Please see the attached sample code. If I turn READERS and WRITERS to 0, the test works fine. Adding another thread in the process by setting a non-zero number to either READERS or WRITER, the test program crashes due to the assertion at line 99. Regards -----Original Message----- From: Waldemar Brodkorb [mailto:wbx@uclibc-ng.org] Sent: Friday, November 18, 2016 5:13 PM To: Frank Liu Cc: 'uclibc@uclibc.org'; devel@uclibc-ng.org; Dushara Jayasinghe (dushara@successful.com.au) Subject: Re: uclibc(1.0.12) mq_send return value and errno issue Hi, Frank Liu wrote,
Hi All,
Kernel version : 4.4.19-linux4sam_5.4 uclibc version : 1.0.12 uclibc threading support : NPTL Processor Arch: ARM
Better you switch to uClibc-ng mailinglist for this question.
We create a NONBLOCKING message queue.
The expected behavior is when the message queue is full, calling mq_send would return -1 and set errno to EAGAIN(11). However we are seeing some inconsistent behaviors of mq_send.
When calling mq_send in a single threaded environment, the expected behavior is observed.
If the program starts a second thread, which is doing completely different task, calling mq_send when the queue is full would return -11 instead of -1. Also, the errno is set to an incorrect value. Values we have seen are 0, 2, which are completely different from the expected EAGAIN(11).
Can you provide a simple test case to check the behaviour? best regards Waldemar -- Click here to report this message as spam: https://console.mailguard.com.au/ras/1PGczunkCB/3fSLfL9xJIP2MKuhQDEQvo/1.5 -- IMPORTANTPrivileged - Private & Confidential This email and files transmitted with it are intended solely for the use of the addressee (s) and may contain information which is confidential or privileged. If you are not the intended recipient, be aware that any disclosure, copying, distribution or use of this email or any attachment is prohibited. If you receive this email and you are not the addressee, or you have received this email in error, please disregard the contents of the email, delete the email and notify the author immediately. It is your responsibility to check any email attachments for email viruses before opening or sending them on.