Import libpulse poller integration, add tests

Since poll() is implemented in terms of kqueue() there,
it doesn't seem like this could have improved anything.

Besides man 3 ev, libevent code, and [1],
I haven't managed to find much relevant information.

[1] https://daniel.haxx.se/blog/2016/10/11/poll-on-mac-10-12-is-broken/

.clang-format

@@ -0,0 +1,32 @@
+# clang-format is fairly limited, and these rules are approximate:
+#  - array initializers can get terribly mangled with clang-format 12.0,
+#  - sometimes it still aligns with space characters,
+#  - struct name NL { NL ... NL } NL name; is unachievable.
+BasedOnStyle: GNU
+ColumnLimit: 80
+IndentWidth: 4
+TabWidth: 4
+UseTab: ForContinuationAndIndentation
+BreakBeforeBraces: Allman
+SpaceAfterCStyleCast: true
+AlignAfterOpenBracket: DontAlign
+AlignOperands: DontAlign
+AlignConsecutiveMacros: Consecutive
+AllowAllArgumentsOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+IndentGotoLabels: false
+
+# IncludeCategories has some potential, but it may also break the build.
+# Note that the documentation says the value should be "Never".
+SortIncludes: false
+
+# This is a compromise, it generally works out aesthetically better.
+BinPackArguments: false
+
+# Unfortunately, this can't be told to align to column 40 or so.
+SpacesBeforeTrailingComments: 2
+
+# liberty-specific macro body wrappers.
+MacroBlockBegin: "BLOCK_START"
+MacroBlockEnd: "BLOCK_END"
+ForEachMacros: ["LIST_FOR_EACH"]

.gitignore

@@ -7,3 +7,5 @@
 /liberty.files
 /liberty.creator*
 /liberty.includes
+/liberty.cflags
+/liberty.cxxflags

CMakeLists.txt

@@ -1,5 +1,5 @@
 project (liberty C)
-cmake_minimum_required (VERSION 2.8.5)
+cmake_minimum_required (VERSION 2.8.12)
 
 # Moar warnings
 if ("${CMAKE_C_COMPILER_ID}" MATCHES "GNU" OR CMAKE_COMPILER_IS_GNUCC)
@@ -36,7 +36,17 @@ endforeach ()
 # Build some unit tests
 include_directories (${PROJECT_SOURCE_DIR})
 enable_testing ()
-foreach (name liberty proto)
+set (tests liberty proto)
+
+pkg_check_modules (libpulse libpulse)
+if (libpulse_FOUND)
+	list (APPEND tests pulse)
+	list (APPEND common_libraries ${libpulse_LIBRARIES})
+	include_directories (${libpulse_INCLUDE_DIRS})
+	link_directories (${libpulse_LIBRARY_DIRS})
+endif ()
+
+foreach (name ${tests})
 	add_executable (test-${name} tests/${name}.c ${common_sources})
 	add_threads (test-${name})
 	target_link_libraries (test-${name} ${common_libraries})

