From 6cf8413e31629183b3c749aa2a17d24be14cbca1 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Sat, 10 Aug 2013 22:55:59 +0200
Subject: curl_easy_perform_ev: debug/test function
This function is meant to work *exactly* as curl_easy_perform() but will
use the event-based libcurl API internally instead of
curl_multi_perform(). To avoid relying on an actual event-based library
and to not use non-portable functions (like epoll or similar), there's a
rather inefficient emulation layer implemented on top of Curl_poll()
instead.
There's currently some convenience logging done in curl_easy_perform_ev
which helps when tracking down problems. They may be suitable to remove
or change once things seem to be fine enough.
curl has a new --test-event option when built with debug enabled that
then uses curl_easy_perform_ev() instead of curl_easy_perform(). If
built without debug, using --test-event will only output a warning
message.
NOTE: curl_easy_perform_ev() is not part if the public API on purpose.
It is only present in debug builds of libcurl and MUST NOT be considered
stable even then. Use it for libcurl-testing purposes only.
runtests.pl now features an -e command line option that makes it use
--test-event for all curl command line tests. The man page is updated.
---
lib/easy.c | 398 +++++++++++++++++++++++++++++++++++++++++++++++++++--------
lib/easyif.h | 3 +
2 files changed, 350 insertions(+), 51 deletions(-)
(limited to 'lib')
diff --git a/lib/easy.c b/lib/easy.c
index 07a42bb5c..2ac92a2f6 100644
--- a/lib/easy.c
+++ b/lib/easy.c
@@ -453,70 +453,275 @@ CURLcode curl_easy_setopt(CURL *curl, CURLoption tag, ...)
return ret;
}
+#ifdef CURLDEBUG
+
+struct monitor {
+ struct monitor *next; /* the next node in the list or NULL */
+ struct pollfd socket; /* socket info of what to monitor */
+};
+
+struct events {
+ long ms; /* timeout, run the timeout function when reached */
+ bool msbump; /* set TRUE when timeout is set by callback */
+ int num_sockets; /* number of nodes in the monitor list */
+ struct monitor *list; /* list of sockets to monitor */
+ int running_handles; /* store the returned number */
+};
+
+/* events_timer
+ *
+ * Callback that gets called with a new value when the timeout should be
+ * updated.
+ */
+
+static int events_timer(CURLM *multi, /* multi handle */
+ long timeout_ms, /* see above */
+ void *userp) /* private callback pointer */
+{
+ struct events *ev = userp;
+ (void)multi;
+ if(timeout_ms == -1)
+ /* timeout removed */
+ timeout_ms = 0;
+ else if(timeout_ms == 0)
+ /* timeout is already reached! */
+ timeout_ms = 1; /* trigger asap */
+
+ ev->ms = timeout_ms;
+ ev->msbump = TRUE;
+ /* fprintf(stderr, "%s: timeout %ld\n", __func__, timeout_ms); */
+ return 0;
+}
+
+
+/* poll2cselect
+ *
+ * convert from poll() bit definitions to libcurl's CURL_CSELECT_* ones
+ */
+static int poll2cselect(int pollmask)
+{
+ int omask=0;
+ if(pollmask & POLLIN)
+ omask |= CURL_CSELECT_IN;
+ if(pollmask & POLLOUT)
+ omask |= CURL_CSELECT_OUT;
+ if(pollmask & POLLERR)
+ omask |= CURL_CSELECT_ERR;
+ return omask;
+}
+
+
+/* socketcb2poll
+ *
+ * convert from libcurl' CURL_POLL_* bit definitions to poll()'s
+ */
+static short socketcb2poll(int pollmask)
+{
+ short omask=0;
+ if(pollmask & CURL_POLL_IN)
+ omask |= POLLIN;
+ if(pollmask & CURL_POLL_OUT)
+ omask |= POLLOUT;
+ return omask;
+}
+
+/* events_socket
+ *
+ * Callback that gets called with information about socket activity to
+ * monitor.
