provide for user defined on-demand compilation drivers

ChangeLog

@@ -1,3 +1,10 @@
+2007-02-04  Aleksey Demakov  <ademakov@gmail.com>
+
+	* include/jit/jit-common.h, include/jit/jit-context.h,
+	* include/jit/jit-function.h, jit/jit-internal.h, jit/jit-context.c,
+	* jit/jit-function.c: provide for user defined on-demand compilation
+	driver and delayed function entry point setup.
+
 2007-01-28  Aleksey Demakov  <ademakov@gmail.com>
 
 	* jit/jit-reg-alloc.c (_jit_regs_gen, set_regdesc_flags): fix bugs

include/jit/jit-common.h

@@ -88,6 +88,13 @@ typedef void (*jit_meta_free_func)(void *data);
  */
 typedef int (*jit_on_demand_func)(jit_function_t func);
 
+/*
+ * Function that is used to control on demand compilation.
+ * Typically, it should take care of the context locking and unlocking,
+ * calling function's on demand compiler, and final compilation.
+ */
+typedef void *(*jit_on_demand_driver_func)(jit_function_t func);
+
 #ifdef	__cplusplus
 };
 #endif

include/jit/jit-context.h

@@ -32,6 +32,9 @@ void jit_context_destroy(jit_context_t context) JIT_NOTHROW;
 int jit_context_supports_threads(jit_context_t context) JIT_NOTHROW;
 void jit_context_build_start(jit_context_t context) JIT_NOTHROW;
 void jit_context_build_end(jit_context_t context) JIT_NOTHROW;
+void jit_context_set_on_demand_driver(
+	jit_context_t context,
+	jit_on_demand_driver_func driver) JIT_NOTHROW;
 int jit_context_set_meta
 	(jit_context_t context, int type, void *data,
 	 jit_meta_free_func free_data) JIT_NOTHROW;

include/jit/jit-function.h

@@ -53,6 +53,8 @@ int jit_function_is_compiled(jit_function_t func) JIT_NOTHROW;
 void jit_function_set_recompilable(jit_function_t func) JIT_NOTHROW;
 void jit_function_clear_recompilable(jit_function_t func) JIT_NOTHROW;
 int jit_function_is_recompilable(jit_function_t func) JIT_NOTHROW;
+int jit_function_compile_entry(jit_function_t func, void **entry_point) JIT_NOTHROW;
+void jit_function_setup_entry(jit_function_t func, void *entry_point) JIT_NOTHROW;
 void *jit_function_to_closure(jit_function_t func) JIT_NOTHROW;
 jit_function_t jit_function_from_closure
 	(jit_context_t context, void *closure) JIT_NOTHROW;
@@ -62,7 +64,8 @@ void *jit_function_to_vtable_pointer(jit_function_t func) JIT_NOTHROW;
 jit_function_t jit_function_from_vtable_pointer
 	(jit_context_t context, void *vtable_pointer) JIT_NOTHROW;
 void jit_function_set_on_demand_compiler
-		(jit_function_t func, jit_on_demand_func on_demand) JIT_NOTHROW;
+	(jit_function_t func, jit_on_demand_func on_demand) JIT_NOTHROW;
+jit_on_demand_func jit_function_get_on_demand_compiler(jit_function_t func) JIT_NOTHROW;
 int jit_function_apply
 	(jit_function_t func, void **args, void *return_area);
 int jit_function_apply_vararg

jit/jit-context.c

@@ -88,6 +88,7 @@ jit_context_t jit_context_create(void)
 	jit_mutex_create(&(context->cache_lock));
 	context->functions = 0;
 	context->last_function = 0;
+	context->on_demand_driver = 0;
 	return context;
 }
 
@@ -158,6 +159,54 @@ void jit_context_build_end(jit_context_t context)
 	jit_mutex_unlock(&(context->builder_lock));
 }
 
+/*@
+ * @deftypefun void jit_context_set_on_demand_driver (jit_context_t context, jit_on_demand_driver_func driver)
+ * Specify the C function to be called to drive on-demand compilation.
+ *
+ * When on-demand compilation is requested the default driver provided by
+ * @code{libjit} takes the following actions:
+ *
+ * @enumerate
+ * @item
+ * The context is locked by calling @code{jit_context_build_start}.
+ *
+ * @item
+ * If the function has already been compiled, @code{libjit} unlocks
+ * the context and returns immediately.  This can happen because of race
+ * conditions between threads: some other thread may have beaten us
+ * to the on-demand compiler.
+ *
+ * @item
+ * The user's on-demand compiler is called.  It is responsible for building
+ * the instructions in the function's body.  It should return one of the
+ * result codes @code{JIT_RESULT_OK}, @code{JIT_RESULT_COMPILE_ERROR},
+ * or @code{JIT_RESULT_OUT_OF_MEMORY}.
+ *
+ * @item
+ * If the user's on-demand function hasn't already done so, @code{libjit}
+ * will call @code{jit_function_compile} to compile the function.
+ *
+ * @item
+ * The context is unlocked by calling @code{jit_context_build_end} and
+ * @code{libjit} jumps to the newly-compiled entry point.  If an error
+ * occurs, a built-in exception of type @code{JIT_RESULT_COMPILE_ERROR}
+ * or @code{JIT_RESULT_OUT_OF_MEMORY} will be thrown.
+ *
+ * @item
+ * The entry point of the compiled function is returned from the
+ * driver.
+ * @end enumerate
+ *
+ * You may need to provide your own driver if some additional actions
+ * are required.
+ *
+ * @end deftypefun
+@*/
+void jit_context_set_on_demand_driver(jit_context_t context, jit_on_demand_driver_func driver)
+{
+	context->on_demand_driver = driver;
+}
+
 /*@
  * @deftypefun int jit_context_set_meta (jit_context_t context, int type, {void *} data, jit_meta_free_func free_data)
  * Tag a context with some metadata.  Returns zero if out of memory.

