Add basic multithreading support to IndepEventDispatcher.

git-svn-id: http://nohands.svn.sourceforge.net/svnroot/nohands/trunk@58 126591fb-c623-4b62-a76d-97a8e4f34109

4 files changed, 414 insertions, 6 deletions

diff --git a/configure.in b/configure.in
index fd8b0bb..746dc9f 100644
--- a/configure.in
+++ b/configure.in
@@ -89,6 +89,7 @@ else
 	fi
 fi
 
+ACX_PTHREAD(use_pthread=yes, use_pthread=no)
 
 AC_ARG_ENABLE(alsa,
 	AC_HELP_STRING([--enable-alsa], [build ALSA backend]),
@@ -306,6 +307,12 @@ if test $want_debug = "yes"; then
 	AC_DEFINE([USE_VERBOSE_DEBUG], [], [Enable extreme debug measures])
 fi
 
+if test $use_pthread = "yes"; then
+	AC_DEFINE([USE_PTHREADS], [], [Enable thread support])
+	libhfp_CXXFLAGS="$libhfp_CXXFLAGS $PTHREAD_CFLAGS"
+	libhfp_LIBS="$libhfp_LIBS $PTHREAD_LIBS"
+fi
+
 if test $use_alsa = "yes"; then
 	AC_DEFINE([USE_ALSA_SOUNDIO], [], [Enable support for libasound])
 	libhfp_CXXFLAGS="$libhfp_CXXFLAGS $ALSA_CFLAGS"
diff --git a/include/libhfp/events-indep.h b/include/libhfp/events-indep.h
index fdb4d67..1fdecc7 100644
--- a/include/libhfp/events-indep.h
+++ b/include/libhfp/events-indep.h
@@ -29,6 +29,10 @@
 
 #include <sys/time.h>
 
+#if defined(USE_PTHREADS)
+#include <pthread.h>
+#endif
+
 #include <libhfp/events.h>
 #include <libhfp/list.h>
 
@@ -47,6 +51,25 @@ private:
 	ListItem	m_sockets;
 	struct timeval	m_last_run;
 
+	bool		m_sleeping;
+
+#if defined(USE_PTHREADS)
+	pthread_mutex_t	m_lock;
+	int		m_wake_pipe[2];
+	SocketNotifier	*m_wake;
+	bool		m_wake_pending;
+	void Lock(void);
+	void Unlock(bool wake = false);
+	void WakeNotify(SocketNotifier *notp, int fh);
+	bool WakeSetup(void);
+	void WakeCleanup(void);
+#else
+	void Lock(void) {}
+	void Unlock(bool wake = false) {}
+	bool WakeSetup(void) { return true; }
+	void WakeCleanup(void) {}
+#endif
+
 	static void PairTimers(ListItem &siblings, ListItem &dest,
 			       unsigned int delta);
 	void AddTimer(IndepTimerNotifier *);
diff --git a/libhfp/events-indep.cpp b/libhfp/events-indep.cpp
index 9840e13..427a966 100644
--- a/libhfp/events-indep.cpp
+++ b/libhfp/events-indep.cpp
@@ -23,17 +23,114 @@
  * Useful for environments lacking a native event loop, e.g. SDL.
  */
 
-#include <stdio.h>
 #include <sys/select.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
 
 #include <libhfp/events-indep.h>
 #include <libhfp/list.h>
 
 using namespace libhfp;
 
