-/* Copyright (C) 1995, 1996, 1997, 1998, 2000 Free Software Foundation, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this software; see the file COPYING. If not, write to
- * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
- * Boston, MA 02111-1307 USA
- *
- * As a special exception, the Free Software Foundation gives permission
- * for additional uses of the text contained in its release of GUILE.
- *
- * The exception is that, if you link the GUILE library with other files
- * to produce an executable, this does not by itself cause the
- * resulting executable to be covered by the GNU General Public License.
- * Your use of that executable is in no way restricted on account of
- * linking the GUILE library code into it.
- *
- * This exception does not however invalidate any other reasons why
- * the executable file might be covered by the GNU General Public License.
- *
- * This exception applies only to the code released by the
- * Free Software Foundation under the name GUILE. If you copy
- * code from other Free Software Foundation releases into a copy of
- * GUILE, as the General Public License permits, the exception does
- * not apply to the code that you add in this way. To avoid misleading
- * anyone as to the status of such modified files, you must delete
- * this exception notice from them.
- *
- * If you write modifications of your own for GUILE, it is your choice
- * whether to permit this exception to apply to your modifications.
- * If you do not wish that, delete this exception notice. */
-
-
-\f
-
-/* This file does some pretty hairy #inclusion. It probably seemed
- like a good idea at the time, but it doesn't now. Here's the
- structure, edited for relevance (!), last I checked:
-
- threads.c:
- threads.h
- coop-defs.h
- iselect.h
- coop-threads.c
- coop-threads.h
- coop-defs.h*
- ../qt/qt.h
- coop.c
- <qt.h>
-
- * second #inclusion
-*/
-
-#include "libguile/_scm.h"
-#include "libguile/dynwind.h"
-#include "libguile/smob.h"
-
-#include "libguile/threads.h"
-
-\f
-
-scm_t_bits scm_tc16_thread;
-scm_t_bits scm_tc16_mutex;
-scm_t_bits scm_tc16_condvar;
-
-\f
-/* Scheme-visible thread functions. */
-
-#ifdef USE_COOP_THREADS
-SCM_REGISTER_PROC(s_single_thread_p, "single-active-thread?", 0, 0, 0, scm_single_thread_p);
-#endif
-
-/* GJB:FIXME:DOC: SCM_REGISTER_PROC needs to permit a docstring,
- or these need to move into the file where the proc is defined. */
-
-SCM_REGISTER_PROC(s_yield, "yield", 0, 0, 0, scm_yield);
-/* If one or more threads are waiting to execute, calling yield forces an
-immediate context switch to one of them. Otherwise, yield has no effect.
-*/
-
-SCM_REGISTER_PROC(s_call_with_new_thread, "call-with-new-thread", 0, 0, 1, scm_call_with_new_thread);
-/* Evaluate @var{(thunk)} in a new thread, and new dynamic context,
-returning a new thread object representing the thread.
-
-If an error occurs during evaluation, call error-thunk, passing it an
-error code describing the condition. [Error codes are currently
-meaningless integers. In the future, real values will be specified.]
-If this happens, the error-thunk is called outside the scope of the new
-root -- it is called in the same dynamic context in which
-with-new-thread was evaluated, but not in the callers thread.
-
-All the evaluation rules for dynamic roots apply to threads.
-*/
-
-SCM_REGISTER_PROC(s_join_thread, "join-thread", 1, 0, 0, scm_join_thread);
-/* Suspend execution of the calling thread until the target @var{thread}
-terminates, unless the target @var{thread} has already terminated.
-*/
-
-SCM_REGISTER_PROC(s_make_mutex, "make-mutex", 0, 0, 0, scm_make_mutex);
-/* Create a new mutex object. */
-
-SCM_REGISTER_PROC(s_lock_mutex, "lock-mutex", 1, 0, 0, scm_lock_mutex);
-/* Lock @var{mutex}. If the mutex is already locked, the calling thread
-blocks until the mutex becomes available. The function returns when
-the calling thread owns the lock on @var{mutex}. */
-
-SCM_REGISTER_PROC(s_unlock_mutex, "unlock-mutex", 1, 0, 0, scm_unlock_mutex);
-/* Unlocks @var{mutex} if the calling thread owns the lock on @var{mutex}.
-Calling unlock-mutex on a mutex not owned by the current thread results
-in undefined behaviour. Once a mutex has been unlocked, one thread
-blocked on @var{mutex} is awakened and grabs the mutex lock. */
-
-SCM_REGISTER_PROC(s_make_condition_variable, "make-condition-variable", 0, 0, 0, scm_make_condition_variable);
-
-SCM_REGISTER_PROC(s_wait_condition_variable, "wait-condition-variable", 2, 0, 0, scm_wait_condition_variable);
-
-SCM_REGISTER_PROC(s_signal_condition_variable, "signal-condition-variable", 1, 0, 0, scm_signal_condition_variable);
-
-\f
-
-#ifdef USE_COOP_THREADS
-#include "libguile/coop-threads.c"
-#endif
-
-\f
-
-void
-scm_init_threads (SCM_STACKITEM *i)
-{
- scm_tc16_thread = scm_make_smob_type ("thread", 0);
- scm_tc16_mutex = scm_make_smob_type ("mutex", sizeof (coop_m));
- scm_tc16_condvar = scm_make_smob_type ("condition-variable", sizeof (coop_c));
-
-#ifndef SCM_MAGIC_SNARFER
-#include "libguile/threads.x"
-#endif
- /* Initialize implementation specific details of the threads support */
- scm_threads_init (i);
-}
-
-/*
- Local Variables:
- c-file-style: "gnu"
- End:
-*/
+/* Copyright (C) 1995,1996,1997,1998,2000,2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+
+\f
+
+#define _GNU_SOURCE
+
+#include "libguile/boehm-gc.h"
+#include "libguile/_scm.h"
+
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <stdio.h>
+#include <assert.h>
+
+#ifdef HAVE_STRING_H
+#include <string.h> /* for memset used by FD_ZERO on Solaris 10 */
+#endif
+
+#if HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+
+#include "libguile/validate.h"
+#include "libguile/root.h"
+#include "libguile/eval.h"
+#include "libguile/async.h"
+#include "libguile/ports.h"
+#include "libguile/threads.h"
+#include "libguile/dynwind.h"
+#include "libguile/iselect.h"
+#include "libguile/fluids.h"
+#include "libguile/continuations.h"
+#include "libguile/gc.h"
+#include "libguile/init.h"
+
+#ifdef __MINGW32__
+#ifndef ETIMEDOUT
+# define ETIMEDOUT WSAETIMEDOUT
+#endif
+# include <fcntl.h>
+# include <process.h>
+# define pipe(fd) _pipe (fd, 256, O_BINARY)
+#endif /* __MINGW32__ */
+
+/*** Queues */
+
+/* Make an empty queue data structure.
+ */
+static SCM
+make_queue ()
+{
+ return scm_cons (SCM_EOL, SCM_EOL);
+}
+
+/* Put T at the back of Q and return a handle that can be used with
+ remqueue to remove T from Q again.
+ */
+static SCM
+enqueue (SCM q, SCM t)
+{
+ SCM c = scm_cons (t, SCM_EOL);
+ if (scm_is_null (SCM_CDR (q)))
+ SCM_SETCDR (q, c);
+ else
+ SCM_SETCDR (SCM_CAR (q), c);
+ SCM_SETCAR (q, c);
+ return c;
+}
+
+/* Remove the element that the handle C refers to from the queue Q. C
+ must have been returned from a call to enqueue. The return value
+ is zero when the element referred to by C has already been removed.
