file: Add LOCK subcommand to do file and directory locking

Provide options to fail without blocking or to block up to a timeout.
Provide options to specify the scope containing the lock so it can be
released automatically at the end of a function, file, or process.

Extend the RunCMake.file test with cases covering the file(LOCK) command
usage and error cases.

1 files changed, 40 insertions, 0 deletions

diff --git a/Tests/RunCMake/file/LOCK.cmake b/Tests/RunCMake/file/LOCK.cmake
new file mode 100644
index 0000000..8eff084
--- /dev/null
+++ b/Tests/RunCMake/file/LOCK.cmake
@@ -0,0 +1,40 @@
+set(lfile "${CMAKE_CURRENT_BINARY_DIR}/file-to-lock")
+set(ldir "${CMAKE_CURRENT_BINARY_DIR}/dir-to-lock")
+
+message(STATUS "Simple lock")
+file(LOCK ${lfile})
+
+message(STATUS "Directory lock")
+file(LOCK ${ldir} DIRECTORY)
+
+message(STATUS "Release")
+file(LOCK ${lfile} RELEASE)
+
+function(foo)
+  file(LOCK "${lfile}" GUARD FUNCTION)
+endfunction()
+
+message(STATUS "Lock function scope")
+foo()
+
+message(STATUS "Lock file scope")
+add_subdirectory(subdir_test_unlock)
+
+message(STATUS "Lock process scope")
+file(LOCK "${lfile}" GUARD PROCESS)
+
+message(STATUS "Error double lock")
+file(LOCK "${lfile}" RESULT_VARIABLE lock_result)
+if(lock_result STREQUAL "File already locked")
+  message(STATUS "Ok")
+else()
+  message(STATUS FATAL_ERROR "Expected error message")
+endif()
+
+message(STATUS "Timeout 0")
+file(LOCK "${lfile}" RELEASE)
+file(LOCK "${lfile}" TIMEOUT 0)
+
+message(STATUS "Timeout not 0")
+file(LOCK "${lfile}" RELEASE)
+file(LOCK "${lfile}" TIMEOUT 3)