vrt_var: Expose bereq.task_deadline in vcl_pipe

The [be]req.task_deadline should eventually be generalized to all
subroutines with read-write access to [be]req. When that happens,
bereq.task_deadline will inherit req.task_deadline during the pipe
transition.

Related tasks should otherwise have independent deadlines, except
sub-request tasks like ESI where there is a hierarchical dependency.

bin/varnishd/cache/cache.h

@@ -419,6 +419,7 @@ struct busyobj {
 	vtim_dur		connect_timeout;
 	vtim_dur		first_byte_timeout;
 	vtim_dur		between_bytes_timeout;
+	vtim_dur		task_deadline;
 
 	/* Timers */
 	vtim_real		t_first;	/* First timestamp logged */

bin/varnishd/cache/cache_backend.c

@@ -366,6 +366,7 @@ vbe_dir_http1pipe(VRT_CTX, VCL_BACKEND d)
 	struct backend *bp;
 	struct v1p_acct v1a;
 	struct pfd *pfd;
+	vtim_real deadline;
 
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
 	CHECK_OBJ_NOTNULL(d, DIRECTOR_MAGIC);
@@ -390,8 +391,15 @@ vbe_dir_http1pipe(VRT_CTX, VCL_BACKEND d)
 		i = V1F_SendReq(ctx->req->wrk, ctx->bo,
 		    &v1a.bereq, &v1a.out);
 		VSLb_ts_req(ctx->req, "Pipe", W_TIM_real(ctx->req->wrk));
-		if (i == 0)
-			retval = V1P_Process(ctx->req, *PFD_Fd(pfd), &v1a);
+		if (i == 0) {
+			deadline = ctx->bo->task_deadline;
+			if (isnan(deadline))
+				deadline = cache_param->pipe_task_deadline;
+			if (deadline > 0.)
+				deadline += ctx->req->sp->t_idle;
+			retval = V1P_Process(ctx->req, *PFD_Fd(pfd), &v1a,
+			    deadline);
+		}
 		VSLb_ts_req(ctx->req, "PipeSess", W_TIM_real(ctx->req->wrk));
 		ctx->bo->htc->doclose = retval;
 		vbe_dir_finish(ctx, d);

bin/varnishd/cache/cache_req_fsm.c

@@ -795,6 +795,7 @@ cnt_pipe(struct worker *wrk, struct req *req)
 	}
 
 	bo->wrk = wrk;
+	bo->task_deadline = NAN; /* XXX: copy req->task_deadline */
 	if (WS_Overflowed(req->ws))
 		wrk->vpi->handling = VCL_RET_FAIL;
 	else

bin/varnishd/cache/cache_vrt_var.c

@@ -409,6 +409,8 @@ VRT_r_bereq_##which(VRT_CTX)					\
 BEREQ_TIMEOUT(connect_timeout)
 BEREQ_TIMEOUT(first_byte_timeout)
 BEREQ_TIMEOUT(between_bytes_timeout)
+BEREQ_TIMEOUT(task_deadline)
+
 
 /*--------------------------------------------------------------------*/
 

bin/varnishd/http1/cache_http1.h

@@ -54,7 +54,8 @@ struct v1p_acct {
 
 int V1P_Enter(void);
 void V1P_Leave(void);
-stream_close_t V1P_Process(const struct req *, int fd, struct v1p_acct *);
+stream_close_t V1P_Process(const struct req *, int fd, struct v1p_acct *,
+    vtim_real deadline);
 void V1P_Charge(struct req *, const struct v1p_acct *, struct VSC_vbe *);
 
 /* cache_http1_line.c */

bin/varnishd/http1/cache_http1_pipe.c

@@ -115,11 +115,11 @@ V1P_Charge(struct req *req, const struct v1p_acct *a, struct VSC_vbe *b)
 }
 
 stream_close_t
-V1P_Process(const struct req *req, int fd, struct v1p_acct *v1a)
+V1P_Process(const struct req *req, int fd, struct v1p_acct *v1a,
+    vtim_real deadline)
 {
 	struct pollfd fds[2];
 	vtim_dur tmo, tmo_task;
-	vtim_real deadline;
 	stream_close_t sc;
 	int i, j;
 
@@ -143,10 +143,6 @@ V1P_Process(const struct req *req, int fd, struct v1p_acct *v1a)
 	fds[1].fd = req->sp->fd;
 	fds[1].events = POLLIN;
 
-	deadline = cache_param->pipe_task_deadline;
-	if (deadline > 0.)
-		deadline += req->sp->t_idle;
-
 	sc = SC_TX_PIPE;
 	while (fds[0].fd > -1 || fds[1].fd > -1) {
 		fds[0].revents = 0;

bin/varnishtest/tests/s00013.vtc

@@ -6,15 +6,12 @@ server s1 {
 	delay 1.1
 	close
 
-	accept
-	rxreq
-	txresp -hdr "transfer-encoding: chunked"
-	expect_close
-
-	accept
-	rxreq
-	txresp -hdr "transfer-encoding: chunked"
-	expect_close
+	loop 3 {
+		accept
+		rxreq
+		txresp -hdr "transfer-encoding: chunked"
+		expect_close
+	}
 
 	accept
 	non_fatal
@@ -28,13 +25,20 @@ server s1 {
 
 varnish v1 -cliok "param.set pipe_timeout 0s"
 varnish v1 -cliok "param.set pipe_task_deadline 0s"
-varnish v1 -vcl+backend "" -start
+varnish v1 -vcl+backend {
+	sub vcl_pipe {
+		if (req.method == "TMO") {
+			set bereq.task_deadline = 1.1s;
+		}
+	}
+} -start
 
 logexpect l1 -v v1 -g raw -q SessClose {
 	expect 1000 * SessClose {^TX_PIPE 1\.}
 	expect 1003 * SessClose {^RX_TIMEOUT 0\.}
 	expect 1006 * SessClose {^RX_TIMEOUT 1\.}
 	expect 1009 * SessClose {^RX_TIMEOUT 1\.}
+	expect 1012 * SessClose {^RX_TIMEOUT 1\.}
 } -start
 
 client c1 {
@@ -51,12 +55,21 @@ varnish v1 -cliok "param.set pipe_timeout 0s"
 varnish v1 -cliok "param.set pipe_task_deadline 1.1s"
 client c1 -run
 
+varnish v1 -cliok "param.set pipe_timeout 0s"
+varnish v1 -cliok "param.set pipe_task_deadline 0s"
+
+client c2 {
+	non_fatal
+	txreq -method TMO
+	rxresp
+} -run
+
 varnish v1 -cliok "param.set pipe_timeout 500ms"
 varnish v1 -cliok "param.set pipe_task_deadline 1.1s"
 client c1 -run
 
 logexpect l1 -wait
 
-varnish v1 -expect MAIN.s_pipe == 4
+varnish v1 -expect MAIN.s_pipe == 5
 varnish v1 -expect MAIN.sc_tx_pipe == 1
-varnish v1 -expect MAIN.sc_rx_timeout == 3
+varnish v1 -expect MAIN.sc_rx_timeout == 4

doc/sphinx/reference/vcl_var.rst

@@ -840,6 +840,20 @@ bereq.retries
 	A count of how many times this request has been retried.
 
 
+.. _bereq.task_deadline:
+
+bereq.task_deadline
+
+	Type: DURATION
+
+	Readable from: vcl_pipe
+
+	Writable from: vcl_pipe
+
+	Deadline for pipe sessions, defaults ``0s``, which falls back to the
+        ``pipe_task_deadline`` parameter, see :ref:`varnishd(1)`
+
+
 .. _bereq.time:
 
 bereq.time