MINOR: stats: use stress mode to force reentrant dumps

Provide alternative code during stats dump when stress mode is active.
The objective is to force the applet to yield on every output line. This
allows to easily test reentrant code paths, in particular while adding
and removing server instances.

To support this, output is interrupted every time the output buffer (or
its equivalent) is not empty. Use COND_STRESS() macro to provide default
and stress alternative conditions.

diff --git a/src/stats.c b/src/stats.c
index 97efa938fabc9f13c874ac72109f381e4dcbadbe..970895c4ff3698a757034227571df3fd9b084fd8 100644 (file)
--- a/src/stats.c
+++ b/src/stats.c
@@ -60,6 +60,7 @@
 #include <haproxy/stats-proxy.h>
 #include <haproxy/stconn.h>
 #include <haproxy/stream.h>
+#include <haproxy/stress.h>
 #include <haproxy/task.h>
 #include <haproxy/ticks.h>
 #include <haproxy/time.h>
@@ -231,7 +232,8 @@ int stats_putchk(struct appctx *appctx, struct buffer *buf, struct htx *htx)
        struct buffer *chk = &ctx->chunk;
 
        if (htx) {
-               if (b_data(chk) > htx_free_data_space(htx)) {
+               if (STRESS_RUN1(!htx_is_empty(htx),
+                               b_data(chk) > htx_free_data_space(htx))) {
                        applet_fl_set(appctx, APPCTX_FL_OUTBLK_FULL);
                        return 0;
                }
@@ -242,7 +244,7 @@ int stats_putchk(struct appctx *appctx, struct buffer *buf, struct htx *htx)
                chunk_reset(chk);
        }
        else if (buf) {
-               if (b_data(chk) > b_room(buf)) {
+               if (STRESS_RUN1(b_data(buf), b_data(chk) > b_room(buf))) {
                        se_fl_set(appctx->sedesc, SE_FL_RCV_MORE | SE_FL_WANT_ROOM);
                        return 0;
                }
@@ -250,29 +252,31 @@ int stats_putchk(struct appctx *appctx, struct buffer *buf, struct htx *htx)
                chunk_reset(chk);
        }
        else {
-               if (applet_putchk(appctx, chk) == -1)
+               if (STRESS_RUN1(applet_putchk_stress(appctx, chk) == -1,
+                               applet_putchk(appctx, chk) == -1)) {
                        return 0;
+               }
        }
        return 1;
 }
 
-
 int stats_is_full(struct appctx *appctx, struct buffer *buf, struct htx *htx)
 {
        if (htx) {
-               if (htx_almost_full(htx)) {
+               if (STRESS_RUN1(!htx_is_empty(htx), htx_almost_full(htx))) {
                        applet_fl_set(appctx, APPCTX_FL_OUTBLK_FULL);
                        goto full;
                }
        }
        else if (buf) {
-               if (buffer_almost_full(buf)) {
+               if (STRESS_RUN1(b_data(buf), buffer_almost_full(buf))) {
                        se_fl_set(appctx->sedesc, SE_FL_RCV_MORE | SE_FL_WANT_ROOM);
                        goto full;
                }
        }
        else {
-               if (buffer_almost_full(&appctx->outbuf))  {
+               if (STRESS_RUN1(b_data(&appctx->outbuf),
+                               buffer_almost_full(&appctx->outbuf))) {
                        applet_fl_set(appctx, APPCTX_FL_OUTBLK_FULL);
                        goto full;
                }