What was Charles Dickens attitude toward the French Revolution? Does he sympathize with the revolutionaries?

You have asked an excellent question. To answer it, how do you feel Dickens presents the situation in France under the French aristocracy? And then how do you think he presents the revolutionaries once the revolution is underway?

Answering these questions, for me, it is clear that Dickens regards the French Revolution with some ambivalence. He seems to support the revolutionary cause but also to condemn the way the Revolution was conducted, often criticising the evil of the revolutionaries themselves. 

It does appear clear however that Dickens shows great empathy for the situation of the French working class and highlights the necessity of a social change. We can see this through the heartless attitude of the Marquis Evremonde to the child his carriage has killed. The Marquis seems to be a symbol of the aristocracy that is used to shamelessly exploiting the nation's poor for its own ends. So whilst this is condemned, Dickens also equally frowns on the method of revolution employed by the peasants. The message seems to be that in fighting oppression with oppression, and acts of barbarism with acts of barbarism, there is no true revolution; rather they are only serving to continue the cycle of violence which they themselves were victims of. This fine line between oppressed and oppressor is perhaps best summed up in the following quote:

Sow the same seed of rapacious license and oppression over again, and it will surely yield the same fruit according to its kind.

So although Dickens viewed the Revolution as a symbol of resurrection and renewal (key themes within the novel), this focus is undercut through the constant emphasis on the violence that was associated with the Revolution, and ultimately did not contribute towards a favourable outcome.