fix(botapi): static SVG + intent buffers to kill cross-thread heap realloc

Round N+1's fresh bot thread realloc'd module-level strings/seqs (SVG buffer, intent stdout/stderr, team messages) left behind by dead round N's thread — same rawDealloc SIGSEGV class as the event queue, seen at graphics.nim:274 (drawText->prepareAdd, core 2490478 @ 03:13:40, battle round 257). - graphics.nim: gSvgBuffer -> array[16384, char] + gSvgLen, appendSvg - bot.nim: intent stdout/stderr -> static char arrays; team messages -> array[16, TeamMessage] + len; buildIntentJson/printToStdOut/Err/ broadcastTeamMessage bounded appends - botThreadEntry: reset graphics+intent buffers on the owning thread Also fixes stale mapActions call sites in tests/ (missing enemyX/enemyY).
2026-08-19 03:32:28 +02:00
parent 64697f917e
commit a4e830531b
11 changed files with 87 additions and 39 deletions
@@ -198,9 +198,21 @@ var gIntentGunColor:      Color = Color(0)
 var gIntentAdjGunBody:    bool = false
 var gIntentAdjRadarBody:  bool = false
 var gIntentAdjRadarGun:   bool = false
-var gIntentTeamMessages:  seq[TeamMessage] = @[]
-var gIntentStdOut:        string = ""
-var gIntentStdErr:        string = ""
+# ponytail: static buffers instead of strings/seq. go()'s stop path returns
+# before buildIntentJson clears these, so a round's last tick can leave heap
+# blocks owned by the exiting bot thread -> the fresh next-round thread
+# reallocs a dead allocator block (rawDealloc SIGSEGV). Static storage:
+# no heap block crosses threads.
+const INTENT_STDOUT_CAP = 4096
+const INTENT_STDERR_CAP = 4096
+const INTENT_MSG_CAP    = 16
+
+var gIntentTeamMessages: array[INTENT_MSG_CAP, TeamMessage]
+var gIntentTeamMsgsLen:  int
+var gIntentStdOut:       array[INTENT_STDOUT_CAP, char]
+var gIntentStdOutLen:    int
+var gIntentStdErr:       array[INTENT_STDERR_CAP, char]
+var gIntentStdErrLen:    int

 proc buildIntentJson*(): string =
  ## Serialise current intent to JSON for sending to server.
@@ -237,9 +249,10 @@ proc buildIntentJson*(): string =
    obj["tracksColor"] = %gIntentTracksColor.toHex
  if gIntentGunColor != Color(0):
    obj["gunColor"]    = %gIntentGunColor.toHex
-  if gIntentTeamMessages.len > 0:
+  if gIntentTeamMsgsLen > 0:
    var msgs = newJArray()
-    for m in gIntentTeamMessages:
+    for i in 0 ..< gIntentTeamMsgsLen:
+      let m = gIntentTeamMessages[i]
      var mo = newJObject()
      mo["message"]     = %m.message
      mo["messageType"] = %m.messageType
@@ -247,13 +260,14 @@ proc buildIntentJson*(): string =
        mo["receiverId"] = %m.receiverId
      msgs.add mo
    obj["teamMessages"] = msgs
-    gIntentTeamMessages.setLen 0
-  if gIntentStdOut.len > 0:
-    obj["stdOut"] = %gIntentStdOut
-    gIntentStdOut = ""
-  if gIntentStdErr.len > 0:
-    obj["stdErr"] = %gIntentStdErr
-    gIntentStdErr = ""
+    for i in 0 ..< gIntentTeamMsgsLen: gIntentTeamMessages[i].reset
+    gIntentTeamMsgsLen = 0
+  if gIntentStdOutLen > 0:
+    obj["stdOut"] = %($gIntentStdOut[0 ..< gIntentStdOutLen])
+    gIntentStdOutLen = 0
+  if gIntentStdErrLen > 0:
+    obj["stdErr"] = %($gIntentStdErr[0 ..< gIntentStdErrLen])
+    gIntentStdErrLen = 0
  let svg = svgOutput()
  if svg.len > 0:
    obj["debugGraphics"] = %svg
@@ -311,19 +325,27 @@ proc setGunColor*(color: Color)    = gIntentGunColor    = color

