P (programming language)
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P is a programming language for asynchronous event-driven programming and the IoT that was developed by Microsoft and University of California, Berkeley.cite-ref-1[1]
P enables programmers to specify systems consisting of a collection of state machines that communicate asynchronously in terms of events.cite-ref-2[2] P programs can run and be analyzed on any platform supported by .NET. Additionally, P programs can generate C# and C code.
Contents
• Example
• See also
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Example
machine BankServer
{
var database: Database;
start state Init {
entry (initialBalance: map[int, int]){
database = new Database((server = this, initialBalance = initialBalance));
goto WaitForWithdrawRequests;
}
}
state WaitForWithdrawRequests {
on eWithDrawReq do (wReq: tWithDrawReq) {
var currentBalance: int;
var response: tWithDrawResp;
// read the current account balance from the database
currentBalance = ReadBankBalance(database, wReq.accountId);
// if there is enough money in account after withdrawal
if(currentBalance - wReq.amount >= 10)
{
UpdateBankBalance(database, wReq.accountId, currentBalance - wReq.amount);
response = (status = WITHDRAW_SUCCESS, accountId = wReq.accountId, balance = currentBalance - wReq.amount, rId = wReq.rId);
}
else // not enough money after withdraw
{
response = (status = WITHDRAW_ERROR, accountId = wReq.accountId, balance = currentBalance, rId = wReq.rId);
}
// send response to the client
send wReq.source, eWithDrawResp, response;
}
}
}
See also
References
cite-note-11. ↑ Microsoft open-sources P language for IoT
cite-note-33. ↑ citerefsergio-de-simoneSergio De Simone. "Microsoft Open-Sources P Language for Safe Async Event-Driven Programming". InfoQ. Retrieved 20 October 2016.
Further reading
• P: Safe asynchronous event-driven programming. Ankush Desai, Vivek Gupta, Ethan Jackson, Shaz Qadeer, Sriram Rajamani, and Damien Zufferey. In Proceedings of ACM SIGPLAN Conference on Programming Language Design and Implementation (PLDI), 2013.
• Systematic testing of asynchronous reactive systems. Ankush Desai, Shaz Qadeer, and Sanjit A. Seshia. In Proceedings of the 2015 10th Joint Meeting on Foundations of Software Engineering (ESEC/FSE 2015).
• Building Reliable Distributed Systems With P. Ankush Desai, Ethan Jackson, Amar Phanishayee, Shaz Qadeer and Sanjit A. Seshia. University of California, Berkeley. Technical Report No. UCB/EECS-2015-198.
External links
• Official website
• Source code on GitHub
• P: Safe Asynchronous Event-Driven Programming
• P: A programming language designed for asynchrony, fault-tolerance and uncertainty