feat(installer): lock package installation

lua/mason-core/installer/init.lua

@@ -16,7 +16,7 @@ local sem = Semaphore.new(settings.current.max_concurrent_installers)
 local M = {}
 
 ---@async
-local function create_prefix_dirs()
+function M.create_prefix_dirs()
     return Result.try(function(try)
         for _, p in ipairs {
             path.install_prefix(),
@@ -52,11 +52,29 @@ function M.context()
     return coroutine.yield(CONTEXT_REQUEST)
 end
 
+---@async
+---@param ctx InstallContext
+local function lock_package(ctx)
+    log.debug("Attempting to lock package", ctx.package)
+    local lockfile = path.package_lock(ctx.package.name)
+    if not ctx.opts.force and fs.async.file_exists(lockfile) then
+        log.error("Lockfile already exists.", ctx.package)
+        return Result.failure(
+            ("Lockfile exists, installation is already running in another process (pid: %s). Run with :MasonInstall --force to bypass."):format(
+                fs.sync.read_file(lockfile)
+            )
+        )
+    end
+    a.scheduler()
+    fs.async.write_file(lockfile, vim.fn.getpid())
+    log.debug("Wrote lockfile", ctx.package)
+    return Result.success(lockfile)
+end
+
 ---@async
 ---@param context InstallContext
 function M.prepare_installer(context)
     return Result.try(function(try)
-        try(create_prefix_dirs())
         local package_build_prefix = path.package_build_prefix(context.package.name)
         if fs.async.dir_exists(package_build_prefix) then
             try(Result.pcall(fs.async.rmrf, package_build_prefix))
@@ -165,61 +183,73 @@ function M.execute(handle, opts)
 
     log.fmt_info("Executing installer for %s %s", pkg, opts)
 
-    return Result.try(function(try)
-        -- 1. prepare directories and initialize cwd
-        local installer = try(M.prepare_installer(context))
-
-        -- 2. execute installer
-        try(run_installer(context, installer))
-
-        -- 3. promote temporary installation dir
-        try(Result.pcall(function()
-            context:promote_cwd()
-        end))
-
-        -- 4. link package
-        try(linker.link(context))
-
-        -- 5. build & write receipt
-        ---@type InstallReceipt
-        local receipt = try(build_receipt(context))
-        try(Result.pcall(function()
-            receipt:write(context.cwd:get())
-        end))
-    end)
+    return M.create_prefix_dirs()
+        :and_then(function()
+            return lock_package(context)
+        end)
+        :and_then(function(lockfile)
+            local release_lock = _.partial(pcall, fs.async.unlink, lockfile)
+            return Result.try(function(try)
+                -- 1. prepare directories and initialize cwd
+                local installer = try(M.prepare_installer(context))
+
+                -- 2. execute installer
+                try(run_installer(context, installer))
+
+                -- 3. promote temporary installation dir
+                try(Result.pcall(function()
+                    context:promote_cwd()
+                end))
+
+                -- 4. link package
+                try(linker.link(context))
+
+                -- 5. build & write receipt
+                ---@type InstallReceipt
+                local receipt = try(build_receipt(context))
+                try(Result.pcall(function()
+                    receipt:write(context.cwd:get())
+                end))
+            end)
+                :on_success(function()
+                    release_lock()
+                    if opts.debug then
+                        context.fs:write_file("mason-debug.log", table.concat(tailed_output, ""))
+                    end
+                end)
+                :on_failure(function()
+                    release_lock()
+                    if not opts.debug then
+                        -- clean up installation dir
+                        pcall(function()
+                            fs.async.rmrf(context.cwd:get())
+                        end)
+                    else
+                        context.fs:write_file("mason-debug.log", table.concat(tailed_output, ""))
+                        context.stdio_sink.stdout(
+                            ("[debug] Installation directory retained at %q.\n"):format(context.cwd:get())
+                        )
+                    end
+
+                    -- unlink linked executables (in the occasion an error occurs after linking)
+                    build_receipt(context):on_success(function(receipt)
+                        linker.unlink(context.package, receipt):on_failure(function(err)
+                            log.error("Failed to unlink failed installation", err)
+                        end)
+                    end)
+                end)
+        end)
         :on_success(function()
             permit:forget()
             handle:close()
             log.fmt_info("Installation succeeded for %s", pkg)
-            if opts.debug then
-                context.fs:write_file("mason-debug.log", table.concat(tailed_output, ""))
-            end
         end)
         :on_failure(function(failure)
             permit:forget()
             log.fmt_error("Installation failed for %s error=%s", pkg, failure)
             context.stdio_sink.stderr(tostring(failure))
             context.stdio_sink.stderr "\n"
 