+ Otherwise, 1 is returned.
+*/
+static int
+remqueue (SCM q, SCM c)
+{
+ SCM p, prev = q;
+ for (p = SCM_CDR (q); !scm_is_null (p); p = SCM_CDR (p))
+ {
+ if (scm_is_eq (p, c))
+ {
+ if (scm_is_eq (c, SCM_CAR (q)))
+ SCM_SETCAR (q, SCM_CDR (c));
+ SCM_SETCDR (prev, SCM_CDR (c));
+ return 1;
+ }
+ prev = p;
+ }
+ return 0;
+}
+
+/* Remove the front-most element from the queue Q and return it.
+ Return SCM_BOOL_F when Q is empty.
+*/
+static SCM
+dequeue (SCM q)
+{
+ SCM c = SCM_CDR (q);
+ if (scm_is_null (c))
+ return SCM_BOOL_F;
+ else
+ {
+ SCM_SETCDR (q, SCM_CDR (c));
+ if (scm_is_null (SCM_CDR (q)))
+ SCM_SETCAR (q, SCM_EOL);
+ return SCM_CAR (c);
+ }
+}
+
+/*** Thread smob routines */
+
+
+static int
+thread_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
+{
+ scm_i_thread *t = SCM_I_THREAD_DATA (exp);
+ scm_puts ("#<thread ", port);
+ scm_uintprint ((size_t)t->pthread, 10, port);
+ scm_puts (" (", port);
+ scm_uintprint ((scm_t_bits)t, 16, port);
+ scm_puts (")>", port);
+ return 1;
+}
+
+static size_t
+thread_free (SCM obj)
+{
+ scm_i_thread *t = SCM_I_THREAD_DATA (obj);
+ assert (t->exited);
+ scm_gc_free (t, sizeof (*t), "thread");
+ return 0;
+}
+
+/*** Blocking on queues. */
+
+/* See also scm_i_queue_async_cell for how such a block is
+ interrputed.
+*/
+
+/* Put the current thread on QUEUE and go to sleep, waiting for it to
+ be woken up by a call to 'unblock_from_queue', or to be
+ interrupted. Upon return of this function, the current thread is
+ no longer on QUEUE, even when the sleep has been interrupted.
+
+ The QUEUE data structure is assumed to be protected by MUTEX and
+ the caller of block_self must hold MUTEX. It will be atomically
+ unlocked while sleeping, just as with scm_i_pthread_cond_wait.
+
+ SLEEP_OBJECT is an arbitrary SCM value that is kept alive as long
+ as MUTEX is needed.
+
+ When WAITTIME is not NULL, the sleep will be aborted at that time.
+
+ The return value of block_self is an errno value. It will be zero
+ when the sleep has been successfully completed by a call to
+ unblock_from_queue, EINTR when it has been interrupted by the
+ delivery of a system async, and ETIMEDOUT when the timeout has
+ expired.
+
+ The system asyncs themselves are not executed by block_self.
+*/
+static int
+block_self (SCM queue, SCM sleep_object, scm_i_pthread_mutex_t *mutex,
+ const scm_t_timespec *waittime)
+{
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+ SCM q_handle;
+ int err;
+
+ if (scm_i_setup_sleep (t, sleep_object, mutex, -1))
+ err = EINTR;
+ else
+ {
+ t->block_asyncs++;
+ q_handle = enqueue (queue, t->handle);
+ if (waittime == NULL)
+ err = scm_i_scm_pthread_cond_wait (&t->sleep_cond, mutex);
+ else
+ err = scm_i_scm_pthread_cond_timedwait (&t->sleep_cond, mutex, waittime);
+
+ /* When we are still on QUEUE, we have been interrupted. We
+ report this only when no other error (such as a timeout) has
+ happened above.
+ */
+ if (remqueue (queue, q_handle) && err == 0)
+ err = EINTR;
+ t->block_asyncs--;
+ scm_i_reset_sleep (t);
+ }
+
+ return err;
+}
+
+/* Wake up the first thread on QUEUE, if any. The caller must hold
+ the mutex that protects QUEUE. The awoken thread is returned, or
+ #f when the queue was empty.
+ */
+static SCM
+unblock_from_queue (SCM queue)
+{
+ SCM thread = dequeue (queue);
+ if (scm_is_true (thread))
+ scm_i_pthread_cond_signal (&SCM_I_THREAD_DATA(thread)->sleep_cond);
+ return thread;
+}
+
+/* Getting into and out of guile mode.
+ */
+
+/* Ken Raeburn observes that the implementation of suspend and resume
+ (and the things that build on top of them) are very likely not
+ correct (see below). We will need fix this eventually, and that's
+ why scm_leave_guile/scm_enter_guile are not exported in the API.
+
+ Ken writes:
+
+ Consider this sequence:
+
+ Function foo, called in Guile mode, calls suspend (maybe indirectly
+ through scm_leave_guile), which does this:
+
+ // record top of stack for the GC
+ t->top = SCM_STACK_PTR (&t); // just takes address of automatic
+ var 't'
+ // save registers.
+ SCM_FLUSH_REGISTER_WINDOWS; // sparc only
+ setjmp (t->regs); // here's most of the magic
+
+ ... and returns.
+
+ Function foo has a SCM value X, a handle on a non-immediate object, in
+ a caller-saved register R, and it's the only reference to the object
+ currently.
+
+ The compiler wants to use R in suspend, so it pushes the current
+ value, X, into a stack slot which will be reloaded on exit from
+ suspend; then it loads stuff into R and goes about its business. The
+ setjmp call saves (some of) the current registers, including R, which
+ no longer contains X. (This isn't a problem for a normal
+ setjmp/longjmp situation, where longjmp would be called before
+ setjmp's caller returns; the old value for X would be loaded back from
+ the stack after the longjmp, before the function returned.)
+
+ So, suspend returns, loading X back into R (and invalidating the jump
+ buffer) in the process. The caller foo then goes off and calls a
+ bunch of other functions out of Guile mode, occasionally storing X on
+ the stack again, but, say, much deeper on the stack than suspend's
+ stack frame went, and the stack slot where suspend had written X has
+ long since been overwritten with other values.
+
+ Okay, nothing actively broken so far. Now, let garbage collection
+ run, triggered by another thread.
+
+ The thread calling foo is out of Guile mode at the time, so the
+ garbage collector just scans a range of stack addresses. Too bad that
+ X isn't stored there. So the pointed-to storage goes onto the free
+ list, and I think you can see where things go from there.
+
+ Is there anything I'm missing that'll prevent this scenario from
+ happening? I mean, aside from, "well, suspend and scm_leave_guile
+ don't have many local variables, so they probably won't need to save
+ any registers on most systems, so we hope everything will wind up in
+ the jump buffer and we'll just get away with it"?
+
+ (And, going the other direction, if scm_leave_guile and suspend push
+ the stack pointer over onto a new page, and foo doesn't make further
+ function calls and thus the stack pointer no longer includes that
+ page, are we guaranteed that the kernel cannot release the now-unused
+ stack page that contains the top-of-stack pointer we just saved? I
+ don't know if any OS actually does that. If it does, we could get
+ faults in garbage collection.)
+
+ I don't think scm_without_guile has to have this problem, as it gets
+ more control over the stack handling -- but it should call setjmp
+ itself. I'd probably try something like:
+
+ // record top of stack for the GC
+ t->top = SCM_STACK_PTR (&t);
+ // save registers.
+ SCM_FLUSH_REGISTER_WINDOWS;
+ setjmp (t->regs);
+ res = func(data);
+ scm_enter_guile (t);
+
+ ... though even that's making some assumptions about the stack
+ ordering of local variables versus caller-saved registers.