liberty-pulse.c

@@ -0,0 +1,348 @@
+/*
+ * liberty-pulse.c: PulseAudio mainloop abstraction
+ *
+ * Copyright (c) 2016 - 2021, Přemysl Eric Janouch <p@janouch.name>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include <pulse/mainloop.h>
+
+// --- PulseAudio mainloop abstraction -----------------------------------------
+
+struct pa_io_event
+{
+	LIST_HEADER (pa_io_event)
+
+	pa_mainloop_api *api;               ///< Parent structure
+	struct poller_fd fd;                ///< Underlying FD event
+
+	pa_io_event_cb_t dispatch;          ///< Dispatcher
+	pa_io_event_destroy_cb_t free;      ///< Destroyer
+	void *user_data;                    ///< User data
+};
+
+struct pa_time_event
+{
+	LIST_HEADER (pa_time_event)
+
+	pa_mainloop_api *api;               ///< Parent structure
+	struct poller_timer timer;          ///< Underlying timer event
+
+	pa_time_event_cb_t dispatch;        ///< Dispatcher
+	pa_time_event_destroy_cb_t free;    ///< Destroyer
+	void *user_data;                    ///< User data
+};
+
+struct pa_defer_event
+{
+	LIST_HEADER (pa_defer_event)
+
+	pa_mainloop_api *api;               ///< Parent structure
+	struct poller_idle idle;            ///< Underlying idle event
+
+	pa_defer_event_cb_t dispatch;       ///< Dispatcher
+	pa_defer_event_destroy_cb_t free;   ///< Destroyer
+	void *user_data;                    ///< User data
+};
+
+struct poller_pa
+{
+	struct poller *poller;              ///< The underlying event loop
+	pa_io_event *io_list;               ///< I/O events
+	pa_time_event *time_list;           ///< Timer events
+	pa_defer_event *defer_list;         ///< Deferred events
+};
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static short
+poller_pa_flags_to_events (pa_io_event_flags_t flags)
+{
+	short result = 0;
+	if (flags & PA_IO_EVENT_ERROR)   result |= POLLERR;
+	if (flags & PA_IO_EVENT_HANGUP)  result |= POLLHUP;
+	if (flags & PA_IO_EVENT_INPUT)   result |= POLLIN;
+	if (flags & PA_IO_EVENT_OUTPUT)  result |= POLLOUT;
+	return result;
+}
+
+static pa_io_event_flags_t
+poller_pa_events_to_flags (short events)
+{
+	pa_io_event_flags_t result = 0;
+	if (events & POLLERR)  result |= PA_IO_EVENT_ERROR;
+	if (events & POLLHUP)  result |= PA_IO_EVENT_HANGUP;
+	if (events & POLLIN)   result |= PA_IO_EVENT_INPUT;
+	if (events & POLLOUT)  result |= PA_IO_EVENT_OUTPUT;
+	return result;
+}
+
+static struct timeval
+poller_pa_get_current_time (void)
+{
+	struct timeval tv;
+#ifdef _POSIX_TIMERS
+	struct timespec tp;
+	hard_assert (clock_gettime (CLOCK_REALTIME, &tp) != -1);
+	tv.tv_sec = tp.tv_sec;
+	tv.tv_usec = tp.tv_nsec / 1000;
+#else
+	gettimeofday (&tv, NULL);
+#endif
+	return tv;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static void
+poller_pa_io_dispatcher (const struct pollfd *pfd, void *user_data)
+{
+	pa_io_event *self = user_data;
+	self->dispatch (self->api, self,
+		pfd->fd, poller_pa_events_to_flags (pfd->revents), self->user_data);
+}
+
+static void
+poller_pa_io_enable (pa_io_event *self, pa_io_event_flags_t events)
+{
+	struct poller_fd *fd = &self->fd;
+	if (events)
+		poller_fd_set (fd, poller_pa_flags_to_events (events));
+	else
+		poller_fd_reset (fd);
+}
+
+static pa_io_event *
+poller_pa_io_new (pa_mainloop_api *api, int fd_, pa_io_event_flags_t events,
+	pa_io_event_cb_t cb, void *userdata)
+{
+	pa_io_event *self = xcalloc (1, sizeof *self);
+	self->api = api;
+	self->dispatch = cb;
+	self->user_data = userdata;
+
+	struct poller_pa *data = api->userdata;
+	self->fd = poller_fd_make (data->poller, fd_);
+	self->fd.user_data = self;
+	self->fd.dispatcher = poller_pa_io_dispatcher;
+
+	// FIXME: under x2go PA tries to register twice for the same FD,
+	//   which fails with our curent poller implementation;
+	//   we could maintain a list of { poller_fd, listeners } structures;
+	//   or maybe we're doing something wrong, which is yet to be determined
+	poller_pa_io_enable (self, events);
+	LIST_PREPEND (data->io_list, self);
+	return self;
+}
+
+static void
+poller_pa_io_free (pa_io_event *self)
+{
+	if (self->free)
+		self->free (self->api, self, self->user_data);
+
+	struct poller_pa *data = self->api->userdata;
+	poller_fd_reset (&self->fd);
+	LIST_UNLINK (data->io_list, self);
+	free (self);
+}
+
+static void
+poller_pa_io_set_destroy (pa_io_event *self, pa_io_event_destroy_cb_t cb)
+{
+	self->free = cb;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static void
+poller_pa_time_dispatcher (void *user_data)
+{
+	pa_time_event *self = user_data;
