was/Stock: add MOUNT_LISTEN_STREAM support

debian/changelog

@@ -1,7 +1,7 @@
 cm4all-beng-proxy (18.0.85) unstable; urgency=low
 
   * fcgi: fix crash bug on error during early process initialization
-  * fcgi: add MOUNT_LISTEN_STREAM support
+  * fcgi, was: add MOUNT_LISTEN_STREAM support
 
  --   
 

src/bp/Main.cxx

@@ -442,6 +442,7 @@ try {
 #ifdef HAVE_LIBWAS
 	instance.was_stock = new WasStock(instance.event_loop,
 					  *instance.spawn_service,
+					  instance.listen_stream_spawn_stock.get(),
 					  child_log_socket, child_log_options,
 					  instance.config.was_stock_limit,
 					  instance.config.was_stock_max_idle);

src/was/Launch.cxx

@@ -3,14 +3,20 @@
 // author: Max Kellermann <[email protected]>
 
 #include "Launch.hxx"
+#include "pool/tpool.hxx"
 #include "spawn/Interface.hxx"
+#include "spawn/ListenStreamSpawnStock.hxx"
+#include "spawn/Mount.hxx"
 #include "spawn/Prepared.hxx"
 #include "spawn/ChildOptions.hxx"
 #include "net/SocketDescriptor.hxx"
 #include "io/FdHolder.hxx"
+#include "AllocatorPtr.hxx"
 
 static auto
 WasLaunch(SpawnService &spawn_service,
+	  ListenStreamSpawnStock *listen_stream_spawn_stock,
+	  SharedLease &listen_stream_lease,
 	  const char *name,
 	  const char *executable_path,
 	  std::span<const char *const> args,
@@ -23,6 +29,22 @@ WasLaunch(SpawnService &spawn_service,
 	p.stdout_fd = socket.output;
 	p.stdin_fd = socket.input;
 
+	const TempPoolLease tpool;
+	if (p.ns.mount.mount_listen_stream.data() != nullptr) {
+		if (listen_stream_spawn_stock == nullptr)
+			throw std::runtime_error{"No ListenStreamSpawnStock"};
+
+		const AllocatorPtr alloc{tpool};
+
+		/* copy the mount list before editing it, which is
+		   currently a shallow copy pointing to inside the
+		   translation cache*/
+		p.ns.mount.mounts = Mount::CloneAll(alloc, p.ns.mount.mounts);
+
+		listen_stream_lease = listen_stream_spawn_stock->Apply(alloc,
+								       p.ns.mount);
+	}
+
 	p.Append(executable_path);
 	for (auto i : args)
 		p.Append(i);
@@ -38,6 +60,7 @@ WasLaunch(SpawnService &spawn_service,
 
 WasProcess
 was_launch(SpawnService &spawn_service,
+	   ListenStreamSpawnStock *listen_stream_spawn_stock,
 	   const char *name,
 	   const char *executable_path,
 	   std::span<const char *const> args,
@@ -50,7 +73,9 @@ was_launch(SpawnService &spawn_service,
 	process.input.SetNonBlocking();
 	process.output.SetNonBlocking();
 
-	process.handle = WasLaunch(spawn_service, name, executable_path, args,
+	process.handle = WasLaunch(spawn_service, listen_stream_spawn_stock,
+				   process.listen_stream_lease,
+				   name, executable_path, args,
 				   options, std::move(stderr_fd),
 				   std::move(s.second));
 	return process;

src/was/Launch.hxx

@@ -6,17 +6,24 @@
 
 #include "was/async/Socket.hxx"
 #include "spawn/ProcessHandle.hxx"
+#include "util/SharedLease.hxx"
 
 #include <memory>
 #include <span>
 
 class SpawnService;
+class ListenStreamSpawnStock;
 class ChildProcessHandle;
 struct ChildOptions;
 
 struct WasProcess : WasSocket {
 	std::unique_ptr<ChildProcessHandle> handle;
 
+	/**
+	 * A lease obtained from #ListenStreamSpawnStock.
+	 */
+	SharedLease listen_stream_lease;
+
 	WasProcess() = default;
 
 	explicit WasProcess(WasSocket &&_socket) noexcept
@@ -30,6 +37,7 @@ struct WasProcess : WasSocket {
  */
 WasProcess
 was_launch(SpawnService &spawn_service,
+	   ListenStreamSpawnStock *listen_stream_spawn_stock,
 	   const char *name,
 	   const char *executable_path,
 	   std::span<const char *const> args,

src/was/Stock.cxx

@@ -37,6 +37,8 @@ class WasChild final : public WasStockConnection, ExitListener {
 
 	std::unique_ptr<ChildProcessHandle> handle;
 
+	SharedLease listen_stream_lease;
+
 	const bool disposable;
 
 public:
@@ -63,6 +65,7 @@ class WasChild final : public WasStockConnection, ExitListener {
 		    const ChildErrorLogOptions &log_options) {
 		auto process =
 			was_launch(was_stock.GetSpawnService(),
+				   was_stock.GetListenStreamSpawnStock(),
 				   GetStockName(),
 				   params.executable_path,
 				   params.args,
@@ -74,6 +77,8 @@ class WasChild final : public WasStockConnection, ExitListener {
 		handle = std::move(process.handle);
 		handle->SetExitListener(*this);
 
+		listen_stream_lease = std::move(process.listen_stream_lease);
+
 		WasSocket &socket = process;
 		Open(std::move(socket));
 	}

src/was/Stock.hxx

@@ -16,12 +16,14 @@ struct pool;
 struct ChildOptions;
 struct WasSocket;
 class SpawnService;
+class ListenStreamSpawnStock;
 
 /**
  * Launch and manage WAS child processes.
  */
 class WasStock final : StockClass {
 	SpawnService &spawn_service;
+	ListenStreamSpawnStock *const listen_stream_spawn_stock;
 	const SocketDescriptor log_socket;
 	const ChildErrorLogOptions log_options;
 
@@ -38,10 +40,12 @@ class WasStock final : StockClass {
 
 public:
 	explicit WasStock(EventLoop &event_loop, SpawnService &_spawn_service,
+			  ListenStreamSpawnStock *_listen_stream_spawn_stock,
 			  const SocketDescriptor _log_socket,
 			  const ChildErrorLogOptions &_log_options,
 			  unsigned limit, unsigned max_idle) noexcept
 		:spawn_service(_spawn_service),
+		 listen_stream_spawn_stock(_listen_stream_spawn_stock),
 		 log_socket(_log_socket), log_options(_log_options),
 		 stock(event_loop, *this, limit, max_idle,
 		       std::chrono::minutes(10)) {}
@@ -50,6 +54,10 @@ public:
 		return spawn_service;
 	}
 
+	auto *GetListenStreamSpawnStock() const noexcept {
+		return listen_stream_spawn_stock;
+	}
+
 	void FadeAll() noexcept {
 		stock.FadeAll();
 	}

test/meson.build

@@ -166,6 +166,7 @@ if libwas.found()
   executable(
     'run_was',
     'run_was.cxx',
+    '../src/spawn/ListenStreamSpawnStock.cxx',
     include_directories: inc,
     dependencies: [
       test_instance_dep,

test/run_was.cxx

@@ -204,7 +204,7 @@ try {
 	LocalSpawnService spawn_service(spawn_config, context.event_loop,
 					child_process_registry);
 
-	context.process = was_launch(spawn_service, "was",
+	context.process = was_launch(spawn_service, nullptr, "was",
 				     argv[1], {},
 				     child_options, {});