1 /*
2 * Copyright (c) 2012 Joyent, Inc. All rights reserved.
3 */
4
5 #ifndef _V8PLUS_GLUE_H
6 #define _V8PLUS_GLUE_H
7
8 #include <stdarg.h>
9 #include <libnvpair.h>
10 #include "v8plus_errno.h"
11
12 #ifdef __cplusplus
13 extern "C" {
14 #endif /* __cplusplus */
15
16 #define __UNUSED __attribute__((__unused__))
17
18 #define V8PLUS_ARG_F_NOEXTRA 0x01
19
20 #define V8PLUS_ERRMSG_LEN 512
21 #define V8PLUS_JSF_COOKIE ".__v8plus_jsfunc_cookie"
22
23 typedef enum v8plus_type {
24 V8PLUS_TYPE_NONE = 0, /* N/A */
25 V8PLUS_TYPE_STRING, /* char * */
26 V8PLUS_TYPE_NUMBER, /* double */
27 V8PLUS_TYPE_BOOLEAN, /* boolean_t */
28 V8PLUS_TYPE_JSFUNC, /* v8plus_jsfunc_t */
29 V8PLUS_TYPE_OBJECT, /* nvlist_t * */
30 V8PLUS_TYPE_NULL, /* -- */
31 V8PLUS_TYPE_UNDEFINED, /* -- */
32 V8PLUS_TYPE_INVALID, /* data_type_t */
33 V8PLUS_TYPE_ANY, /* nvpair_t * */
34 V8PLUS_TYPE_STRNUMBER64, /* uint64_t */
35 V8PLUS_TYPE_INL_OBJECT /* ... */
36 } v8plus_type_t;
37
38 typedef uint64_t v8plus_jsfunc_t;
39
40 /*
41 * C constructor, destructor, and method prototypes. See README.md.
42 */
43 typedef nvlist_t *(*v8plus_c_ctor_f)(const nvlist_t *, void **);
44 typedef nvlist_t *(*v8plus_c_static_f)(const nvlist_t *);
45 typedef nvlist_t *(*v8plus_c_method_f)(void *, const nvlist_t *);
46 typedef void (*v8plus_c_dtor_f)(void *);
47
48 typedef struct v8plus_method_descr {
49 const char *md_name;
50 v8plus_c_method_f md_c_func;
51 } v8plus_method_descr_t;
52
53 typedef struct v8plus_static_descr {
54 const char *sd_name;
55 v8plus_c_static_f sd_c_func;
56 } v8plus_static_descr_t;
57
58 extern __thread v8plus_errno_t _v8plus_errno;
59 extern __thread char _v8plus_errmsg[V8PLUS_ERRMSG_LEN];
60
61 /*
62 * Set the errno and message, indicating an error. The code and
63 * printf-formatted message, if one is given, will be used in constructing
64 * an exception to be thrown in JavaScript if your method later returns NULL
65 * or an nvlist with an "err" member.
66 */
67 extern nvlist_t *v8plus_verror(v8plus_errno_t, const char *, va_list);
68 extern nvlist_t *v8plus_error(v8plus_errno_t, const char *, ...);
69
70 /*
71 * Suicide. It's always an option. Try to avoid using this as it's not
72 * very nice to kill the entire node process; if at all possible we need
73 * to throw a JavaScript exception instead.
74 */
75 extern void v8plus_panic(const char *, ...) __PRINTFLIKE(1) __NORETURN;
76
77 /*
78 * As above, this convenience function sets the error code and message based
79 * on the nvlist-generated error code in its first argument. The second
80 * argument, which may be NULL, should contain the name of the member on
81 * which the error occurred.
82 */
83 extern nvlist_t *v8plus_nverr(int, const char *);
84
85 /*
86 * Similarly, for system errors. Not all possible errno values are handled.
87 */
88 extern nvlist_t *v8plus_syserr(int, const char *, ...);
89
90 /*
91 * Clear the errno and message. This is needed only when one wishes to return
92 * NULL from a C method whose return type is effectively void. The idiom is
93 *
94 * return (v8plus_void());
95 */
96 extern nvlist_t *v8plus_void(void);
97
98 /*
99 * Find the named V8 function in the nvlist. Analogous to other lookup
100 * routines; see libnvpair(3lib), with an important exception: the
101 * nvlist_lookup_v8plus_jsfunc() and nvpair_value_v8plus_jsfunc() functions
102 * place a hold on the underlying function object, which must be released by C
103 * code when it is no longer needed. See the documentation to understand how
104 * this works. The add routine is of very limited utility because there is no
105 * mechanism for creating a JS function from C. It can however be used to
106 * return a function (or object containing one, etc.) from a deferred
107 * completion routine in which a JS function has been invoked that returned
108 * such a thing to us.
109 */
110 extern int nvlist_lookup_v8plus_jsfunc(const nvlist_t *, const char *,
111 v8plus_jsfunc_t *);
112 extern int nvpair_value_v8plus_jsfunc(const nvpair_t *, v8plus_jsfunc_t *);
113 extern void v8plus_jsfunc_hold(v8plus_jsfunc_t);
114 extern void v8plus_jsfunc_rele(v8plus_jsfunc_t);
115 extern void v8plus_jsfunc_rele_direct(v8plus_jsfunc_t);
116
117 /*
118 * Place or release a hold on the V8 representation of the specified C object.
