Is the hiperfifo.c example thread safe

Question

I see numerous references on how a curl multi handle should not be used across threads concurrently. However in the hiperfifo.c example, the handle seems to be accessed concurrently from fifo_cb, timer_cb and event_cb. Is it implicit that some synchornization should be added by the curl programmer? Or is libevent serializing the callbacks?

Answer 1

libevent is serializing the callbacks. It works within a single thread.

(and the recently created canonical URL for information about libcurl's threadsafeness is: http://curl.haxx.se/libcurl/c/threadsafe.html)