+
+ For something like scm_leave_guile to work, I don't think it can just
+ rely on invalidated jump buffers. A valid jump buffer, and a handle
+ on the stack state at the point when the jump buffer was initialized,
+ together, would work fine, but I think then we're talking about macros
+ invoking setjmp in the caller's stack frame, and requiring that the
+ caller of scm_leave_guile also call scm_enter_guile before returning,
+ kind of like pthread_cleanup_push/pop calls that have to be paired up
+ in a function. (In fact, the pthread ones have to be paired up
+ syntactically, as if they might expand to a compound statement
+ incorporating the user's code, and invoking a compiler's
+ exception-handling primitives. Which might be something to think
+ about for cases where Guile is used with C++ exceptions or
+ pthread_cancel.)
+*/
+
+scm_i_pthread_key_t scm_i_thread_key;
+
+static void
+resume (scm_i_thread *t)
+{
+ t->top = NULL;
+ if (t->clear_freelists_p)
+ {
+ *SCM_FREELIST_LOC (scm_i_freelist) = SCM_EOL;
+ *SCM_FREELIST_LOC (scm_i_freelist2) = SCM_EOL;
+ t->clear_freelists_p = 0;
+ }
+}
+
+typedef void* scm_t_guile_ticket;
+
+static void
+scm_enter_guile (scm_t_guile_ticket ticket)
+{
+ scm_i_thread *t = (scm_i_thread *)ticket;
+ if (t)
+ {
+ scm_i_pthread_mutex_lock (&t->heap_mutex);
+ resume (t);
+ }
+}
+
+static scm_i_thread *
+suspend (void)
+{
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+
+ /* record top of stack for the GC */
+ t->top = SCM_STACK_PTR (&t);
+ /* save registers. */
+ SCM_FLUSH_REGISTER_WINDOWS;
+ setjmp (t->regs);
+ return t;
+}
+
+static scm_t_guile_ticket
+scm_leave_guile ()
+{
+ scm_i_thread *t = suspend ();
+ scm_i_pthread_mutex_unlock (&t->heap_mutex);
+ return (scm_t_guile_ticket) t;
+}
+
+static scm_i_pthread_mutex_t thread_admin_mutex = SCM_I_PTHREAD_MUTEX_INITIALIZER;
+static scm_i_thread *all_threads = NULL;
+static int thread_count;
+
+static SCM scm_i_default_dynamic_state;
+
+/* Perform first stage of thread initialisation, in non-guile mode.
+ */
+static void
+guilify_self_1 (SCM_STACKITEM *base)
+{
+ scm_i_thread *t = scm_gc_malloc (sizeof (scm_i_thread), "thread");
+
+ t->pthread = scm_i_pthread_self ();
+ t->handle = SCM_BOOL_F;
+ t->result = SCM_BOOL_F;
+ t->join_queue = SCM_EOL;
+ t->dynamic_state = SCM_BOOL_F;
+ t->dynwinds = SCM_EOL;
+ t->active_asyncs = SCM_EOL;
+ t->block_asyncs = 1;
+ t->pending_asyncs = 1;
+ t->last_debug_frame = NULL;
+ t->base = base;
+ t->continuation_root = SCM_EOL;
+ t->continuation_base = base;
+ scm_i_pthread_cond_init (&t->sleep_cond, NULL);
+ t->sleep_mutex = NULL;
+ t->sleep_object = SCM_BOOL_F;
+ t->sleep_fd = -1;
+ /* XXX - check for errors. */
+ pipe (t->sleep_pipe);
+ scm_i_pthread_mutex_init (&t->heap_mutex, NULL);
+ t->clear_freelists_p = 0;
+ t->gc_running_p = 0;
+ t->current_mark_stack_ptr = NULL;
+ t->current_mark_stack_limit = NULL;
+ t->exited = 0;
+
+ t->freelist = SCM_EOL;
+ t->freelist2 = SCM_EOL;
+ SCM_SET_FREELIST_LOC (scm_i_freelist, &t->freelist);
+ SCM_SET_FREELIST_LOC (scm_i_freelist2, &t->freelist2);
+
+ scm_i_pthread_setspecific (scm_i_thread_key, t);
+
+ scm_i_pthread_mutex_lock (&t->heap_mutex);
+
+ scm_i_pthread_mutex_lock (&thread_admin_mutex);
+ t->next_thread = all_threads;
+ all_threads = t;
+ thread_count++;
+ scm_i_pthread_mutex_unlock (&thread_admin_mutex);
+}
+
+/* Perform second stage of thread initialisation, in guile mode.
+ */
+static void
+guilify_self_2 (SCM parent)
+{
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+
+ SCM_NEWSMOB (t->handle, scm_tc16_thread, t);
+
+ t->continuation_root = scm_cons (t->handle, SCM_EOL);
+ t->continuation_base = t->base;
+
+ if (scm_is_true (parent))
+ t->dynamic_state = scm_make_dynamic_state (parent);
+ else
+ t->dynamic_state = scm_i_make_initial_dynamic_state ();
+
+ t->join_queue = make_queue ();
+ t->block_asyncs = 0;
+}
+
+/* Perform thread tear-down, in guile mode.
+ */
+static void *
+do_thread_exit (void *v)
+{
+ scm_i_thread *t = (scm_i_thread *)v;
+
+ scm_i_scm_pthread_mutex_lock (&thread_admin_mutex);
+
+ t->exited = 1;
+ close (t->sleep_pipe[0]);
+ close (t->sleep_pipe[1]);
+ while (scm_is_true (unblock_from_queue (t->join_queue)))
+ ;
+
+ scm_i_pthread_mutex_unlock (&thread_admin_mutex);
+ return NULL;
+}
+
+static void
+on_thread_exit (void *v)
+{
+ scm_i_thread *t = (scm_i_thread *)v, **tp;
+
+ scm_i_pthread_setspecific (scm_i_thread_key, v);
+
+ /* Unblocking the joining threads needs to happen in guile mode
+ since the queue is a SCM data structure.
+ */
+ scm_with_guile (do_thread_exit, v);
+
+ /* Removing ourself from the list of all threads needs to happen in
+ non-guile mode since all SCM values on our stack become
+ unprotected once we are no longer in the list.
+ */
+ scm_leave_guile ();
+ scm_i_pthread_mutex_lock (&thread_admin_mutex);
+ for (tp = &all_threads; *tp; tp = &(*tp)->next_thread)
+ if (*tp == t)
+ {
+ *tp = t->next_thread;
+ break;
+ }
+ thread_count--;
+ scm_i_pthread_mutex_unlock (&thread_admin_mutex);
+
+ scm_i_pthread_setspecific (scm_i_thread_key, NULL);
+}
+
+static scm_i_pthread_once_t init_thread_key_once = SCM_I_PTHREAD_ONCE_INIT;
+
+static void
+init_thread_key (void)
+{
+ scm_i_pthread_key_create (&scm_i_thread_key, on_thread_exit);
+}
+
+/* Perform any initializations necessary to bring the current thread
+ into guile mode, initializing Guile itself, if necessary.
+
+ BASE is the stack base to use with GC.
+
+ PARENT is the dynamic state to use as the parent, ot SCM_BOOL_F in
+ which case the default dynamic state is used.
+
+ Return zero when the thread was in guile mode already; otherwise
+ return 1.
+*/
+
+static int
+scm_i_init_thread_for_guile (SCM_STACKITEM *base, SCM parent)
+{
+ scm_i_thread *t;
+
+ scm_i_pthread_once (&init_thread_key_once, init_thread_key);
+
+ if ((t = SCM_I_CURRENT_THREAD) == NULL)
+ {
+ /* This thread has not been guilified yet.
