Support select in libc VFS plugin by read_ready()

repos/dde_rump/src/lib/vfs/rump/vfs_rump.cc

@@ -470,6 +470,8 @@ class Vfs::Rump_file_system : public File_system
 			return READ_OK;
 		}
 
+		bool read_ready(Vfs_handle *) override { return true; }
+
 		Ftruncate_result ftruncate(Vfs_handle *vfs_handle, file_size len) override
 		{
 			Rump_vfs_handle *handle =
@@ -525,7 +527,8 @@ class Rump_factory : public Vfs::File_system_factory
 
 		Vfs::File_system *create(Genode::Env       &env,
 		                         Genode::Allocator &alloc,
-		                         Genode::Xml_node   config) override
+		                         Genode::Xml_node   config,
+		                         Vfs::Io_response_handler &) override
 		{
 			return new (alloc) Vfs::Rump_file_system(config);
 		}
@@ -538,10 +541,11 @@ extern "C" Vfs::File_system_factory *vfs_file_system_factory(void)
 	{
 		Vfs::File_system *create(Genode::Env &env,
 		                         Genode::Allocator &alloc,
-		                         Genode::Xml_node node) override
+		                         Genode::Xml_node node,
+		                         Vfs::Io_response_handler &io_handler) override
 		{
 			static Rump_factory factory(env, alloc);
-			return factory.create(env, alloc, node);
+			return factory.create(env, alloc, node, io_handler);
 		}
 	};
 

repos/libports/run/libc_select.run

@@ -1,6 +1,6 @@
 set build_components {
-	core init drivers/timer
-	test/libc_select
+	core init drivers/timer server/terminal_crosslink
+	test/libc_select test/libc_counter
 }
 
 build $build_components
@@ -29,19 +29,33 @@ set config {
 		<resource name="RAM" quantum="2M"/>
 		<provides> <service name="Timer"/> </provides>
 	</start>
+	<start name="terminal_crosslink">
+		<resource name="RAM" quantum="1M"/>
+		<provides> <service name="Terminal"/> </provides>
+	</start>
 
+	<start name="test-libc_counter-source">
+		<resource name="RAM" quantum="8M"/>
+		<config ld_verbose="yes">
+			<vfs>
+				<dir name="dev"> <terminal/> <log/> </dir>
+			</vfs>
+			<libc stdin="/dev/terminal" stdout="/dev/terminal" stderr="/dev/log"/>
+		</config>
+	</start>
 	<start name="test-libc_select">
 		<resource name="RAM" quantum="4M"/>
 		<config>
 			<arg value="test-libc_select"/>
 			<arg value="/dev/log"/>
+			<arg value="/dev/terminal"/>
 			<!--
 			<arg value=":"/>
 			<arg value="/dev/log"/>
 			-->
 			<vfs>
 				<dir name="dev">
-					<log/> <null/> <zero/>
+					<log/> <null/> <zero/> <terminal/>
 				</dir>
 			</vfs>
 			<libc stdin="/dev/null" stdout="/dev/log" stderr="/dev/log"/>
@@ -53,8 +67,8 @@ set config {
 install_config $config
 
 set boot_modules {
-	core init timer
-	test-libc_select
+	core init timer terminal_crosslink
+	test-libc_counter-source test-libc_select
 	ld.lib.so libc.lib.so libm.lib.so stdcxx.lib.so pthread.lib.so
 	libc_pipe.lib.so
 }

repos/libports/src/lib/libc/file_operations.cc

@@ -2,11 +2,13 @@
  * \brief  libc file operations
  * \author Christian Prochaska
  * \author Norman Feske
+ * \author Emery Hemingway
+ * \author Christian Helmuth
  * \date   2010-01-21
  */
 
 /*
- * Copyright (C) 2010-2013 Genode Labs GmbH
+ * Copyright (C) 2010-2017 Genode Labs GmbH
  *
  * This file is part of the Genode OS framework, which is distributed
  * under the terms of the GNU General Public License version 2.
@@ -216,8 +218,10 @@ extern "C" int chdir(const char *path)
 }
 
 
-extern "C" int _close(int libc_fd) {
-	FD_FUNC_WRAPPER(close, libc_fd); }
+extern "C" int _close(int libc_fd)
+{
+	FD_FUNC_WRAPPER(close, libc_fd);
+}
 
 
 extern "C" int close(int libc_fd) { return _close(libc_fd); }
@@ -538,8 +542,10 @@ extern "C" int pipe(int pipefd[2])
 }
 