+namespace libhfp {
+
+#if defined(USE_PTHREADS)
+void IndepEventDispatcher::
+Lock(void)
+{
+	pthread_mutex_lock(&m_lock);
+}
+
+void IndepEventDispatcher::
+Unlock(bool wake)
+{
+	ssize_t res;
+	assert(pthread_mutex_trylock(&m_lock));
+	if (wake && m_sleeping && !m_wake_pending) {
+		res = write(m_wake_pipe[1], "\0", 1);
+		assert(res == 1);
+		m_wake_pending = true;
+	}
+	pthread_mutex_unlock(&m_lock);
+}
+
+void IndepEventDispatcher::
+WakeNotify(SocketNotifier *notp, int fh)
+{
+	char buf[1];
+	ssize_t res;
+
+	Lock();
+
+	assert(notp == m_wake);
+	assert(fh == m_wake_pipe[0]);
+	res = read(m_wake_pipe[0], buf, sizeof(buf));
+	if (res < 0) {
+		LogError("Dispatch: Pipe read failure: %s",
+			 strerror(errno));
+	}
+	else if (res != sizeof(buf)) {
+		LogError("Dispatch: Short pipe read: exp %zd got %zd",
+			 sizeof(buf), res);
+	}
+
+	m_wake_pending = false;
+	Unlock();
+}
+
+bool IndepEventDispatcher::
+WakeSetup(void)
+{
+	int res;
+	res = pthread_mutex_init(&m_lock, 0);
+	if (res)
+		return false;
+	res = pipe(m_wake_pipe);
+	if (res < 0) {
+		LogError("Dispatch: pipe: %s",
+			 strerror(errno));
+		res = pthread_mutex_destroy(&m_lock);
+		assert(!res);
+		return false;
+	}
+	(void) SetNonBlock(m_wake_pipe[0], true);
+	m_wake = NewSocket(m_wake_pipe[0], false);
+	if (!m_wake) {
+		LogError("Dispatch: Could not create wake pipe notifier");
+		close(m_wake_pipe[0]);
+		close(m_wake_pipe[1]);
+		res = pthread_mutex_destroy(&m_lock);
+		assert(!res);
+		return false;
+	}
+
+	m_wake->Register(this, &IndepEventDispatcher::WakeNotify);
+
+	return true;
+}
+
+void IndepEventDispatcher::
+WakeCleanup(void)
+{
+	int res;
+
+	if (m_wake) {
+		delete m_wake;
+		m_wake = 0;
+		close(m_wake_pipe[0]);
+		m_wake_pipe[0] = -1;
+		close(m_wake_pipe[1]);
+		m_wake_pipe[1] = -1;
+		res = pthread_mutex_destroy(&m_lock);
+		assert(!res);
+	}
+}
+#endif  /* defined(USE_PTHREADS) */
+
 /*
  * Timers are stored in a Pairing Heap structure with the values
  * represented as a delta hierarchy.  All children of a particular
@@ -41,7 +138,7 @@ using namespace libhfp;
  * m_msec_delta.
  */
 
-namespace libhfp {
+
 class IndepTimerNotifier : public TimerNotifier {
 public:
 	ListItem		m_links;
@@ -50,14 +147,18 @@ public:
 	IndepEventDispatcher	*m_dispatcher;
 
 	virtual void Set(int msec) {
+		m_dispatcher->Lock();
 		if (!m_links.Empty())
 			m_dispatcher->RemoveTimer(this);
 		m_msec_delta = msec;
 		m_dispatcher->AddTimer(this);
+		m_dispatcher->Unlock(true);
 	}
 	virtual void Cancel(void) {
+		m_dispatcher->Lock();
 		if (!m_links.Empty())
 			m_dispatcher->RemoveTimer(this);
+		m_dispatcher->Unlock();
 	}
 	IndepTimerNotifier(IndepEventDispatcher *disp)
 		: m_dispatcher(disp) {}
@@ -205,7 +306,9 @@ RunTimers(unsigned int ms_elapsed)
 		IndepTimerNotifier *to;
 		to = GetContainer(runlist.next, IndepTimerNotifier, m_links);
 		to->m_links.Unlink();
+		Unlock();
 		(*to)(to);
+		Lock();
 	}
 }
 