+ */
+
+ scm_i_pthread_mutex_lock (&scm_i_init_mutex);
+ if (scm_initialized_p == 0)
+ {
+ /* First thread ever to enter Guile. Run the full
+ initialization.
+ */
+ scm_i_init_guile (base);
+ scm_i_pthread_mutex_unlock (&scm_i_init_mutex);
+ }
+ else
+ {
+ /* Guile is already initialized, but this thread enters it for
+ the first time. Only initialize this thread.
+ */
+ scm_i_pthread_mutex_unlock (&scm_i_init_mutex);
+ guilify_self_1 (base);
+ guilify_self_2 (parent);
+ }
+ return 1;
+ }
+ else if (t->top)
+ {
+ /* This thread is already guilified but not in guile mode, just
+ resume it.
+
+ XXX - base might be lower than when this thread was first
+ guilified.
+ */
+ scm_enter_guile ((scm_t_guile_ticket) t);
+ return 1;
+ }
+ else
+ {
+ /* Thread is already in guile mode. Nothing to do.
+ */
+ return 0;
+ }
+}
+
+#if SCM_USE_PTHREAD_THREADS
+/* pthread_getattr_np not available on MacOS X and Solaris 10. */
+#if HAVE_PTHREAD_ATTR_GETSTACK && HAVE_PTHREAD_GETATTR_NP
+
+#define HAVE_GET_THREAD_STACK_BASE
+
+static SCM_STACKITEM *
+get_thread_stack_base ()
+{
+ pthread_attr_t attr;
+ void *start, *end;
+ size_t size;
+
+ pthread_getattr_np (pthread_self (), &attr);
+ pthread_attr_getstack (&attr, &start, &size);
+ end = (char *)start + size;
+
+ /* XXX - pthread_getattr_np from LinuxThreads does not seem to work
+ for the main thread, but we can use scm_get_stack_base in that
+ case.
+ */
+
+#ifndef PTHREAD_ATTR_GETSTACK_WORKS
+ if ((void *)&attr < start || (void *)&attr >= end)
+ return scm_get_stack_base ();
+ else
+#endif
+ {
+#if SCM_STACK_GROWS_UP
+ return start;
+#else
+ return end;
+#endif
+ }
+}
+
+#endif /* HAVE_PTHREAD_ATTR_GETSTACK && HAVE_PTHREAD_GETATTR_NP */
+
+#else /* !SCM_USE_PTHREAD_THREADS */
+
+#define HAVE_GET_THREAD_STACK_BASE
+
+static SCM_STACKITEM *
+get_thread_stack_base ()
+{
+ return scm_get_stack_base ();
+}
+
+#endif /* !SCM_USE_PTHREAD_THREADS */
+
+#ifdef HAVE_GET_THREAD_STACK_BASE
+
+void
+scm_init_guile ()
+{
+ scm_i_init_thread_for_guile (get_thread_stack_base (),
+ scm_i_default_dynamic_state);
+}
+
+#endif
+
+void *
+scm_with_guile (void *(*func)(void *), void *data)
+{
+ return scm_i_with_guile_and_parent (func, data,
+ scm_i_default_dynamic_state);
+}
+
+void *
+scm_i_with_guile_and_parent (void *(*func)(void *), void *data,
+ SCM parent)
+{
+ void *res;
+ int really_entered;
+ SCM_STACKITEM base_item;
+ really_entered = scm_i_init_thread_for_guile (&base_item, parent);
+ res = scm_c_with_continuation_barrier (func, data);
+ if (really_entered)
+ scm_leave_guile ();
+ return res;
+}
+
+void *
+scm_without_guile (void *(*func)(void *), void *data)
+{
+ void *res;
+ scm_t_guile_ticket t;
+ t = scm_leave_guile ();
+ res = func (data);
+ scm_enter_guile (t);
+ return res;
+}
+
+/*** Thread creation */
+
+typedef struct {
+ SCM parent;
+ SCM thunk;
+ SCM handler;
+ SCM thread;
+ scm_i_pthread_mutex_t mutex;
+ scm_i_pthread_cond_t cond;
+} launch_data;
+
+static void *
+really_launch (void *d)
+{
+ launch_data *data = (launch_data *)d;
+ SCM thunk = data->thunk, handler = data->handler;
+ scm_i_thread *t;
+
+ t = SCM_I_CURRENT_THREAD;
+
+ scm_i_scm_pthread_mutex_lock (&data->mutex);
+ data->thread = scm_current_thread ();
+ scm_i_pthread_cond_signal (&data->cond);
+ scm_i_pthread_mutex_unlock (&data->mutex);
+
+ if (SCM_UNBNDP (handler))
+ t->result = scm_call_0 (thunk);
+ else
+ t->result = scm_catch (SCM_BOOL_T, thunk, handler);
+
+ return 0;
+}
+
+static void *
+launch_thread (void *d)
+{
+ launch_data *data = (launch_data *)d;
+ scm_i_pthread_detach (scm_i_pthread_self ());
+ scm_i_with_guile_and_parent (really_launch, d, data->parent);
+ return NULL;
+}
+
+SCM_DEFINE (scm_call_with_new_thread, "call-with-new-thread", 1, 1, 0,
+ (SCM thunk, SCM handler),
+ "Call @code{thunk} in a new thread and with a new dynamic state,\n"
+ "returning a new thread object representing the thread. The procedure\n"
+ "@var{thunk} is called via @code{with-continuation-barrier}.\n"
+ "\n"
+ "When @var{handler} is specified, then @var{thunk} is called from\n"
+ "within a @code{catch} with tag @code{#t} that has @var{handler} as its\n"
+ "handler. This catch is established inside the continuation barrier.\n"
+ "\n"
+ "Once @var{thunk} or @var{handler} returns, the return value is made\n"
+ "the @emph{exit value} of the thread and the thread is terminated.")
