[譯]curl_multi_add_handle

NAME
curl_multi_add_handle - add an easy handle to a multi session
添加easy handle到multi session中

SYNOPSIS
#include <curl/curl.h>
CURLMcode curl_multi_add_handle(CURLM *multi_handle, CURL *easy_handle);

DESCRIPTION
Adds a standard easy handle to the multi stack. This function call will make this multi_handle control the specified easy_handle.
添加一個標準的easy handle到Multi stack中。

While an easy handle is added to a multi stack, you can not and you must not use curl_easy_perform on that handle. After having removed the easy handle from the multi stack again, it is perfectly fine to use it with the easy interface again.
當一個easy handle被添加到multi stack中，你不能再對這個easy handle使用curl_esay_perform。
當這個easy handle被從multi stack中移除，又能夠再次對這個easy handle使用esay_curl接口了。

If the easy handle is not set to use a shared (CURLOPT_SHARE) or global DNS cache (CURLOPT_DNS_USE_GLOBAL_CACHE), it will be made to use the DNS cache that is shared between all easy handles within the multi handle when curl_multi_add_handle is called.
當調用curl_multi_add_handle時，若是easy handle沒有設置使用shared (CURLOPT_SHARE)，或者全局DNS緩存(CURLOPT_DNS_USE_GLOBAL_CACHE)，
則會使用multi handle中的share的dns緩存。
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When an easy interface is added to a multi handle, it will use a shared connection cache owned by the multi handle. Removing and adding new easy handles will not affect the pool of connections or the ability to do connection re-use.
當一個新的easy handle被加入到multi handle中，他會使用一個multi handle緩存的shared鏈接。
移除和添加easy handle不會影響鏈接池或者鏈接複用。

If you have CURLMOPT_TIMERFUNCTION set in the multi handle (and you really should if you're working event-based with curl_multi_socket_action and friends), that callback will be called from within this function to ask for an updated timer so that your main event loop will get the activity on this handle to get started.
若是multi handle設置了CURLMOPT_TIMERFUNCTION（若是你使用curl_multi_socket_action，應該設置），
回調函數會被觸發

The easy handle will remain added to the multi handle until you remove it again with curl_multi_remove_handle - even when a transfer with that specific easy handle is completed.

You should remove the easy handle from the multi stack before you terminate first the easy handle and then the multi handle:

1 - curl_multi_remove_handle

2 - curl_easy_cleanup

3 - curl_multi_cleanup

RETURN VALUE

CURLMcode type, general libcurl multi interface error code.