I wrote:
> Andres Freund <and...@anarazel.de> writes:
>> Perhaps we could just have isolationtester check to which
>> isolationtester session the backend pid belongs? And then print the
>> session name instead of the pid? That should be fairly easy, and would
>> probably give us all we need?
> Oh, that's a good idea -- it's already tracking all the backend PIDs,
> so probably not much extra work to do it like that.
I found out that to avoid confusion, one really wants the message to
identify both the sending and receiving sessions. Here's a patch
that does it that way and extends the async-notify.spec test to
perform basic end-to-end checks on LISTEN/NOTIFY.
I intentionally made the test show the lack of NOTIFY de-deduplication
that currently happens with subtransactions. If we change this as I
proposed in <17822.1564186...@sss.pgh.pa.us>, this test output will
change.
regards, tom lane
diff --git a/src/test/isolation/expected/async-notify.out b/src/test/isolation/expected/async-notify.out
index 92d281a..3dc1227 100644
--- a/src/test/isolation/expected/async-notify.out
+++ b/src/test/isolation/expected/async-notify.out
@@ -1,17 +1,82 @@
Parsed test spec with 2 sessions
-starting permutation: listen begin check notify check
-step listen: LISTEN a;
-step begin: BEGIN;
-step check: SELECT pg_notification_queue_usage() > 0 AS nonzero;
+starting permutation: listenc notify1 notify2 notify3
+step listenc: LISTEN c1; LISTEN c2;
+step notify1: NOTIFY c1;
+notifier: NOTIFY "c1" with payload "" from notifier
+step notify2: NOTIFY c2, 'payload';
+notifier: NOTIFY "c2" with payload "payload" from notifier
+step notify3: NOTIFY c3, 'payload3';
+
+starting permutation: listenc notifyd notifys1
+step listenc: LISTEN c1; LISTEN c2;
+step notifyd: NOTIFY c2, 'payload'; NOTIFY c1; NOTIFY "c2", 'payload';
+notifier: NOTIFY "c2" with payload "payload" from notifier
+notifier: NOTIFY "c1" with payload "" from notifier
+step notifys1:
+ BEGIN;
+ NOTIFY c1, 'payload1'; NOTIFY "c2", 'payload2';
+ NOTIFY c1, 'payload1'; NOTIFY "c2", 'payload2';
+ SAVEPOINT s1;
+ NOTIFY c1, 'payload1'; NOTIFY "c2", 'payload2';
+ NOTIFY c1, 'payload1s'; NOTIFY "c2", 'payload2s';
+ NOTIFY c1, 'payload1'; NOTIFY "c2", 'payload2';
+ NOTIFY c1, 'payload1s'; NOTIFY "c2", 'payload2s';
+ RELEASE SAVEPOINT s1;
+ SAVEPOINT s2;
+ NOTIFY c1, 'rpayload1'; NOTIFY "c2", 'rpayload2';
+ NOTIFY c1, 'rpayload1s'; NOTIFY "c2", 'rpayload2s';
+ NOTIFY c1, 'rpayload1'; NOTIFY "c2", 'rpayload2';
+ NOTIFY c1, 'rpayload1s'; NOTIFY "c2", 'rpayload2s';
+ ROLLBACK TO SAVEPOINT s2;
+ COMMIT;
+
+notifier: NOTIFY "c1" with payload "payload1" from notifier
+notifier: NOTIFY "c2" with payload "payload2" from notifier
+notifier: NOTIFY "c1" with payload "payload1" from notifier
+notifier: NOTIFY "c2" with payload "payload2" from notifier
+notifier: NOTIFY "c1" with payload "payload1s" from notifier
+notifier: NOTIFY "c2" with payload "payload2s" from notifier
+
+starting permutation: llisten notify1 notify2 notify3 lcheck
+step llisten: LISTEN c1; LISTEN c2;
+step notify1: NOTIFY c1;
+step notify2: NOTIFY c2, 'payload';
+step notify3: NOTIFY c3, 'payload3';
+step lcheck: SELECT 1 AS x;
+x
+
+1
+listener: NOTIFY "c1" with payload "" from notifier
+listener: NOTIFY "c2" with payload "payload" from notifier
+
+starting permutation: listenc llisten notify1 notify2 notify3 lcheck
+step listenc: LISTEN c1; LISTEN c2;
+step llisten: LISTEN c1; LISTEN c2;
+step notify1: NOTIFY c1;
+notifier: NOTIFY "c1" with payload "" from notifier
+step notify2: NOTIFY c2, 'payload';
+notifier: NOTIFY "c2" with payload "payload" from notifier
+step notify3: NOTIFY c3, 'payload3';
+step lcheck: SELECT 1 AS x;
+x
+
+1
+listener: NOTIFY "c1" with payload "" from notifier
+listener: NOTIFY "c2" with payload "payload" from notifier
+
+starting permutation: llisten lbegin usage bignotify usage
+step llisten: LISTEN c1; LISTEN c2;
+step lbegin: BEGIN;
+step usage: SELECT pg_notification_queue_usage() > 0 AS nonzero;
nonzero
f
-step notify: SELECT count(pg_notify('a', s::text)) FROM generate_series(1, 1000) s;
+step bignotify: SELECT count(pg_notify('c1', s::text)) FROM generate_series(1, 1000) s;
count
1000
-step check: SELECT pg_notification_queue_usage() > 0 AS nonzero;
+step usage: SELECT pg_notification_queue_usage() > 0 AS nonzero;
nonzero
t
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 6ab19b1..98e5bf2 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -23,10 +23,12 @@
/*
* conns[0] is the global setup, teardown, and watchdog connection. Additional
- * connections represent spec-defined sessions.