+#define FUNC_NAME s_scm_call_with_new_thread
+{
+ launch_data data;
+ scm_i_pthread_t id;
+ int err;
+
+ SCM_ASSERT (scm_is_true (scm_thunk_p (thunk)), thunk, SCM_ARG1, FUNC_NAME);
+ SCM_ASSERT (SCM_UNBNDP (handler) || scm_is_true (scm_procedure_p (handler)),
+ handler, SCM_ARG2, FUNC_NAME);
+
+ data.parent = scm_current_dynamic_state ();
+ data.thunk = thunk;
+ data.handler = handler;
+ data.thread = SCM_BOOL_F;
+ scm_i_pthread_mutex_init (&data.mutex, NULL);
+ scm_i_pthread_cond_init (&data.cond, NULL);
+
+ scm_i_scm_pthread_mutex_lock (&data.mutex);
+ err = scm_i_pthread_create (&id, NULL, launch_thread, &data);
+ if (err)
+ {
+ scm_i_pthread_mutex_unlock (&data.mutex);
+ errno = err;
+ scm_syserror (NULL);
+ }
+ scm_i_scm_pthread_cond_wait (&data.cond, &data.mutex);
+ scm_i_pthread_mutex_unlock (&data.mutex);
+
+ return data.thread;
+}
+#undef FUNC_NAME
+
+typedef struct {
+ SCM parent;
+ scm_t_catch_body body;
+ void *body_data;
+ scm_t_catch_handler handler;
+ void *handler_data;
+ SCM thread;
+ scm_i_pthread_mutex_t mutex;
+ scm_i_pthread_cond_t cond;
+} spawn_data;
+
+static void *
+really_spawn (void *d)
+{
+ spawn_data *data = (spawn_data *)d;
+ scm_t_catch_body body = data->body;
+ void *body_data = data->body_data;
+ scm_t_catch_handler handler = data->handler;
+ void *handler_data = data->handler_data;
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+
+ scm_i_scm_pthread_mutex_lock (&data->mutex);
+ data->thread = scm_current_thread ();
+ scm_i_pthread_cond_signal (&data->cond);
+ scm_i_pthread_mutex_unlock (&data->mutex);
+
+ if (handler == NULL)
+ t->result = body (body_data);
+ else
+ t->result = scm_internal_catch (SCM_BOOL_T,
+ body, body_data,
+ handler, handler_data);
+
+ return 0;
+}
+
+static void *
+spawn_thread (void *d)
+{
+ spawn_data *data = (spawn_data *)d;
+ scm_i_pthread_detach (scm_i_pthread_self ());
+ scm_i_with_guile_and_parent (really_spawn, d, data->parent);
+ return NULL;
+}
+
+SCM
+scm_spawn_thread (scm_t_catch_body body, void *body_data,
+ scm_t_catch_handler handler, void *handler_data)
+{
+ spawn_data data;
+ scm_i_pthread_t id;
+ int err;
+
+ data.parent = scm_current_dynamic_state ();
+ data.body = body;
+ data.body_data = body_data;
+ data.handler = handler;
+ data.handler_data = handler_data;
+ data.thread = SCM_BOOL_F;
+ scm_i_pthread_mutex_init (&data.mutex, NULL);
+ scm_i_pthread_cond_init (&data.cond, NULL);
+
+ scm_i_scm_pthread_mutex_lock (&data.mutex);
+ err = scm_i_pthread_create (&id, NULL, spawn_thread, &data);
+ if (err)
+ {
+ scm_i_pthread_mutex_unlock (&data.mutex);
+ errno = err;
+ scm_syserror (NULL);
+ }
+ scm_i_scm_pthread_cond_wait (&data.cond, &data.mutex);
+ scm_i_pthread_mutex_unlock (&data.mutex);
+
+ return data.thread;
+}
+
+SCM_DEFINE (scm_yield, "yield", 0, 0, 0,
+ (),
+"Move the calling thread to the end of the scheduling queue.")
+#define FUNC_NAME s_scm_yield
+{
+ return scm_from_bool (scm_i_sched_yield ());
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_join_thread, "join-thread", 1, 0, 0,
+ (SCM thread),
+"Suspend execution of the calling thread until the target @var{thread} "
+"terminates, unless the target @var{thread} has already terminated. ")
+#define FUNC_NAME s_scm_join_thread
+{
+ scm_i_thread *t;
+ SCM res;
+
+ SCM_VALIDATE_THREAD (1, thread);
+ if (scm_is_eq (scm_current_thread (), thread))
+ SCM_MISC_ERROR ("can not join the current thread", SCM_EOL);
+
+ scm_i_scm_pthread_mutex_lock (&thread_admin_mutex);
+
+ t = SCM_I_THREAD_DATA (thread);
+ if (!t->exited)
+ {
+ while (1)
+ {
+ block_self (t->join_queue, thread, &thread_admin_mutex, NULL);
+ if (t->exited)
+ break;
+ scm_i_pthread_mutex_unlock (&thread_admin_mutex);
+ SCM_TICK;
+ scm_i_scm_pthread_mutex_lock (&thread_admin_mutex);
+ }
+ }
+ res = t->result;
+
+ scm_i_pthread_mutex_unlock (&thread_admin_mutex);
+ return res;
+}
+#undef FUNC_NAME
+
+/*** Fat mutexes */
+
+/* We implement our own mutex type since we want them to be 'fair', we
+ want to do fancy things while waiting for them (like running
+ asyncs) and we might want to add things that are nice for
+ debugging.
+*/
+
+typedef struct {
+ scm_i_pthread_mutex_t lock;
+ SCM owner;
+ int level; /* how much the owner owns us.
+ < 0 for non-recursive mutexes */
+ SCM waiting; /* the threads waiting for this mutex. */
+} fat_mutex;
+
+#define SCM_MUTEXP(x) SCM_SMOB_PREDICATE (scm_tc16_mutex, x)
+#define SCM_MUTEX_DATA(x) ((fat_mutex *) SCM_SMOB_DATA (x))
+
+
+static size_t
+fat_mutex_free (SCM mx)
+{
+ fat_mutex *m = SCM_MUTEX_DATA (mx);
+ scm_i_pthread_mutex_destroy (&m->lock);
+ scm_gc_free (m, sizeof (fat_mutex), "mutex");
+ return 0;
+}
+
+static int
+fat_mutex_print (SCM mx, SCM port, scm_print_state *pstate SCM_UNUSED)
+{
+ fat_mutex *m = SCM_MUTEX_DATA (mx);
+ scm_puts ("#<mutex ", port);
+ scm_uintprint ((scm_t_bits)m, 16, port);
+ scm_puts (">", port);
+ return 1;
+}
+
+static SCM
+make_fat_mutex (int recursive)
+{
+ fat_mutex *m;
+ SCM mx;
+
+ m = scm_gc_malloc (sizeof (fat_mutex), "mutex");
+ scm_i_pthread_mutex_init (&m->lock, NULL);
+ m->owner = SCM_BOOL_F;
+ m->level = recursive? 0 : -1;
+ m->waiting = SCM_EOL;
+ SCM_NEWSMOB (mx, scm_tc16_mutex, (scm_t_bits) m);
+ m->waiting = make_queue ();
+ return mx;
+}
+
+SCM_DEFINE (scm_make_mutex, "make-mutex", 0, 0, 0,
+ (void),
+ "Create a new mutex. ")
+#define FUNC_NAME s_scm_make_mutex
+{
