[Cloud System Booster Serial Producer
Ainoha Sistek
I figured it out. Silly mistake on my part, I was not actually deleting the element from the queue, I was just reading the first element. I modified the code and the code below no works. Thanks all for the help.
I'm trying to implement the producer consumer problem using boost, which is actually part of a bigger project. I have implemented a program from examples on the internet and even some help I found here. However currently my code just hangs. Based on some good advice, I decided to use the boost ciruclar buffer to hold my data between the producer and consumer. Lots of similar code out there and I was able to pool ideas from those and write something on my own. However, I still seem to be having same problem as before (which is my program just hangs). I thought that I did not make the same mistake as before..
My buffer capacity is correctly initialized to 100. The consumer thread waits and reports that the "buffer is empty" for the 5 seconds, but after that I just get the "buffer is full" from the put method and "Data : 10" from the consumer function alternating on stdout. As you can see 10 is the first element that I put in. It seems that the buffer is getting filled up and not notifiying the consumer but I checked my locks, and think they are right. Any help on this is greatly appreciated.
First of all, instead of writing your own list, you could just wrap std::list in pcdQueueinstead of writing your own. It is correct, that std::list is not thread-safe as-is, but you are providing the necessary synchronisation primitives in your class anyway.
The reason why your program hangs:You keep the lock and fill the queue until it is full. Your notificaiton of the consumer via notify_one is useless, because your consumer will lock right again, since the mutex is already taken (by the lock in the producer).
When you finally release the lock (when the queue is full) by waiting on the condition_variable, you don't wake up your consumer, so both your consumer and your producer are blocked and your program hangs.
In general, take care and note that notifications only have an effect, if someone is waiting. Otherwise, they are "lost". Furthermore, note that you don't need to keep the mutex locked when calling notify_one (in fact, it can lead to additional context-switch overhead, because you wake up the other thread which will then wait on a mutex that is currently (still) locked (by you). So first, release the mutex, then tell the other thread to continue.
Please note, that both threads run infinitely, so your main program will still hang at the first join() and never exit. You could include a stopping flag that you checkn in your while-loops to tell your threads to finish.
It's a fairly recent addition, so I don't think it's part of many standard packages yet. On the other hand, this looks like mostly headers, all depending on fairly low-level system stuff which has been in boost for a long time.
I came across the same issue of hanging. Thanks to Johannes' answer, I was able to make it work completely. However, I had to usefull.wait_for(lock, boost::chrono::milliseconds(100));in both the consumer and the producer to prevent hanging when using very short circular buffer (3-4 elements).
Microsoft Open Technologies (China) today published the OData Producer for SugarCRM to GitHub, an open source plugin tool that aims to help organizations gain more value from their corporate assets by promoting the more efficient exchange of information between diverse data systems.
Enterprises often need to use a variety of data process and analysis software packages to exploit the information and carry out complicated computing tasks. Yet, the differences among business application software (from databases to data formatting) often impede efficient data exchange. One way that the industry has come together to help address related interoperability challenges has been through the creation of standards like the Open Data Protocol (OData).
The OData protocol is the open data interface standard currently accepted by Organization for the Advancement of Structured Information Standards (OASIS). This specification supports universal data formats and simplifies the methods of data query, sharing, and reuse among applications for enterprises and cloud on mobile devices, so that people can more easily obtain information from various data sources, such as relational database, file system, content management system, and traditional websites.
The OData Producer for SugarCRM plugin strives to increase the flow of information at a reduced cost by increasing interoperability between SugarCRM, a globally influential open source CRM system, and Microsoft Office. With this open source tool, enterprise users can now analyze SugarCRM data sources with Office 365, Power BI, Tableau or other OData application clients.
SugarCRM is an open source customer relation management (CRM) system used by organizations around the world. Its code was written in PHP, a popular scripting language used by web developers. SugarCRM also broadly compatible with a diverse range of operating systems. In addition, the software is highly extensible, and it is possible to add new functions and modules on demand. All of these factors presented a strong opportunity for Microsoft to take this project forward, and to enable enterprise users working with SugarCRM to derive added benefit from being able to efficiently generate and analyze data in Office365, Power BI and Tableau.
The OData Producer for SugarCRM plugin acts as a bridge between data producers and consumers. OData Producer converts data in the SugarCRM database into a standard OData format. Meanwhile, any OData third-party clients including Office 365, Power BI and Tableau can reanalyze and reprocess exported data to derive greater value from their SugarCRM system.
This open source tool allows organizations to build a data bridge on demand. The plugin interface is easy to use, as it was specifically customized to support both SugarCRM administrators and common users. An administrator can readily configure various data assets using this tool, while common users have the ability to export pertinent data to an OData third-party client, such as Office365 quickly and easily. The plugin and its tutorial can be accessed and downloaded from Github .
The African Cocoa Marketplace (ACM), a newly introduced platform for cocoa farmers, aims to help them keep solid business relationships with buyers, develop value propositions for their products, and build solid sustainability credentials for their wares.
Cocoa farmers usually sell their wares through producer organisations. The ACM will be used by the person in said organisations that is responsible for marketing and sales, who will act as a tribune for farmers in their organisation. The platform, Leissle hopes, will allow these producer organisations to get better prices.
Ensuring that cocoa conforms to the EUDR raises challenges for large manufacturers, farmers on the ground, and everyone in between. Thus, having a system through which to maintain sustainability standards is vital.
The main challenge for cocoa farmers regarding EUDR compliance is data management and, maybe even more importantly, data validation. The types of data that the EUDR requires to prove that a supply chain is deforestation-free are meaningful within the EU, but that doesn't mean they are universally used or valued, Leissle told us.
One of the reasons their livelihoods may be compromised by EUDR is that cocoa farmers measure their farms in very different ways to polygon maps and satellite imagery. There are specific measures that farmers use to understand where the boundary of their farm lies, or where a forest boundary lies, and these are totally dependent upon cultural, social, and environmental context. A farmers' own measures of their farm would be impossible to capture in a polygon map.
Similarly, it is working on traceability standards. One of the biggest challenges to meeting traceability standards is that data is not often collected or managed on the cocoa supplier side in a way that meets expectations at the other end of the value chain.
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In this lab, you will extend the single node EOSIO blockchain to use multiple nodes. You will install various EOSIO software components to set up your multi node EOSIO blockchain. Finally, you will perform some node operator tasks on your new EOSIO blockchain.
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An EOSIO blockchain is a highly efficient, deterministic, distributed state machine that can operate in a decentralized fashion. The blockchain keeps track of transactions within a sequence of interchanged blocks. Each block cryptographically commits to the previous blocks along the same chain. It is therefore intractable to modify a transaction recorded on a given block without breaking the cryptographic checks of successive blocks. This simple fact makes blockchain transactions immutable and secure. Block production and block validation are performed by special nodes called Block Producers.
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