1 /*
2 * This file is part of the libsigrokdecode project.
3 *
4 * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
5 * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
6 *
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 */
20
21 #include <config.h>
22 #include "libsigrokdecode-internal.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
23 #include "libsigrokdecode.h"
24 #include <glib.h>
25
26 /** @cond PRIVATE */
27
28 /* Python module search paths */
29 SRD_PRIV GSList *searchpaths = NULL;
30
31 /* session.c */
32 extern SRD_PRIV GSList *sessions;
33 extern SRD_PRIV int max_session_id;
34
35 /** @endcond */
36
37 /**
38 * @mainpage libsigrokdecode API
39 *
40 * @section sec_intro Introduction
41 *
42 * The <a href="http://sigrok.org">sigrok</a> project aims at creating a
43 * portable, cross-platform, Free/Libre/Open-Source signal analysis software
44 * suite that supports various device types (such as logic analyzers,
45 * oscilloscopes, multimeters, and more).
46 *
47 * <a href="http://sigrok.org/wiki/Libsigrokdecode">libsigrokdecode</a> is a
48 * shared library written in C which provides the basic API for (streaming)
49 * protocol decoding functionality.
50 *
51 * The <a href="http://sigrok.org/wiki/Protocol_decoders">protocol decoders</a>
52 * are written in Python (>= 3.0).
53 *
54 * @section sec_api API reference
55 *
56 * See the "Modules" page for an introduction to various libsigrokdecode
57 * related topics and the detailed API documentation of the respective
58 * functions.
59 *
60 * You can also browse the API documentation by file, or review all
61 * data structures.
62 *
63 * @section sec_mailinglists Mailing lists
64 *
65 * There is one mailing list for sigrok/libsigrokdecode: <a href="https://lists.sourceforge.net/lists/listinfo/sigrok-devel">sigrok-devel</a>.
66 *
67 * @section sec_irc IRC
68 *
69 * You can find the sigrok developers in the
70 * <a href="irc://chat.freenode.net/sigrok">\#sigrok</a>
71 * IRC channel on Freenode.
72 *
73 * @section sec_website Website
74 *
75 * <a href="http://sigrok.org/wiki/Libsigrokdecode">sigrok.org/wiki/Libsigrokdecode</a>
76 */
77
78 /**
79 * @file
80 *
81 * Initializing and shutting down libsigrokdecode.
82 */
83
84 /**
85 * @defgroup grp_init Initialization
86 *
87 * Initializing and shutting down libsigrokdecode.
88 *
89 * Before using any of the libsigrokdecode functionality, srd_init() must
90 * be called to initialize the library.
91 *
92 * When libsigrokdecode functionality is no longer needed, srd_exit() should
93 * be called.
94 *
95 * @{
96 */
97
searchpath_add_xdg_dir(const char * datadir)98 static int searchpath_add_xdg_dir(const char *datadir)
99 {
100 char *decdir;
101 int ret;
102
103 decdir = g_build_filename(datadir, PACKAGE_TARNAME, "decoders", NULL);
104
105 if (g_file_test(decdir, G_FILE_TEST_IS_DIR))
106 ret = srd_decoder_searchpath_add(decdir);
107 else
108 ret = SRD_OK; /* Just ignore non-existing directory. */
109
110 g_free(decdir);
111
112 return ret;
113 }
114
print_versions(void)115 static void print_versions(void)
116 {
117 GString *s;
118 GSList *l, *l_orig, *m;
119 char *str;
120 const char *lib, *version;
121
122 srd_dbg("libsigrokdecode %s/%s (rt: %s/%s).",
123 SRD_PACKAGE_VERSION_STRING, SRD_LIB_VERSION_STRING,
124 srd_package_version_string_get(), srd_lib_version_string_get());
125
126 s = g_string_sized_new(200);
127 g_string_append(s, "Libs: ");
128 l_orig = srd_buildinfo_libs_get();
129 for (l = l_orig; l; l = l->next) {
130 m = l->data;
131 lib = m->data;
132 version = m->next->data;
133 g_string_append_printf(s, "%s %s, ", lib, version);
134 g_slist_free_full(m, g_free);
135 }
136 g_slist_free(l_orig);
137 s->str[s->len - 2] = '.';
138 s->str[s->len - 1] = '\0';
139 srd_dbg("%s", s->str);
140 g_string_free(s, TRUE);
141
142 str = srd_buildinfo_host_get();
143 srd_dbg("Host: %s.", str);
144 g_free(str);
145 }
146
print_searchpaths(void)147 static int print_searchpaths(void)
148 {
149 PyObject *py_paths, *py_path, *py_bytes;
150 PyGILState_STATE gstate;
151 GString *s;
152 GSList *l;
153 int i;
154
155 s = g_string_sized_new(500);
156 g_string_append(s, "Protocol decoder search paths:\n");
157 for (l = searchpaths; l; l = l->next)
158 g_string_append_printf(s, " - %s\n", (const char *)l->data);