+	// XXX: the meaning of the time argument is undocumented,
+	//   so let's just put current Unix time in there
+	struct timeval now = poller_pa_get_current_time ();
+	self->dispatch (self->api, self, &now, self->user_data);
+}
+
+static void
+poller_pa_time_restart (pa_time_event *self, const struct timeval *tv)
+{
+	struct poller_timer *timer = &self->timer;
+	if (tv)
+	{
+		struct timeval now = poller_pa_get_current_time ();
+		poller_timer_set (timer,
+			(tv->tv_sec  - now.tv_sec)  * 1000 +
+			(tv->tv_usec - now.tv_usec) / 1000);
+	}
+	else
+		poller_timer_reset (timer);
+}
+
+static pa_time_event *
+poller_pa_time_new (pa_mainloop_api *api, const struct timeval *tv,
+	pa_time_event_cb_t cb, void *userdata)
+{
+	pa_time_event *self = xcalloc (1, sizeof *self);
+	self->api = api;
+	self->dispatch = cb;
+	self->user_data = userdata;
+
+	struct poller_pa *data = api->userdata;
+	self->timer = poller_timer_make (data->poller);
+	self->timer.user_data = self;
+	self->timer.dispatcher = poller_pa_time_dispatcher;
+
+	poller_pa_time_restart (self, tv);
+	LIST_PREPEND (data->time_list, self);
+	return self;
+}
+
+static void
+poller_pa_time_free (pa_time_event *self)
+{
+	if (self->free)
+		self->free (self->api, self, self->user_data);
+
+	struct poller_pa *data = self->api->userdata;
+	poller_timer_reset (&self->timer);
+	LIST_UNLINK (data->time_list, self);
+	free (self);
+}
+
+static void
+poller_pa_time_set_destroy (pa_time_event *self, pa_time_event_destroy_cb_t cb)
+{
+	self->free = cb;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static void
+poller_pa_defer_dispatcher (void *user_data)
+{
+	pa_defer_event *self = user_data;
+	self->dispatch (self->api, self, self->user_data);
+}
+
+static pa_defer_event *
+poller_pa_defer_new (pa_mainloop_api *api,
+	pa_defer_event_cb_t cb, void *userdata)
+{
+	pa_defer_event *self = xcalloc (1, sizeof *self);
+	self->api = api;
+	self->dispatch = cb;
+	self->user_data = userdata;
+
+	struct poller_pa *data = api->userdata;
+	self->idle = poller_idle_make (data->poller);
+	self->idle.user_data = self;
+	self->idle.dispatcher = poller_pa_defer_dispatcher;
+
+	poller_idle_set (&self->idle);
+	LIST_PREPEND (data->defer_list, self);
+	return self;
+}
+
+static void
+poller_pa_defer_enable (pa_defer_event *self, int enable)
+{
+	struct poller_idle *idle = &self->idle;
+	if (enable)
+		poller_idle_set (idle);
+	else
+		poller_idle_reset (idle);
+}
+
+static void
+poller_pa_defer_free (pa_defer_event *self)
+{
+	if (self->free)
+		self->free (self->api, self, self->user_data);
+
+	struct poller_pa *data = self->api->userdata;
+	poller_idle_reset (&self->idle);
+	LIST_UNLINK (data->defer_list, self);
+	free (self);
+}
+
+static void
+poller_pa_defer_set_destroy (pa_defer_event *self,
+	pa_defer_event_destroy_cb_t cb)
+{
+	self->free = cb;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static void
+poller_pa_quit (pa_mainloop_api *api, int retval)
+{
+	(void) api;
+	(void) retval;
+
+	// This is not called from within libpulse
+	hard_assert (!"quitting the libpulse event loop is unimplemented");
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static struct pa_mainloop_api g_poller_pa_template =
+{
+	.io_new            = poller_pa_io_new,
+	.io_enable         = poller_pa_io_enable,
+	.io_free           = poller_pa_io_free,
+	.io_set_destroy    = poller_pa_io_set_destroy,
+
+	.time_new          = poller_pa_time_new,
+	.time_restart      = poller_pa_time_restart,
+	.time_free         = poller_pa_time_free,
+	.time_set_destroy  = poller_pa_time_set_destroy,
+
+	.defer_new         = poller_pa_defer_new,
+	.defer_enable      = poller_pa_defer_enable,
+	.defer_free        = poller_pa_defer_free,
+	.defer_set_destroy = poller_pa_defer_set_destroy,
+
+	.quit              = poller_pa_quit,
+};
+
+static struct pa_mainloop_api *
+poller_pa_new (struct poller *self)
+{
+	struct poller_pa *data = xcalloc (1, sizeof *data);
+	data->poller = self;
+
+	struct pa_mainloop_api *api = xmalloc (sizeof *api);
+	*api = g_poller_pa_template;
+	api->userdata = data;
+	return api;
+}
+
+static void
+poller_pa_destroy (struct pa_mainloop_api *api)
+{
+	struct poller_pa *data = api->userdata;
+
+	LIST_FOR_EACH (pa_io_event, iter, data->io_list)
+		poller_pa_io_free (iter);
+	LIST_FOR_EACH (pa_time_event, iter, data->time_list)
+		poller_pa_time_free (iter);
+	LIST_FOR_EACH (pa_defer_event, iter, data->defer_list)
+		poller_pa_defer_free (iter);
+
+	free (data);
+	free (api);
+}

