[VxWorks] vxworks 加载共享库, 求帮助!

lwhay 2008-1-29 18:42 楼主

struct FindWellKnownSymbolCallbackInfo {
char *name;
UINT16 group;
};

static BOOL
findWellKnownSymbolCB(char *name,
      int val,
      SYM_TYPE type,
      int arg,
      UINT16 group)
{
struct FindWellKnownSymbolCallbackInfo *info =
(struct FindWellKnownSymbolCallbackInfo *) arg;

if (!strcmp(name, info->name)) {
info->group = group;
return FALSE;
}
return TRUE;
}

/* Returns CVM_TRUE upon success, CVM_FALSE upon error */
static CVMBool
getWellKnownSymbolGroupId(UINT16* group)
{

static CVMBool gotId = CVM_FALSE;
static UINT16 id;

if (gotId == CVM_FALSE) {
struct FindWellKnownSymbolCallbackInfo info;
SYMBOL* sym;
#ifdef CVM_DYNLINKSYM_PREPEND_UNDERSCORE
info.name = "_CVMgcUnsafeExecuteJavaMethod";
#else
info.name = "CVMgcUnsafeExecuteJavaMethod";
#endif

sym = symEach(sysSymTbl, (FUNCPTR) &findWellKnownSymbolCB,
      (int) &info);
/* If sym is NULL, failed to find symbol -- should not happen. */
if (sym == NULL) {
      return CVM_FALSE;
}

id = info.group;
gotId = CVM_TRUE;
}

*group = id;
return gotId;
}

struct CallbackInfo {
char *name;
UINT16 group;
void *val;
};

static BOOL
findSymbolCB(char *name,
      int val,
      SYM_TYPE type,
      int arg,
      UINT16 group)
{
struct CallbackInfo *info = (struct CallbackInfo *) arg;

if ((!strcmp(name, info->name)) &&
(info->group == group)) {
/* Found the symbol we're looking for. Returning FALSE from
   this callback will cause symEach() to return the current
   symbol to its caller. */
info->val = (void *) val;
return FALSE;
}
return TRUE;
}

void *
CVMdynlinkSym(void *dsoHandle, const void *nameArg)
{
VxWorksLibraryHandle* handle = (VxWorksLibraryHandle*)dsoHandle;
const char* name = (const char*)nameArg;
struct CallbackInfo info;
SYMBOL* sym;
void *value;

#ifdef CVM_DYNLINKSYM_PREPEND_UNDERSCORE
/*
   * %comment: mam051
   * It might be nice if we could modify nameArg in place.
   */
char *buf = malloc(strlen(nameArg) + 1 + 1);
if (buf == NULL) {
return NULL;
}
strcpy(buf, "_");
strcat(buf, nameArg);
name = buf;
#endif

assert(handle != NULL);

if (handle->isGlobal) {
/* Look up a well-known CVM symbol and match its group
   ID. This protects us whether cvm.o is dynamically loaded,
   or statically linked into the kernel. */
if (getWellKnownSymbolGroupId(&info.group) == CVM_FALSE) {
      value = NULL;
      goto done;
}
} else {
MODULE_ID mid;
MODULE_INFO mInfo;

mid = handle->id;
if (moduleInfoGet(mid, &mInfo) == ERROR) {
      value = NULL;
      goto done;
}
info.group = (UINT16) mInfo.group;
}
info.name = (char*)name;
sym = symEach(sysSymTbl, (FUNCPTR) &findSymbolCB, (int) &info);
if (sym == NULL) {
value = NULL;
} else {
value = info.val;
}

done:
#ifdef CVM_DYNLINKSYM_PREPEND_UNDERSCORE
free(buf);
#endif
return value;
}

void
CVMdynlinkClose(void *dsoHandle)
{
VxWorksLibraryHandle* handle = (VxWorksLibraryHandle *)dsoHandle;
if (handle->id != NULL) {
unldByModuleId(handle->id, 0);
}
free(handle);
}