openGL buffer mapping query

//SETUP
jointsInstancedBufferID = glCreateBuffers();
glBindBuffer(GL_SHADER_STORAGE_BUFFER, jointsInstancedBufferID);

int flags = GL_MAP_WRITE_BIT | GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT;
int buffersize = MAX_INSTANCED_SKELETAL_MESHES * MAX_JOINTS * MATRIX_SIZE_BYTES;

var jointsDataInstancedBuffer = MemoryUtil.memAllocFloat(buffersize);
glNamedBufferStorage(jointsInstancedBufferID, jointsDataInstancedBuffer, flags);
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 0, jointsInstancedBufferID);

glBindBuffer(GL_SHADER_STORAGE_BUFFER, 0);
MemoryUtil.memFree(jointsDataInstancedBuffer);

jointsInstancedBuffer = glMapNamedBufferRange(jointsInstancedBufferID, 0, buffersize,flags).asFloatBuffer();syncObj = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);

//                          UPDATE DATA

for(var Mesh: instanceMeshes) {
    int waitReturn = GL_UNSIGNALED;
    while (waitReturn != GL_ALREADY_SIGNALED && waitReturn != GL_CONDITION_SATISFIED) {
        waitReturn = glClientWaitSync(syncObj, GL_SYNC_FLUSH_COMMANDS_BIT, 1);
    }

    jointsInstancedBuffer.rewind();
    //...update buffer by using buffer.put()
    jointsInstancedBuffer.flip();

    glDeleteSync(syncObj);
    syncObj = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);

    // instance render models belonging to the current mesh
}
// This for loop is repeated two more times in another shader in the same frame