Refresh MYSQL UDF - mysql

Question

I am trying to use my own UDF (written in c++) as a mysql extension. I was able to install the function via
CREATE FUNCTION decrypt RETURNS STRING SONAME "libudf_func.so";
and use it. I could also drop the function via
DROP FUNCTION decrypt;
After that it would not be listed in the mysql.func table, so Im pretty sure it was successfully deleted.
Now I want to use an updated version of my function, and therefore reload it in mysql. However, mysql only reloads the old version of my file (which I completely removed from the computer). Even if I remove ALL files named "libudf_func.so" it will be reloaded.
I'm using mysql version 8.0.28 for macos12.0 on localhost.
How can I remove this cached version or force mysql to reload?
EDIT
All my steps, from loading the first version to my attempt to load the updated version:
I used: CREATE FUNCTION decrypt RETURNS STRING SONAME "libudf.so"; to initially create the function decrypt
I changed something in my udf.cpp file.
I used: DROP FUNCTION decrypt; to remove the function decrypt
I used CREATE FUNCTION decrypt RETURNS STRING SONAME "libudf.so"; as an attempt to reload/refresh the function decrypt (NO ERRORS)
the behaviors did not change (among other things I wanted to output a different error message, so that was pretty obviously the old behavior)
I renamed libudf.so to lubudf_func.so
I replicated this with the new name.
I deleted ALL files with the names libudf.so or lubudf_func.so from my machine
I could still execute CREATE FUNCTION decrypt RETURNS STRING SONAME "libudf.so"; without any errors
I tried to call CREATE FUNCTION decrypt RETURNS STRING SONAME "libudf_xyz.so"; (never existed), which failed. Error message: "Error Code: 1126. Can't open shared library 'libudf_xyz.so' (errno: 2 dlopen(/usr/local/opt/mysql/lib/plugin/libudf_xyz.so, 0x0002): tried: '/usr/local/opt/mysql/lib/plugin/libudf_xyz.so' (no such f)"
plugin_dir: /usr/local/opt/mysql/lib/plugin/
--->(this is where the .so file WAS located, but is not anymore)
How did I notice the old behavior was still present? The dead giveaway was that the function used the old error message ("Please use plaintext(int), iv(string), key(string)"), and not the new message ("Please use plaintext(string), iv(string), key(string)") after step no. 4
Also add the content of the plugins/ directory, which CREATE FUNCTION uses to load the function: I wrote the library in c++, then built it as a shared library. The c++ code would be as follows (but Im not sure this is relevant):
extern "C" {
bool decrypt_init(UDF_INIT *initid, UDF_ARGS *args, char *message);
char *decrypt(UDF_INIT *initid, UDF_ARGS *args, char *result, unsigned long *length, char *is_null, char *error);
void decrypt_deinit(UDF_INIT *initid);
}
bool decrypt_init(UDF_INIT *initid, UDF_ARGS *args, char *message) {
if (args->arg_count != 3 or
args->arg_type[0] != STRING_RESULT or
args->arg_type[1] != STRING_RESULT or
args->arg_type[2] != STRING_RESULT
) {
strcpy(message, "Usage: decrypt_poly(string ctext, string key, string iv)");
return 1;
}
if (args->lengths[2] != 48) {
strcpy(message, "Only 24-length IVs are allowed. Make sure IV is hexed.");
return 1;
}
initid->ptr = new char[args->lengths[0]];
initid->maybe_null = 1;
return 0;
}
char *decrypt(UDF_INIT *initid, UDF_ARGS *args,
char *result, unsigned long *length,
char *is_null, char *error) {
std::string dvalue;
if (NULL != args->args[0]) {
std::string value = std::string(args->args[0], args->lengths[0]);
std::string key = std::string(args->args[1], args->lengths[1]);
std::string iv = std::string(args->args[2], args->lengths[2]);
try {
dvalue = ((encryption::poly_based_encryption::decrypt(value, key, iv))));
}
catch (CryptoPP::Exception &e) {
std::cerr << e.what() << std::endl;
*error = 1;
}
} else {
dvalue = "";
*is_null = 1;
*error = 1;
return NULL;
}
strcpy(initid->ptr, dvalue.c_str());
*length = dvalue.length();
result = initid->ptr;
*is_null = 0;
*error = 0;
return result;
}
void decrypt_deinit(UDF_INIT *initid) {
if (initid->ptr)
delete[] initid->ptr;
}