@@ -231,16 +334,22 @@ public:
 	IndepSocketNotifier(IndepEventDispatcher *disp, int fh, bool writable)
 		: m_dispatcher(disp), m_fh(fh), m_writable(writable) {}
 	virtual void SetEnabled(bool enable) {
-		if (!enable == m_links.Empty())
+		m_dispatcher->Lock();
+		if (!enable == m_links.Empty()) {
+			m_dispatcher->Unlock();
 			return;
+		}
 		if (enable)
 			m_dispatcher->AddSocket(this);
 		else
 			m_dispatcher->RemoveSocket(this);
+		m_dispatcher->Unlock(true);
 	}
 	virtual ~IndepSocketNotifier() {
+		m_dispatcher->Lock();
 		if (!m_links.Empty())
 			m_dispatcher->RemoveSocket(this);
+		m_dispatcher->Unlock();
 	}
 };
 } /* namespace libhfp */
@@ -270,7 +379,9 @@ NewSocket(int fh, bool writable)
 	IndepSocketNotifier *sockp;
 	sockp = new IndepSocketNotifier(this, fh, writable);
 
+	Lock();
 	AddSocket(sockp);
+	Unlock(true);
 	return sockp;
 }
 
@@ -295,12 +406,17 @@ RunOnce(int max_sleep_ms)
 	FD_ZERO(&readi);
 	FD_ZERO(&writei);
 
+	Lock();
+	assert(!m_sleeping);
+
 	/* Run nonwaiting timers */
 	RunTimers(0);
 
-	if (m_timers.Empty() && m_sockets.Empty() && (max_sleep_ms < 0))
+	if (m_timers.Empty() && m_sockets.Empty() && (max_sleep_ms < 0)) {
 		/* Nothing to wait for, we'll wait forever! */
+		Unlock();
 		return;
+	}
 
 	/* Move sockets to the I/O run list */
 	maxfh = 0;
@@ -362,8 +478,14 @@ RunOnce(int max_sleep_ms)
 		timeout.tv_usec = (ms_elapsed % 1000) * 1000;
 	}
 
+	m_sleeping = true;
+	Unlock();
+
 	res = select(maxfh + 1, &readi, &writei, NULL, top);
 
+	Lock();
+	m_sleeping = false;
+
 	/* Compute elapsed time */
 	gettimeofday(&etime, NULL);
 	if (timercmp(&m_last_run, &etime, >)) {
@@ -394,16 +516,27 @@ RunOnce(int max_sleep_ms)
 		m_sockets.AppendItem(sp->m_links);
 
 		if ((sp->m_writable && FD_ISSET(sp->m_fh, &writei)) ||
-		    (!sp->m_writable && FD_ISSET(sp->m_fh, &readi)))
+		    (!sp->m_writable && FD_ISSET(sp->m_fh, &readi))) {
+			Unlock();
 			(*sp)(sp, sp->m_fh);
+			Lock();
+		}
 	}
+
+	Unlock();
 }
 
 void IndepEventDispatcher::
 Run(void)
 {
+	bool empty;
+
 	while (1) {
-		if (m_timers.Empty() && m_sockets.Empty())
+		Lock();
+		empty = (m_timers.Empty() && m_sockets.Empty());
+		Unlock();
+
+		if (empty)
 			return;
 
 		RunOnce(-1);
@@ -412,11 +545,15 @@ Run(void)
 
 IndepEventDispatcher::
 IndepEventDispatcher(void)
+	: m_sleeping(false)
 {
+	if (!WakeSetup())
+		abort();
 	gettimeofday(&m_last_run, NULL);
 }
 
