iLiad FBReader 0.8.17 problem

[ericshliao]

I have built FBReader 0.8.17 for iLiad.
It works in Scratchbox enviroment but fialed on iLiad.
I added some notification into its source code and found where it failed. But I can't figure why.

This is the main entrance in "main.cpp"

int main(int argc, char **argv) {
	printf("1\n");//my personal addon
	if (!ZLibrary::init(argc, argv)) {
		printf("!ZLibrary::init\n");
		return 1;
	}
	printf("2\n");//my personal addon
	ZLibrary::run(new FBReader(argc == 1 ? std::string() : argv[1]));
	printf("3\n");//my personal addon
	ZLibrary::shutdown();
	return 0;
}

"ZLibrary.cpp" called by "main.cpp"

bool ZLibrary::init(int &argc, char **&argv) {
#ifdef ZLSHARED
	const std::string pluginPath = std::string(LIBDIR) + "/zlibrary/ui";

	void *handle = 0;
	printf("11\n");//my personal addon
	fflush(stdout);
	if ((argc > 2) && std::string("-zlui") == argv[1]) {
		handle = dlopen((pluginPath + "/zlui-" + argv[2] + ".so").c_str(), RTLD_NOW);
		argc -= 2;
		argv += 2;
	}
	printf("12\n");//my personal addon
	fflush(stdout);
	if (handle == 0) {
		DIR *dir = opendir(pluginPath.c_str());
		if (dir == 0) {
			return false;
		}
		std::vector<std::string> names;
		const dirent *file;
		struct stat fileInfo;
		while ((file = readdir(dir)) != 0) {
			const std::string shortName = file->d_name;
			if ((shortName.substr(0, 5) != "zlui-") ||
					!ZLStringUtil::stringEndsWith(shortName, ".so")) {
				continue;
			}
			const std::string fullName = pluginPath + "/" + shortName;
			stat(fullName.c_str(), &fileInfo);
			if (!S_ISREG(fileInfo.st_mode)) {
				continue;
			}
			names.push_back(fullName);
		}
		closedir(dir);
	printf("13\n");//my personal addon
fflush(stdout);
		std::sort(names.begin(), names.end());
		for (std::vector<std::string>::const_iterator it = names.begin();
				 (it != names.end()) && (handle == 0); ++it) {
			handle = dlopen(it->c_str(), RTLD_NOW);
		}

		if (handle == 0) {
			return false;
		}
	}
	dlerror();
	printf("14\n");//my personal addon
fflush(stdout);
	void (*initLibrary)();
	*(void**)&initLibrary = dlsym(handle, "initLibrary");
	if (dlerror() != 0) {
		return false;
	}
#endif /* ZLSHARED */
	printf("15\n");
fflush(stdout);
	initLibrary();
	printf("16\n");//my personal addon
fflush(stdout);
	if (ZLibraryImplementation::Instance == 0) {
		return false;
	}
	printf("17\n");//my personal addon
fflush(stdout);
	ZLibraryImplementation::Instance->init(argc, argv);
	return true;
}

When I execute FBReader in mrxvt on iLiad, I got output:

1
!ZLibrary::init

Then FBReader stopped. And ZLibrary::init didn't output anything. (The reasone that ZLibrary::init() didn't output anything was caused by my forgetting to update lib file. ZLibrary::init() did executed to printf("13\n") and returned false.)

[Adam B.]

Change "RTLD_NOW" to "RTLD_LAZY". This bug took me forever to hunt down.

[ericshliao]

Changing RTLD_NOW to RTLD_LAZY seems not work. Still the same situation.
But your suggestion did help me to identify that it has something to do with dlop(). Because ZLibrary::init() executed the following and return false:

		std::sort(names.begin(), names.end());
		for (std::vector<std::string>::const_iterator it = names.begin();
				 (it != names.end()) && (handle == 0); ++it) {
			handle = dlopen(it->c_str(), RTLD_LAZY);
		}

		if (handle == 0) {
			return false;
		}

[ericshliao]

More info for developers:
When I execute fbreader in Scrachbox, it will execute to

handle = dlopen(it->c_str(), RTLD_NOW);

the first parameter passed to dlopen is:
"-prefix-/fbreader/lib/zlibrary/ui/zlui-gtk.so"
and dlopen() will return a non-zero value. Then fbreader will continue. On iLiad, dlopen returned 0 to handle, henceforth fbreader stopped.

Added:
I have changed RTLD_NOW to RTLD_LAZY, still the same problem.

[ericshliao]

I added a line after dlopen():

printf ("Error: %s\n", dlerror());

Then I found I don't have "libgio-2.0.so.0". It seems the real cause.

[ericshliao]

The difference between RTLD_NOW and RTLD_LAZY is whether libs are checked in the begining. When I have fixed all needed libs, it is a good idea to use RTLD_LAZY to save some execution time.
Currently, I am still looking for what lib is needed to run fbreader on iLiad, using RTLD_NOW will tell me what lib is missing in the begining.

[Adam B.]

If you're using the VMware image or Antartica's toolchain, you can you the libtool.sh script to generate the necessary libraries.

[igorsk]

Originally Posted by ericshliao

More info for developers:
When I execute fbreader in Scrachbox, it will execute to

handle = dlopen(it->c_str(), RTLD_NOW);

the first parameter passed to dlopen is:
"-prefix-/fbreader/lib/zlibrary/ui/zlui-gtk.so"
and dlopen() will return a non-zero value. Then fbreader will continue. On iLiad, dlopen returned 0 to handle, henceforth fbreader stopped.

This path is not right. To check where it comes from, look at the first line of the function:

const std::string pluginPath = std::string(LIBDIR) + "/zlibrary/ui";

So most likely configure step didn't work right and LIBDIR variable was not set correctly.

[ericshliao]

Thanx. I'll try the libtool.sh.

The path is ok. That "-prefix-" is not real input parameter to dlopen(). Just for temporary convenience for discussion.

Added:
In fact, I have all the needed lib ready in my compile environment. The problem is how to identify which one is really needed (using ldd might generate a list) and some required config for individual lib.

I can enter FBReader GUI, but all characters are represented by weired rectangle. It seems some required config for Pango is missing.

[ericshliao]

The pango config on iLilad is for older version, not compatible to newer version. I have solved it now.Page-flipbar on iLiad is working for FBReader, too. Now, the only issue is how to control led light properly.

[ericshliao]

I am facing another problem with dlopen(). To control iLiad led light from FBReader, I tried to add erIpcStartClient() into FBReader source code. The compilation is ok. At run time, FBreader only looks for erIpcStartClient() in "/lib/zlibrary/ui/zlui-gtk.so", and of course, there is not such function in that shared object.