Prevent multiple processes from bootstrapping vcpkg simultaneously

lucpelletier · Nov 11, 2021 · 7332335 · 7332335
1 parent 806aec6
commit 7332335
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Showing 3 changed files with 70 additions and 27 deletions.
diff --git a/pmm/conan.cmake b/pmm/conan.cmake
@@ -113,32 +113,14 @@ function(_pmm_conan_managed_ensure_installed)
 
     # Before we continue, lock access to the virtualenv
     _pmm_log(DEBUG "PMM Conan venv directory is [${_PMM_CONAN_MANAGED_VENV_DIR}]")
-    file(
-        LOCK "${_PMM_CONAN_MANAGED_VENV_DIR}" DIRECTORY
-        GUARD FUNCTION
-        TIMEOUT 3
-        RESULT_VARIABLE lock_res
+    _pmm_verbose_lock(
+        "${_PMM_CONAN_MANAGED_VENV_DIR}" DIRECTORY
+        FIRST_MESSAGE "Anohter CMake instance is installing Conan. Please wait..."
+        FAIL_MESSAGE "Unable to obtain the virtualenv lock. Check if there is a stuck process holding it open."
+        RESULT_VARIABLE did_lock
         )
-    if(lock_res)
-        _pmm_log("Another CMake instance is installing Conan. Please wait...")
-        file(
-            LOCK "${_PMM_CONAN_MANAGED_VENV_DIR}" DIRECTORY
-            GUARD FUNCTION
-            TIMEOUT 60
-            RESULT_VARIABLE lock_res
-            )
-        if(lock_res)
-            _pmm_log("Unable to obtain lock after 60 seconds. We'll try for one more minute...")
-            file(
-                LOCK "${_PMM_CONAN_MANAGED_VENV_DIR}" DIRECTORY
-                GUARD FUNCTION
-                TIMEOUT 60
-                RESULT_VARIABLE lock_res
-                )
-            if(lock_res)
-                message(FATAL_ERROR "Unable to obtain exclusive lock on directory ${_PMM_CONAN_MANAGED_VENV_DIR}. Abort.")
-            endif()
-        endif()
+    if(NOT did_lock)
+        message(FATAL_ERROR "Unable to obtain exclusive lock on directory ${_PMM_CONAN_MANAGED_VENV_DIR}. Abort.")
     endif()
 
     if(NOT must_reinstall)
@@ -173,11 +155,13 @@ function(_pmm_conan_managed_ensure_installed)
     endif()
 
     if(NOT must_reinstall)
+        file(LOCK "${_PMM_CONAN_MANAGED_VENV_DIR}" DIRECTORY RELEASE)
         return()
     endif()
 
     if(PMM_CONAN_MANAGED_NO_INSTALL)
         # Caller has requested that we do not run an install.
+        file(LOCK "${_PMM_CONAN_MANAGED_VENV_DIR}" DIRECTORY RELEASE)
         return()
     endif()
 
@@ -193,6 +177,7 @@ function(_pmm_conan_managed_ensure_installed)
     if(NOT PMM_CONAN_EXECUTABLE)
         message(FATAL_ERROR "We failed to install Conan in a new virtualenv.")
     endif()
+    file(LOCK "${_PMM_CONAN_MANAGED_VENV_DIR}" DIRECTORY RELEASE)
 endfunction()
 
 

diff --git a/pmm/util.cmake b/pmm/util.cmake
@@ -132,6 +132,7 @@ function(_pmm_get_var_from_file filepath varname)
     set(${varname} ${propt} PARENT_SCOPE)
 endfunction()
 
+
 function(_pmm_generate_cli_scripts force)
     # The sh scipt
     if(NOT EXISTS "${CMAKE_BINARY_DIR}/pmm-cli.sh" OR ${force})
@@ -148,6 +149,7 @@ function(_pmm_generate_cli_scripts force)
     endif()
 endfunction()
 
