MINOR: cli: add the new "show pools" command

show pools
  Dump the status of internal memory pools. This is useful to track memory
  usage when suspecting a memory leak for example. It does exactly the same
  as the SIGQUIT when running in foreground except that it does not flush
  the pools.

doc/configuration.txt

@@ -12725,6 +12725,12 @@ show map [<map>]
   Dump info about map converters. Without argument, the list of all available
   maps is returned. If a <map> is specified, its contents are dumped.
 
+show pools
+  Dump the status of internal memory pools. This is useful to track memory
+  usage when suspecting a memory leak for example. It does exactly the same
+  as the SIGQUIT when running in foreground except that it does not flush
+  the pools.
+
 show sess
   Dump all known sessions. Avoid doing this on slow connections as this can
   be huge. This command is restricted and can only be issued on sockets

include/common/memory.h

@@ -145,6 +145,7 @@ struct pool_head *create_pool(char *name, unsigned int size, unsigned int flags)
 
 /* Dump statistics on pools usage.
  */
+void dump_pools_to_trash();
 void dump_pools(void);
 
 /*

src/dumpstats.c

@@ -81,9 +81,11 @@ enum {
 	STAT_CLI_O_MAPS,     /* list all maps */
 	STAT_CLI_O_MAP,      /* list all map entries of a map */
 	STAT_CLI_O_MLOOK,    /* lookup a map entry */
+	STAT_CLI_O_POOLS,    /* dump memory pools */
 };
 
 static int stats_dump_info_to_buffer(struct stream_interface *si);
+static int stats_dump_pools_to_buffer(struct stream_interface *si);
 static int stats_dump_full_sess_to_buffer(struct stream_interface *si, struct session *sess);
 static int stats_dump_sess_to_buffer(struct stream_interface *si);
 static int stats_dump_errors_to_buffer(struct stream_interface *si);
@@ -133,6 +135,7 @@ static const char stats_sock_usage_msg[] =
 	"  prompt         : toggle interactive mode with prompt\n"
 	"  quit           : disconnect\n"
 	"  show info      : report information about the running process\n"
+	"  show pools     : report information about the memory pools usage\n"
 	"  show stat      : report counters for each proxy and server\n"
 	"  show errors    : report last request and response errors for each proxy\n"
 	"  show sess [id] : report the list of current sessions or dump this session\n"
@@ -1053,6 +1056,10 @@ static int stats_sock_parse_request(struct stream_interface *si, char *line)
 			appctx->st2 = STAT_ST_INIT;
 			appctx->st0 = STAT_CLI_O_INFO; // stats_dump_info_to_buffer
 		}
+		else if (strcmp(args[1], "pools") == 0) {
+			appctx->st2 = STAT_ST_INIT;
+			appctx->st0 = STAT_CLI_O_POOLS; // stats_dump_pools_to_buffer
+		}
 		else if (strcmp(args[1], "sess") == 0) {
 			appctx->st2 = STAT_ST_INIT;
 			if (s->listener->bind_conf->level < ACCESS_LVL_OPER) {
@@ -2173,6 +2180,10 @@ static void cli_io_handler(struct stream_interface *si)
 			case STAT_CLI_O_MLOOK:
 				if (stats_map_lookup(si))
 					appctx->st0 = STAT_CLI_PROMPT;
+			case STAT_CLI_O_POOLS:
+				if (stats_dump_pools_to_buffer(si))
+					appctx->st0 = STAT_CLI_PROMPT;
+				break;
 			default: /* abnormal state */
 				appctx->st0 = STAT_CLI_PROMPT;
 				break;
@@ -2333,6 +2344,18 @@ static int stats_dump_info_to_buffer(struct stream_interface *si)
 	return 1;
 }
 
+/* This function dumps memory usage information onto the stream interface's
+ * read buffer. It returns 0 as long as it does not complete, non-zero upon
+ * completion. No state is used.
+ */
+static int stats_dump_pools_to_buffer(struct stream_interface *si)
+{
+	dump_pools_to_trash();
+	if (bi_putchk(si->ib, &trash) == -1)
+		return 0;
+	return 1;
+}
+
 /* Dumps a frontend's line to the trash for the current proxy <px> and uses
  * the state from stream interface <si>. The caller is responsible for clearing
  * the trash if needed. Returns non-zero if it emits anything, zero otherwise.

src/memory.c

@@ -10,6 +10,7 @@
  *
  */
 
+#include <types/global.h>
 #include <common/config.h>
 #include <common/debug.h>
 #include <common/memory.h>
@@ -176,18 +177,17 @@ void *pool_destroy2(struct pool_head *pool)
 	return NULL;
 }
 
-/* Dump statistics on pools usage.
- */
-void dump_pools(void)
+/* This function dumps memory usage information into the trash buffer. */
+void dump_pools_to_trash()
 {
 	struct pool_head *entry;
 	unsigned long allocated, used;
 	int nbpools;
 
 	allocated = used = nbpools = 0;
-	qfprintf(stderr, "Dumping pools usage.\n");
+	chunk_printf(&trash, "Dumping pools usage. Use SIGQUIT to flush them.\n");
 	list_for_each_entry(entry, &pools, list) {
-		qfprintf(stderr, "  - Pool %s (%d bytes) : %d allocated (%u bytes), %d used, %d users%s\n",
+		chunk_appendf(&trash, "  - Pool %s (%d bytes) : %d allocated (%u bytes), %d used, %d users%s\n",
 			 entry->name, entry->size, entry->allocated,
 			 entry->size * entry->allocated, entry->used,
 			 entry->users, (entry->flags & MEM_F_SHARED) ? " [SHARED]" : "");
@@ -196,10 +196,17 @@ void dump_pools(void)
 		used += entry->used * entry->size;
 		nbpools++;
 	}
-	qfprintf(stderr, "Total: %d pools, %lu bytes allocated, %lu used.\n",
+	chunk_appendf(&trash, "Total: %d pools, %lu bytes allocated, %lu used.\n",
 		 nbpools, allocated, used);
 }
 
+/* Dump statistics on pools usage. */
+void dump_pools(void)
+{
+	dump_pools_to_trash();
+	qfprintf(stderr, "%s", trash.str);
+}
+
 /*
  * Local variables:
  *  c-indent-level: 8