 
-extern "C" ssize_t _read(int libc_fd, void *buf, ::size_t count) {
-	FD_FUNC_WRAPPER(read, libc_fd, buf, count); }
+extern "C" ssize_t _read(int libc_fd, void *buf, ::size_t count)
+{
+	FD_FUNC_WRAPPER(read, libc_fd, buf, count);
+}
 
 
 extern "C" ssize_t read(int libc_fd, void *buf, ::size_t count)

repos/libports/src/lib/libc/libc_file.h

@@ -1,11 +1,12 @@
 /*
  * \brief  File-operation utilities
  * \author Christian Helmuth
+ * \author Emery Hemingway
  * \date   2015-06-30
  */
 
 /*
- * Copyright (C) 2015 Genode Labs GmbH
+ * Copyright (C) 2015-2017 Genode Labs GmbH
  *
  * This file is part of the Genode OS framework, which is distributed
  * under the terms of the GNU General Public License version 2.
@@ -72,5 +73,4 @@ static inline Libc::File_descriptor *libc_fd_to_fd(int libc_fd, const char *func
 #define FNAME_FUNC_WRAPPER(func_name, path, ...) \
 	FNAME_FUNC_WRAPPER_GENERIC(return, func_name, path, ##__VA_ARGS__ )
 
-
 #endif /* _LIBC_FILE_H_ */

repos/libports/src/lib/libc/vfs_plugin.cc

@@ -1,11 +1,13 @@
 /*
- * \brief   Libc plugin for using a process-local virtual file system
- * \author  Norman Feske
- * \date    2014-04-09
+ * \brief  Libc plugin for using a process-local virtual file system
+ * \author Norman Feske
+ * \author Christian Helmuth
+ * \author Emery Hemingway
+ * \date   2014-04-09
  */
 
 /*
- * Copyright (C) 2014-2016 Genode Labs GmbH
+ * Copyright (C) 2014-2017 Genode Labs GmbH
  *
  * This file is part of the Genode OS framework, which is distributed
  * under the terms of the GNU General Public License version 2.
@@ -36,7 +38,7 @@
 #include <vfs_plugin.h>
 
 /* libc-internal includes */
-#include <libc_mem_alloc.h>
+#include "libc_mem_alloc.h"
 #include "libc_errno.h"
 #include "task.h"
 
@@ -725,3 +727,72 @@ int Libc::Vfs_plugin::munmap(void *addr, ::size_t)
 	Libc::mem_alloc()->free(addr);
 	return 0;
 }
+
+
+bool Libc::Vfs_plugin::supports_select(int nfds,
+                                       fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+                                       struct timeval *timeout)
+{
+	/* return true if any file descriptor (which is set) belongs to the VFS */
+	for (int fd = 0; fd < nfds; ++fd) {
+
+		if (FD_ISSET(fd, readfds) || FD_ISSET(fd, writefds) || FD_ISSET(fd, exceptfds)) {
+
+			Libc::File_descriptor *fdo =
+				Libc::file_descriptor_allocator()->find_by_libc_fd(fd);
+
+			if (fdo && (fdo->plugin == this))
+				return true;
+		}
+	}
+	return false;
+}
+
+
+int Libc::Vfs_plugin::select(int nfds,
+                             fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+                             struct timeval *timeout)
+{
+	int nready = 0;
+
+	fd_set const in_readfds  = *readfds;
+	fd_set const in_writefds = *writefds;
+	/* XXX exceptfds not supported */
+
+	/* clear fd sets */
+	FD_ZERO(readfds);
+	FD_ZERO(writefds);
+	FD_ZERO(exceptfds);
+
+	for (int fd = 0; fd < nfds; ++fd) {
+
+		Libc::File_descriptor *fdo =
+			Libc::file_descriptor_allocator()->find_by_libc_fd(fd);
+
+		/* handle only fds that belong to this plugin */
+		if (!fdo || (fdo->plugin != this))
+			continue;
+
+		Vfs::Vfs_handle *handle = vfs_handle(fdo);
+		if (!handle) continue;
+
+		if (FD_ISSET(fd, &in_readfds)) {
+			if (handle->fs().read_ready(handle)) {
+				FD_SET(fd, readfds);
+				++nready;
+			} else {
+//				handle->fs().notify_read_ready(handle);
+			}
+		}
+
+		if (FD_ISSET(fd, &in_writefds)) {
+			if (true /* XXX always writeable */) {
+				FD_SET(fd, writefds);
+				++nready;
+			}
+		}
+
+		/* XXX exceptfds not supported */
+	}
+	return nready;
+}

repos/libports/src/lib/libc/vfs_plugin.h

@@ -1,11 +1,13 @@
 /*
- * \brief   Libc plugin for using a process-local virtual file system
- * \author  Norman Feske
- * \date    2014-04-09
+ * \brief  Libc plugin for using a process-local virtual file system
+ * \author Norman Feske
+ * \author Emery Hemingway
+ * \author Christian Helmuth
+ * \date   2014-04-09
  */
 
