Bug 1673513 - ProfilerParent::RequestGatherProfileProgress(aChildPid) - r=florian

This helper function in ProfilerParent sends a progress request to a child process. If successfully sent, the response will resolve the returned promise.

Differential Revision: https://phabricator.services.mozilla.com/D135486

tools/profiler/gecko/ProfilerParent.cpp

@@ -660,6 +660,17 @@ ProfilerParent::GatherProfiles() {
   return results;
 }
 
+/* static */
+RefPtr<ProfilerParent::SingleProcessProgressPromise>
+ProfilerParent::RequestGatherProfileProgress(base::ProcessId aChildPid) {
+  RefPtr<SingleProcessProgressPromise> promise;
+  ProfilerParentTracker::ForChild(
+      aChildPid, [&promise](ProfilerParent* profilerParent) {
+        promise = profilerParent->SendGetGatherProfileProgress();
+      });
+  return promise;
+}
+
 // Magic value for ProfileBufferChunkManagerUpdate::unreleasedBytes meaning
 // that this is a final update from a child.
 constexpr static uint64_t scUpdateUnreleasedBytesFINAL = uint64_t(-1);

tools/profiler/public/ProfilerParent.h

@@ -45,6 +45,9 @@ class ProfilerParent final : public PProfilerParent {
     base::ProcessId childPid;
   };
 
+  using SingleProcessProgressPromise =
+      MozPromise<GatherProfileProgress, ResponseRejectReason, true>;
+
   // The following static methods can be called on any thread, but they are
   // no-ops on anything other than the main thread.
   // If called on the main thread, the call will be broadcast to all
@@ -59,6 +62,15 @@ class ProfilerParent final : public PProfilerParent {
   // Returns the profiles to expect, as promises and child pids.
   static nsTArray<SingleProcessProfilePromiseAndChildPid> GatherProfiles();
 
+  // Send a request to get the GatherProfiles() progress update from one child
+  // process, returns a promise to be resolved with that progress.
+  // The promise RefPtr may be null if the child process is unknown.
+  // Progress may be invalid, if the request arrived after the child process
+  // had already responded to the main GatherProfile() IPC, or something went
+  // very wrong in that process.
+  static RefPtr<SingleProcessProgressPromise> RequestGatherProfileProgress(
+      base::ProcessId aChildPid);
+
   static void ProfilerStarted(nsIProfilerStartParams* aParams);
   static void ProfilerWillStopIfStarted();
   static void ProfilerStopped();