FAQ: expand the thread-safe section

... with a mention of *NOSIGNAL, based on talk in bug #1386

diff --git a/docs/FAQ b/docs/FAQ
index 29355f0..0850bd4 100644 (file)
--- a/docs/FAQ
+++ b/docs/FAQ
@@ -1099,6 +1099,12 @@ FAQ
   your system has such.  Note that you must never share the same handle in
   multiple threads.
 
   your system has such.  Note that you must never share the same handle in
   multiple threads.
 

+  libcurl's implementation of timeouts might use signals (depending on what it
+  was built to use for name resolving), and signal handling is generally not
+  thread-safe.  Multi-threaded Applicationss that call libcurl from different
+  threads (on different handles) might want to use CURLOPT_NOSIGNAL, e.g.:
+
+    curl_easy_setopt(handle, CURLOPT_NOSIGNAL, true);

 
   If you use a OpenSSL-powered libcurl in a multi-threaded environment, you
   need to provide one or two locking functions:
 
   If you use a OpenSSL-powered libcurl in a multi-threaded environment, you
   need to provide one or two locking functions: