1CURLSHOPT_LOCKFUNC(3) libcurl Manual CURLSHOPT_LOCKFUNC(3)
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6 CURLSHOPT_LOCKFUNC - mutex lock callback
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9 #include <curl/curl.h>
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11 void lockcb(CURL *handle, curl_lock_data data, curl_lock_access access,
12 void *userptr);
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14 CURLSHcode curl_share_setopt(CURLSH *share, CURLSHOPT_LOCKFUNC, lockcb);
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17 Set a mutex lock callback for the share object, to allow it to get used
18 by multiple threads concurrently. There's a corresponding CURLSHOPT_UN‐
19 LOCKFUNC(3) callback called when the mutex is again released.
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21 The lockcb argument must be a pointer to a function matching the proto‐
22 type shown above. The arguments to the callback are:
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24 handle is the currently active easy handle in use when the share object
25 is intended to get used.
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27 The data argument tells what kind of data libcurl wants to lock. Make
28 sure that the callback uses a different lock for each kind of data.
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30 access defines what access type libcurl wants, shared or single.
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32 userptr is the private pointer you set with CURLSHOPT_USERDATA. This
33 pointer is not used by libcurl itself.
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36 All
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39 CURLSHcode sh;
40 share = curl_share_init();
41 sh = curl_share_setopt(share, CURLSHOPT_LOCKFUNC, mutex_lock);
42 if(sh)
43 printf("Error: %s\n", curl_share_strerror(sh));
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46 Added in 7.10
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49 CURLSHE_OK (zero) means that the option was set properly, non-zero
50 means an error occurred. See libcurl-errors(3) for the full list with
51 descriptions.
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54 CURLSHOPT_UNLOCKFUNC(3), curl_share_setopt(3), curl_share_cleanup(3),
55 curl_share_init(3)
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59libcurl 7.85.0 May 17, 2022 CURLSHOPT_LOCKFUNC(3)