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authorDaniel Stenberg <daniel@haxx.se>2010-04-12 11:09:55 +0200
committerDaniel Stenberg <daniel@haxx.se>2010-04-12 11:09:55 +0200
commitf9db721c1c7723517be72a86b586f64b8af772b1 (patch)
treeeb964036f26fea9e88408b179a20d18fd3807505 /lib/README.multi_socket
parentcf9145973befdae6d4b0532ebd147ef864e1aed2 (diff)
update the section on timeouts
The section that describes how to work with timeouts was misleading and could easily trick users to use the wrong API.
Diffstat (limited to 'lib/README.multi_socket')
-rw-r--r--lib/README.multi_socket30
1 files changed, 9 insertions, 21 deletions
diff --git a/lib/README.multi_socket b/lib/README.multi_socket
index 606638670..d91e1d9f2 100644
--- a/lib/README.multi_socket
+++ b/lib/README.multi_socket
@@ -16,28 +16,16 @@ Implementation of the curl_multi_socket API
information about what socket to wait for what action on, and the callback
only gets called if the status of that socket has changed.
- In the API draft from before, we have a timeout argument on a per socket
- basis and we also allowed curl_multi_socket_action() to pass in an 'easy
- handle' instead of socket to allow libcurl to shortcut a lookup and work on
- the affected easy handle right away. Both these turned out to be bad ideas.
-
- The timeout argument was removed from the socket callback since after much
- thinking I came to the conclusion that we really don't want to handle
- timeouts on a per socket basis. We need it on a per transfer (easy handle)
- basis and thus we can't provide it in the callbacks in a nice way. Instead,
- we have to offer a curl_multi_timeout() that returns the largest amount of
- time we should wait before we call the "timeout action" of libcurl, to
- trigger the proper internal timeout action on the affected transfer. To get
- this to work, I added a struct to each easy handle in which we store an
- "expire time" (if any). The structs are then "splay sorted" so that we can
- add and remove times from the linked list and yet somewhat swiftly figure
- out 1 - how long time there is until the next timer expires and 2 - which
- timer (handle) should we take care of now. Of course, the upside of all this
- is that we get a curl_multi_timeout() that should also work with old-style
- applications that use curl_multi_perform().
-
We also added a timer callback that makes libcurl call the application when
- the timeout value changes, and you set that with curl_multi_setopt().
+ the timeout value changes, and you set that with curl_multi_setopt() and the
+ CURLMOPT_TIMERFUNCTION option. To get this to work, Internally, there's an
+ added a struct to each easy handle in which we store an "expire time" (if
+ any). The structs are then "splay sorted" so that we can add and remove
+ times from the linked list and yet somewhat swiftly figure out both how long
+ time there is until the next nearest timer expires and which timer (handle)
+ we should take care of now. Of course, the upside of all this is that we get
+ a curl_multi_timeout() that should also work with old-style applications
+ that use curl_multi_perform().
We created an internal "socket to easy handles" hash table that given
a socket (file descriptor) return the easy handle that waits for action on