint64
+
+proc talk(
+    client: var IPCClient, state: var HTMLParserData, process: FerusProcess
+) {.inline.} =
   var count: cint
   discard nix.ioctl(client.socket.getFd().cint, nix.FIONREAD, addr(count))
 
@@ -53,13 +59,21 @@ proc talk(client: var IPCClient, process: FerusProcess) {.inline.} =
 
     client.send(data)
     client.setState(Idling)
+
+    inc state.documentsParsed
+  of feGoodbye:
+    info "html: got goodbye packet, exiting."
+    info "html: we parsed " & $state.documentsParsed &
+      " documents throughout this process's lifetime"
+    state.running = false
   else:
     discard
 
 proc htmlParserProcessLogic*(client: var IPCClient, process: FerusProcess) {.inline.} =
   info "Entering HTML parser process logic."
+  var data = HTMLParserData()
   client.setState(Idling)
   client.poll()
 
-  while true:
-    client.talk(process)
+  while data.running:
+    client.talk(data, process)

src/ferus.nim

@@ -75,7 +75,7 @@ proc main() {.inline.} =
   tab1.load()
   tabs.add(tab1.move())
 
-  while true:
+  while tabs[0].master.alive:
     master.poll()
     for i, _ in tabs:
       tabs[i].heartbeat()