liberty.c

@@ -1749,10 +1749,9 @@ poller_run (struct poller *self)
 	self->revents_len = 0;
 }
 
-#elif defined (BSD)
+// Sort of similar to the epoll version.  Let's hope Darwin isn't broken,
-
+// that'd mean reimplementing this in terms of select() just because of Crapple.
-// Mac OS X's kqueue is fatally broken, or so I've been told; leaving it out.
+#elif defined (BSD) || defined (__APPLE__)
-// Otherwise this is sort of similar to the epoll version.
 
 #include <sys/types.h>
 #include <sys/event.h>
@@ -3247,7 +3246,7 @@ get_xdg_config_dirs (struct strv *out)
 	str_free (&config_home);
 
 	const char *xdg_config_dirs;
-	if (!(xdg_config_dirs = getenv ("XDG_CONFIG_DIRS")))
+	if (!(xdg_config_dirs = getenv ("XDG_CONFIG_DIRS")) || !*xdg_config_dirs)
 		xdg_config_dirs = "/etc/xdg";
 	cstr_split (xdg_config_dirs, ":", true, out);
 }
@@ -3272,7 +3271,7 @@ get_xdg_data_dirs (struct strv *out)
 	str_free (&data_home);
 
 	const char *xdg_data_dirs;
-	if (!(xdg_data_dirs = getenv ("XDG_DATA_DIRS")))
+	if (!(xdg_data_dirs = getenv ("XDG_DATA_DIRS")) || !*xdg_data_dirs)
 		xdg_data_dirs = "/usr/local/share/:/usr/share/";
 	cstr_split (xdg_data_dirs, ":", true, out);
 }
@@ -4713,8 +4712,10 @@ config_item_write_string (struct str *output, const struct str *s)
 		else if (c == '\t')  str_append (output, "\\t");
 		else if (c == '\\')  str_append (output, "\\\\");
 		else if (c == '"')   str_append (output, "\\\"");
-		else if (c < 32)     str_append_printf (output, "\\x%02x", c);
+		else if (iscntrl_ascii (c))
-		else                 str_append_c      (output, c);
+			str_append_printf (output, "\\x%02x", c);
+		else
+			str_append_c (output, c);
 	}
 	str_append_c (output, '"');
 }

