Changeset 60aaa492db336e5685ff19f3a2600bbbaf074cef

Timestamp:

06/03/11 00:44:00 (2 years ago)

Author:

Nedko Arnaudov <nedko@…>

Children:

78f07f7ad1a4778a5aa49083c4341cbbb4af1556

Parents:

cd3c2e4af45af43b3d3330f84180c6a7a74941a3

git-committer:

Nedko Arnaudov <nedko@arnaudov.name> / 2011-06-03T00:44:00Z+0300

Message:

Make alsapid work when libasound is loaded with dlopen(). Fix for #180

when alsapid is preloaded libasound is not loaded yet
for some unknown reason, late call to dlvsym() fails as well,
at least for mididings (python loads _mididings.so that
implicitly loads libasound.so)

this changeset implements the late symbol lookup,
because it makes the code smaller

the actual fix is to LD_PRELOAD libasound.so as well

Files:

• alsapid/lib.c (modified) (2 diffs)
• daemon/loader.c (modified) (3 diffs)

alsapid/lib.c

@@ -3 +3 @@
  * LADI Session Handler (ladish)
  *
- * Copyright (C) 2010 Nedko Arnaudov <nedko@arnaudov.name>
+ * Copyright (C) 2010, 2011 Nedko Arnaudov <nedko@arnaudov.name>
  *
  **************************************************************************
@@ -77 +77 @@
 //static int (* real_snd_seq_create_simple_port)(snd_seq_t * seq, const char * name, unsigned int caps, unsigned int type);
 
-static void __attribute__ ((constructor)) init(void);
-
-/* Library constructor */
-void init(void)
-{
-//  real_snd_seq_open               = dlvsym(RTLD_NEXT, "snd_seq_open",               API_VERSION);
-  real_snd_seq_set_client_name    = dlvsym(RTLD_NEXT, "snd_seq_set_client_name",    API_VERSION);
-  real_snd_seq_close              = dlvsym(RTLD_NEXT, "snd_seq_close",              API_VERSION);
-//  real_snd_seq_create_port        = dlvsym(RTLD_NEXT, "snd_seq_create_port",        API_VERSION);
-//  real_snd_seq_create_simple_port = dlvsym(RTLD_NEXT, "snd_seq_create_simple_port", API_VERSION);
-}
-
 #define CHECK_FUNC(func)                                                \
   if (real_ ## func == NULL)                                            \
   {                                                                     \
-    fprintf(stderr, "dlvsym(\"" #func "\", \""API_VERSION"\") failed.\n"); \
-    return -1;                                                          \
+    real_ ## func = dlvsym(RTLD_NEXT, #func, API_VERSION);              \
+    if (real_ ## func == NULL)                                          \
+    {                                                                   \
+      fprintf(stderr, "dlvsym(\""#func"\", \""API_VERSION"\") failed. %s\n", dlerror()); \
+      return -1;                                                        \
+    }                                                                   \
   }
 

daemon/loader.c

@@ -485 +485 @@
 }
 
+#define LD_PRELOAD_ADD "libalsapid.so libasound.so"
+
 static void set_ldpreload(void)
 {
@@ -493 +495 @@
   if (old != NULL)
   {
-    new = catdup3("libalsapid.so", " ", old);
+    new = catdup3(LD_PRELOAD_ADD, " ", old);
     if (new == NULL)
     {
@@ -502 +504 @@
   else
   {
-    new = "libalsapid.so";
+    new = LD_PRELOAD_ADD;
   }