+
 function(_pmm_generate_shim name executable)
     # The sh scipt
     if (NOT EXISTS "${CMAKE_BINARY_DIR}/${name}.sh")
@@ -163,3 +165,47 @@ function(_pmm_generate_shim name executable)
         file(WRITE "${CMAKE_BINARY_DIR}/${name}.bat" "@echo off\n\"${executable}\" %*")
     endif ()
 endfunction()
+
+
+function(_pmm_verbose_lock fpath)
+    _pmm_parse_args(
+        . DIRECTORY
+        - FIRST_MESSAGE FAIL_MESSAGE RESULT_VARIABLE
+        )
+    set(arg_dir)
+    if(ARG_DIRECTORY)
+        set(arg_dir "DIRECTORY")
+    endif()
+    set("${ARG_RESULT_VARIABLE}" TRUE PARENT_SCOPE)
+    file(
+        LOCK "${fpath}" ${arg_dir}
+        GUARD PROCESS
+        TIMEOUT 3
+        RESULT_VARIABLE lock_res
+        )
+    if(NOT lock_res)
+        return()
+    endif()
+    # Couldn't get the lock
+    _pmm_log("${ARG_FIRST_MESSAGE}")
+    file(
+        LOCK "${dir}" ${arg_dir}
+        GUARD PROCESS
+        TIMEOUT 60
+        RESULT_VARIABLE lock_res
+        )
+    if(NOT lock_res)
+        return()
+    endif()
+    _pmm_log("Unable to obtain lock after 60 seconds. We'll try for one more minute...")
+    file(
+        LOCK "${_PMM_CONAN_MANAGED_VENV_DIR}" ${arg_dir}
+        GUARD PROCESS
+        TIMEOUT 60
+        RESULT_VARIABLE lock_res
+        )
+    if(lock_res)
+        message(WARNING "${ARG_FAIL_MESSAGE}")
+        set("${ARG_RESULT_VARIABLE}" FALSE PARENT_SCOPE)
+    endif()
+endfunction()
diff --git a/pmm/vcpkg.cmake b/pmm/vcpkg.cmake
@@ -1,15 +1,25 @@
 # Download vcpkg at revision `rev` and place the built result in `dir`
 function(_pmm_ensure_vcpkg dir rev)
+    _pmm_verbose_lock(
+        "${dir}" DIRECTORY
+        FIRST_MESSAGE "Another CMake instance is bootstrapping vcpkg. Please wait..."
+        FAIL_MESSAGE "Unable to obtain vcpkg bootstrapping lock. Check if there is a stuck process holding it open."
+        RESULT_VARIABLE did_lock
+        )
+    if(NOT did_lock)
+        message(FATAL_ERROR "Unable to obtain exclusive lock on directory ${_PMM_CONAN_MANAGED_VENV_DIR}. Abort.")
+    endif()
     # The final executable is deterministically placed:
     set(PMM_VCPKG_EXECUTABLE "${dir}/vcpkg${CMAKE_EXECUTABLE_SUFFIX}"
         CACHE FILEPATH
         "Path to vcpkg for this project"
         FORCE
         )
     _pmm_log(DEBUG "Expecting vcpkg executable at ${PMM_VCPKG_EXECUTABLE}")
-    # Check if the given directory already exists, which means we've already
+    # Check if the vcpkg exe already exists, which means we've already
     # bootstrapped and installed it
-    if(IS_DIRECTORY "${dir}")
+    if(EXISTS "${PMM_VCPKG_EXECUTABLE}")
+        file(LOCK "${dir}" DIRECTORY RELEASE)
         return()
     endif()
     # We do the build in a temporary directory, then rename that temporary dir
@@ -81,6 +91,8 @@ function(_pmm_ensure_vcpkg dir rev)
     _pmm_log("vcpkg successfully bootstrapped to ${dir}")
     # Fix for "Could not detect vcpkg-root."
     execute_process(COMMAND ${CMAKE_COMMAND} -E sleep 1)
+    # Release the exclusive lock on the directory we obtained at the top of this fn
+    file(LOCK "${dir}" DIRECTORY RELEASE)
 endfunction()
 
 function(_pmm_vcpkg_default_triplet out)