+ return make_fat_mutex (0);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_make_recursive_mutex, "make-recursive-mutex", 0, 0, 0,
+ (void),
+ "Create a new recursive mutex. ")
+#define FUNC_NAME s_scm_make_recursive_mutex
+{
+ return make_fat_mutex (1);
+}
+#undef FUNC_NAME
+
+static char *
+fat_mutex_lock (SCM mutex)
+{
+ fat_mutex *m = SCM_MUTEX_DATA (mutex);
+ SCM thread = scm_current_thread ();
+ char *msg = NULL;
+
+ scm_i_scm_pthread_mutex_lock (&m->lock);
+ if (scm_is_false (m->owner))
+ m->owner = thread;
+ else if (scm_is_eq (m->owner, thread))
+ {
+ if (m->level >= 0)
+ m->level++;
+ else
+ msg = "mutex already locked by current thread";
+ }
+ else
+ {
+ while (1)
+ {
+ block_self (m->waiting, mutex, &m->lock, NULL);
+ if (scm_is_eq (m->owner, thread))
+ break;
+ scm_i_pthread_mutex_unlock (&m->lock);
+ SCM_TICK;
+ scm_i_scm_pthread_mutex_lock (&m->lock);
+ }
+ }
+ scm_i_pthread_mutex_unlock (&m->lock);
+ return msg;
+}
+
+SCM_DEFINE (scm_lock_mutex, "lock-mutex", 1, 0, 0,
+ (SCM mx),
+"Lock @var{mutex}. If the mutex is already locked, the calling thread "
+"blocks until the mutex becomes available. The function returns when "
+"the calling thread owns the lock on @var{mutex}. Locking a mutex that "
+"a thread already owns will succeed right away and will not block the "
+"thread. That is, Guile's mutexes are @emph{recursive}. ")
+#define FUNC_NAME s_scm_lock_mutex
+{
+ char *msg;
+
+ SCM_VALIDATE_MUTEX (1, mx);
+ msg = fat_mutex_lock (mx);
+ if (msg)
+ scm_misc_error (NULL, msg, SCM_EOL);
+ return SCM_BOOL_T;
+}
+#undef FUNC_NAME
+
+void
+scm_dynwind_lock_mutex (SCM mutex)
+{
+ scm_dynwind_unwind_handler_with_scm ((void(*)(SCM))scm_unlock_mutex, mutex,
+ SCM_F_WIND_EXPLICITLY);
+ scm_dynwind_rewind_handler_with_scm ((void(*)(SCM))scm_lock_mutex, mutex,
+ SCM_F_WIND_EXPLICITLY);
+}
+
+static char *
+fat_mutex_trylock (fat_mutex *m, int *resp)
+{
+ char *msg = NULL;
+ SCM thread = scm_current_thread ();
+
+ *resp = 1;
+ scm_i_pthread_mutex_lock (&m->lock);
+ if (scm_is_false (m->owner))
+ m->owner = thread;
+ else if (scm_is_eq (m->owner, thread))
+ {
+ if (m->level >= 0)
+ m->level++;
+ else
+ msg = "mutex already locked by current thread";
+ }
+ else
+ *resp = 0;
+ scm_i_pthread_mutex_unlock (&m->lock);
+ return msg;
+}
+
+SCM_DEFINE (scm_try_mutex, "try-mutex", 1, 0, 0,
+ (SCM mutex),
+"Try to lock @var{mutex}. If the mutex is already locked by someone "
+"else, return @code{#f}. Else lock the mutex and return @code{#t}. ")
+#define FUNC_NAME s_scm_try_mutex
+{
+ char *msg;
+ int res;
+
+ SCM_VALIDATE_MUTEX (1, mutex);
+
+ msg = fat_mutex_trylock (SCM_MUTEX_DATA (mutex), &res);
+ if (msg)
+ scm_misc_error (NULL, msg, SCM_EOL);
+ return scm_from_bool (res);
+}
+#undef FUNC_NAME
+
+static char *
+fat_mutex_unlock (fat_mutex *m)
+{
+ char *msg = NULL;
+
+ scm_i_scm_pthread_mutex_lock (&m->lock);
+ if (!scm_is_eq (m->owner, scm_current_thread ()))
+ {
+ if (scm_is_false (m->owner))
+ msg = "mutex not locked";
+ else
+ msg = "mutex not locked by current thread";
+ }
+ else if (m->level > 0)
+ m->level--;
+ else
+ m->owner = unblock_from_queue (m->waiting);
+ scm_i_pthread_mutex_unlock (&m->lock);
+
+ return msg;
+}
+
+SCM_DEFINE (scm_unlock_mutex, "unlock-mutex", 1, 0, 0,
+ (SCM mx),
+"Unlocks @var{mutex} if the calling thread owns the lock on "
+"@var{mutex}. Calling unlock-mutex on a mutex not owned by the current "
+"thread results in undefined behaviour. Once a mutex has been unlocked, "
+"one thread blocked on @var{mutex} is awakened and grabs the mutex "
+"lock. Every call to @code{lock-mutex} by this thread must be matched "
+"with a call to @code{unlock-mutex}. Only the last call to "
+"@code{unlock-mutex} will actually unlock the mutex. ")
+#define FUNC_NAME s_scm_unlock_mutex
+{
+ char *msg;
+ SCM_VALIDATE_MUTEX (1, mx);
+
+ msg = fat_mutex_unlock (SCM_MUTEX_DATA (mx));
+ if (msg)
+ scm_misc_error (NULL, msg, SCM_EOL);
+ return SCM_BOOL_T;
+}
+#undef FUNC_NAME
+
+#if 0
+
+SCM_DEFINE (scm_mutex_owner, "mutex-owner", 1, 0, 0,
+ (SCM mx),
+ "Return the thread owning @var{mx}, or @code{#f}.")
+#define FUNC_NAME s_scm_mutex_owner
+{
+ SCM_VALIDATE_MUTEX (1, mx);
+ return (SCM_MUTEX_DATA(mx))->owner;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_mutex_level, "mutex-level", 1, 0, 0,
+ (SCM mx),
+ "Return the lock level of a recursive mutex, or -1\n"
+ "for a standard mutex.")
+#define FUNC_NAME s_scm_mutex_level
+{
+ SCM_VALIDATE_MUTEX (1, mx);
+ return scm_from_int (SCM_MUTEX_DATA(mx)->level);
+}
+#undef FUNC_NAME
+
+#endif
+
+/*** Fat condition variables */
+
+typedef struct {
+ scm_i_pthread_mutex_t lock;
+ SCM waiting; /* the threads waiting for this condition. */
+} fat_cond;
+
+#define SCM_CONDVARP(x) SCM_SMOB_PREDICATE (scm_tc16_condvar, x)
+#define SCM_CONDVAR_DATA(x) ((fat_cond *) SCM_SMOB_DATA (x))
+
+static size_t
+fat_cond_free (SCM mx)
+{
+ fat_cond *c = SCM_CONDVAR_DATA (mx);
+ scm_i_pthread_mutex_destroy (&c->lock);
+ scm_gc_free (c, sizeof (fat_cond), "condition-variable");
+ return 0;
+}
+
+static int
+fat_cond_print (SCM cv, SCM port, scm_print_state *pstate SCM_UNUSED)
+{
+ fat_cond *c = SCM_CONDVAR_DATA (cv);
+ scm_puts ("#<condition-variable ", port);
+ scm_uintprint ((scm_t_bits)c, 16, port);
+ scm_puts (">", port);
+ return 1;
+}
+
+SCM_DEFINE (scm_make_condition_variable, "make-condition-variable", 0, 0, 0,
+ (void),
+ "Make a new condition variable.")
