From 8502912e2c249fabead204ee2e563e91e9eb7292 Mon Sep 17 00:00:00 2001
From: Giulio Moro <giuliomoro@yahoo.it>
Date: Fri, 31 May 2024 19:03:56 -0500
Subject: [PATCH] AuxTaskRT: if the desired queue parameters do not work, try
 with system defaults. This helps when running with stock max limits on
 popular distros. Also do not cleanup queues if not properly created)

---
 core/AuxTaskRT.cpp  | 54 ++++++++++++++++++++++++++++++++-------------
 include/AuxTaskRT.h |  1 +
 2 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/core/AuxTaskRT.cpp b/core/AuxTaskRT.cpp
index 4bd312d0a..895a3a92b 100644
--- a/core/AuxTaskRT.cpp
+++ b/core/AuxTaskRT.cpp
@@ -4,34 +4,58 @@
 #include <stdlib.h>
 #include <vector>
 #include <string.h>
+
 AuxTaskRT::~AuxTaskRT()
 {
 	lShouldStop = true;
-	struct timespec absoluteTimeout = {0, 0};
-	// non blocking write, so if the queue is full it won't fail
-	char c = 0;
-	int ret = BELA_RT_WRAP(mq_timedsend(queueDesc, &c, sizeof(c), 0, &absoluteTimeout));
-	if(ret)
-		fprintf(stderr, "Error mq_timedsend: %d %s\n", errno, strerror(errno));
+	if(queueValid)
+	{
+		struct timespec absoluteTimeout = {0, 0};
+		// non blocking write, so if the queue is full it won't fail
+		char c = 0;
+		int ret = BELA_RT_WRAP(mq_timedsend(queueDesc, &c, sizeof(c), 0, &absoluteTimeout));
+		if(ret)
+			fprintf(stderr, "Error mq_timedsend: %d %s\n", errno, strerror(errno));
+	}
 	join();
-	ret = BELA_RT_WRAP(mq_close(queueDesc));
-	if(ret)
-		fprintf(stderr, "Error closing queueDesc: %d %s\n", errno, strerror(errno));
-	ret = BELA_RT_WRAP(mq_unlink(queueName.c_str()));
-	if(ret)
-		fprintf(stderr, "Error unlinking queue: %d %s\n", errno, strerror(errno));
+	if(queueValid)
+	{
+		int ret = BELA_RT_WRAP(mq_close(queueDesc));
+		if(ret)
+			fprintf(stderr, "Error closing queueDesc: %d %s\n", errno, strerror(errno));
+		ret = BELA_RT_WRAP(mq_unlink(queueName.c_str()));
+		if(ret)
+			fprintf(stderr, "Error unlinking queue: %d %s\n", errno, strerror(errno));
+	}
 }
 
 int AuxTaskRT::commsInit()
 {
 	// create a queue, with prefixed name
-	queueName = std::string("/q_") + name;
+	queueName = std::string("/q_") + name + std::to_string((long long unsigned)(this));
 	struct mq_attr attr;
 	attr.mq_maxmsg = 100;
 	attr.mq_msgsize = 100000;
-	queueDesc = BELA_RT_WRAP(mq_open(queueName.c_str(), O_CREAT | O_RDWR, 0644, &attr));
-	if((mqd_t)-1 == queueDesc)
+	// first try with our desired queue properties, failing that try with the system defaults
+	for(auto& ptr : {&attr, (struct mq_attr*)nullptr})
+	{
+		queueDesc = BELA_RT_WRAP(mq_open(queueName.c_str(), O_CREAT | O_RDWR, 0644, ptr));
+		queueValid = ((mqd_t)-1 != queueDesc);
+		if(queueValid)
+		{
+			break;
+		} else {
+			if(&attr == ptr)
+			{
+				fprintf(stderr, "Opening queue %s with desired settings failed, trying with system defaults\n", queueName.c_str());
+			}
+		}
+	}
+	if(!queueValid)
+	{
+		fprintf(stderr, "Error creating queue %s: %d %s\n", queueName.c_str(), errno, strerror(errno));
 		return 1;
+	}
 	return 0;
 }
 
diff --git a/include/AuxTaskRT.h b/include/AuxTaskRT.h
index 080c67ba1..8e2837ec3 100644
--- a/include/AuxTaskRT.h
+++ b/include/AuxTaskRT.h
@@ -18,5 +18,6 @@ class AuxTaskRT : public SchedulableThread
 	int commsSend(const void* buf, size_t size);
 	ssize_t commsReceive(char* buf, size_t size);
 	mqd_t queueDesc;
+	bool queueValid = false;
 	std::string queueName;
 };