+ */
+static int events_socket(CURL *easy, /* easy handle */
+ curl_socket_t s, /* socket */
+ int what, /* see above */
+ void *userp, /* private callback
+ pointer */
+ void *socketp) /* private socket
+ pointer */
+{
+ struct events *ev = userp;
+ struct monitor *m;
+ struct monitor *prev=NULL;
+ (void)socketp;
+
+ m = ev->list;
+ while(m) {
+ if(m->socket.fd == s) {
+
+ if(what == CURL_POLL_REMOVE) {
+ struct monitor *nxt = m->next;
+ /* remove this node from the list of monitored sockets */
+ if(prev)
+ prev->next = nxt;
+ else
+ ev->list = nxt;
+ free(m);
+ m = nxt;
+ infof(easy, "socket cb: socket %d REMOVED\n", s);
+ }
+ else {
+ /* The socket 's' is already being monitored, update the activity
+ mask. Convert from libcurl bitmask to the poll one. */
+ m->socket.events = socketcb2poll(what);
+ infof(easy, "socket cb: socket %d UPDATED as %s%s\n", s,
+ what&CURL_POLL_IN?"IN":"",
+ what&CURL_POLL_OUT?"OUT":"");
+ }
+ break;
+ }
+ prev = m;
+ m = m->next; /* move to next node */
+ }
+ if(!m) {
+ if(what == CURL_POLL_REMOVE) {
+ /* this happens a bit too often, libcurl fix perhaps? */
+ /* fprintf(stderr,
+ "%s: socket %d asked to be REMOVED but not present!\n",
+ __func__, s); */
+ }
+ else {
+ m = malloc(sizeof(struct monitor));
+ m->next = ev->list;
+ m->socket.fd = s;
+ m->socket.events = socketcb2poll(what);
+ m->socket.revents = 0;
+ ev->list = m;
+ infof(easy, "socket cb: socket %d ADDED as %s%s\n", s,
+ what&CURL_POLL_IN?"IN":"",
+ what&CURL_POLL_OUT?"OUT":"");
+ }
+ }
+
+ return 0;
+}
+
+
/*
- * curl_easy_perform() is the external interface that performs a blocking
- * transfer as previously setup.
+ * events_setup()
*
- * CONCEPT: This function creates a multi handle, adds the easy handle to it,
- * runs curl_multi_perform() until the transfer is done, then detaches the
- * easy handle, destroys the multi handle and returns the easy handle's return
- * code.
+ * Do the multi handle setups that only event-based transfers need.
+ */
+static void events_setup(CURLM *multi, struct events *ev)
+{
+ /* timer callback */
+ curl_multi_setopt(multi, CURLMOPT_TIMERFUNCTION, events_timer);
+ curl_multi_setopt(multi, CURLMOPT_TIMERDATA, ev);
+
+ /* socket callback */
+ curl_multi_setopt(multi, CURLMOPT_SOCKETFUNCTION, events_socket);
+ curl_multi_setopt(multi, CURLMOPT_SOCKETDATA, ev);
+}
+
+
+/* wait_or_timeout()
*
- * REALITY: it can't just create and destroy the multi handle that easily. It
- * needs to keep it around since if this easy handle is used again by this
- * function, the same multi handle must be re-used so that the same pools and
- * caches can be used.
+ * waits for activity on any of the given sockets, or the timeout to trigger.
