[Concurrency] Emit async task running/waitingOn metadata inline into CPUTrace.

This allows tracking async code execution throughout a task's lifetime.

rdar://137230240

Author: mikeash

stdlib/public/Concurrency/TaskPrivate.h

@@ -728,10 +728,11 @@ class alignas(2 * sizeof(void*)) ActiveTaskStatus {
     return record_iterator::rangeBeginning(getInnermostRecord());
   }
 
-  void traceStatusChanged(AsyncTask *task, bool isStarting) {
+  void traceStatusChanged(AsyncTask *task, bool isStarting, bool wasRunning) {
     concurrency::trace::task_status_changed(
         task, static_cast<uint8_t>(getStoredPriority()), isCancelled(),
-        isStoredPriorityEscalated(), isStarting, isRunning(), isEnqueued());
+        isStoredPriorityEscalated(), isStarting, isRunning(), isEnqueued(),
+        wasRunning);
   }
 };
 
@@ -971,7 +972,7 @@ inline void AsyncTask::flagAsRunning() {
       if (_private()._status().compare_exchange_weak(oldStatus, newStatus,
                /* success */ std::memory_order_relaxed,
                /* failure */ std::memory_order_relaxed)) {
-        newStatus.traceStatusChanged(this, true);
+        newStatus.traceStatusChanged(this, true, oldStatus.isRunning());
         adoptTaskVoucher(this);
         swift_task_enterThreadLocalContext(
             (char *)&_private().ExclusivityAccessSet[0]);

stdlib/public/Concurrency/TaskStatus.cpp

@@ -94,8 +94,9 @@ static void withStatusRecordLock(
               status, newStatus,
               /*success*/ SWIFT_MEMORY_ORDER_CONSUME,
               /*failure*/ std::memory_order_relaxed)) {
+        bool wasRunning = status.isRunning();
         status = newStatus;
-        status.traceStatusChanged(task, false);
+        status.traceStatusChanged(task, false, wasRunning);
         break;
       }
     }
@@ -130,7 +131,7 @@ static void withStatusRecordLock(
             status, newStatus,
             /*success*/ std::memory_order_relaxed,
             /*failure*/ std::memory_order_relaxed)) {
-      newStatus.traceStatusChanged(task, false);
+      newStatus.traceStatusChanged(task, false, status.isRunning());
       break;
     }
   }
@@ -196,7 +197,7 @@ bool swift::addStatusRecord(AsyncTask *task, TaskStatusRecord *newRecord,
       if (task->_private()._status().compare_exchange_weak(oldStatus, newStatus,
               /*success*/ std::memory_order_release,
               /*failure*/ std::memory_order_relaxed)) {
-        newStatus.traceStatusChanged(task, false);
+        newStatus.traceStatusChanged(task, false, oldStatus.isRunning());
         return true;
       } else {
         // Retry
@@ -302,7 +303,7 @@ void swift::removeStatusRecord(AsyncTask *task, TaskStatusRecord *record,
             oldStatus, newStatus,
             /*success*/ std::memory_order_relaxed,
             /*failure*/ std::memory_order_relaxed)) {
-      newStatus.traceStatusChanged(task, false);
+      newStatus.traceStatusChanged(task, false, oldStatus.isRunning());
       return;
     }
 
@@ -904,7 +905,7 @@ static void swift_task_cancelImpl(AsyncTask *task) {
     }
   }
 
-  newStatus.traceStatusChanged(task, false);
+  newStatus.traceStatusChanged(task, false, oldStatus.isRunning());
   if (newStatus.getInnermostRecord() == nullptr) {
      // No records, nothing to propagate
      return;

stdlib/public/Concurrency/Tracing.h

@@ -63,7 +63,8 @@ void task_create(AsyncTask *task, AsyncTask *parent, TaskGroup *group,
 void task_destroy(AsyncTask *task);
 
 void task_status_changed(AsyncTask *task, uint8_t maxPriority, bool isCancelled,
-                         bool isEscalated, bool isStarting, bool isRunning, bool isEnqueued);
+                         bool isEscalated, bool isStarting, bool isRunning,
+                         bool isEnqueued, bool wasRunning);
 
 void task_flags_changed(AsyncTask *task, uint8_t jobPriority, bool isChildTask,
                         bool isFuture, bool isGroupChildTask,

stdlib/public/Concurrency/TracingSignpost.h

@@ -28,6 +28,10 @@
 #include <os/log.h>
 #include <os/signpost.h>
 
+#if defined(__arm64__) && __has_include(<os/apt_private.h>)
+#include <os/apt_private.h>
+#endif
+
 // Compatibility notes:
 //
 // These signposts can be read by external software that isn't synced with the
@@ -210,7 +214,24 @@ inline void task_destroy(AsyncTask *task) {
 
 inline void task_status_changed(AsyncTask *task, uint8_t maxPriority,
                                 bool isCancelled, bool isEscalated,
-                                bool isStarting, bool isRunning, bool isEnqueued) {
+                                bool isStarting, bool isRunning,
+                                bool isEnqueued, bool wasRunning) {
+#if !TARGET_OS_SIMULATOR
+#if OS_APT_SPI_VERSION >= 20241023
+  uint64_t taskId = task->getTaskId();
+  if (isRunning) {
+    if (SWIFT_RUNTIME_WEAK_CHECK(os_apt_msg_async_task_running_4swift)) {
+      SWIFT_RUNTIME_WEAK_USE(os_apt_msg_async_task_running_4swift(taskId));
+    }
+  } else if (!isRunning && wasRunning) {
+#if OS_APT_SPI_VERSION >= 20250710
+    if (SWIFT_RUNTIME_WEAK_CHECK(os_apt_msg_async_task_stopped_4swift)) {
+      SWIFT_RUNTIME_WEAK_USE(os_apt_msg_async_task_stopped_4swift(taskId));
+    }
+#endif // OS_APT_SPI_VERSION >= 20250710
+  }
+#endif // OS_APT_SPI_VERSION >= 20241023
+#endif // !TARGET_OS_SIMULATOR
   ENSURE_LOGS();
   auto id = os_signpost_id_make_with_pointer(TaskLog, task);
   os_signpost_event_emit(

stdlib/public/Concurrency/TracingStubs.h

@@ -56,7 +56,8 @@ inline void task_resume(AsyncTask *task) {}
 
 inline void task_status_changed(AsyncTask *task, uint8_t maxPriority,
                                 bool isCancelled, bool isEscalated,
-                                bool isStarting, bool isRunning, bool isEnqueued) {}
+                                bool isStarting, bool isRunning,
+                                bool isEnqueued, bool wasRunning) {}
 
 inline void task_flags_changed(AsyncTask *task, uint8_t jobPriority,
                                bool isChildTask, bool isFuture,