jit/jit-function.c

@@ -49,6 +49,9 @@
 jit_function_t jit_function_create(jit_context_t context, jit_type_t signature)
 {
 	jit_function_t func;
+#if defined(jit_redirector_size)
+	jit_on_demand_driver_func on_demand_driver;
+#endif
 #if defined(jit_redirector_size) || defined(jit_indirector_size)
 	jit_cache_t cache;
 #endif
@@ -104,20 +107,24 @@ jit_function_t jit_function_create(jit_context_t context, jit_type_t signature)
 	func->context = context;
 	func->signature = jit_type_copy(signature);
 
-#if defined(jit_redirector_size) && !defined(JIT_BACKEND_INTERP)
+#if defined(jit_redirector_size)
 	/* If we aren't using interpretation, then point the function's
 	   initial entry point at the redirector, which in turn will
 	   invoke the on-demand compiler */
+	on_demand_driver = context->on_demand_driver;
+	if(!on_demand_driver)
+	{
+		on_demand_driver = _jit_function_compile_on_demand;
+	}
 	func->entry_point = _jit_create_redirector
-		(func->redirector, (void *)_jit_function_compile_on_demand,
+		(func->redirector, (void *) on_demand_driver,
 		 func, jit_type_get_abi(signature));
 	jit_flush_exec(func->redirector, jit_redirector_size);
-
+#endif
 # if defined(jit_indirector_size)
 	_jit_create_indirector(func->indirector, (void**) &(func->entry_point));
 	jit_flush_exec(func->indirector, jit_indirector_size);
 # endif
-#endif
 
 	/* Add the function to the context list */
 	func->next = 0;
@@ -618,34 +625,10 @@ static void compile_block(jit_gencode_t gen, jit_function_t func,
 }
 
 /*
- * Information that is stored for an exception region in the cache.
+ * Compile a function and return its entry point.
  */
-typedef struct jit_cache_eh *jit_cache_eh_t;
-struct jit_cache_eh
-{
-	jit_label_t		handler_label;
-	unsigned char  *handler;
-	jit_cache_eh_t	previous;
-};
-
-/*@
- * @deftypefun int jit_function_compile (jit_function_t func)
- * Compile a function to its executable form.  If the function was
- * already compiled, then do nothing.  Returns zero on error.
- *
- * If an error occurs, you can use @code{jit_function_abandon} to
- * completely destroy the function.  Once the function has been compiled
- * successfully, it can no longer be abandoned.
- *
- * Sometimes you may wish to recompile a function, to apply greater
- * levels of optimization the second time around.  You must call
- * @code{jit_function_set_recompilable} before you compile the function
- * the first time.  On the second time around, build the function's
- * instructions again, and call @code{jit_function_compile}
- * a second time.
- * @end deftypefun
-@*/
-int jit_function_compile(jit_function_t func)
+static int
+compile(jit_function_t func, void **entry_point)
 {
 	struct jit_gencode gen;
 	jit_cache_t cache;
@@ -657,22 +640,6 @@ int jit_function_compile(jit_function_t func)
 	int have_prolog;
 #endif
 
-	/* Bail out if we have nothing to do */
-	if(!func)
-	{
-		return 0;
-	}
-	if(func->is_compiled && !(func->builder))
-	{
-		/* The function is already compiled, and we don't need to recompile */
-		return 1;
-	}
-	if(!(func->builder))
-	{
-		/* We don't have anything to compile at all */
-		return 0;
-	}
-
 	/* We need the cache lock while we are compiling the function */
 	jit_mutex_lock(&(func->context->cache_lock));
 
@@ -809,7 +776,6 @@ int jit_function_compile(jit_function_t func)
 				block->fixup_absolute_list = 0;
 			}
 		}
-
 	}
 	while(result == JIT_CACHE_END_RESTART);
 
@@ -841,18 +807,146 @@ int jit_function_compile(jit_function_t func)
 		func->no_return = 1;
 	}
 
-	/* Record the entry point */
-	func->entry_point = start;
-	func->is_compiled = 1;
-
 	/* Free the builder structure, which we no longer require */
 	_jit_function_free_builder(func);
 