159 s->str[s->len - 1] = '\0';
160 srd_dbg("%s", s->str);
161 g_string_free(s, TRUE);
162
163 gstate = PyGILState_Ensure();
164
165 py_paths = PySys_GetObject("path");
166 if (!py_paths)
167 goto err;
168
169 s = g_string_sized_new(500);
170 g_string_append(s, "Python system search paths:\n");
171 for (i = 0; i < PyList_Size(py_paths); i++) {
172 py_path = PyList_GetItem(py_paths, i);
173 py_bytes = PyUnicode_AsUTF8String(py_path);
174 g_string_append_printf(s, " - %s\n", PyBytes_AsString(py_bytes));
175 Py_DECREF(py_bytes);
176 }
177 s->str[s->len - 1] = '\0';
178 srd_dbg("%s", s->str);
179 g_string_free(s, TRUE);
180
181 PyGILState_Release(gstate);
182
183 return SRD_OK;
184
185 err:
186 srd_err("Unable to query Python system search paths.");
187 PyGILState_Release(gstate);
188
189 return SRD_ERR_PYTHON;
190 }
191
192 /**
193 * Initialize libsigrokdecode.
194 *
195 * This initializes the Python interpreter, and creates and initializes
196 * a "sigrokdecode" Python module.
197 *
198 * Then, it searches for sigrok protocol decoders in the "decoders"
199 * subdirectory of the the libsigrokdecode installation directory.
200 * All decoders that are found are loaded into memory and added to an
201 * internal list of decoders, which can be queried via srd_decoder_list().
202 *
203 * The caller is responsible for calling the clean-up function srd_exit(),
204 * which will properly shut down libsigrokdecode and free its allocated memory.
205 *
206 * Multiple calls to srd_init(), without calling srd_exit() in between,
207 * are not allowed.
208 *
209 * @param path Path to an extra directory containing protocol decoders
210 * which will be added to the Python sys.path. May be NULL.
211 *
212 * @return SRD_OK upon success, a (negative) error code otherwise.
213 * Upon Python errors, SRD_ERR_PYTHON is returned. If the decoders
214 * directory cannot be accessed, SRD_ERR_DECODERS_DIR is returned.
215 * If not enough memory could be allocated, SRD_ERR_MALLOC is returned.
216 *
217 * @since 0.1.0
218 */
srd_init(const char * path)219 SRD_API int srd_init(const char *path)
220 {
221 const char *const *sys_datadirs;
222 const char *env_path;
223 size_t i;
224 int ret;
225
226 if (max_session_id != -1) {
227 srd_err("libsigrokdecode is already initialized.");
228 return SRD_ERR;
229 }
230
231 print_versions();
232
233 srd_dbg("Initializing libsigrokdecode.");
234
235 /* Add our own module to the list of built-in modules. */
236 PyImport_AppendInittab("sigrokdecode", PyInit_sigrokdecode);
237
238 /* Initialize the Python interpreter. */
239 Py_InitializeEx(0);
240
241 /* Locations relative to the XDG system data directories. */
242 sys_datadirs = g_get_system_data_dirs();
243 for (i = g_strv_length((char **)sys_datadirs); i > 0; i--) {
244 ret = searchpath_add_xdg_dir(sys_datadirs[i - 1]);
245 if (ret != SRD_OK) {
246 Py_Finalize();
247 return ret;
248 }
249 }
250 #ifdef DECODERS_DIR
251 /* Hardcoded decoders install location, if defined. */
252 if ((ret = srd_decoder_searchpath_add(DECODERS_DIR)) != SRD_OK) {
253 Py_Finalize();
254 return ret;
255 }
256 #endif
257 /* Location relative to the XDG user data directory. */
258 ret = searchpath_add_xdg_dir(g_get_user_data_dir());
259 if (ret != SRD_OK) {
260 Py_Finalize();
261 return ret;
262 }
263
264 /* Path specified by the user. */
265 if (path) {
266 if ((ret = srd_decoder_searchpath_add(path)) != SRD_OK) {
267 Py_Finalize();
268 return ret;
269 }
270 }
271
272 /* Environment variable overrides everything, for debugging. */
273 if ((env_path = g_getenv("SIGROKDECODE_DIR"))) {
274 if ((ret = srd_decoder_searchpath_add(env_path)) != SRD_OK) {
275 Py_Finalize();
276 return ret;
277 }
278 }
279
280 /* Initialize the Python GIL (this also happens to acquire it). */
281 PyEval_InitThreads();
282
283 /* Release the GIL (ignore return value, we don't need it here). */
284 (void)PyEval_SaveThread();
285
286 max_session_id = 0;
287
288 print_searchpaths();
289
290 return SRD_OK;
291 }
292
srd_session_destroy_cb(void * arg,void * ignored)293 static void srd_session_destroy_cb(void *arg, void *ignored)
294 {
295 (void)ignored; // Prevent unused warning
296 srd_session_destroy((struct srd_session *)arg);
297 }
298
299 /**
300 * Shutdown libsigrokdecode.