*/
-CURLcode curl_easy_perform(CURL *easy)
+
+static CURLcode wait_or_timeout(struct Curl_multi *multi, struct events *ev)
{
- CURLM *multi;
- CURLMcode mcode;
- CURLcode code = CURLE_OK;
- CURLMsg *msg;
bool done = FALSE;
- int rc;
- struct SessionHandle *data = easy;
- int without_fds = 0; /* count number of consecutive returns from
- curl_multi_wait() without any filedescriptors */
- struct timeval before;
- SIGPIPE_VARIABLE(pipe_st);
+ CURLMcode mcode;
+ CURLcode rc = CURLE_OK;
+
+ while(!done) {
+ CURLMsg *msg;
+ struct monitor *m;
+ struct pollfd *f;
+ struct pollfd fds[4];
+ int numfds=0;
+ int pollrc;
+ int i;
+ struct timeval before;
+ struct timeval after;
+
+ /* populate the fds[] array */
+ for(m = ev->list, f=&fds[0]; m; m = m->next) {
+ f->fd = m->socket.fd;
+ f->events = m->socket.events;
+ f->revents = 0;
+ /* fprintf(stderr, "poll() %d check socket %d\n", numfds, f->fd); */
+ f++;
+ numfds++;
+ }
- if(!easy)
- return CURLE_BAD_FUNCTION_ARGUMENT;
+ /* get the time stamp to use to figure out how long poll takes */
+ before = curlx_tvnow();
- if(data->multi) {
- failf(data, "easy handled already used in multi handle");
- return CURLE_FAILED_INIT;
- }
+ /* fprintf(stderr, "poll(), %d numfds\n", numfds); */
- if(data->multi_easy)
- multi = data->multi_easy;
- else {
- /* this multi handle will only ever have a single easy handled attached
- to it, so make it use minimal hashes */
- multi = Curl_multi_handle(1, 3);
- if(!multi)
- return CURLE_OUT_OF_MEMORY;
- data->multi_easy = multi;
- }
+ /* wait for activity or timeout */
+ pollrc = Curl_poll(fds, numfds, (int)ev->ms);
- /* Copy the MAXCONNECTS option to the multi handle */
- curl_multi_setopt(multi, CURLMOPT_MAXCONNECTS, data->set.maxconnects);
+ after = curlx_tvnow();
- mcode = curl_multi_add_handle(multi, easy);
- if(mcode) {
- curl_multi_cleanup(multi);
- if(mcode == CURLM_OUT_OF_MEMORY)
- return CURLE_OUT_OF_MEMORY;
- else
- return CURLE_FAILED_INIT;
+ ev->msbump = FALSE; /* reset here */
+
+ if(0 == pollrc) {
+ /* timeout! */
+ ev->ms = 0;
+ /* fprintf(stderr, "call curl_multi_socket_action( TIMEOUT )\n"); */
+ mcode = curl_multi_socket_action(multi, CURL_SOCKET_TIMEOUT, 0,
+ &ev->running_handles);
+ }
+ else if(pollrc > 0) {
+ /* loop over the monitored sockets to see which ones had activity */
+ for(i = 0; i< numfds; i++) {
+ if(fds[i].revents) {
+ /* socket activity, tell libcurl */
+ int act = poll2cselect(fds[i].revents); /* convert */
+ infof(multi->easyp, "call curl_multi_socket_action( socket %d )\n",
+ fds[i].fd);
+ mcode = curl_multi_socket_action(multi, fds[i].fd, act,
+ &ev->running_handles);
+ }
+ }
+
+ if(!ev->msbump)
+ /* If nothing updated the timeout, we decrease it by the spent time.
+ * If it was updated, it has the new timeout time stored already.
+ */
+ ev->ms += curlx_tvdiff(after, before);
+
+ }
+ if(mcode)
+ return CURLE_URL_MALFORMAT; /* TODO: return a proper error! */
+
+ /* we don't really care about the "msgs_in_queue" value returned in the
+ second argument */
+ msg = curl_multi_info_read(multi, &pollrc);
+ if(msg) {
+ rc = msg->data.result;
+ done = TRUE;
+ }
}
- sigpipe_ignore(data, &pipe_st);
+ return rc;
+}
- /* assign this after curl_multi_add_handle() since that function checks for
- it and rejects this handle otherwise */
- data->multi = multi;
+
+/* easy_events()
+ *
+ * Runs a transfer in a blocking manner using the events-based API
+ */
+static CURLcode easy_events(CURLM *multi)
+{
+ struct events evs= {2, FALSE, 0, NULL, 0};
+
+ /* if running event-based, do some further multi inits */
+ events_setup(multi, &evs);
+
+ return wait_or_timeout(multi, &evs);
+}
+#endif
+
+static CURLcode easy_transfer(CURLM *multi)
+{
+ bool done = FALSE;
+ CURLMcode mcode = CURLM_OK;
+ CURLcode code;
+ struct timeval before;
+ int without_fds = 0; /* count number of consecutive returns from
+ curl_multi_wait() without any filedescriptors */
while(!done && !mcode) {
int still_running;
@@ -556,13 +761,82 @@ CURLcode curl_easy_perform(CURL *easy)
/* only read 'still_running' if curl_multi_perform() return OK */
if((mcode == CURLM_OK) && !still_running) {
- msg = curl_multi_info_read(multi, &rc);
+ int rc;
+ CURLMsg *msg = curl_multi_info_read(multi, &rc);
if(msg) {
code = msg->data.result;
done = TRUE;
}
}
}
+ return code;
+}
+
+
+/*
+ * easy_perform() is the external interface that performs a blocking
+ * transfer as previously setup.
