Using the libcurl share interface we can share data between the separate curl easy handles in the pool. For more about this see:
https://curl.se/libcurl/c/CURLSHOPT_SHARE.html https://gist.github.com/bagder/7eccf74f8b6d70b5abefeb7f288dba9b https://everything.curl.dev/libcurl/sharing --- plugins/curl/pool.c | 65 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) diff --git a/plugins/curl/pool.c b/plugins/curl/pool.c index 10f9011d7..e9f387c38 100644 --- a/plugins/curl/pool.c +++ b/plugins/curl/pool.c @@ -52,6 +52,7 @@ #include <nbdkit-plugin.h> +#include "array-size.h" #include "ascii-ctype.h" #include "ascii-string.h" #include "cleanup.h" @@ -72,6 +73,18 @@ static int get_content_length_accept_range (struct curl_handle *ch); static bool try_fallback_GET_method (struct curl_handle *ch); static size_t header_cb (void *ptr, size_t size, size_t nmemb, void *opaque); static size_t error_cb (char *ptr, size_t size, size_t nmemb, void *opaque); +static void lock_cb (CURL *handle, curl_lock_data data, + curl_lock_access access, void *userptr); +static void unlock_cb (CURL *handle, curl_lock_data data, + void *userptr); + +/* These locks protect access to the curl share data. See: + * https://gist.github.com/bagder/7eccf74f8b6d70b5abefeb7f288dba9b + */ +static pthread_rwlock_t sharelocks[CURL_LOCK_DATA_LAST]; + +/* Curl share data. */ +static CURLSH *share; /* This lock protects access to the curl_handles vector below. */ static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER; @@ -93,6 +106,22 @@ static size_t in_use = 0, waiting = 0; void load_pool (void) { + size_t i; + + for (i = 0; i < ARRAY_SIZE (sharelocks); ++i) + pthread_rwlock_init (&sharelocks[i], NULL); + + share = curl_share_init (); + if (share == NULL) { + nbdkit_error ("curl_share_init: %m"); + exit (EXIT_FAILURE); + } + curl_share_setopt (share, CURLSHOPT_LOCKFUNC, lock_cb); + curl_share_setopt (share, CURLSHOPT_UNLOCKFUNC, unlock_cb); + curl_share_setopt (share, CURLSHOPT_SHARE, CURL_LOCK_DATA_CONNECT); + curl_share_setopt (share, CURLSHOPT_SHARE, CURL_LOCK_DATA_COOKIE); + curl_share_setopt (share, CURLSHOPT_SHARE, CURL_LOCK_DATA_DNS); + curl_share_setopt (share, CURLSHOPT_SHARE, CURL_LOCK_DATA_SSL_SESSION); } /* Close and free all handles in the pool. */ @@ -108,6 +137,12 @@ unload_pool (void) for (i = 0; i < curl_handles.len; ++i) free_handle (curl_handles.ptr[i]); curl_handle_list_reset (&curl_handles); + + /* Free share data. */ + curl_share_cleanup (share); + + for (i = 0; i < ARRAY_SIZE (sharelocks); ++i) + pthread_rwlock_destroy (&sharelocks[i]); } /* Get a handle from the pool. @@ -230,6 +265,9 @@ allocate_handle (void) goto err; } + /* Share settings with other handles. */ + curl_easy_setopt (ch->c, CURLOPT_SHARE, share); + /* Various options we always set. * * NB: Both here and below constants must be explicitly long because @@ -621,3 +659,30 @@ error_cb (char *ptr, size_t size, size_t nmemb, void *opaque) return 0; /* in older curl, any size < requested will also be an error */ #endif } + +static void +lock_cb (CURL *handle, curl_lock_data data, curl_lock_access access, + void *userptr) +{ + assert (data < ARRAY_SIZE (sharelocks)); + + switch (access) { + case CURL_LOCK_ACCESS_SHARED: + pthread_rwlock_rdlock (&sharelocks[data]); + break; + case CURL_LOCK_ACCESS_SINGLE: + pthread_rwlock_wrlock (&sharelocks[data]); + break; + default: + /* CURL_LOCK_ACCESS_NONE is never used in the current libcurl code. */ + abort (); + } +} + +static void +unlock_cb (CURL *handle, curl_lock_data data, void *userptr) +{ + assert (data < ARRAY_SIZE (sharelocks)); + + pthread_rwlock_unlock (&sharelocks[data]); +} -- 2.41.0 _______________________________________________ Libguestfs mailing list Libguestfs@redhat.com https://listman.redhat.com/mailman/listinfo/libguestfs
