On Thu, Jul 27, 2023 at 01:59:54PM +0200, Laszlo Ersek wrote: > On 7/27/23 13:46, Richard W.M. Jones wrote: > > 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(+) > > Can you document the benefits of this change in the commit message? > (Faster downloads / lower CPU demand / lower memory usage -- just guessing.)
I would do if I knew what they were :-/ There are a bunch of complexities which I don't understand. I'm going to ask a question on the curl mailing list about this in a min. Rich. > Acked-by: Laszlo Ersek <ler...@redhat.com> > > Thanks > Laszlo > > > > > 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]); > > +} -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org _______________________________________________ Libguestfs mailing list Libguestfs@redhat.com https://listman.redhat.com/mailman/listinfo/libguestfs
