From 3248cb7c6a6b1f3fcd5a98776151846a72954807 Mon Sep 17 00:00:00 2001
From: Mattias Axelsson <mattiaax@axis.com>
Date: Fri, 30 Aug 2024 20:21:28 +0200
Subject: [PATCH] Replace pthread_mutex with std::mutex

This allows use of std::scoped_lock and a few gotos can be removed.

Change-Id: I9f2ec9ccac35d3600d64ae438a277432fd53a5b2
---
 src/inference.cpp     |  8 +-------
 src/inference.h       |  3 ++-
 src/video_capture.cpp | 23 +++++------------------
 src/video_capture.h   |  3 ++-
 4 files changed, 10 insertions(+), 27 deletions(-)

diff --git a/src/inference.cpp b/src/inference.cpp
index 0cbd1b5..49caf24 100644
--- a/src/inference.cpp
+++ b/src/inference.cpp
@@ -68,11 +68,6 @@ Inference::Inference(const bool verbose,
 
     TRACELOG << "Init chipId=" << chipId << endl;
 
-    if (pthread_mutex_init(&_mtx, NULL) != 0) {
-        ERRORLOG << "Init mutex FAILED" << endl;
-        throw runtime_error("Could not Init Inference Service");
-    }
-
     // Connect to larod service
     if (!larodConnect(&_conn, &error)) {
         PrintError("Connecting to larod FAILED", error);
@@ -189,7 +184,7 @@ Status Inference::Predict(ServerContext* context,
     auto& model = model_it->second;
 
     // Make larod calls atomic and threadsafe
-    pthread_mutex_lock(&_mtx);
+    scoped_lock lock(_mutex);
 
     // Clear class data
     _ppModel = nullptr;
@@ -309,7 +304,6 @@ Status Inference::Predict(ServerContext* context,
     larodDestroyModel(&_ppModel);
     CloseTmpFiles(inFiles);
     CloseTmpFiles(outFiles);
-    pthread_mutex_unlock(&_mtx);
     larodClearError(&error);
     return status;
 }
diff --git a/src/inference.h b/src/inference.h
index 3cd4786..1dd38a4 100644
--- a/src/inference.h
+++ b/src/inference.h
@@ -17,6 +17,7 @@
 #include "prediction_service.grpc.pb.h"
 #include "video_capture.h"
 #include <larod.h>
+#include <mutex>
 
 namespace acap_runtime {
 class Inference : public tensorflow::serving::PredictionService::Service {
@@ -77,7 +78,7 @@ class Inference : public tensorflow::serving::PredictionService::Service {
     std::map<std::string, larodModel*> _models;
     larodModel* _ppModel;
     larodMap* _ppMap;
-    pthread_mutex_t _mtx;
+    std::mutex _mutex;
     larodTensor** _ppInputTensors;
     larodTensor** _ppOutputTensors;
     larodTensor** _inputTensors;
diff --git a/src/video_capture.cpp b/src/video_capture.cpp
index 52d38df..0472d88 100644
--- a/src/video_capture.cpp
+++ b/src/video_capture.cpp
@@ -40,11 +40,6 @@ namespace acap_runtime {
 // Initialize the capture service
 Capture::Capture(const bool verbose) : _verbose(verbose) {
     TRACELOG << "Init" << endl;
-
-    if (pthread_mutex_init(&_mutex, NULL) != 0) {
-        ERRORLOG << "Init mutex failed" << endl;
-        throw runtime_error("Could not initialize VideoCapture service");
-    }
 }
 
 // Create a new stream
@@ -182,7 +177,7 @@ bool Capture::GetImgDataFromStream(unsigned int stream,
         PrintStreamInfo(vdoStream);
     }
 
-    pthread_mutex_lock(&_mutex);
+    scoped_lock lock(_mutex);
 
     MaybeDeleteOldestFrame(currentStream->second);
 
@@ -205,8 +200,6 @@ bool Capture::GetImgDataFromStream(unsigned int stream,
 
     frameRef = SaveFrame(currentStream->second, buffer, size);
 
-    pthread_mutex_unlock(&_mutex);
-
     return true;
 }
 
@@ -240,8 +233,7 @@ void Capture::MaybeDeleteOldestFrame(Stream& stream) {
 
 // Find a frame based on the frame reference and put its data into the response
 bool Capture::GetDataFromSavedFrame(Stream& stream, uint32_t frameRef, GetFrameResponse* response) {
-    pthread_mutex_lock(&_mutex);
-    bool ret = false;
+    scoped_lock lock(_mutex);
     gpointer data = NULL;
 
     // Find the buffer
@@ -250,7 +242,7 @@ bool Capture::GetDataFromSavedFrame(Stream& stream, uint32_t frameRef, GetFrameR
     });
     if (buffer == stream.buffers.end()) {
         ERRORLOG << "Frame reference " << frameRef << " not found" << endl;
-        goto end;
+        return false;
     }
 
     TRACELOG << "Found saved VDO buffer. ID: " << buffer->id << endl;
@@ -258,17 +250,12 @@ bool Capture::GetDataFromSavedFrame(Stream& stream, uint32_t frameRef, GetFrameR
     data = vdo_buffer_get_data(buffer->vdo_buffer);
     if (nullptr == data) {
         ERRORLOG << "Getting data from saved buffer failed" << endl;
-        goto end;
+        return false;
     }
 
     response->set_data(data, buffer->size);
     response->set_size(buffer->size);
-
-    ret = true;
-
-end:
-    pthread_mutex_unlock(&_mutex);
-    return ret;
+    return true;
 }
 
 // Print dimensions and fps of the stream
diff --git a/src/video_capture.h b/src/video_capture.h
index de8222a..2da1dce 100644
--- a/src/video_capture.h
+++ b/src/video_capture.h
@@ -22,6 +22,7 @@
 
 #include <deque>
 #include <map>
+#include <mutex>
 
 #include "videocapture.grpc.pb.h"
 
@@ -83,7 +84,7 @@ class Capture final : public videocapture::v1::VideoCapture::Service {
     std::map<unsigned int, Stream> _streams;
     bool _verbose;
     const uint32_t MAX_NBR_SAVED_FRAMES = 3;
-    pthread_mutex_t _mutex;
+    std::mutex _mutex;
 };
 }  // namespace acap_runtime