119 * This is rarely necessary; v8plus_defer() performs this action for you, but
120 * other asynchronous mechanisms may require it. If you are returning from
121 * a method call but have stashed a reference to the object somewhere and are
122 * not calling v8plus_defer(), you must call this first. Holds and releases
123 * must be balanced. Use of the object within a thread after releasing is a
124 * bug.
125 */
126 extern void v8plus_obj_hold(const void *);
127 extern void v8plus_obj_rele(const void *);
128 extern void v8plus_obj_rele_direct(const void *);
129
130 /*
131 * Convenience functions for dealing with JS arguments.
132 */
133 extern v8plus_type_t v8plus_typeof(const nvpair_t *);
134 extern int v8plus_args(const nvlist_t *, uint_t, v8plus_type_t t, ...);
135 extern nvlist_t *v8plus_obj(v8plus_type_t, ...);
136 extern int v8plus_obj_setprops(nvlist_t *, v8plus_type_t, ...);
137
138 /*
139 * Perform a background, possibly blocking and/or expensive, task. First,
140 * the worker function will be enqueued for execution on another thread; its
141 * first argument is a pointer to the C object on which to operate, and the
142 * second is arbitrary per-call context, arguments, etc. defined by the caller.
143 * When that worker function has completed execution, the completion function
144 * will be invoked in the main thread. Its arguments are the C object, the
145 * original context pointer, and the return value from the worker function.
146 * See the documentation for a typical use case.
147 */
148 typedef void *(*v8plus_worker_f)(void *, void *);
149 typedef void (*v8plus_completion_f)(void *, void *, void *);
150
151 extern void v8plus_defer(void *, void *, v8plus_worker_f, v8plus_completion_f);
152
153 /*
154 * Call an opaque JavaScript function from C. The caller is responsible for
155 * freeing the returned list. The first argument is not const because it is
156 * possible for the JS code to modify the function represented by the cookie.
157 */
158 extern nvlist_t *v8plus_call(v8plus_jsfunc_t, const nvlist_t *);
159 extern nvlist_t *v8plus_call_direct(v8plus_jsfunc_t, const nvlist_t *);
160
161 /*
162 * Call the named JavaScript function in the context of the JS object
163 * represented by the native object. Calling and return conventions are the
164 * same as for the C interfaces; i.e., the nvlist will be converted into JS
165 * objects and the return value or exception will be in the "res" or "err"
166 * members of the nvlist that is returned, respectively. If an internal
167 * error occurs, NULL is returned and _v8plus_errno set accordingly. The
168 * results of calling a method implemented in C via this interface are
169 * undefined.
170 *
171 * These methods can be used in concert with JS code to emit events
172 * asynchronously; see the documentation.
173 *
174 * Note: As JavaScript functions must be called from the event loop thread,
175 * v8plus_method_call() contains logic to determine whether we are in the
176 * correct context or not. If we are running on some other thread we will
177 * queue the request and sleep, waiting for the event loop thread to make the
178 * call. In the simple case, where we are already in the correct thread,
179 * we make the call directly. v8plus_method_call_direct() assumes we are
180 * on the correct thread and always makes the call directly.
181 */
182 extern nvlist_t *v8plus_method_call(void *, const char *, const nvlist_t *);
183 extern nvlist_t *v8plus_method_call_direct(void *, const char *,
184 const nvlist_t *);
185
186 /*
187 * These functions allow the consumer to hold the V8 event loop open for
188 * potential input from other threads. If your process blocks in another
189 * thread, e.g. an event subscription thread, you must signal to v8plus
190 * that the event loop should remain active. Calls to v8plus_eventloop_hold()
191 * and v8plus_eventloop_rele() should be balanced. It is safe to call
192 * v8plus_eventloop_rele() from outside the event loop thread.
193 *
194 * Note: Holds obtained via v8plus_obj_hold() and v8plus_jsfunc_hold() will
195 * also automatically hold the event loop, removing the need to use this
196 * interface explicitly.
197 */
198 extern void v8plus_eventloop_hold(void);
199 extern void v8plus_eventloop_rele(void);
200 extern void v8plus_eventloop_rele_direct(void);
201
202 /*
203 * These methods are analogous to strerror(3c) and similar functions; they
204 * translate among error names, codes, and default messages. There is
205 * normally little need for these functions in C methods, as everything
206 * necessary to construct a JavaScript exception is done by v8+, but these
207 * may be useful in the construction of supplementary exception decorations
208 * for debugging purposes.
209 */
210 extern const char *v8plus_strerror(v8plus_errno_t);
211 extern const char *v8plus_errname(v8plus_errno_t);
212 extern const char *v8plus_excptype(v8plus_errno_t);
213
214 /*
215 * Provided by C code. See README.md.
216 */
217 extern const v8plus_c_ctor_f v8plus_ctor;
218 extern const v8plus_c_dtor_f v8plus_dtor;
219 extern const char *v8plus_js_factory_name;
220 extern const char *v8plus_js_class_name;
221 extern const v8plus_method_descr_t v8plus_methods[];
222 extern const uint_t v8plus_method_count;
223 extern const v8plus_static_descr_t v8plus_static_methods[];
224 extern const uint_t v8plus_static_method_count;
225
226 /*
227 * Private methods.
228 */
229 extern boolean_t v8plus_in_event_thread(void);
230 extern void v8plus_crossthread_init(void);
231
232 #ifdef __cplusplus
233 }
234 #endif /* __cplusplus */
235
236 #endif /* _V8PLUS_GLUE_H */