lib-http: Add ioloop and lock wait information to timeout messages.

It'll now log for example:
9007 Request timed out (Request sent 7.087 secs ago, 0.076 in other ioloops, 7.012 in locks, connected 7.087 secs ago)

Which points out that the problem wasn't really with the HTTP, but with
locking. This likely should be fixed in some way also in lib-http so that
it gives a bit of extra time for reading the request, but that's a separate
fix.

src/lib-http/http-client-connection.c

@@ -11,6 +11,7 @@
 #include "istream-timeout.h"
 #include "ostream.h"
 #include "time-util.h"
+#include "file-lock.h"
 #include "iostream-rawlog.h"
 #include "iostream-ssl.h"
 #include "http-response-parser.h"
@@ -199,6 +200,24 @@ http_client_connection_get_timing_info(struct http_client_connection *conn)
 				    (*requestp)->attempts + 1,
 				    total_msecs/1000, total_msecs%1000);
 		}
+		int other_ioloop_msecs = (ioloop_global_wait_usecs -
+			(*requestp)->sent_global_ioloop_usecs + 999) / 1000;
+		if (conn->client->ioloop != NULL) {
+			int http_ioloop_msecs =
+				(io_loop_get_wait_usecs(conn->client->ioloop) + 999) / 1000;
+			other_ioloop_msecs -= http_ioloop_msecs;
+			str_printfa(str, ", %d.%03d in http ioloop",
+				    http_ioloop_msecs/1000, http_ioloop_msecs%1000);
+		}
+		str_printfa(str, ", %d.%03d in other ioloops",
+			    other_ioloop_msecs/1000, other_ioloop_msecs%1000);
+
+		int lock_msecs = (file_lock_wait_get_total_usecs() -
+				  (*requestp)->sent_lock_usecs + 999) / 1000;
+		if (lock_msecs > 0) {
+			str_printfa(str, ", %d.%03d in locks",
+				    lock_msecs/1000, lock_msecs%1000);
+		}
 	} else {
 		str_append(str, "No requests");
 		if (conn->conn.last_input != 0) {

src/lib-http/http-client-private.h

@@ -95,6 +95,8 @@ struct http_client_request {
 
 	unsigned int attempts;
 	unsigned int redirects;
+	uint64_t sent_global_ioloop_usecs;
+	uint64_t sent_lock_usecs;
 
 	unsigned int delayed_error_status;
 	const char *delayed_error;

src/lib-http/http-client-request.c

@@ -9,6 +9,7 @@
 #include "time-util.h"
 #include "istream.h"
 #include "ostream.h"
+#include "file-lock.h"
 #include "dns-lookup.h"
 #include "http-url.h"
 #include "http-date.h"
@@ -1006,6 +1007,8 @@ static int http_client_request_send_real(struct http_client_request *req,
 
 	req->state = HTTP_REQUEST_STATE_PAYLOAD_OUT;
 	req->sent_time = ioloop_timeval;
+	req->sent_lock_usecs = file_lock_wait_get_total_usecs();
+	req->sent_global_ioloop_usecs = ioloop_global_wait_usecs;
 	o_stream_cork(output);
 	if (o_stream_sendv(output, iov, N_ELEMENTS(iov)) < 0) {
 		*error_r = t_strdup_printf("write(%s) failed: %s",