]> sigrok.org Git - libsigrokdecode.git/blame - srd.c
configure.ac: Bump package version to 0.5.1.
[libsigrokdecode.git] / srd.c
CommitLineData
190b71cf
BV
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
36784362 21#include <config.h>
f6c7eade
MC
22#include "libsigrokdecode-internal.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
23#include "libsigrokdecode.h"
190b71cf
BV
24#include <glib.h>
25
26/** @cond PRIVATE */
27
ea81b49a
BV
28/* Python module search paths */
29SRD_PRIV GSList *searchpaths = NULL;
30
190b71cf 31/* session.c */
23a29d24
UH
32extern SRD_PRIV GSList *sessions;
33extern SRD_PRIV int max_session_id;
190b71cf 34
190b71cf
BV
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 *
3b884e85 65 * There is one mailing list for sigrok/libsigrokdecode: <a href="https://lists.sourceforge.net/lists/listinfo/sigrok-devel">sigrok-devel</a>.
190b71cf
BV
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
40c6ac1d
DE
98static 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
cdb49509
UH
115static 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
2ba06442
UH
147static 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 }
176 s->str[s->len - 1] = '\0';
177 srd_dbg("%s", s->str);
178 g_string_free(s, TRUE);
179
180 PyGILState_Release(gstate);
181
182 return SRD_OK;
183
184err:
185 srd_err("Unable to query Python system search paths.");
186 PyGILState_Release(gstate);
187
188 return SRD_ERR_PYTHON;
189}
190
191SRD_API GSList *srd_searchpaths_get(void)
192{
193 return g_slist_copy_deep(searchpaths, (GCopyFunc)g_strdup, NULL);
194}
195
190b71cf
BV
196/**
197 * Initialize libsigrokdecode.
198 *
199 * This initializes the Python interpreter, and creates and initializes
200 * a "sigrokdecode" Python module.
201 *
202 * Then, it searches for sigrok protocol decoders in the "decoders"
203 * subdirectory of the the libsigrokdecode installation directory.
204 * All decoders that are found are loaded into memory and added to an
205 * internal list of decoders, which can be queried via srd_decoder_list().
206 *
207 * The caller is responsible for calling the clean-up function srd_exit(),
208 * which will properly shut down libsigrokdecode and free its allocated memory.
209 *
210 * Multiple calls to srd_init(), without calling srd_exit() in between,
211 * are not allowed.
212 *
213 * @param path Path to an extra directory containing protocol decoders
214 * which will be added to the Python sys.path. May be NULL.
215 *
216 * @return SRD_OK upon success, a (negative) error code otherwise.
217 * Upon Python errors, SRD_ERR_PYTHON is returned. If the decoders
218 * directory cannot be accessed, SRD_ERR_DECODERS_DIR is returned.
219 * If not enough memory could be allocated, SRD_ERR_MALLOC is returned.
220 *
221 * @since 0.1.0
222 */
223SRD_API int srd_init(const char *path)
224{
40c6ac1d
DE
225 const char *const *sys_datadirs;
226 const char *env_path;
227 size_t i;
190b71cf 228 int ret;
190b71cf
BV
229
230 if (max_session_id != -1) {
231 srd_err("libsigrokdecode is already initialized.");
232 return SRD_ERR;
233 }
234
cdb49509
UH
235 print_versions();
236
190b71cf
BV
237 srd_dbg("Initializing libsigrokdecode.");
238
239 /* Add our own module to the list of built-in modules. */
240 PyImport_AppendInittab("sigrokdecode", PyInit_sigrokdecode);
241
242 /* Initialize the Python interpreter. */
45883c6b 243 Py_InitializeEx(0);
190b71cf 244
40c6ac1d
DE
245 /* Locations relative to the XDG system data directories. */
246 sys_datadirs = g_get_system_data_dirs();
247 for (i = g_strv_length((char **)sys_datadirs); i > 0; i--) {
248 ret = searchpath_add_xdg_dir(sys_datadirs[i-1]);
249 if (ret != SRD_OK) {
250 Py_Finalize();
251 return ret;
252 }
253 }
254#ifdef DECODERS_DIR
255 /* Hardcoded decoders install location, if defined. */
190b71cf
BV
256 if ((ret = srd_decoder_searchpath_add(DECODERS_DIR)) != SRD_OK) {
257 Py_Finalize();
258 return ret;
259 }
40c6ac1d
DE
260#endif
261 /* Location relative to the XDG user data directory. */
262 ret = searchpath_add_xdg_dir(g_get_user_data_dir());
263 if (ret != SRD_OK) {
264 Py_Finalize();
265 return ret;
266 }
190b71cf
BV
267
268 /* Path specified by the user. */
269 if (path) {
270 if ((ret = srd_decoder_searchpath_add(path)) != SRD_OK) {
271 Py_Finalize();
272 return ret;
273 }
274 }
275
276 /* Environment variable overrides everything, for debugging. */
40c6ac1d 277 if ((env_path = g_getenv("SIGROKDECODE_DIR"))) {
190b71cf
BV
278 if ((ret = srd_decoder_searchpath_add(env_path)) != SRD_OK) {
279 Py_Finalize();
280 return ret;
281 }
282 }
283
2ba06442
UH
284 /* Initialize the Python GIL (this also happens to acquire it). */
285 PyEval_InitThreads();
286
287 /* Release the GIL (ignore return value, we don't need it here). */
288 (void)PyEval_SaveThread();
289
190b71cf
BV
290 max_session_id = 0;
291
2ba06442
UH
292 print_searchpaths();
293
190b71cf
BV
294 return SRD_OK;
295}
296
297/**
298 * Shutdown libsigrokdecode.