 /*
- * Copyright (C) 2014-2016 Genode Labs GmbH
+ * Copyright (C) 2014-2017 Genode Labs GmbH
  *
  * This file is part of the Genode OS framework, which is distributed
  * under the terms of the GNU General Public License version 2.
@@ -71,9 +73,6 @@ class Libc::Vfs_plugin : public Libc::Plugin
 
 	public:
 
-		/**
-		 * Constructor
-		 */
 		Vfs_plugin(Libc::Env &env, Genode::Allocator &alloc)
 		:
 			_alloc(alloc), _root_dir(env.vfs())
@@ -96,7 +95,7 @@ class Libc::Vfs_plugin : public Libc::Plugin
 				});
 		}
 
-		~Vfs_plugin() { }
+		~Vfs_plugin() final { }
 
 		bool supports_access(const char *, int)                override { return true; }
 		bool supports_mkdir(const char *, mode_t)              override { return true; }
@@ -109,6 +108,10 @@ class Libc::Vfs_plugin : public Libc::Plugin
 		bool supports_unlink(const char *)                     override { return true; }
 		bool supports_mmap()                                   override { return true; }
 
+		bool supports_select(int nfds,
+		                     fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+		                     struct timeval *timeout) override;
+
 		Libc::File_descriptor *open(const char *, int, int libc_fd);
 
 		Libc::File_descriptor *open(const char *path, int flags) override
@@ -138,6 +141,7 @@ class Libc::Vfs_plugin : public Libc::Plugin
 		ssize_t write(Libc::File_descriptor *, const void *, ::size_t ) override;
 		void   *mmap(void *, ::size_t, int, int, Libc::File_descriptor *, ::off_t) override;
 		int     munmap(void *, ::size_t) override;
+		int     select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout) override;
 };
 
 #endif

repos/libports/src/lib/vfs/jitterentropy/vfs.cc

@@ -21,7 +21,8 @@
 struct Jitterentropy_factory : Vfs::File_system_factory
 {
 	Vfs::File_system *create(Genode::Env&, Genode::Allocator &alloc,
-	                         Genode::Xml_node  node) override
+	                         Genode::Xml_node node,
+	                         Vfs::Io_response_handler &) override
 	{
 		return new (alloc) Jitterentropy_file_system(node);
 	}

repos/libports/src/lib/vfs/jitterentropy/vfs_jitterentropy.h

@@ -98,6 +98,8 @@ class Jitterentropy_file_system : public Vfs::Single_file_system
 
 			return READ_OK;
 		}
+
+		bool read_ready(Vfs::Vfs_handle *) override { return true; }
 };
 
 #endif /* _JITTERENTROPY_FILE_SYSTEM_H_ */

repos/os/include/vfs/dir_file_system.h

@@ -1,11 +1,13 @@
 /*
  * \brief  Directory file system
  * \author Norman Feske
+ * \author Emery Hemingway
+ * \author Christian Helmuth
  * \date   2012-04-23
  */
 
 /*
- * Copyright (C) 2011-2016 Genode Labs GmbH
+ * Copyright (C) 2011-2017 Genode Labs GmbH
  *
  * This file is part of the Genode OS framework, which is distributed
  * under the terms of the GNU General Public License version 2.
@@ -601,6 +603,14 @@ class Vfs::Dir_file_system : public File_system
 		{
 			return FTRUNCATE_ERR_NO_PERM;
 		}
+
+		bool read_ready(Vfs_handle *handle) override
+		{
+			if (&handle->fs() == this)
+				return true;
+
+			return handle->fs().read_ready(handle);
+		}
 };
 
 #endif /* _INCLUDE__VFS__DIR_FILE_SYSTEM_H_ */

repos/os/include/vfs/file_io_service.h

@@ -76,6 +76,11 @@ struct Vfs::File_io_service
 	                                  file_size &out_count)
 	{ return read(vfs_handle, dst, count, out_count); }
 
+	/**
+	 * Return true if the handle has readable data
+	 */
+	virtual bool read_ready(Vfs_handle *) = 0;
+
 
 	/***************
 	 ** Ftruncate **

repos/os/src/lib/vfs/block_file_system.h

@@ -312,6 +312,8 @@ class Vfs::Block_file_system : public Single_file_system
 			return READ_OK;
 		}
 
+		bool read_ready(Vfs_handle *) override { return true; }
+
 		Ftruncate_result ftruncate(Vfs_handle *vfs_handle, file_size) override
 		{
 			return FTRUNCATE_OK;

repos/os/src/lib/vfs/fs_file_system.h

@@ -629,6 +629,8 @@ class Vfs::Fs_file_system : public File_system
 			return READ_OK;
 		}
 
