tests: fix sidecar agent-info timing races in request-replayer and debugger tests

Replace unreliable dummy-flush + sleep synchronization with the
dd_trace_internal_fn('await_agent_info') primitive (already used in
client_side_stats.phpt) which polls ddog_is_agent_info_ready() until
the sidecar has received and applied the agent /info response.

- client_side_stats_peer_tags.phpt: drop dummy flush, use await_agent_info
- client_side_stats_trace_filters.phpt: drop dummy flush, use await_agent_info
- dd_trace_agent_env.phpt: replace broken floor(delta)*100000 sleep with await_agent_info
- debugger_metric_probe.phpt: add 100ms pause after probe installation to let
  sidecar finish wiring the DogStatsD endpoint before foo() fires

Author: Leiyks

tests/ext/live-debugger/debugger_metric_probe.phpt

@@ -34,6 +34,11 @@ $span = await_probe_installation(function() {
     return \DDTrace\start_span(); // submit span data
 });
 
+// Give the sidecar a moment to fully wire the probe before invoking foo().
+// await_probe_installation() detects the hook install but the sidecar may still be
+// finalising the DogStatsD endpoint binding on first use.
+usleep(100000); // 100 ms
+
 foo();
 
 $server->dump(1);

tests/ext/request-replayer/client_side_stats_peer_tags.phpt

@@ -39,16 +39,10 @@ include __DIR__ . '/../includes/request_replayer.inc';
 
 $rr = new RequestReplayer();
 
-// Flush a dummy trace and wait for the sidecar to process it.  The sidecar polls the agent
-// /info endpoint on the same interval, so by the time we return here it will have written
-// the peer_tags from the agent info (set in SKIPIF) to the shared-memory segment that
-// ddog_apply_agent_info_concentrator_config reads.
-$dummy = \DDTrace\start_trace_span();
-$dummy->name = "dummy";
-$dummy->service = "dummy-service";
-\DDTrace\close_span();
-dd_trace_internal_fn('synchronous_flush');
-$rr->waitForDataAndReplay();
+// Block until the sidecar has received and applied the agent /info response (which carries
+// peer_tags set in SKIPIF). This ensures ddog_apply_agent_info_concentrator_config() will
+// pick up the peer_tags from the SHM segment before the concentrator processes our span.
+dd_trace_internal_fn('await_agent_info');
 
 // Now create the span whose stats we want to inspect. When this span is fed to the
 // concentrator, ddog_apply_agent_info_concentrator_config() is called first, picks up

tests/ext/request-replayer/client_side_stats_trace_filters.phpt

@@ -8,7 +8,8 @@ if (PHP_VERSION_ID >= 80100) {
     echo "nocache\n";
 }
 // Configure the request-replayer to return these filter rules from the /info endpoint.
-// The sidecar will pick them up on its next poll cycle (triggered by the dummy flush below).
+// The sidecar will pick them up on its next poll cycle; await_agent_info() in --FILE--
+// blocks until the sidecar has applied the config before any test spans are flushed.
 //
 // Filters configured:
 //   filter_tags.require:        filter_required:yes
@@ -60,15 +61,10 @@ include __DIR__ . '/../includes/request_replayer.inc';
 
 $rr = new RequestReplayer();
 
-// Flush a dummy trace so the sidecar polls /info and picks up the filter config that was
-// written to the request-replayer in SKIPIF.  By the time waitForDataAndReplay() returns
-// the sidecar has had at least one poll cycle.
-$dummy = \DDTrace\start_trace_span();
-$dummy->name  = 'dummy';
-$dummy->service = 'dummy-service';
-\DDTrace\close_span();
-dd_trace_internal_fn('synchronous_flush');
-$rr->waitForDataAndReplay();
+// Block until the sidecar has received and applied the agent /info response (which carries
+// the filter_tags / filter_tags_regex / ignore_resources config set in SKIPIF). This
+// guarantees the filter rules are in place before any test spans are flushed.
+dd_trace_internal_fn('await_agent_info');
 
 // Each test case is a separate root span (= separate trace), because trace filters are
 // evaluated per trace (root span properties / tags).
@@ -123,26 +119,24 @@ makeSpan('op.blocked.regex_require', 'GET /other4', [
 
 dd_trace_internal_fn('synchronous_flush');
 
-// Capture ALL trace requests from the second flush before consuming them.
-// The first flush's data was already consumed by waitForDataAndReplay() above, so only
-// second-flush requests remain.  Poll until at least one trace request arrives, then
-// collect everything that arrived in that batch.
-$secondFlushTraces = [];
+// Capture ALL trace requests from this flush before consuming them.
+// Poll until at least one trace request arrives, then collect everything in that batch.
+$flushTraces = [];
 for ($i = 0; $i < 1000; $i++) {
     usleep(50000);  // 50 ms  (same interval as RequestReplayer::flushInterval)
     $reqs = $rr->replayAllRequests() ?? [];
     $traces = array_values(array_filter($reqs, function ($r) {
         return strpos($r['uri'] ?? '', 'traces') !== false;
     }));
     if (!empty($traces)) {
-        $secondFlushTraces = $traces;
+        $flushTraces = $traces;
         break;
     }
 }
 
 // Extract span names from every trace request in this flush.
 $namesInTraces = [];
-foreach ($secondFlushTraces as $req) {
+foreach ($flushTraces as $req) {
     $body = json_decode($req['body'] ?? '', true);
     if (!is_array($body)) continue;
     if (isset($body['chunks'])) {
@@ -170,9 +164,8 @@ foreach (array_keys($namesInTraces) as $n) {
 }
 
 // Wait for a stats payload that contains our service.
-// Stats from the second flush arrive a few seconds after waitForDataAndReplay() returns;
-// use a matcher so we wait for the right payload rather than returning the first one
-// (which contains the dummy span from the first flush).
+// Use a matcher to wait for the right payload rather than returning the first one
+// (SKIPIF may have generated earlier requests under this token).
 $statsRequest = $rr->waitForStats(function ($request) {
     $payload = json_decode($request['body'], true);
     foreach ($payload['Stats'] ?? [] as $bucket) {

tests/ext/request-replayer/dd_trace_agent_env.phpt

@@ -36,12 +36,10 @@ $rr = new RequestReplayer();
 
 $span = \DDTrace\start_span();
 
-// make sure sidecar keeps up with us
-$start = microtime(true);
-\DDTrace\start_trace_span();
-\DDTrace\close_span();
-$rr->waitForDataAndReplay();
-usleep(floor(microtime(true) - $start) * 100000);
+// Block until the sidecar has received and applied the agent /info response (which carries
+// default_env set in SKIPIF). This ensures $span->env reflects the agent-provided env
+// before we read it.
+dd_trace_internal_fn('await_agent_info');
 
 \DDTrace\close_span();
 var_dump($span->env);