+ *
+ * CONCEPT: This function creates a multi handle, adds the easy handle to it,
+ * runs curl_multi_perform() until the transfer is done, then detaches the
+ * easy handle, destroys the multi handle and returns the easy handle's return
+ * code.
+ *
+ * REALITY: it can't just create and destroy the multi handle that easily. It
+ * needs to keep it around since if this easy handle is used again by this
+ * function, the same multi handle must be re-used so that the same pools and
+ * caches can be used.
+ *
+ * DEBUG: if 'events' is set TRUE, this function will use a replacement engine
+ * instead of curl_multi_perform() and use curl_multi_socket_action().
+ */
+static CURLcode easy_perform(CURL *easy, bool events)
+{
+ CURLM *multi;
+ CURLMcode mcode;
+ CURLcode code = CURLE_OK;
+ struct SessionHandle *data = easy;
+ SIGPIPE_VARIABLE(pipe_st);
+
+ if(!easy)
+ return CURLE_BAD_FUNCTION_ARGUMENT;
+
+ if(data->multi) {
+ failf(data, "easy handled already used in multi handle");
+ return CURLE_FAILED_INIT;
+ }
+
+ if(data->multi_easy)
+ multi = data->multi_easy;
+ else {
+ /* this multi handle will only ever have a single easy handled attached
+ to it, so make it use minimal hashes */
+ multi = Curl_multi_handle(1, 3);
+ if(!multi)
+ return CURLE_OUT_OF_MEMORY;
+ data->multi_easy = multi;
+ }
+
+ /* Copy the MAXCONNECTS option to the multi handle */
+ curl_multi_setopt(multi, CURLMOPT_MAXCONNECTS, data->set.maxconnects);
+
+ mcode = curl_multi_add_handle(multi, easy);
+ if(mcode) {
+ curl_multi_cleanup(multi);
+ if(mcode == CURLM_OUT_OF_MEMORY)
+ return CURLE_OUT_OF_MEMORY;
+ else
+ return CURLE_FAILED_INIT;
+ }
+
+ sigpipe_ignore(data, &pipe_st);
+
+ /* assign this after curl_multi_add_handle() since that function checks for
+ it and rejects this handle otherwise */
+ data->multi = multi;
+
+ /* run the transfer */
+ code = events ? easy_events(multi) : easy_transfer(multi);
/* ignoring the return code isn't nice, but atm we can't really handle
a failure here, room for future improvement! */
@@ -574,6 +848,28 @@ CURLcode curl_easy_perform(CURL *easy)
return code;
}
+
+/*
+ * curl_easy_perform() is the external interface that performs a blocking
+ * transfer as previously setup.
+ */
+CURLcode curl_easy_perform(CURL *easy)
+{
+ return easy_perform(easy, FALSE);
+}
+
+#ifdef CURLDEBUG
+/*
+ * curl_easy_perform_ev() is the external interface that performs a blocking
+ * transfer using the event-based API internally.
+ */
+CURLcode curl_easy_perform_ev(CURL *easy)
+{
+ return easy_perform(easy, TRUE);
+}
+
+#endif
+
/*
* curl_easy_cleanup() is the external interface to cleaning/freeing the given
* easy handle.
diff --git a/lib/easyif.h b/lib/easyif.h
index c55819396..eed160577 100644
--- a/lib/easyif.h
+++ b/lib/easyif.h
@@ -25,6 +25,9 @@
/*
* Prototypes for library-wide functions provided by easy.c
*/
+#ifdef CURLDEBUG
+CURLcode curl_easy_perform_ev(CURL *easy);
+#endif
#endif /* HEADER_CURL_EASYIF_H */
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