llmediaimplgstreamer_syms.cpp

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#if LL_GSTREAMER_ENABLED

extern "C" {
#include <gst/gst.h>

#include <apr-1/apr_pools.h>
#include <apr-1/apr_dso.h>
}

#include "llmediaimplgstreamer.h"

#define LL_GST_SYM(REQ, GSTSYM, RTN, ...) RTN (*ll##GSTSYM)(__VA_ARGS__) = NULL
#include "llmediaimplgstreamer_syms_raw.inc"
#include "llmediaimplgstreamer_syms_rawa.inc"
#include "llmediaimplgstreamer_syms_rawv.inc"
#undef LL_GST_SYM


static bool sSymsGrabbed = false;
static apr_pool_t *sSymGSTDSOMemoryPool = NULL;
static apr_dso_handle_t *sSymGSTDSOHandleG = NULL;
static apr_dso_handle_t *sSymGSTDSOHandleV = NULL;
static apr_dso_handle_t *sSymGSTDSOHandleA = NULL;


bool grab_gst_syms(std::string gst_dso_name,
                   std::string gst_dso_name_vid,
                   std::string gst_dso_name_aud)
{
        if (sSymsGrabbed)
        {
                // already have grabbed good syms
                return TRUE;
        }

        bool sym_error = false;
        bool rtn = false;
        apr_status_t rv;
        apr_dso_handle_t *sSymGSTDSOHandle = NULL;

#define LL_GST_SYM(REQ, GSTSYM, RTN, ...) do{rv = apr_dso_sym((apr_dso_handle_sym_t*)&ll##GSTSYM, sSymGSTDSOHandle, #GSTSYM); if (rv != APR_SUCCESS) {INFOMSG("Failed to grab symbol: %s", #GSTSYM); if (REQ) sym_error = true;} else DEBUGMSG("grabbed symbol: %s from %p", #GSTSYM, (void*)ll##GSTSYM);}while(0)

        //attempt to load the shared libraries
        apr_pool_create(&sSymGSTDSOMemoryPool, NULL);
  
        if ( APR_SUCCESS == (rv = apr_dso_load(&sSymGSTDSOHandle,
                                               gst_dso_name.c_str(),
                                               sSymGSTDSOMemoryPool) ))
        {
                INFOMSG("Found DSO: %s", gst_dso_name.c_str());
#include "llmediaimplgstreamer_syms_raw.inc"
      
                if ( sSymGSTDSOHandle )
                {
                        sSymGSTDSOHandleG = sSymGSTDSOHandle;
                        sSymGSTDSOHandle = NULL;
                }
      
                if ( APR_SUCCESS == (rv = apr_dso_load(&sSymGSTDSOHandle,
                                                    gst_dso_name_aud.c_str(),
                                                       sSymGSTDSOMemoryPool) ))
                {
                        INFOMSG("Found DSO: %s", gst_dso_name_aud.c_str());
#include "llmediaimplgstreamer_syms_rawa.inc"
                        
                        if ( sSymGSTDSOHandle )
                        {
                                sSymGSTDSOHandleA = sSymGSTDSOHandle;
                                sSymGSTDSOHandle = NULL;
                        }
          
                        if ( APR_SUCCESS ==
                             (rv = apr_dso_load(&sSymGSTDSOHandle,
                                                gst_dso_name_vid.c_str(),
                                                sSymGSTDSOMemoryPool) ))
                        {
                                INFOMSG("Found DSO: %s", gst_dso_name_vid.c_str());
#include "llmediaimplgstreamer_syms_rawv.inc"
                        }
                        else
                        {
                                INFOMSG("Couldn't load DSO: %s", gst_dso_name_vid.c_str());
                                rtn = false; // failure
                        }
                }
                else
                {
                        INFOMSG("Couldn't load DSO: %s", gst_dso_name_aud.c_str());
                        rtn = false; // failure
                }
                
                rtn = !sym_error;
        }
        else
        {
                INFOMSG("Couldn't load DSO: %s", gst_dso_name.c_str());
                rtn = false; // failure
        }

        if (sym_error)
        {
                WARNMSG("Failed to find necessary symbols in GStreamer libraries.");
        }
        
        if ( sSymGSTDSOHandle )
        {
                sSymGSTDSOHandleV = sSymGSTDSOHandle;
                sSymGSTDSOHandle = NULL;
        }
#undef LL_GST_SYM

        sSymsGrabbed = !!rtn;
        return rtn;
}


void ungrab_gst_syms()
{ 
        // should be safe to call regardless of whether we've
        // actually grabbed syms.

        if ( sSymGSTDSOHandleG )
        {
                apr_dso_unload(sSymGSTDSOHandleG);
                sSymGSTDSOHandleG = NULL;
        }
        
        if ( sSymGSTDSOHandleA )
        {
                apr_dso_unload(sSymGSTDSOHandleA);
                sSymGSTDSOHandleA = NULL;
        }
        
        if ( sSymGSTDSOHandleV )
        {
                apr_dso_unload(sSymGSTDSOHandleV);
                sSymGSTDSOHandleV = NULL;
        }
        
        if ( sSymGSTDSOMemoryPool )
        {
                apr_pool_destroy(sSymGSTDSOMemoryPool);
                sSymGSTDSOMemoryPool = NULL;
        }
        
        // NULL-out all of the symbols we'd grabbed
#define LL_GST_SYM(REQ, GSTSYM, RTN, ...) do{ll##GSTSYM = NULL;}while(0)
#include "llmediaimplgstreamer_syms_raw.inc"
#include "llmediaimplgstreamer_syms_rawa.inc"
#include "llmediaimplgstreamer_syms_rawv.inc"
#undef LL_GST_SYM

        sSymsGrabbed = false;
}


#endif // LL_GSTREAMER_ENABLED

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