siphash.c

@@ -82,4 +82,3 @@ siphash (const unsigned char key[16], const unsigned char *m, size_t len)
 
 	return v0 ^ v1 ^ v2 ^ v3;
 }
-

tests/pulse.c

@@ -0,0 +1,127 @@
+/*
+ * tests/pulse.c
+ *
+ * Copyright (c) 2021, Přemysl Eric Janouch <p@janouch.name>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#define PROGRAM_NAME "test"
+#define PROGRAM_VERSION "0"
+
+#define LIBERTY_WANT_POLLER
+
+#include "../liberty.c"
+#include "../liberty-pulse.c"
+
+// --- Tests -------------------------------------------------------------------
+
+enum
+{
+	EVENT_IO    =  1 << 0,
+	EVENT_TIME  =  1 << 1,
+	EVENT_DEFER =  1 << 2,
+	EVENT_ALL   = (1 << 3) - 1
+};
+
+static intptr_t g_events = 0;
+static intptr_t g_destroys = 0;
+
+static void
+io_event_cb (pa_mainloop_api *a,
+	pa_io_event *e, int fd, pa_io_event_flags_t events, void *userdata)
+{
+	(void) a; (void) e; (void) fd; (void) events;
+	g_events |= (intptr_t) userdata;
+}
+
+static void
+io_event_destroy_cb (pa_mainloop_api *a, pa_io_event *e, void *userdata)
+{
+	(void) a; (void) e;
+	g_destroys += (intptr_t) userdata;
+}
+
+static void
+time_event_cb (pa_mainloop_api *a,
+	pa_time_event *e, const struct timeval *tv, void *userdata)
+{
+	(void) a; (void) e; (void) tv;
+	g_events |= (intptr_t) userdata;
+}
+
+static void
+time_event_destroy_cb (pa_mainloop_api *a, pa_time_event *e, void *userdata)
+{
+	(void) a; (void) e;
+	g_destroys += (intptr_t) userdata;
+}
+
+static void
+defer_event_cb (pa_mainloop_api *a, pa_defer_event *e, void *userdata)
+{
+	(void) a; (void) e;
+	g_events |= (intptr_t) userdata;
+}
+
+static void
+defer_event_destroy_cb (pa_mainloop_api *a, pa_defer_event *e, void *userdata)
+{
+	(void) a; (void) e;
+	g_destroys += (intptr_t) userdata;
+}
+
+static void
+test_pulse (void)
+{
+	struct poller poller;
+	poller_init (&poller);
+
+	// Let's just get this over with, not aiming for high test coverage here
+	pa_mainloop_api *api = poller_pa_new (&poller);
+
+	pa_io_event *ie = api->io_new (api, STDOUT_FILENO, PA_IO_EVENT_OUTPUT,
+		io_event_cb, (void *) EVENT_IO);
+	api->io_set_destroy (ie, io_event_destroy_cb);
+
+	const struct timeval tv = poller_pa_get_current_time ();
+	pa_time_event *te = api->time_new (api, &tv,
+		time_event_cb, (void *) EVENT_TIME);
+	api->time_set_destroy (te, time_event_destroy_cb);
+	api->time_restart (te, &tv);
+
+	pa_defer_event *de = api->defer_new (api,
+		defer_event_cb, (void *) EVENT_DEFER);
+	api->defer_set_destroy (de, defer_event_destroy_cb);
+	api->defer_enable (api->defer_new (api,
+		defer_event_cb, (void *) EVENT_DEFER), false);
+
+	alarm (1);
+	while (g_events != EVENT_ALL)
+		poller_run (&poller);
+
+	poller_pa_destroy (api);
+	soft_assert (g_destroys == EVENT_ALL);
+	poller_free (&poller);
+}
+
+// --- Main --------------------------------------------------------------------
+
+int
+main (int argc, char *argv[])
+{
+	struct test test;
+	test_init (&test, argc, argv);
+	test_add_simple (&test, "/pulse", NULL, test_pulse);
+	return test_run (&test);
+}