+ * connections represent spec-defined sessions. We also track the backend
+ * PID, in numeric and string formats, for each connection.
*/
static PGconn **conns = NULL;
-static const char **backend_pids = NULL;
+static int *backend_pids = NULL;
+static const char **backend_pid_strs = NULL;
static int nconns = 0;
/* In dry run only output permutations to be run by the tester. */
@@ -41,7 +43,7 @@ static void run_permutation(TestSpec *testspec, int nsteps, Step **steps);
#define STEP_NONBLOCK 0x1 /* return 0 as soon as cmd waits for a lock */
#define STEP_RETRY 0x2 /* this is a retry of a previously-waiting cmd */
-static bool try_complete_step(Step *step, int flags);
+static bool try_complete_step(TestSpec *testspec, Step *step, int flags);
static int step_qsort_cmp(const void *a, const void *b);
static int step_bsearch_cmp(const void *a, const void *b);
@@ -159,9 +161,11 @@ main(int argc, char **argv)
* extra for lock wait detection and global work.
*/
nconns = 1 + testspec->nsessions;
- conns = calloc(nconns, sizeof(PGconn *));
+ conns = (PGconn **) pg_malloc0(nconns * sizeof(PGconn *));
+ backend_pids = pg_malloc0(nconns * sizeof(*backend_pids));
+ backend_pid_strs = pg_malloc0(nconns * sizeof(*backend_pid_strs));
atexit(disconnect_atexit);
- backend_pids = calloc(nconns, sizeof(*backend_pids));
+
for (i = 0; i < nconns; i++)
{
conns[i] = PQconnectdb(conninfo);
@@ -187,26 +191,9 @@ main(int argc, char **argv)
blackholeNoticeProcessor,
NULL);
- /* Get the backend pid for lock wait checking. */
- res = PQexec(conns[i], "SELECT pg_catalog.pg_backend_pid()");
- if (PQresultStatus(res) == PGRES_TUPLES_OK)
- {
- if (PQntuples(res) == 1 && PQnfields(res) == 1)
- backend_pids[i] = pg_strdup(PQgetvalue(res, 0, 0));
- else
- {
- fprintf(stderr, "backend pid query returned %d rows and %d columns, expected 1 row and 1 column",
- PQntuples(res), PQnfields(res));
- exit(1);
- }
- }
- else
- {
- fprintf(stderr, "backend pid query failed: %s",
- PQerrorMessage(conns[i]));
- exit(1);
- }
- PQclear(res);
+ /* Save each connection's backend PID for subsequent use. */
+ backend_pids[i] = PQbackendPID(conns[i]);
+ backend_pid_strs[i] = psprintf("%d", backend_pids[i]);
}
/* Set the session index fields in steps. */
@@ -231,9 +218,9 @@ main(int argc, char **argv)
appendPQExpBufferStr(&wait_query,
"SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
/* The spec syntax requires at least one session; assume that here. */
- appendPQExpBufferStr(&wait_query, backend_pids[1]);
+ appendPQExpBufferStr(&wait_query, backend_pid_strs[1]);
for (i = 2; i < nconns; i++)
- appendPQExpBuffer(&wait_query, ",%s", backend_pids[i]);
+ appendPQExpBuffer(&wait_query, ",%s", backend_pid_strs[i]);
appendPQExpBufferStr(&wait_query, "}')");
res = PQprepare(conns[0], PREP_WAITING, wait_query.data, 0, NULL);
@@ -549,7 +536,7 @@ run_permutation(TestSpec *testspec, int nsteps, Step **steps)
oldstep = waiting[w];
/* Wait for previous step on this connection. */
- try_complete_step(oldstep, STEP_RETRY);
+ try_complete_step(testspec, oldstep, STEP_RETRY);
/* Remove that step from the waiting[] array. */
if (w + 1 < nwaiting)
@@ -571,7 +558,8 @@ run_permutation(TestSpec *testspec, int nsteps, Step **steps)
