82009c4220
Replace the `volatile int dirty` with a reference counter protected by a mutex when available. Solve the problem of when to call application's lock function by adding a volatile flag that indicates a share has been added to easy handles in its lifetime. That flag ever goes from FALSE to TRUE, so volatile might work (in the absence of a mutex). (The problem is that the lock/unlock functions need 2-3 `curl_share_setopt()` invocations to become usable and there is no way of telling if the third will ever happen. Calling the lock function before the 3rd setopt may crash the application.) When removing a share from an easy handle (or replacing it with another share), detach the easy connection on a share with a connection pool. When cleaning up a share, allow this even if it is still used in easy handles. It will be destroyed when the reference count drops to 0. Closes #20870
1.6 KiB
| c | SPDX-License-Identifier | Title | Section | Source | See-also | Protocol | Added-in | |||
|---|---|---|---|---|---|---|---|---|---|---|
| Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. | curl | curl_share_cleanup | 3 | libcurl |
|
|
7.10 |
NAME
curl_share_cleanup - close a shared object
SYNOPSIS
#include <curl/curl.h>
CURLSHcode curl_share_cleanup(CURLSH *share_handle);
DESCRIPTION
This function deletes a shared object. The share handle cannot be used anymore when this function has been called. The share fails the call if it is still being used in any easy handle.
Passing in a NULL pointer in share_handle makes this function return immediately with no action.
Any use of the share_handle after this function has been called and have returned, is illegal.
For applications that use a share in several threads, it is critical that the destruction of the share is only done when all other threads have stopped using it. While libcurl tracks how many easy handles are using a share, it can not observe how many pointers to the share the application has.
%PROTOCOLS%
EXAMPLE
int main(void)
{
CURLSHcode sh;
CURLSH *share = curl_share_init();
sh = curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_CONNECT);
/* use the share, then ... */
curl_share_cleanup(share);
}
%AVAILABILITY%
RETURN VALUE
CURLSHE_OK (zero) means that the option was set properly, non-zero means an error occurred as <curl/curl.h> defines. See the libcurl-errors(3) man page for the full list with descriptions. If an error occurs, then the share object is not deleted.