fix: register halt_irq PM ops to poll sockets during cooperative scheduler idle

.github/workflows/test-examples.yml

@@ -223,6 +223,9 @@ jobs:
           - example: networking-py
             args: "--net -- /urllib_get.py"
             expect: "SUCCESS: urllib GET worked!"
+          - example: networking-py
+            args: "--net -- /urllib_get_no_timeout.py"
+            expect: "SUCCESS: urllib GET \\(no timeout\\) worked!"
           - example: networking-py
             args: "--port 8080 -- /echo_server_test.py"
             expect: "SUCCESS: bind\\+listen on port 8080 allowed"
@@ -613,6 +616,9 @@ jobs:
           - example: networking-py
             args: "--net -- /urllib_get.py"
             expect: "SUCCESS: urllib GET worked!"
+          - example: networking-py
+            args: "--net -- /urllib_get_no_timeout.py"
+            expect: "SUCCESS: urllib GET \\(no timeout\\) worked!"
           - example: networking-py
             args: "--port 8080 -- /echo_server_test.py"
             expect: "SUCCESS: bind\\+listen on port 8080 allowed"
@@ -753,16 +759,30 @@ jobs:
             }
           }
 
+          # Helper: run a command with a per-test timeout (seconds).
+          function Invoke-WithTimeout {
+            param([int]$Seconds, [string]$Exe, [string[]]$ArgList)
+            $outFile = Join-Path $env:RUNNER_TEMP 'hl-test-out.log'
+            $proc = Start-Process -FilePath $Exe -ArgumentList $ArgList `
+              -NoNewWindow -RedirectStandardOutput $outFile -RedirectStandardError "$outFile.err" -PassThru
+            if (-not $proc.WaitForExit($Seconds * 1000)) {
+              Stop-Process -Id $proc.Id -Force -ErrorAction SilentlyContinue
+              Write-Host "FAIL: timed out after ${Seconds}s"
+              Get-Content $outFile -ErrorAction SilentlyContinue
+              exit 1
+            }
+            $script:out = Get-Content $outFile -Raw -ErrorAction SilentlyContinue
+            $script:rc = $proc.ExitCode
+          }
+
           switch ($driver) {
             'multifn-test' {
-              $out = & multifn-test $kernel $cpio 2>&1
-              $rc = $LASTEXITCODE
+              Invoke-WithTimeout -Seconds 60 -Exe 'multifn-test' -ArgList @($kernel, $cpio)
             }
             'pydriver-run' {
               "print('hello from driver')" | Out-File -Encoding ascii tiny.py
               $tiny = (Resolve-Path "tiny.py").Path
-              $out = & pydriver-run $kernel $cpio $tiny 2>&1
-              $rc = $LASTEXITCODE
+              Invoke-WithTimeout -Seconds 120 -Exe 'pydriver-run' -ArgList @($kernel, $cpio, $tiny)
             }
             default {
               $argList = @()
@@ -773,16 +793,15 @@ jobs:
               if ($memory -ne '') {
                 $memArgs = @('-m', $memory)
               }
-              $out = & hyperlight-unikraft -q @memArgs `
-                $kernel --initrd $cpio @mountArgs @toolArgs @argList 2>&1
-              $rc = $LASTEXITCODE
+              Invoke-WithTimeout -Seconds 120 -Exe 'hyperlight-unikraft' `
+                -ArgList (@('-q') + $memArgs + @($kernel, '--initrd', $cpio) + $mountArgs + $toolArgs + $argList)
             }
           }
 
-          $outStr = ($out | Out-String)
+          if ($null -eq $out) { $out = '' }
           Write-Host "=== output (exit=$rc) ==="
-          Write-Host $outStr
-          if (-not ($outStr -match $expect)) {
+          Write-Host $out
+          if (-not ($out -match $expect)) {
             Write-Host "FAIL: did not match /$expect/"
             exit 1
           }

examples/networking-py/Dockerfile

@@ -8,6 +8,7 @@ FROM ${BASE} AS rootfs
 COPY http_get.py /http_get.py
 COPY echo_server.py /echo_server.py
 COPY urllib_get.py /urllib_get.py
+COPY urllib_get_no_timeout.py /urllib_get_no_timeout.py
 COPY https_test.py /https_test.py
 COPY echo_server_test.py /echo_server_test.py
 

examples/networking-py/urllib_get_no_timeout.py

@@ -0,0 +1,25 @@
+"""HTTP GET using urllib WITHOUT an explicit timeout.
+
+Same as urllib_get.py but omits the timeout= argument to urlopen().
+This exercises the code path used by mxc, where the Unikraft guest
+kernel relies on the idle thread's halt_irq callback to poll sockets
+via __hl_sleep rather than an explicit timeout-driven poll cycle.
+"""
+import urllib.request
+import sys
+
+URL = "http://example.com/"
+
+print(f"Fetching {URL} (no timeout) ...")
+try:
+    with urllib.request.urlopen(URL) as resp:
+        body = resp.read().decode("utf-8", errors="replace")
+        print(f"Status: {resp.status}")
+        print(f"Body length: {len(body)} bytes")
+        if "Example Domain" in body:
+            print("SUCCESS: urllib GET (no timeout) worked!")
+        else:
+            print("WARNING: unexpected body content")
+except Exception as e:
+    print(f"FAILED: {e}")
+    sys.exit(1)