+#define FUNC_NAME s_scm_make_condition_variable
+{
+ fat_cond *c;
+ SCM cv;
+
+ c = scm_gc_malloc (sizeof (fat_cond), "condition variable");
+ scm_i_pthread_mutex_init (&c->lock, 0);
+ c->waiting = SCM_EOL;
+ SCM_NEWSMOB (cv, scm_tc16_condvar, (scm_t_bits) c);
+ c->waiting = make_queue ();
+ return cv;
+}
+#undef FUNC_NAME
+
+static int
+fat_cond_timedwait (SCM cond, SCM mutex,
+ const scm_t_timespec *waittime)
+{
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+ fat_cond *c = SCM_CONDVAR_DATA (cond);
+ fat_mutex *m = SCM_MUTEX_DATA (mutex);
+ const char *msg;
+ int err = 0;
+
+ while (1)
+ {
+ scm_i_scm_pthread_mutex_lock (&c->lock);
+ msg = fat_mutex_unlock (m);
+ t->block_asyncs++;
+ if (msg == NULL)
+ {
+ err = block_self (c->waiting, cond, &c->lock, waittime);
+ scm_i_pthread_mutex_unlock (&c->lock);
+ fat_mutex_lock (mutex);
+ }
+ else
+ scm_i_pthread_mutex_unlock (&c->lock);
+ t->block_asyncs--;
+ scm_async_click ();
+
+ if (msg)
+ scm_misc_error (NULL, msg, SCM_EOL);
+
+ scm_remember_upto_here_2 (cond, mutex);
+
+ if (err == 0)
+ return 1;
+ if (err == ETIMEDOUT)
+ return 0;
+ if (err != EINTR)
+ {
+ errno = err;
+ scm_syserror (NULL);
+ }
+ }
+}
+
+SCM_DEFINE (scm_timed_wait_condition_variable, "wait-condition-variable", 2, 1, 0,
+ (SCM cv, SCM mx, SCM t),
+"Wait until @var{cond-var} has been signalled. While waiting, "
+"@var{mutex} is atomically unlocked (as with @code{unlock-mutex}) and "
+"is locked again when this function returns. When @var{time} is given, "
+"it specifies a point in time where the waiting should be aborted. It "
+"can be either a integer as returned by @code{current-time} or a pair "
+"as returned by @code{gettimeofday}. When the waiting is aborted the "
+"mutex is locked and @code{#f} is returned. When the condition "
+"variable is in fact signalled, the mutex is also locked and @code{#t} "
+"is returned. ")
+#define FUNC_NAME s_scm_timed_wait_condition_variable
+{
+ scm_t_timespec waittime, *waitptr = NULL;
+
+ SCM_VALIDATE_CONDVAR (1, cv);
+ SCM_VALIDATE_MUTEX (2, mx);
+
+ if (!SCM_UNBNDP (t))
+ {
+ if (scm_is_pair (t))
+ {
+ waittime.tv_sec = scm_to_ulong (SCM_CAR (t));
+ waittime.tv_nsec = scm_to_ulong (SCM_CAR (t)) * 1000;
+ }
+ else
+ {
+ waittime.tv_sec = scm_to_ulong (t);
+ waittime.tv_nsec = 0;
+ }
+ waitptr = &waittime;
+ }
+
+ return scm_from_bool (fat_cond_timedwait (cv, mx, waitptr));
+}
+#undef FUNC_NAME
+
+static void
+fat_cond_signal (fat_cond *c)
+{
+ scm_i_scm_pthread_mutex_lock (&c->lock);
+ unblock_from_queue (c->waiting);
+ scm_i_pthread_mutex_unlock (&c->lock);
+}
+
+SCM_DEFINE (scm_signal_condition_variable, "signal-condition-variable", 1, 0, 0,
+ (SCM cv),
+ "Wake up one thread that is waiting for @var{cv}")
+#define FUNC_NAME s_scm_signal_condition_variable
+{
+ SCM_VALIDATE_CONDVAR (1, cv);
+ fat_cond_signal (SCM_CONDVAR_DATA (cv));
+ return SCM_BOOL_T;
+}
+#undef FUNC_NAME
+
+static void
+fat_cond_broadcast (fat_cond *c)
+{
+ scm_i_scm_pthread_mutex_lock (&c->lock);
+ while (scm_is_true (unblock_from_queue (c->waiting)))
+ ;
+ scm_i_pthread_mutex_unlock (&c->lock);
+}
+
+SCM_DEFINE (scm_broadcast_condition_variable, "broadcast-condition-variable", 1, 0, 0,
+ (SCM cv),
+ "Wake up all threads that are waiting for @var{cv}. ")
+#define FUNC_NAME s_scm_broadcast_condition_variable
+{
+ SCM_VALIDATE_CONDVAR (1, cv);
+ fat_cond_broadcast (SCM_CONDVAR_DATA (cv));
+ return SCM_BOOL_T;
+}
+#undef FUNC_NAME
+
+/*** Marking stacks */
+
+/* XXX - what to do with this? Do we need to handle this for blocked
+ threads as well?
+*/
+#ifdef __ia64__
+# define SCM_MARK_BACKING_STORE() do { \
+ ucontext_t ctx; \
+ SCM_STACKITEM * top, * bot; \
+ getcontext (&ctx); \
+ scm_mark_locations ((SCM_STACKITEM *) &ctx.uc_mcontext, \
+ ((size_t) (sizeof (SCM_STACKITEM) - 1 + sizeof ctx.uc_mcontext) \
+ / sizeof (SCM_STACKITEM))); \
+ bot = (SCM_STACKITEM *) scm_ia64_register_backing_store_base (); \
+ top = (SCM_STACKITEM *) scm_ia64_ar_bsp (&ctx); \
+ scm_mark_locations (bot, top - bot); } while (0)
+#else
+# define SCM_MARK_BACKING_STORE()
+#endif
+
+
+
+/*** Select */
+
+int
+scm_std_select (int nfds,
+ SELECT_TYPE *readfds,
+ SELECT_TYPE *writefds,
+ SELECT_TYPE *exceptfds,
+ struct timeval *timeout)
+{
+ fd_set my_readfds;
+ int res, eno, wakeup_fd;
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+ scm_t_guile_ticket ticket;
+
+ if (readfds == NULL)
+ {
+ FD_ZERO (&my_readfds);
+ readfds = &my_readfds;
+ }
+
+ while (scm_i_setup_sleep (t, SCM_BOOL_F, NULL, t->sleep_pipe[1]))
+ SCM_TICK;
+
+ wakeup_fd = t->sleep_pipe[0];
+ ticket = scm_leave_guile ();
+ FD_SET (wakeup_fd, readfds);
+ if (wakeup_fd >= nfds)
+ nfds = wakeup_fd+1;
+ res = select (nfds, readfds, writefds, exceptfds, timeout);
+ t->sleep_fd = -1;
+ eno = errno;
+ scm_enter_guile (ticket);
+
+ scm_i_reset_sleep (t);
+
+ if (res > 0 && FD_ISSET (wakeup_fd, readfds))
+ {
+ char dummy;
+ read (wakeup_fd, &dummy, 1);
+ FD_CLR (wakeup_fd, readfds);
+ res -= 1;
+ if (res == 0)
+ {
+ eno = EINTR;
+ res = -1;
+ }
+ }
+ errno = eno;
+ return res;
+}
+
+/* Convenience API for blocking while in guile mode. */
+
+#if SCM_USE_PTHREAD_THREADS
+
+int
+scm_pthread_mutex_lock (scm_i_pthread_mutex_t *mutex)
+{
+ scm_t_guile_ticket t = scm_leave_guile ();
+ int res = scm_i_pthread_mutex_lock (mutex);
+ scm_enter_guile (t);
+ return res;
+}
+
+static void
+do_unlock (void *data)
+{
+ scm_i_pthread_mutex_unlock ((scm_i_pthread_mutex_t *)data);
+}
+
+void
+scm_dynwind_pthread_mutex_lock (scm_i_pthread_mutex_t *mutex)
+{
+ scm_i_scm_pthread_mutex_lock (mutex);
+ scm_dynwind_unwind_handler (do_unlock, mutex, SCM_F_WIND_EXPLICITLY);
+}
+
+int
+scm_pthread_cond_wait (scm_i_pthread_cond_t *cond, scm_i_pthread_mutex_t *mutex)
+{
+ scm_t_guile_ticket t = scm_leave_guile ();
+ int res = scm_i_pthread_cond_wait (cond, mutex);
+ scm_enter_guile (t);
+ return res;
+}
+
+int
+scm_pthread_cond_timedwait (scm_i_pthread_cond_t *cond,
+ scm_i_pthread_mutex_t *mutex,
+ const scm_t_timespec *wt)
+{
+ scm_t_guile_ticket t = scm_leave_guile ();
+ int res = scm_i_pthread_cond_timedwait (cond, mutex, wt);
+ scm_enter_guile (t);
+ return res;
+}
+
+#endif
+
+unsigned long
+scm_std_usleep (unsigned long usecs)
+{
+ struct timeval tv;
+ tv.tv_usec = usecs % 1000000;
+ tv.tv_sec = usecs / 1000000;
+ scm_std_select (0, NULL, NULL, NULL, &tv);
+ return tv.tv_sec * 1000000 + tv.tv_usec;
+}
+
+unsigned int
+scm_std_sleep (unsigned int secs)
+{
+ struct timeval tv;
+ tv.tv_usec = 0;
+ tv.tv_sec = secs;
+ scm_std_select (0, NULL, NULL, NULL, &tv);
+ return tv.tv_sec;
+}
+
+/*** Misc */
+
+SCM_DEFINE (scm_current_thread, "current-thread", 0, 0, 0,
+ (void),
+ "Return the thread that called this function.")