 proc printToStdOut*(s: string) =
  ## Append s to this tick's stdOut payload (sent to server in BotIntent).
-  gIntentStdOut.add s
+  let n = min(s.len, INTENT_STDOUT_CAP - gIntentStdOutLen)
+  for i in 0 ..< n: gIntentStdOut[gIntentStdOutLen + i] = s[i]
+  inc gIntentStdOutLen, n

 proc printToStdErr*(s: string) =
  ## Append s to this tick's stdErr payload (sent to server in BotIntent).
-  gIntentStdErr.add s
+  let n = min(s.len, INTENT_STDERR_CAP - gIntentStdErrLen)
+  for i in 0 ..< n: gIntentStdErr[gIntentStdErrLen + i] = s[i]
+  inc gIntentStdErrLen, n

 proc broadcastTeamMessage*(message: string) =
  ## Send a message to all teammates this tick.
-  gIntentTeamMessages.add TeamMessage(message: message, messageType: "String")
+  if gIntentTeamMsgsLen < INTENT_MSG_CAP:
+    gIntentTeamMessages[gIntentTeamMsgsLen] = TeamMessage(message: message, messageType: "String")
+    inc gIntentTeamMsgsLen

 proc sendTeamMessage*(botId: int; message: string) =
  ## Send a message to a specific teammate this tick.
-  gIntentTeamMessages.add TeamMessage(message: message, messageType: "String", receiverId: botId)
+  if gIntentTeamMsgsLen < INTENT_MSG_CAP:
+    gIntentTeamMessages[gIntentTeamMsgsLen] = TeamMessage(message: message, messageType: "String", receiverId: botId)
+    inc gIntentTeamMsgsLen

 proc setAdjustGunForBodyTurn*(v: bool)   = gIntentAdjGunBody   = v
 proc setAdjustRadarForBodyTurn*(v: bool) = gIntentAdjRadarBody = v
@@ -808,6 +830,16 @@ proc botThreadEntry() {.thread.} =
      "  prevDir=" & $gPreviousDirection &
      "  prevGunDir=" & $gPreviousGunDirection)

+    # Reset graphics + intent buffers on the thread that owns them. go()'s
+    # stop path (round end) returns before buildIntentJson/clearGraphics, so
+    # the previous round's thread can leave content behind; resetting here
+    # keeps it from leaking into this round's first intent.
+    clearGraphics()
+    gIntentStdOutLen = 0
+    gIntentStdErrLen = 0
+    for i in 0 ..< gIntentTeamMsgsLen: gIntentTeamMessages[i].reset
+    gIntentTeamMsgsLen = 0
+
    dispatchPendingEvents(gBot)  # dispatch events embedded in the first tick

    try:
@@ -9,13 +9,29 @@ import ./color
 # Module-level state (single bot per process)
 # ---------------------------------------------------------------------------

-var gSvgBuffer:   string
+# ponytail: static char array + length instead of a heap string. A fresh bot
+# thread runs each round; a module-level string grown by thread N and cleared
+# ("") by thread N+1 free/reallocs a dead thread's allocator block ->
+# rawDealloc SIGSEGV (same crash class as the event queue seq; gdb-confirmed
+# in drawText mid-campaign). Static storage: no heap block crosses threads.
+const SVG_BUFFER_CAP = 16384
+
+var gSvgLen:       int
+var gSvgBuffer:    array[SVG_BUFFER_CAP, char]
 var gStrokeColor: Color = WHITE
 var gFillColor:   Color = WHITE
 var gStrokeWidth: float = 1.0
-var gFontFamily:  string = "Arial"
+var gFontFamily:  string = "Arial"  # never rebound at runtime (setFont unused)
 var gFontSize:    float = 12.0

+proc appendSvg(s: string) =
+  ## Append an SVG fragment, dropping anything past the static cap.
+  let room = SVG_BUFFER_CAP - gSvgLen
+  if room > 0:
+    let n = min(room, s.len)
+    for i in 0 ..< n: gSvgBuffer[gSvgLen + i] = s[i]
+    inc gSvgLen, n
+
 # ---------------------------------------------------------------------------
 # Internal helpers
 # ---------------------------------------------------------------------------
@@ -26,12 +42,12 @@ proc svgAttrs(): string =

 proc svgOutput*(): string =
  ## Returns the SVG fragment for this tick, or "" if nothing was drawn.
-  if gSvgBuffer.len == 0: return ""
-  "<g>" & gSvgBuffer & "</g>"
+  if gSvgLen == 0: return ""
+  "<g>" & $gSvgBuffer[0 ..< gSvgLen] & "</g>"

