Import guile-1.8 as multiple upstream tarball component

[lilypond.git] / guile18 / libguile / fluids.h

diff --git a/guile18/libguile/fluids.h b/guile18/libguile/fluids.h
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+/* classes: h_files */
+
+#ifndef SCM_FLUIDS_H
+#define SCM_FLUIDS_H
+
+/* Copyright (C) 1996,2000,2001, 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
+
+#include "libguile/__scm.h"
+#include "libguile/root.h"
+#include "libguile/vectors.h"
+
+/* Fluids.
+
+   Fluids are objects of a certain type (a smob) that can hold one SCM
+   value per dynamic state.  That is, modifications to this value are
+   only visible to code that executes with the same dynamic state as
+   the modifying code.  When a new dynamic state is constructed, it
+   inherits the values from its parent.  Because each thread executes
+   with its own dynamic state, you can use fluids for thread local
+   storage.
+
+   Each fluid is identified by a small integer.  This integer is used
+   to index a vector that holds the values of all fluids.  A dynamic
+   state consists of this vector, wrapped in a smob so that the vector
+   can grow.
+ */
+
+/* The fastest way to acces/modify the value of a fluid.  These macros
+   do no error checking at all.  The first argument is the index
+   number of the fluid, obtained via SCM_FLUID_NUM, not the fluid
+   itself.  You must make sure that the fluid remains protected as
+   long you use its number since numbers of unused fluids are reused
+   eventually.
+*/
+
+#define SCM_FLUID_NUM(x)             scm_i_fluid_num (x)
+#define SCM_FAST_FLUID_REF(n)        scm_i_fast_fluid_ref (n)
+#define SCM_FAST_FLUID_SET_X(n, val) scm_i_fast_fluid_set_x ((n),(val))
+
+SCM_API SCM scm_make_fluid (void);
+SCM_API int scm_is_fluid (SCM obj);
+SCM_API SCM scm_fluid_p (SCM fl);
+SCM_API SCM scm_fluid_ref (SCM fluid);
+SCM_API SCM scm_fluid_set_x (SCM fluid, SCM value);
+SCM_API size_t scm_i_fluid_num (SCM fl);
+SCM_API SCM scm_i_fast_fluid_ref (size_t n);
+SCM_API void scm_i_fast_fluid_set_x (size_t n, SCM val);
+
+SCM_API SCM scm_c_with_fluids (SCM fluids, SCM vals,
+                              SCM (*cproc)(void *), void *cdata);
+SCM_API SCM scm_c_with_fluid (SCM fluid, SCM val,
+                             SCM (*cproc)(void *), void *cdata);
+SCM_API SCM scm_with_fluids (SCM fluids, SCM vals, SCM thunk);
+SCM_API SCM scm_with_fluid (SCM fluid, SCM val, SCM thunk);
+
+SCM_API void scm_dynwind_fluid (SCM fluid, SCM value);
+
+SCM_API SCM scm_make_dynamic_state (SCM parent);
+SCM_API SCM scm_dynamic_state_p (SCM obj);
+SCM_API int scm_is_dynamic_state (SCM obj);
+SCM_API SCM scm_current_dynamic_state (void);
+SCM_API SCM scm_set_current_dynamic_state (SCM state);
+SCM_API void scm_dynwind_current_dynamic_state (SCM state);
+SCM_API void *scm_c_with_dynamic_state (SCM state, 
+                                       void *(*func)(void *), void *data);
+SCM_API SCM scm_with_dynamic_state (SCM state, SCM proc);
+
+SCM_API SCM scm_i_make_initial_dynamic_state (void);
+
+SCM_API void scm_fluids_prehistory (void);
+SCM_API void scm_init_fluids (void);
+
+#endif  /* SCM_FLUIDS_H */
+
+/*
+  Local Variables:
+  c-file-style: "gnu"
+  End:
+*/