Lock Cache before downloading Dart SDK on Windows (#7931)
diff --git a/bin/flutter.bat b/bin/flutter.bat
index 5f98b4f..1bdb90a 100644
--- a/bin/flutter.bat
+++ b/bin/flutter.bat
@@ -17,6 +17,7 @@
FOR %%i IN ("%~dp0..") DO SET FLUTTER_ROOT=%%~fi
SET flutter_tools_dir=%FLUTTER_ROOT%\packages\flutter_tools
+SET cache_dir=%FLUTTER_ROOT%\bin\cache
SET snapshot_path=%FLUTTER_ROOT%\bin\cache\flutter_tools.snapshot
SET stamp_path=%FLUTTER_ROOT%\bin\cache\flutter_tools.stamp
SET script_path=%flutter_tools_dir%\bin\flutter_tools.dart
@@ -33,42 +34,57 @@
EXIT /B
)
+REM Ensure that bin/cache exists.
+IF NOT EXIST "%cache_dir%" MKDIR "%cache_dir%"
+
REM To debug the tool, you can uncomment the following line to enable checked mode and set an observatory port:
REM SET FLUTTER_TOOL_ARGS="--observe=65432 --checked"
-PUSHD "%flutter_root%"
-FOR /f %%r IN ('git rev-parse HEAD') DO SET revision=%%r
-POPD
+:acquire_lock
+2>NUL (
+ REM "3" is now stderr because of "2>NUL".
+ CALL :subroutine %* 2>&3 9> "%cache_dir%\flutter.bat.lock" || GOTO acquire_lock
+)
+GOTO :after_subroutine
-REM The following IF conditions are all linked with a logical OR. However,
-REM there is no OR operator in batch and a GOTO construct is used as replacement.
-IF NOT EXIST "%snapshot_path%" GOTO do_snapshot
-IF NOT EXIST "%stamp_path%" GOTO do_snapshot
-SET /p stamp_value=<"%stamp_path%"
-IF !stamp_value! NEQ !revision! GOTO do_snapshot
-REM Get modified timestamps
-FOR %%f IN ("%flutter_tools_dir%\pubspec.yaml") DO SET yamlt=%%~tf
-FOR %%a IN ("%flutter_tools_dir%\pubspec.lock") DO SET lockt=%%~ta
-IF !lockt! LSS !yamlt! GOTO do_snapshot
-
-GOTO after_snapshot
-
-:do_snapshot
- MKDIR "%FLUTTER_ROOT%\bin\cache" 2> NUL
- ECHO: > "%FLUTTER_ROOT%\bin\cache\.dartignore"
-
- ECHO Checking Dart SDK version...
- CALL PowerShell.exe -ExecutionPolicy Bypass -Command "& '%FLUTTER_ROOT%/bin/internal/update_dart_sdk.ps1'"
-
- ECHO Updating flutter tool...
- del "%flutter_tools_dir%\pubspec.lock"
- PUSHD "%flutter_tools_dir%"
- CALL "%pub%" get --verbosity=error --no-packages-dir
+:subroutine
+ PUSHD "%flutter_root%"
+ FOR /f %%r IN ('git rev-parse HEAD') DO SET revision=%%r
POPD
- CALL "%dart%" --snapshot="%snapshot_path%" --packages="%flutter_tools_dir%\.packages" "%script_path%"
- >"%stamp_path%" ECHO %revision%
-:after_snapshot
+ REM The following IF conditions are all linked with a logical OR. However,
+ REM there is no OR operator in batch and a GOTO construct is used as replacement.
+ IF NOT EXIST "%snapshot_path%" GOTO do_snapshot
+ IF NOT EXIST "%stamp_path%" GOTO do_snapshot
+ SET /p stamp_value=<"%stamp_path%"
+ IF !stamp_value! NEQ !revision! GOTO do_snapshot
+ REM Get modified timestamps
+ FOR %%f IN ("%flutter_tools_dir%\pubspec.yaml") DO SET yamlt=%%~tf
+ FOR %%a IN ("%flutter_tools_dir%\pubspec.lock") DO SET lockt=%%~ta
+ IF !lockt! LSS !yamlt! GOTO do_snapshot
+
+ REM Everything is uptodate - exit subroutine
+ EXIT /B
+
+ :do_snapshot
+ MKDIR "%FLUTTER_ROOT%\bin\cache" 2> NUL
+ ECHO: > "%FLUTTER_ROOT%\bin\cache\.dartignore"
+
+ ECHO Checking Dart SDK version...
+ CALL PowerShell.exe -ExecutionPolicy Bypass -Command "& '%FLUTTER_ROOT%/bin/internal/update_dart_sdk.ps1'"
+
+ ECHO Updating flutter tool...
+ del "%flutter_tools_dir%\pubspec.lock"
+ PUSHD "%flutter_tools_dir%"
+ CALL "%pub%" get --verbosity=error --no-packages-dir
+ POPD
+ CALL "%dart%" --snapshot="%snapshot_path%" --packages="%flutter_tools_dir%\.packages" "%script_path%"
+ >"%stamp_path%" ECHO %revision%
+
+ REM Exit Subroutine
+ EXIT /B
+
+:after_subroutine
CALL "%dart%" %FLUTTER_TOOL_ARGS% "%snapshot_path%" %*