-            if not opts.debug then
-                -- clean up installation dir
-                pcall(function()
-                    fs.async.rmrf(context.cwd:get())
-                end)
-            else
-                context.fs:write_file("mason-debug.log", table.concat(tailed_output, ""))
-                context.stdio_sink.stdout(
-                    ("[debug] Installation directory retained at %q.\n"):format(context.cwd:get())
-                )
-            end
-
-            -- unlink linked executables (in the occasion an error occurs after linking)
-            build_receipt(context):on_success(function(receipt)
-                linker.unlink(context.package, receipt):on_failure(function(err)
-                    log.error("Failed to unlink failed installation", err)
-                end)
-            end)
-
             if not handle:is_closed() and not handle.is_terminated then
                 handle:close()
             end

lua/mason-core/path.lua

@@ -58,6 +58,11 @@ function M.package_build_prefix(name)
     return M.concat { M.install_prefix "staging", name }
 end
 
+---@param name string
+function M.package_lock(name)
+    return M.package_build_prefix(("%s.lock"):format(name))
+end
+
 function M.registry_prefix()
     return M.install_prefix "registries"
 end

tests/mason-core/installer/installer_spec.lua

@@ -167,4 +167,48 @@ describe("installer", function()
             assert.equals("spawn: bash failed with exit code 42 and signal 0. ", tostring(result:err_or_nil()))
         end)
     )
+
+    it(
+        "should lock package",
+        async_test(function()
+            local handle = InstallHandleGenerator "dummy"
+            local callback = spy.new()
+            stub(handle.package.spec, "install", function()
+                a.sleep(3000)
+            end)
+
+            a.run(function()
+                return installer.execute(handle, { debug = true })
+            end, callback)
+
+            assert.wait_for(function()
+                assert.is_true(fs.sync.file_exists(path.package_lock "dummy"))
+            end)
+            handle:terminate()
+            assert.wait_for(function()
+                assert.spy(callback).was_called(1)
+            end)
+            assert.is_false(fs.sync.file_exists(path.package_lock "dummy"))
+        end)
+    )
+
+    it(
+        "should not run installer if package lock exists",
+        async_test(function()
+            local handle = InstallHandleGenerator "dummy"
+            local install = spy.new()
+            stub(handle.package.spec, "install", install)
+
+            fs.sync.write_file(path.package_lock "dummy", "dummypid")
+            local result = installer.execute(handle, { debug = true })
+            assert.is_true(fs.sync.file_exists(path.package_lock "dummy"))
+            fs.sync.unlink(path.package_lock "dummy")
+
+            assert.spy(install).was_not_called()
+            assert.equals(
+                "Lockfile exists, installation is already running in another process (pid: dummypid). Run with :MasonInstall --force to bypass.",
+                result:err_or_nil()
+            )
+        end)
+    )
 end)

tests/mason-core/managers/cargo_spec.lua

@@ -18,7 +18,7 @@ describe("cargo manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle, { version = "42.13.37" })
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(ctx, cargo.crate "my-crate")
             assert.spy(ctx.spawn.cargo).was_called(1)
             assert.spy(ctx.spawn.cargo).was_called_with {
@@ -39,7 +39,7 @@ describe("cargo manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle)
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(ctx, cargo.crate("my-crate", { git = { url = "https://my-crate.git" } }))
             assert.spy(ctx.spawn.cargo).was_called(1)
             assert.spy(ctx.spawn.cargo).was_called_with {
@@ -60,7 +60,7 @@ describe("cargo manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle)
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(ctx, cargo.crate("crate-name", { git = { url = "https://my-crate.git" } }))
             assert.spy(ctx.spawn.cargo).was_called(1)
             assert.spy(ctx.spawn.cargo).was_called_with {
@@ -81,7 +81,7 @@ describe("cargo manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle, { version = "42.13.37" })
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(ctx, cargo.crate("my-crate", { features = "lsp" }))
             assert.spy(ctx.spawn.cargo).was_called(1)
             assert.spy(ctx.spawn.cargo).was_called_with {
@@ -104,7 +104,7 @@ describe("cargo manager", function()
             stub(github, "tag")
             github.tag.returns { tag = "v2.1.1", with_receipt = mockx.just_runs }
             local ctx = InstallContextGenerator(handle, { version = "42.13.37" })
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(
                 ctx,
                 cargo.crate("my-crate", {
@@ -133,7 +133,7 @@ describe("cargo manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle)
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(ctx, cargo.crate "main-package")
             assert.same({
                 type = "cargo",