299 *
300 * This frees all the memory allocated for protocol decoders and shuts down
301 * the Python interpreter.
302 *
303 * This function should only be called if there was a (successful!) invocation
304 * of srd_init() before. Calling this function multiple times in a row, without
305 * any successful srd_init() calls in between, is not allowed.
306 *
307 * @return SRD_OK upon success, a (negative) error code otherwise.
308 *
309 * @since 0.1.0
310 */
311SRD_API int srd_exit(void)
312{
190b71cf
BV
313 srd_dbg("Exiting libsigrokdecode.");
314
95e40a0c 315 g_slist_foreach(sessions, (GFunc)srd_session_destroy, NULL);
190b71cf
BV
316
317 srd_decoder_unload_all();
ea81b49a
BV
318 g_slist_free_full(searchpaths, g_free);
319 searchpaths = NULL;
190b71cf 320
2ba06442
UH
321 /*
322 * Acquire the GIL, otherwise Py_Finalize() might have issues.
323 * Ignore the return value, we don't need it here.
324 */
325 if (Py_IsInitialized())
326 (void)PyGILState_Ensure();
327
190b71cf
BV
328 /* Py_Finalize() returns void, any finalization errors are ignored. */
329 Py_Finalize();
330
2ba06442
UH
331 /* Note: No need to release the GIL since Python is shut down now. */
332
190b71cf
BV
333 max_session_id = -1;
334
335 return SRD_OK;
336}
337
338/**
339 * Add an additional search directory for the protocol decoders.
340 *
341 * The specified directory is prepended (not appended!) to Python's sys.path,
342 * in order to search for sigrok protocol decoders in the specified
343 * directories first, and in the generic Python module directories (and in
344 * the current working directory) last. This avoids conflicts if there are
345 * Python modules which have the same name as a sigrok protocol decoder in
346 * sys.path or in the current working directory.
347 *
348 * @param path Path to the directory containing protocol decoders which shall
349 * be added to the Python sys.path, or NULL.
350 *
351 * @return SRD_OK upon success, a (negative) error code otherwise.
352 *
353 * @private
354 *
355 * @since 0.1.0
356 */
357SRD_PRIV int srd_decoder_searchpath_add(const char *path)
358{
359 PyObject *py_cur_path, *py_item;
2ba06442 360 PyGILState_STATE gstate;
190b71cf
BV
361
362 srd_dbg("Adding '%s' to module path.", path);
363
2ba06442
UH
364 gstate = PyGILState_Ensure();
365
190b71cf 366 py_cur_path = PySys_GetObject("path");
d8d40959 367 if (!py_cur_path)
2ba06442 368 goto err;
d8d40959
DE
369
370 py_item = PyUnicode_FromString(path);
371 if (!py_item) {
372 srd_exception_catch("Failed to create Unicode object");
2ba06442 373 goto err;
d8d40959
DE
374 }
375 if (PyList_Insert(py_cur_path, 0, py_item) < 0) {
376 srd_exception_catch("Failed to insert path element");
377 Py_DECREF(py_item);
2ba06442 378 goto err;
190b71cf 379 }
d8d40959 380 Py_DECREF(py_item);
190b71cf 381
2ba06442
UH
382 PyGILState_Release(gstate);
383
d8d40959 384 searchpaths = g_slist_prepend(searchpaths, g_strdup(path));
190b71cf
BV
385
386 return SRD_OK;
2ba06442
UH
387
388err:
389 PyGILState_Release(gstate);
390
391 return SRD_ERR_PYTHON;
190b71cf
BV
392}
393
394/** @} */