+#define FUNC_NAME s_scm_current_thread
+{
+ return SCM_I_CURRENT_THREAD->handle;
+}
+#undef FUNC_NAME
+
+static SCM
+scm_c_make_list (size_t n, SCM fill)
+{
+ SCM res = SCM_EOL;
+ while (n-- > 0)
+ res = scm_cons (fill, res);
+ return res;
+}
+
+SCM_DEFINE (scm_all_threads, "all-threads", 0, 0, 0,
+ (void),
+ "Return a list of all threads.")
+#define FUNC_NAME s_scm_all_threads
+{
+ /* We can not allocate while holding the thread_admin_mutex because
+ of the way GC is done.
+ */
+ int n = thread_count;
+ scm_i_thread *t;
+ SCM list = scm_c_make_list (n, SCM_UNSPECIFIED), *l;
+
+ scm_i_pthread_mutex_lock (&thread_admin_mutex);
+ l = &list;
+ for (t = all_threads; t && n > 0; t = t->next_thread)
+ {
+ SCM_SETCAR (*l, t->handle);
+ l = SCM_CDRLOC (*l);
+ n--;
+ }
+ *l = SCM_EOL;
+ scm_i_pthread_mutex_unlock (&thread_admin_mutex);
+ return list;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_thread_exited_p, "thread-exited?", 1, 0, 0,
+ (SCM thread),
+ "Return @code{#t} iff @var{thread} has exited.\n")
+#define FUNC_NAME s_scm_thread_exited_p
+{
+ return scm_from_bool (scm_c_thread_exited_p (thread));
+}
+#undef FUNC_NAME
+
+int
+scm_c_thread_exited_p (SCM thread)
+#define FUNC_NAME s_scm_thread_exited_p
+{
+ scm_i_thread *t;
+ SCM_VALIDATE_THREAD (1, thread);
+ t = SCM_I_THREAD_DATA (thread);
+ return t->exited;
+}
+#undef FUNC_NAME
+
+static scm_i_pthread_cond_t wake_up_cond;
+int scm_i_thread_go_to_sleep;
+static int threads_initialized_p = 0;
+
+void
+scm_i_thread_put_to_sleep ()
+{
+ if (threads_initialized_p)
+ {
+ scm_i_thread *t;
+
+ scm_leave_guile ();
+ scm_i_pthread_mutex_lock (&thread_admin_mutex);
+
+ /* Signal all threads to go to sleep
+ */
+ scm_i_thread_go_to_sleep = 1;
+ for (t = all_threads; t; t = t->next_thread)
+ scm_i_pthread_mutex_lock (&t->heap_mutex);
+ scm_i_thread_go_to_sleep = 0;
+ }
+}
+
+void
+scm_i_thread_invalidate_freelists ()
+{
+ /* thread_admin_mutex is already locked. */
+
+ scm_i_thread *t;
+ for (t = all_threads; t; t = t->next_thread)
+ if (t != SCM_I_CURRENT_THREAD)
+ t->clear_freelists_p = 1;
+}
+
+void
+scm_i_thread_wake_up ()
+{
+ if (threads_initialized_p)
+ {
+ scm_i_thread *t;
+
+ scm_i_pthread_cond_broadcast (&wake_up_cond);
+ for (t = all_threads; t; t = t->next_thread)
+ scm_i_pthread_mutex_unlock (&t->heap_mutex);
+ scm_i_pthread_mutex_unlock (&thread_admin_mutex);
+ scm_enter_guile ((scm_t_guile_ticket) SCM_I_CURRENT_THREAD);
+ }
+}
+
+void
+scm_i_thread_sleep_for_gc ()
+{
+ scm_i_thread *t = suspend ();
+ scm_i_pthread_cond_wait (&wake_up_cond, &t->heap_mutex);
+ resume (t);
+}
+
+/* This mutex is used by SCM_CRITICAL_SECTION_START/END.
+ */
+scm_i_pthread_mutex_t scm_i_critical_section_mutex;
+int scm_i_critical_section_level = 0;
+
+static SCM dynwind_critical_section_mutex;
+
+void
+scm_dynwind_critical_section (SCM mutex)
+{
+ if (scm_is_false (mutex))
+ mutex = dynwind_critical_section_mutex;
+ scm_dynwind_lock_mutex (mutex);
+ scm_dynwind_block_asyncs ();
+}
+
+/*** Initialization */
+
+scm_i_pthread_key_t scm_i_freelist, scm_i_freelist2;
+scm_i_pthread_mutex_t scm_i_misc_mutex;
+
+#if SCM_USE_PTHREAD_THREADS
+pthread_mutexattr_t scm_i_pthread_mutexattr_recursive[1];
+#endif
+
+void
+scm_threads_prehistory (SCM_STACKITEM *base)
+{
+#if SCM_USE_PTHREAD_THREADS
+ pthread_mutexattr_init (scm_i_pthread_mutexattr_recursive);
+ pthread_mutexattr_settype (scm_i_pthread_mutexattr_recursive,
+ PTHREAD_MUTEX_RECURSIVE);
+#endif
+
+ scm_i_pthread_mutex_init (&scm_i_critical_section_mutex,
+ scm_i_pthread_mutexattr_recursive);
+ scm_i_pthread_mutex_init (&scm_i_misc_mutex, NULL);
+ scm_i_pthread_cond_init (&wake_up_cond, NULL);
+ scm_i_pthread_key_create (&scm_i_freelist, NULL);
+ scm_i_pthread_key_create (&scm_i_freelist2, NULL);
+
+ guilify_self_1 (base);
+}
+
+scm_t_bits scm_tc16_thread;
+scm_t_bits scm_tc16_mutex;
+scm_t_bits scm_tc16_condvar;
+
+void
+scm_init_threads ()
+{
+ scm_tc16_thread = scm_make_smob_type ("thread", sizeof (scm_i_thread));
+ scm_set_smob_print (scm_tc16_thread, thread_print);
+ scm_set_smob_free (scm_tc16_thread, thread_free); /* XXX: Could be removed */
+
+ scm_tc16_mutex = scm_make_smob_type ("mutex", sizeof (fat_mutex));
+ scm_set_smob_print (scm_tc16_mutex, fat_mutex_print);
+ scm_set_smob_free (scm_tc16_mutex, fat_mutex_free);
+
+ scm_tc16_condvar = scm_make_smob_type ("condition-variable",
+ sizeof (fat_cond));
+ scm_set_smob_print (scm_tc16_condvar, fat_cond_print);
+ scm_set_smob_free (scm_tc16_condvar, fat_cond_free);
+
+ scm_i_default_dynamic_state = SCM_BOOL_F;
+ guilify_self_2 (SCM_BOOL_F);
+ threads_initialized_p = 1;
+
+ dynwind_critical_section_mutex =
+ scm_permanent_object (scm_make_recursive_mutex ());
+}
+
+void
+scm_init_threads_default_dynamic_state ()
+{
+ SCM state = scm_make_dynamic_state (scm_current_dynamic_state ());
+ scm_i_default_dynamic_state = scm_permanent_object (state);
+}
+
+void
+scm_init_thread_procs ()
+{
+#include "libguile/threads.x"
+}
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/
HCoop / bpt / guile.git / blobdiff