A Windows program for synchronising command execution.
withlockfile is a small utility program which can be used to synchronise
command executions on Microsoft Windows via a lock file. This is useful to
ensure that commands accessing shared resources (and which don't synchronise
such accesses internally) always only do so sequentially.
To compile the source code, Visual Studio 2008 or later is required. No extra dependencies are imposed, and generating the executable should be a matter of running
cl /nologo /MT /W2 /EHsc withlockfile.cpp shlwapi.lib
Simply prefix an arbitrary command line with withlockfile <lockfile>, e.g.
instead of running
symstore add ... /s \\myserver\symbols
use
withlockfile "%TEMP%\mylock.lck" symstore add ... /s \\myserver\symbols
This guards the 'symstore' invocation such that no two executions are running
at the same time, using a lock file in %TEMP%\mylock.lck for synchronisation.
The original use case was adding debug symbol information to a symbol store. Writing data to a symbol store is done using the SymStore program, but the manual explains:
SymStore does not support simultaneous transactions from multiple users. It is recommended that one user be designated "administrator" of the symbol store and be responsible for all add and del transactions.
This is a problem in case the software builds generating debug symbols may be done concurrently on multiple build machines, and it's possible that two (independant) builds finish at roughly the same time and hence try to update the symbol store in parallel.
This software is licensed under the terms of the GNU General Public License Version 3.