tests/mason-core/managers/composer_spec.lua

@@ -14,7 +14,7 @@ describe("composer manager", function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle, { version = "42.13.37" })
             ctx.fs.file_exists = spy.new(mockx.returns(false))
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(
                 ctx,
                 composer.packages { "main-package", "supporting-package", "supporting-package2" }
@@ -41,7 +41,7 @@ describe("composer manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle, { version = "42.13.37" })
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(
                 ctx,
                 composer.packages { "main-package", "supporting-package", "supporting-package2" }

tests/mason-core/managers/dotnet_spec.lua

@@ -7,7 +7,7 @@ describe("dotnet manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle, { version = "42.13.37" })
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(ctx, dotnet.package "main-package")
             assert.spy(ctx.spawn.dotnet).was_called(1)
             assert.spy(ctx.spawn.dotnet).was_called_with {
@@ -27,7 +27,7 @@ describe("dotnet manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle, { version = "42.13.37" })
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(ctx, dotnet.package "main-package")
             assert.same({
                 type = "dotnet",

tests/mason-core/managers/gem_spec.lua

@@ -15,7 +15,7 @@ describe("gem manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle, { version = "42.13.37" })
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(ctx, gem.packages { "main-package", "supporting-package", "supporting-package2" })
             assert.spy(ctx.spawn.gem).was_called(1)
             assert.spy(ctx.spawn.gem).was_called_with(match.tbl_containing {
@@ -39,7 +39,7 @@ describe("gem manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle, { version = "42.13.37" })
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(ctx, gem.packages { "main-package", "supporting-package", "supporting-package2" })
             assert.same({
                 type = "gem",

tests/mason-core/managers/git_spec.lua

@@ -14,7 +14,7 @@ describe("git manager", function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle)
             local err = assert.has_error(function()
-                installer.prepare_installer(ctx)
+                installer.prepare_installer(ctx):get_or_throw()
                 installer.exec_in_context(ctx, function()
                     git.clone {}
                 end)
@@ -29,7 +29,7 @@ describe("git manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle)
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(ctx, function()
                 git.clone { "https://github.com/williamboman/mason.nvim.git" }
             end)
@@ -50,7 +50,7 @@ describe("git manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle, { version = "1337" })
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(ctx, function()
                 git.clone { "https://github.com/williamboman/mason.nvim.git" }
             end)
@@ -79,7 +79,7 @@ describe("git manager", function()
         async_test(function()
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle)
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             installer.exec_in_context(ctx, function()
                 git.clone({ "https://github.com/williamboman/mason.nvim.git" }).with_receipt()
             end)

tests/mason-core/managers/github_spec.lua

@@ -14,7 +14,7 @@ describe("github release file", function()
             stub(providers.github, "get_latest_release")
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle)
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             local source = installer.exec_in_context(ctx, function()
                 return github.release_file {
                     repo = "williamboman/mason.nvim",
@@ -40,7 +40,7 @@ describe("github release file", function()
             }))
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle)
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             local source = installer.exec_in_context(ctx, function()
                 return github.release_file {
                     repo = "williamboman/mason.nvim",
@@ -68,7 +68,7 @@ describe("github release version", function()
             stub(providers.github, "get_latest_release")
             local handle = InstallHandleGenerator "dummy"
             local ctx = InstallContextGenerator(handle)
-            installer.prepare_installer(ctx)
+            installer.prepare_installer(ctx):get_or_throw()
             local source = installer.exec_in_context(ctx, function()
                 return github.release_version {
                     repo = "williamboman/mason.nvim",
@@ -88,7 +88,7 @@ describe("github release version", function()
                 providers.github.get_latest_release.returns(Result.success { tag_name = "v42" })
                 local handle = InstallHandleGenerator "dummy"
                 local ctx = InstallContextGenerator(handle)
-                installer.prepare_installer(ctx)
+                installer.prepare_installer(ctx):get_or_throw()
                 local source = installer.exec_in_context(ctx, function()
                     return github.release_version {
                         repo = "williamboman/mason.nvim",