 IndepEventDispatcher::
 ~IndepEventDispatcher()
 {
+	WakeCleanup();
 }
diff --git a/m4/acx_pthread.m4 b/m4/acx_pthread.m4
new file mode 100644
index 0000000..7c5507d
--- /dev/null
+++ b/m4/acx_pthread.m4
@@ -0,0 +1,241 @@
+dnl @synopsis ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
+dnl @summary figure out how to build C programs using POSIX threads
+dnl @category InstalledPackages
+dnl
+dnl This macro figures out how to build C programs using POSIX
+dnl threads.  It sets the PTHREAD_LIBS output variable to the threads
+dnl library and linker flags, and the PTHREAD_CFLAGS output variable
+dnl to any special C compiler flags that are needed.  (The user can also
+dnl force certain compiler flags/libs to be tested by setting these
+dnl environment variables.)
+dnl
+dnl Also sets PTHREAD_CC to any special C compiler that is needed for
+dnl multi-threaded programs (defaults to the value of CC otherwise).
+dnl (This is necessary on AIX to use the special cc_r compiler alias.)
+dnl
+dnl NOTE: You are assumed to not only compile your program with these
+dnl flags, but also link it with them as well.  e.g. you should link
+dnl with $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS
+dnl
+dnl If you are only building threads programs, you may wish to
+dnl use these variables in your default LIBS, CFLAGS, and CC:
+dnl
+dnl        LIBS="$PTHREAD_LIBS $LIBS"
+dnl        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+dnl        CC="$PTHREAD_CC"
+dnl
+dnl In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute
+dnl constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE
+dnl to that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
+dnl
+dnl ACTION-IF-FOUND is a list of shell commands to run if a threads
+dnl library is found, and ACTION-IF-NOT-FOUND is a list of commands
+dnl to run it if it is not found.  If ACTION-IF-FOUND is not specified,
+dnl the default action will define HAVE_PTHREAD.
+dnl
+dnl Please let the authors know if this macro fails on any platform,
+dnl or if you have any other suggestions or comments.  This macro was
+dnl based on work by SGJ on autoconf scripts for FFTW (www.fftw.org)
+dnl (with help from M. Frigo), as well as ac_pthread and hb_pthread
+dnl macros posted by Alejandro Forero Cuervo to the autoconf macro
+dnl repository.  We are also grateful for the helpful feedback of
+dnl numerous users.
+dnl
+dnl @version 2006-05-29
+dnl @license GPLWithACException
+dnl @author Steven G. Johnson <stevenj@alum.mit.edu>
+
+AC_DEFUN([ACX_PTHREAD], [
+AC_REQUIRE([AC_CANONICAL_HOST])
+AC_LANG_SAVE
+AC_LANG_C
+acx_pthread_ok=no
+
+# We used to check for pthread.h first, but this fails if pthread.h
+# requires special compiler flags (e.g. on True64 or Sequent).
+# It gets checked for in the link test anyway.
+
+# First of all, check if the user has set any of the PTHREAD_LIBS,
+# etcetera environment variables, and if threads linking works using
+# them:
+if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
+        save_CFLAGS="$CFLAGS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+        save_LIBS="$LIBS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
+        AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)
+        AC_MSG_RESULT($acx_pthread_ok)
+        if test x"$acx_pthread_ok" = xno; then
+                PTHREAD_LIBS=""
+                PTHREAD_CFLAGS=""
+        fi
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+fi
+
+# We must check for the threads library under a number of different
+# names; the ordering is very important because some systems
+# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
+# libraries is broken (non-POSIX).
+
+# Create a list of thread flags to try.  Items starting with a "-" are
+# C compiler flags, and other items are library names, except for "none"
+# which indicates that we try without any flags at all, and "pthread-config"
+# which is a program returning the flags for the Pth emulation library.
+
+acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
+
+# The ordering *is* (sometimes) important.  Some notes on the
+# individual items follow:
+
+# pthreads: AIX (must check this before -lpthread)
+# none: in case threads are in libc; should be tried before -Kthread and
+#       other compiler flags to prevent continual compiler warnings
+# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
+# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
+# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
+# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
+# -pthreads: Solaris/gcc
+# -mthreads: Mingw32/gcc, Lynx/gcc
+# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
+#      doesn't hurt to check since this sometimes defines pthreads too;
+#      also defines -D_REENTRANT)
+#      ... -mt is also the pthreads flag for HP/aCC