+		bool read_ready(Vfs_handle *) override { return true; }
+
 		Ftruncate_result ftruncate(Vfs_handle *vfs_handle, file_size len) override
 		{
 			Fs_vfs_handle const *handle = static_cast<Fs_vfs_handle *>(vfs_handle);

repos/os/src/lib/vfs/inline_file_system.h

@@ -96,6 +96,8 @@ class Vfs::Inline_file_system : public Single_file_system
 			out_count = num_bytes;
 			return READ_OK;
 		}
+
+		bool read_ready(Vfs_handle *) override { return true; }
 };
 
 #endif /* _INCLUDE__VFS__INLINE_FILE_SYSTEM_H_ */

repos/os/src/lib/vfs/log_file_system.h

@@ -90,6 +90,8 @@ class Vfs::Log_file_system : public Single_file_system
 			out_count = 0;
 			return READ_OK;
 		}
+
+		bool read_ready(Vfs_handle *) override { return false; }
 };
 
 #endif /* _INCLUDE__VFS__LOG_FILE_SYSTEM_H_ */

repos/os/src/lib/vfs/null_file_system.h

@@ -53,6 +53,8 @@ struct Vfs::Null_file_system : Single_file_system
 		return READ_OK;
 	}
 
+	bool read_ready(Vfs_handle *) override { return false; }
+
 	Ftruncate_result ftruncate(Vfs_handle *vfs_handle, file_size) override
 	{
 		return FTRUNCATE_OK;

repos/os/src/lib/vfs/ram_file_system.h

@@ -764,6 +764,8 @@ class Vfs::Ram_file_system : public Vfs::File_system
 			return READ_OK;
 		}
 
+		bool read_ready(Vfs_handle *) override { return true; }
+
 		Ftruncate_result ftruncate(Vfs_handle *vfs_handle, file_size len) override
 		{
 			if ((vfs_handle->status_flags() & OPEN_MODE_ACCMODE) ==  OPEN_MODE_RDONLY)

repos/os/src/lib/vfs/rom_file_system.h

@@ -142,6 +142,8 @@ class Vfs::Rom_file_system : public Single_file_system
 			out_count = num_bytes;
 			return READ_OK;
 		}
+
+		bool read_ready(Vfs_handle *) override { return true; }
 };
 
 #endif /* _INCLUDE__VFS__ROM_FILE_SYSTEM_H_ */

repos/os/src/lib/vfs/rtc_file_system.h

@@ -98,6 +98,8 @@ class Vfs::Rtc_file_system : public Single_file_system
 
 			return READ_OK;
 		}
+
+		bool read_ready(Vfs_handle *) override { return true; }
 };
 
 #endif /* _INCLUDE__VFS__RTC_FILE_SYSTEM_H_ */

repos/os/src/lib/vfs/symlink_file_system.h

@@ -82,6 +82,8 @@ class Vfs::Symlink_file_system : public Single_file_system
 		Read_result read(Vfs_handle *, char *, file_size, file_size &) override {
 			return READ_ERR_INVALID; }
 
+		bool read_ready(Vfs_handle *) override { return false; }
+
 		Ftruncate_result ftruncate(Vfs_handle *, file_size) override {
 			return FTRUNCATE_ERR_NO_PERM; }
 };

repos/os/src/lib/vfs/tar_file_system.h

@@ -611,6 +611,8 @@ class Vfs::Tar_file_system : public File_system
 		{
 			return FTRUNCATE_ERR_NO_PERM;
 		}
+
+		bool read_ready(Vfs_handle *) override { return true; }
 };
 
 #endif /* _INCLUDE__VFS__TAR_FILE_SYSTEM_H_ */

repos/os/src/lib/vfs/terminal_file_system.h

@@ -101,6 +101,11 @@ class Vfs::Terminal_file_system : public Single_file_system
 			return _read(vfs_handle, dst, count, out_count);
 		}
 
+		bool read_ready(Vfs_handle *) override
+		{
+			return _terminal.avail();
+		}
+
 		Ftruncate_result ftruncate(Vfs_handle *vfs_handle, file_size) override
 		{
 			return FTRUNCATE_OK;

repos/os/src/lib/vfs/zero_file_system.h

@@ -53,6 +53,8 @@ struct Vfs::Zero_file_system : Single_file_system
 
 		return READ_OK;
 	}
+
+	bool read_ready(Vfs_handle *) override { return true; }
 };
 
 #endif /* _INCLUDE__VFS__ZERO_FILE_SYSTEM_H_ */