301 *
302 * This frees all the memory allocated for protocol decoders and shuts down
303 * the Python interpreter.
304 *
305 * This function should only be called if there was a (successful!) invocation
306 * of srd_init() before. Calling this function multiple times in a row, without
307 * any successful srd_init() calls in between, is not allowed.
308 *
309 * @return SRD_OK upon success, a (negative) error code otherwise.
310 *
311 * @since 0.1.0
312 */
srd_exit(void)313 SRD_API int srd_exit(void)
314 {
315 srd_dbg("Exiting libsigrokdecode.");
316
317 g_slist_foreach(sessions, srd_session_destroy_cb, NULL);
318 g_slist_free(sessions);
319 sessions = NULL;
320
321 srd_decoder_unload_all();
322 g_slist_free_full(searchpaths, g_free);
323 searchpaths = NULL;
324
325 /*
326 * Acquire the GIL, otherwise Py_Finalize() might have issues.
327 * Ignore the return value, we don't need it here.
328 */
329 if (Py_IsInitialized())
330 (void)PyGILState_Ensure();
331
332 /* Py_Finalize() returns void, any finalization errors are ignored. */
333 Py_Finalize();
334
335 /* Note: No need to release the GIL since Python is shut down now. */
336
337 max_session_id = -1;
338
339 return SRD_OK;
340 }
341
342 /**
343 * Add an additional search directory for the protocol decoders.
344 *
345 * The specified directory is prepended (not appended!) to Python's sys.path,
346 * in order to search for sigrok protocol decoders in the specified
347 * directories first, and in the generic Python module directories (and in
348 * the current working directory) last. This avoids conflicts if there are
349 * Python modules which have the same name as a sigrok protocol decoder in
350 * sys.path or in the current working directory.
351 *
352 * @param path Path to the directory containing protocol decoders which shall
353 * be added to the Python sys.path, or NULL.
354 *
355 * @return SRD_OK upon success, a (negative) error code otherwise.
356 *
357 * @private
358 */
srd_decoder_searchpath_add(const char * path)359 SRD_PRIV int srd_decoder_searchpath_add(const char *path)
360 {
361 PyObject *py_cur_path, *py_item;
362 PyGILState_STATE gstate;
363
364 srd_dbg("Adding '%s' to module path.", path);
365
366 gstate = PyGILState_Ensure();
367
368 py_cur_path = PySys_GetObject("path");
369 if (!py_cur_path)
370 goto err;
371
372 py_item = PyUnicode_FromString(path);
373 if (!py_item) {
374 srd_exception_catch("Failed to create Unicode object");
375 goto err;
376 }
377 if (PyList_Insert(py_cur_path, 0, py_item) < 0) {
378 srd_exception_catch("Failed to insert path element");
379 Py_DECREF(py_item);
380 goto err;
381 }
382 Py_DECREF(py_item);
383
384 PyGILState_Release(gstate);
385
386 searchpaths = g_slist_prepend(searchpaths, g_strdup(path));
387
388 return SRD_OK;
389
390 err:
391 PyGILState_Release(gstate);
392
393 return SRD_ERR_PYTHON;
394 }
395
396 /**
397 * Return the list of protocol decoder search paths.
398 *
399 * @return The list of search paths used when loading protocol decoders.
400 *
401 * @since 0.5.1
402 */
srd_searchpaths_get(void)403 SRD_API GSList *srd_searchpaths_get(void)
404 {
405 GSList *paths = NULL;
406
407 for (GSList *l = searchpaths; l; l = l->next)
408 paths = g_slist_append(paths, g_strdup(l->data));
409
410 return paths;
411 }
412
413 /** @} */
414