nerrorstep = 0;
while (w < nwaiting)
{
- if (try_complete_step(waiting[w], STEP_NONBLOCK | STEP_RETRY))
+ if (try_complete_step(testspec, waiting[w],
+ STEP_NONBLOCK | STEP_RETRY))
{
/* Still blocked on a lock, leave it alone. */
w++;
@@ -600,14 +588,15 @@ run_permutation(TestSpec *testspec, int nsteps, Step **steps)
}
/* Try to complete this step without blocking. */
- mustwait = try_complete_step(step, STEP_NONBLOCK);
+ mustwait = try_complete_step(testspec, step, STEP_NONBLOCK);
/* Check for completion of any steps that were previously waiting. */
w = 0;
nerrorstep = 0;
while (w < nwaiting)
{
- if (try_complete_step(waiting[w], STEP_NONBLOCK | STEP_RETRY))
+ if (try_complete_step(testspec, waiting[w],
+ STEP_NONBLOCK | STEP_RETRY))
w++;
else
{
@@ -630,7 +619,7 @@ run_permutation(TestSpec *testspec, int nsteps, Step **steps)
/* Wait for any remaining queries. */
for (w = 0; w < nwaiting; ++w)
{
- try_complete_step(waiting[w], STEP_RETRY);
+ try_complete_step(testspec, waiting[w], STEP_RETRY);
report_error_message(waiting[w]);
}
@@ -693,7 +682,7 @@ run_permutation(TestSpec *testspec, int nsteps, Step **steps)
* a lock, returns true. Otherwise, returns false.
*/
static bool
-try_complete_step(Step *step, int flags)
+try_complete_step(TestSpec *testspec, Step *step, int flags)
{
PGconn *conn = conns[1 + step->session];
fd_set read_set;
@@ -702,6 +691,7 @@ try_complete_step(Step *step, int flags)
int sock = PQsocket(conn);
int ret;
PGresult *res;
+ PGnotify *notify;
bool canceled = false;
if (sock < 0)
@@ -738,7 +728,7 @@ try_complete_step(Step *step, int flags)
bool waiting;
res = PQexecPrepared(conns[0], PREP_WAITING, 1,
- &backend_pids[step->session + 1],
+ &backend_pid_strs[step->session + 1],
NULL, NULL, 0);
if (PQresultStatus(res) != PGRES_TUPLES_OK ||
PQntuples(res) != 1)
@@ -858,6 +848,35 @@ try_complete_step(Step *step, int flags)
PQclear(res);
}
+ /* Report any available NOTIFY messages, too */
+ PQconsumeInput(conn);
+ while ((notify = PQnotifies(conn)) != NULL)
+ {
+ /* Try to identify which session it came from */
+ const char *sendername = NULL;
+ char pidstring[32];
+
+ for (int i = 0; i < testspec->nsessions; i++)
+ {
+ if (notify->be_pid == backend_pids[i + 1])
+ {
+ sendername = testspec->sessions[i]->name;
+ break;
+ }
+ }
+ if (sendername == NULL)
+ {
+ /* Doesn't seem to be any test session, so show the hard way */
+ snprintf(pidstring, sizeof(pidstring), "PID %d", notify->be_pid);
+ sendername = pidstring;
+ }
+ printf("%s: NOTIFY \"%s\" with payload \"%s\" from %s\n",
+ testspec->sessions[step->session]->name,
+ notify->relname, notify->extra, sendername);
+ PQfreemem(notify);
+ PQconsumeInput(conn);
+ }
+
return false;
}
diff --git a/src/test/isolation/specs/async-notify.spec b/src/test/isolation/specs/async-notify.spec
index 8adad42..498e357 100644
--- a/src/test/isolation/specs/async-notify.spec
+++ b/src/test/isolation/specs/async-notify.spec
@@ -1,14 +1,68 @@
-# Verify that pg_notification_queue_usage correctly reports a non-zero result,
-# after submitting notifications while another connection is listening for
-# those notifications and waiting inside an active transaction.
