From 0129c2c686dc306d721f36d342a1813565f3f235 Mon Sep 17 00:00:00 2001
From: Dhanya Thattil <33750417+thattil@users.noreply.github.com>
Date: Tue, 10 May 2022 15:23:39 +0200
Subject: [PATCH] M3: master starts twice (non blocking) part 2 (#445)

* slaves and master vectors empty means all positions included: fixing double acquisition in masters

* debug print out
---
 slsDetectorSoftware/src/DetectorImpl.cpp | 33 +++++++++++++++---------
 slsDetectorSoftware/src/DetectorImpl.h   |  2 +-
 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/slsDetectorSoftware/src/DetectorImpl.cpp b/slsDetectorSoftware/src/DetectorImpl.cpp
index 3522c5e21..45e1a1373 100644
--- a/slsDetectorSoftware/src/DetectorImpl.cpp
+++ b/slsDetectorSoftware/src/DetectorImpl.cpp
@@ -1173,31 +1173,40 @@ int DetectorImpl::acquire() {
     return OK;
 }
 
-void DetectorImpl::startAcquisition(bool blocking, Positions pos) {
+void DetectorImpl::startAcquisition(bool blocking, std::vector<int> positions) {
     if (shm()->detType == defs::MYTHEN3 && size() > 1) {
         std::vector<int> master;
         std::vector<int> slaves;
-        auto is_master = Parallel(&Module::isMaster, pos);
-        // could be all slaves in pos
-        slaves.reserve(pos.size()); 
-        for (size_t i = 0; i != pos.size(); ++i) {
+        if (positions.empty() ||
+            (positions.size() == 1 && positions[0] == -1)) {
+            positions.resize(modules.size());
+            std::iota(begin(positions), end(positions), 0);
+        }
+        // could be all slaves in positions
+        slaves.reserve(positions.size()); 
+        auto is_master = Parallel(&Module::isMaster, positions);
+        for (size_t i : positions) {
             if (is_master[i]) 
                 master.push_back(i);
             else
                 slaves.push_back(i);
         }
 
-        Parallel(&Module::startAcquisition, slaves);
-        if (blocking) {
-            Parallel(&Module::startAndReadAll, master);
-        } else {
-            Parallel(&Module::startAcquisition, master);
+        if (!slaves.empty()) {
+            Parallel(&Module::startAcquisition, slaves);
+        }
+        if (!master.empty()) {
+            if (blocking) {
+                Parallel(&Module::startAndReadAll, master);
+            } else {
+                Parallel(&Module::startAcquisition, master);
+            }
         }
     } else {
         if (blocking) {
-            Parallel(&Module::startAndReadAll, pos);
+            Parallel(&Module::startAndReadAll, positions);
         } else {
-            Parallel(&Module::startAcquisition, pos);
+            Parallel(&Module::startAcquisition, positions);
         }
     }
 }
diff --git a/slsDetectorSoftware/src/DetectorImpl.h b/slsDetectorSoftware/src/DetectorImpl.h
index 1ef51fd75..7f6ec43be 100644
--- a/slsDetectorSoftware/src/DetectorImpl.h
+++ b/slsDetectorSoftware/src/DetectorImpl.h
@@ -279,7 +279,7 @@ class DetectorImpl : public virtual slsDetectorDefs {
     int acquire();
 
     /** also takes care of master and slave for multi module mythen */
-    void startAcquisition(bool blocking, Positions pos);
+    void startAcquisition(bool blocking, std::vector<int> positions);
 
     /**
      * Combines data from all readouts and gives it to the gui