Home | History | Annotate | Download | only in linux 
      1 /*
      2  * libjingle
      3  * Copyright 2004--2010, Google Inc.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  *  1. Redistributions of source code must retain the above copyright notice,
      9  *     this list of conditions and the following disclaimer.
     10  *  2. Redistributions in binary form must reproduce the above copyright notice,
     11  *     this list of conditions and the following disclaimer in the documentation
     12  *     and/or other materials provided with the distribution.
     13  *  3. The name of the author may not be used to endorse or promote products
     14  *     derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include "webrtc/modules/audio_device/linux/latebindingsymboltable_linux.h"
     29 
     30 #ifdef WEBRTC_LINUX
     31 #include <dlfcn.h>
     32 #endif
     33 
     34 // TODO(grunell): Either put inside webrtc namespace or use webrtc:: instead.
     35 using namespace webrtc;
     36 
     37 namespace webrtc_adm_linux {
     38 
     39 inline static const char *GetDllError() {
     40 #ifdef WEBRTC_LINUX
     41   char *err = dlerror();
     42   if (err) {
     43     return err;
     44   } else {
     45     return "No error";
     46   }
     47 #else
     48 #error Not implemented
     49 #endif
     50 }
     51 
     52 DllHandle InternalLoadDll(const char dll_name[]) {
     53 #ifdef WEBRTC_LINUX
     54   DllHandle handle = dlopen(dll_name, RTLD_NOW);
     55 #else
     56 #error Not implemented
     57 #endif
     58   if (handle == kInvalidDllHandle) {
     59     WEBRTC_TRACE(kTraceWarning, kTraceAudioDevice, -1,
     60                "Can't load %s : %s", dll_name, GetDllError());
     61   }
     62   return handle;
     63 }
     64 
     65 void InternalUnloadDll(DllHandle handle) {
     66 #ifdef WEBRTC_LINUX
     67   if (dlclose(handle) != 0) {
     68     WEBRTC_TRACE(kTraceError, kTraceAudioDevice, -1,
     69                "%s", GetDllError());
     70   }
     71 #else
     72 #error Not implemented
     73 #endif
     74 }
     75 
     76 static bool LoadSymbol(DllHandle handle,
     77                        const char *symbol_name,
     78                        void **symbol) {
     79 #ifdef WEBRTC_LINUX
     80   *symbol = dlsym(handle, symbol_name);
     81   char *err = dlerror();
     82   if (err) {
     83     WEBRTC_TRACE(kTraceError, kTraceAudioDevice, -1,
     84                "Error loading symbol %s : %d", symbol_name, err);
     85     return false;
     86   } else if (!*symbol) {
     87     WEBRTC_TRACE(kTraceError, kTraceAudioDevice, -1,
     88                "Symbol %s is NULL", symbol_name);
     89     return false;
     90   }
     91   return true;
     92 #else
     93 #error Not implemented
     94 #endif
     95 }
     96 
     97 // This routine MUST assign SOME value for every symbol, even if that value is
     98 // NULL, or else some symbols may be left with uninitialized data that the
     99 // caller may later interpret as a valid address.
    100 bool InternalLoadSymbols(DllHandle handle,
    101                          int num_symbols,
    102                          const char *const symbol_names[],
    103                          void *symbols[]) {
    104 #ifdef WEBRTC_LINUX
    105   // Clear any old errors.
    106   dlerror();
    107 #endif
    108   for (int i = 0; i < num_symbols; ++i) {
    109     if (!LoadSymbol(handle, symbol_names[i], &symbols[i])) {
    110       return false;
    111     }
    112   }
    113   return true;
    114 }
    115 
    116 }  // namespace webrtc_adm_linux
    117