 proc clearGraphics*() =
  ## Reset buffer and all style globals to defaults. Called after each tick.
-  gSvgBuffer   = ""
+  gSvgLen      = 0
  gStrokeColor = WHITE
  gFillColor   = WHITE
  gStrokeWidth = 1.0
@@ -54,26 +70,26 @@ proc setFont*(family: string; size: float) =
 # ---------------------------------------------------------------------------

 proc drawLine*(x1, y1, x2, y2: float) =
-  gSvgBuffer.add &"<line x1=\"{x1}\" y1=\"{y1}\" x2=\"{x2}\" y2=\"{y2}\" {svgAttrs()}/>"
+  appendSvg(&"<line x1=\"{x1}\" y1=\"{y1}\" x2=\"{x2}\" y2=\"{y2}\" {svgAttrs()}/>")

 proc drawRectangle*(x, y, w, h: float) =
  let attrs = &"stroke=\"{gStrokeColor.toHex}\" fill=\"none\" stroke-width=\"{gStrokeWidth}\""
-  gSvgBuffer.add &"<rect x=\"{x}\" y=\"{y}\" width=\"{w}\" height=\"{h}\" {attrs}/>"
+  appendSvg(&"<rect x=\"{x}\" y=\"{y}\" width=\"{w}\" height=\"{h}\" {attrs}/>")

 proc fillRectangle*(x, y, w, h: float) =
  let attrs = &"stroke=\"none\" fill=\"{gFillColor.toHex}\""
-  gSvgBuffer.add &"<rect x=\"{x}\" y=\"{y}\" width=\"{w}\" height=\"{h}\" {attrs}/>"
+  appendSvg(&"<rect x=\"{x}\" y=\"{y}\" width=\"{w}\" height=\"{h}\" {attrs}/>")

 proc drawCircle*(x, y, r: float) =
  let attrs = &"stroke=\"{gStrokeColor.toHex}\" fill=\"none\" stroke-width=\"{gStrokeWidth}\""
-  gSvgBuffer.add &"<circle cx=\"{x}\" cy=\"{y}\" r=\"{r}\" {attrs}/>"
+  appendSvg(&"<circle cx=\"{x}\" cy=\"{y}\" r=\"{r}\" {attrs}/>")

 proc fillCircle*(x, y, r: float) =
  let attrs = &"stroke=\"none\" fill=\"{gFillColor.toHex}\""
-  gSvgBuffer.add &"<circle cx=\"{x}\" cy=\"{y}\" r=\"{r}\" {attrs}/>"
+  appendSvg(&"<circle cx=\"{x}\" cy=\"{y}\" r=\"{r}\" {attrs}/>")

 proc drawText*(text: string; x, y: float) =
-  gSvgBuffer.add &"<text x=\"{x}\" y=\"{y}\" font-family=\"{gFontFamily}\" font-size=\"{gFontSize}\">{text}</text>"
+  appendSvg(&"<text x=\"{x}\" y=\"{y}\" font-family=\"{gFontFamily}\" font-size=\"{gFontSize}\">{text}</text>")

 proc drawPolygon*(points: seq[(float, float)]) =
  var pts = ""
@@ -81,7 +97,7 @@ proc drawPolygon*(points: seq[(float, float)]) =
    if pts.len > 0: pts.add ' '
    pts.add &"{px},{py}"
  let attrs = &"stroke=\"{gStrokeColor.toHex}\" fill=\"none\" stroke-width=\"{gStrokeWidth}\""
-  gSvgBuffer.add &"<polygon points=\"{pts}\" {attrs}/>"
+  appendSvg(&"<polygon points=\"{pts}\" {attrs}/>")

 proc fillPolygon*(points: seq[(float, float)]) =
  var pts = ""
@@ -89,4 +105,4 @@ proc fillPolygon*(points: seq[(float, float)]) =
    if pts.len > 0: pts.add ' '
    pts.add &"{px},{py}"
  let attrs = &"stroke=\"none\" fill=\"{gFillColor.toHex}\""
-  gSvgBuffer.add &"<polygon points=\"{pts}\" {attrs}/>"
+  appendSvg(&"<polygon points=\"{pts}\" {attrs}/>")