+# pthread: Linux, etcetera
+# --thread-safe: KAI C++
+# pthread-config: use pthread-config program (for GNU Pth library)
+
+case "${host_cpu}-${host_os}" in
+        *solaris*)
+
+        # On Solaris (at least, for some versions), libc contains stubbed
+        # (non-functional) versions of the pthreads routines, so link-based
+        # tests will erroneously succeed.  (We need to link with -pthreads/-mt/
+        # -lpthread.)  (The stubs are missing pthread_cleanup_push, or rather
+        # a function called by this macro, so we could check for that, but
+        # who knows whether they'll stub that too in a future libc.)  So,
+        # we'll just look for -pthreads and -lpthread first:
+
+        acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags"
+        ;;
+esac
+
+if test x"$acx_pthread_ok" = xno; then
+for flag in $acx_pthread_flags; do
+
+        case $flag in
+                none)
+                AC_MSG_CHECKING([whether pthreads work without any flags])
+                ;;
+
+                -*)
+                AC_MSG_CHECKING([whether pthreads work with $flag])
+                PTHREAD_CFLAGS="$flag"
+                ;;
+
+		pthread-config)
+		AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no)
+		if test x"$acx_pthread_config" = xno; then continue; fi
+		PTHREAD_CFLAGS="`pthread-config --cflags`"
+		PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
+		;;
+
+                *)
+                AC_MSG_CHECKING([for the pthreads library -l$flag])
+                PTHREAD_LIBS="-l$flag"
+                ;;
+        esac
+
+        save_LIBS="$LIBS"
+        save_CFLAGS="$CFLAGS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+
+        # Check for various functions.  We must include pthread.h,
+        # since some functions may be macros.  (On the Sequent, we
+        # need a special flag -Kthread to make this header compile.)
+        # We check for pthread_join because it is in -lpthread on IRIX
+        # while pthread_create is in libc.  We check for pthread_attr_init
+        # due to DEC craziness with -lpthreads.  We check for
+        # pthread_cleanup_push because it is one of the few pthread
+        # functions on Solaris that doesn't have a non-functional libc stub.
+        # We try pthread_create on general principles.
+        AC_TRY_LINK([#include <pthread.h>],
+                    [pthread_t th; pthread_join(th, 0);
+                     pthread_attr_init(0); pthread_cleanup_push(0, 0);
+                     pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
+                    [acx_pthread_ok=yes])
+
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+
+        AC_MSG_RESULT($acx_pthread_ok)
+        if test "x$acx_pthread_ok" = xyes; then
+                break;
+        fi
+
+        PTHREAD_LIBS=""
+        PTHREAD_CFLAGS=""
+done
+fi
+
+# Various other checks:
+if test "x$acx_pthread_ok" = xyes; then
+        save_LIBS="$LIBS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        save_CFLAGS="$CFLAGS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+
+        # Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
+	AC_MSG_CHECKING([for joinable pthread attribute])
+	attr_name=unknown
+	for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
+	    AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;],
+                        [attr_name=$attr; break])
+	done
+        AC_MSG_RESULT($attr_name)
+        if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
+            AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,
+                               [Define to necessary symbol if this constant
+                                uses a non-standard name on your system.])
+        fi
+
+        AC_MSG_CHECKING([if more special flags are required for pthreads])
+        flag=no
+        case "${host_cpu}-${host_os}" in
+            *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;
+            *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
+        esac
+        AC_MSG_RESULT(${flag})
+        if test "x$flag" != xno; then
+            PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
+        fi
+
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+
+        # More AIX lossage: must compile with xlc_r or cc_r
+	if test x"$GCC" != xyes; then
+          AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC})
+        else
+          PTHREAD_CC=$CC
+	fi
+else
+        PTHREAD_CC="$CC"
+fi
+
+AC_SUBST(PTHREAD_LIBS)
+AC_SUBST(PTHREAD_CFLAGS)
+AC_SUBST(PTHREAD_CC)
+
+# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
+if test x"$acx_pthread_ok" = xyes; then
+        ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
+        :
+else
+        acx_pthread_ok=no
+        $2
+fi
+AC_LANG_RESTORE
+])dnl ACX_PTHREAD