+# Tests for LISTEN/NOTIFY
-session "listener"
-step "listen" { LISTEN a; }
-step "begin" { BEGIN; }
-teardown { ROLLBACK; UNLISTEN *; }
+# Most of these tests use only the "notifier" session and hence exercise only
+# self-notifies, which are convenient because they minimize timing concerns.
+# Note we assume that each step is delivered to the backend as a single Query
+# message so it will run as one transaction.
session "notifier"
-step "check" { SELECT pg_notification_queue_usage() > 0 AS nonzero; }
-step "notify" { SELECT count(pg_notify('a', s::text)) FROM generate_series(1, 1000) s; }
+step "listenc" { LISTEN c1; LISTEN c2; }
+step "notify1" { NOTIFY c1; }
+step "notify2" { NOTIFY c2, 'payload'; }
+step "notify3" { NOTIFY c3, 'payload3'; } # not listening to c3
+step "notifyd" { NOTIFY c2, 'payload'; NOTIFY c1; NOTIFY "c2", 'payload'; }
+step "notifys1" {
+ BEGIN;
+ NOTIFY c1, 'payload1'; NOTIFY "c2", 'payload2';
+ NOTIFY c1, 'payload1'; NOTIFY "c2", 'payload2';
+ SAVEPOINT s1;
+ NOTIFY c1, 'payload1'; NOTIFY "c2", 'payload2';
+ NOTIFY c1, 'payload1s'; NOTIFY "c2", 'payload2s';
+ NOTIFY c1, 'payload1'; NOTIFY "c2", 'payload2';
+ NOTIFY c1, 'payload1s'; NOTIFY "c2", 'payload2s';
+ RELEASE SAVEPOINT s1;
+ SAVEPOINT s2;
+ NOTIFY c1, 'rpayload1'; NOTIFY "c2", 'rpayload2';
+ NOTIFY c1, 'rpayload1s'; NOTIFY "c2", 'rpayload2s';
+ NOTIFY c1, 'rpayload1'; NOTIFY "c2", 'rpayload2';
+ NOTIFY c1, 'rpayload1s'; NOTIFY "c2", 'rpayload2s';
+ ROLLBACK TO SAVEPOINT s2;
+ COMMIT;
+}
+step "usage" { SELECT pg_notification_queue_usage() > 0 AS nonzero; }
+step "bignotify" { SELECT count(pg_notify('c1', s::text)) FROM generate_series(1, 1000) s; }
+teardown { UNLISTEN *; }
+
+# The listener session is used for cross-backend notify checks.
+
+session "listener"
+step "llisten" { LISTEN c1; LISTEN c2; }
+step "lcheck" { SELECT 1 AS x; }
+step "lbegin" { BEGIN; }
+teardown { UNLISTEN *; }
+
+
+# Trivial cases.
+permutation "listenc" "notify1" "notify2" "notify3"
+
+# Check simple and less-simple deduplication.
+permutation "listenc" "notifyd" "notifys1"
+
+# Cross-backend notification delivery. We use a "select 1" to force the
+# listener session to check for notifies. In principle we could just wait
+# for delivery, but that would require extra support in isolationtester
+# and might have portability-of-timing issues.
+permutation "llisten" "notify1" "notify2" "notify3" "lcheck"
+
+# Again, with local delivery too.
+permutation "listenc" "llisten" "notify1" "notify2" "notify3" "lcheck"
+
+# Verify that pg_notification_queue_usage correctly reports a non-zero result,
+# after submitting notifications while another connection is listening for
+# those notifications and waiting inside an active transaction. We have to
+# fill a page of the notify SLRU to make this happen, which is a good deal
+# of traffic. To not bloat the expected output, we intentionally don't
+# commit the listener's transaction, so that it never reports these events.
+# Hence, this should be the last test in this script.
-permutation "listen" "begin" "check" "notify" "check"
+permutation "llisten" "lbegin" "usage" "bignotify" "usage"