 	/* The function has been compiled successfully */
 	jit_mutex_unlock(&(func->context->cache_lock));
+
+	/* Record the entry point */
+	if(entry_point)
+	{
+		*entry_point = start;
+	}
+
 	return 1;
 }
 
+/*
+ * Information that is stored for an exception region in the cache.
+ */
+typedef struct jit_cache_eh *jit_cache_eh_t;
+struct jit_cache_eh
+{
+	jit_label_t		handler_label;
+	unsigned char  *handler;
+	jit_cache_eh_t	previous;
+};
+
+/*@
+ * @deftypefun int jit_function_compile (jit_function_t func)
+ * Compile a function to its executable form.  If the function was
+ * already compiled, then do nothing.  Returns zero on error.
+ *
+ * If an error occurs, you can use @code{jit_function_abandon} to
+ * completely destroy the function.  Once the function has been compiled
+ * successfully, it can no longer be abandoned.
+ *
+ * Sometimes you may wish to recompile a function, to apply greater
+ * levels of optimization the second time around.  You must call
+ * @code{jit_function_set_recompilable} before you compile the function
+ * the first time.  On the second time around, build the function's
+ * instructions again, and call @code{jit_function_compile}
+ * a second time.
+ * @end deftypefun
+@*/
+int jit_function_compile(jit_function_t func)
+{
+	int result;
+	void *entry_point;
+
+	/* Bail out if we have nothing to do */
+	if(!func)
+	{
+		return 0;
+	}
+	if(func->is_compiled && !(func->builder))
+	{
+		/* The function is already compiled, and we don't need to recompile */
+		return 1;
+	}
+	if(!(func->builder))
+	{
+		/* We don't have anything to compile at all */
+		return 0;
+	}
+
+	/* Compile and record the entry point. */
+	result = compile(func, &entry_point);
+	if(result)
+	{
+		func->entry_point = entry_point;
+		func->is_compiled = 1;
+	}
+
+	return result;
+}
+
+/*@
+ * @deftypefun int jit_function_compile_entry (jit_function_t func, void **entry_point)
+ * Compile a function to its executable form but do not make it
+ * available for invocation yet. It may be made available later
+ * with @code{jit_function_setup_entry}.
+ * @end deftypefun
+@*/
+int
+jit_function_compile_entry(jit_function_t func, void **entry_point)
+{
+	/* Init entry_point */
+	if(entry_point)
+	{
+		*entry_point = 0;
+	}
+	else
+	{
+		return 0;
+	}
+
+	/* Bail out if we have nothing to do */
+	if(!func)
+	{
+		return 0;
+	}
+	if(func->is_compiled && !(func->builder))
+	{
+		/* The function is already compiled, and we don't need to recompile */
+		return 1;
+	}
+	if(!(func->builder))
+	{
+		/* We don't have anything to compile at all */
+		return 0;
+	}
+
+	/* Compile and return the entry point. */
+	return compile(func, entry_point);
+}
+
+/*@
+ * @deftypefun int jit_function_setup_entry (jit_function_t func, void *entry_point)
+ * Make a function compiled with @code{jit_function_compile_entry}
+ * available for invocation and free the resources used for
+ * compilation. If @code{entry_point} is null then it only
+ * frees the resources.
+ * @end deftypefun
+@*/
+void
+jit_function_setup_entry(jit_function_t func, void *entry_point)
+{
+	/* Bail out if we have nothing to do */
+	if(!func)
+	{
+		return;
+	}
+	/* Record the entry point */
+	if(entry_point)
+	{
+		func->entry_point = entry_point;
+		func->is_compiled = 1;
+	}
+	_jit_function_free_builder(func);
+}
+
 /*@
  * @deftypefun int jit_function_recompile (jit_function_t func)
  * Force @code{func} to be recompiled, by calling its on-demand
@@ -1202,10 +1296,28 @@ jit_function_t jit_function_from_vtable_pointer(jit_context_t context, void *vta
  * just after you create it with @code{jit_function_create}.
  * @end deftypefun
 @*/
-void jit_function_set_on_demand_compiler
-		(jit_function_t func, jit_on_demand_func on_demand)
+void
+jit_function_set_on_demand_compiler(jit_function_t func, jit_on_demand_func on_demand)
+{
+	if(func)
+	{
+		func->on_demand = on_demand;
+	}
+}
+
+/*@
+ * @deftypefun jit_on_demand_func jit_function_get_on_demand_compiler (jit_function_t func)
+ * Returns function's on-demand compiler.
+ * @end deftypefun
+@*/
+jit_on_demand_func
+jit_function_get_on_demand_compiler(jit_function_t func)
 {
-	func->on_demand = on_demand;
+	if(func)
+	{
+		return func->on_demand;
+	}
+	return 0;
 }
 
 void *_jit_function_compile_on_demand(jit_function_t func)

jit/jit-internal.h

@@ -478,6 +478,9 @@ struct _jit_context
 	/* Debugger support */
 	jit_debugger_hook_func debug_hook;
 	jit_debugger_t		debugger;
+
+	/* On-demand compilation driver */
+	jit_on_demand_driver_func	on_demand_driver;
 };
 
 /*