Without this patch, calling sys_mq_open() with same names specified
results in two separate queues being opened and their descriptors
returned instead of the same descriptor being returned for both.
Do the initialisation and comparison properly, so that when the
same name is specified to sys_mq_open multiple times in same
process or different process, the same opened queue descriptor is
returned.
This patch adds functionality to request an asynchronous notification
if some other process has send a message to it. We currently send a
SIGALRM to avoid any changes to core infrastructure of signal handling.
Ideally we should implement a separate signal for this. Currently there
is an obvious disadvantage of not being able to use SIGALRM with alarm,
if we are using this functionality.
Currently we only allow users to get and set number of queues. The
operation is always non blocking. There is no provision for non
blocking operation at the moment.
The queue sizes are set to MAX 256 by default. If a user changes the
attributes and sets the queue size or number of messages in a queue
to less than 256, it is the responsibility of the user to close any
queues which were opened with a descriptor greater than the value
currently set.
For example, by default queue sizes are 256. If 150 queues are opened
and then the user sets the number of queues to 32, all open descriptors
and queues from 32 to 150 must be closed. Note that descriptor number
allocation starts with zero and not one.
Functional specification mandates returning a message with a higher
timestamp in case two messages have the same priority. Somehow we
missed this in the implementation. This also introduced a bug where
all messages with same priority could cause problems.
Fixed the following bugs:
1. Message priority was not set at all at two places
2. Limits check was not correct while returning error values
3. We are suppose to allow multiple users operate on the same queue
using a named descriptor. However any one user calling close before
the other would result in closing the queue even when other users
might be using it. Track number of users and close only if number of
users is zero. Yet to do functional tests for this, so this is untested,
but introduce it anyway at this juncture.
This patch allows user processes to send messages to kernel. Without
this change, trying to do a system call for using message queues like
sys_mq_open will fail with ECALLDENIED error number -210.
Implement message queues support for Minix.
Pending tasks:
Blocking or non blocking for send receive?
Sort by priority and time?
Test codes?
Bug fixes?
This commit adds preparatory support for forthcoming message
queue implementation to the Minix kernel. The core implementation
will be added with the next commit.
- the userland call is now made to PM only, and PM relays the call to
other servers as appropriate; this is an ABI change that will
ultimately allow us to add proper support for wait3() and the like;
for the moment there is backward compatibility;
- the getrusage-specific kernel subcall has been removed, as it
provided only redundant functionality, and did not provide the means
to be extended correctly in the future - namely, allowing the kernel
to return different values depending on whether resource usage of
the caller (self) or its children was requested;
- VM is now told whether resource usage of the caller (self) or its
children is requested, and it refrains from filling in wrong values
for information it does not have;
- VM now uses the correct unit for the ru_maxrss values;
- VFS is cut out of the loop entirely, since it does not provide any
values at the moment; a comment explains how it should be readded.
Change-Id: I27b0f488437dec3d8e784721c67b03f2f853120f
The current value was both wrong (counting spawned kernel signals
rather than delivered user signals) and returned for the calling
process even if the request was for the process's children.
For now we are better off not populating this field at all.
Change-Id: I6c660be266b5746b7c3db57ae88fa7f872961ee2
Currently, the userland ABI uses a single field ('user_sp') far
into the very large 'kinfo' structure on the shared kernel
information page. This precludes us from modifying or getting
rid of 'kinfo' in the future without breaking userland. This
patch adds a separate 'kuserinfo' structure to the kernel
information page, with only information that is part of the
userland ABI, in an extensible manner. Userland now uses this
field if it is present, and falls back to the old field if not.
Change-Id: Ib7b24b53a440f40a2edc28cdfa48447ac2179288
This change serves to reduce the clutter inside the top-level kerninfo
structure, and allows other ARM-specific values to be added on the
kernel page in one place.
Change-Id: I36a6aada9dbd1230b25014728be675d389088667
Please note that this information is for use by system services only!
The clock facility is not ready to be used directly by userland, and
thus, this kernel page extension is NOT part of the userland ABI.
For service programmers' convenience, change the prototype of the
getticks(3) to return the uptime clock value directly, since the call
can no longer fail.
Correct the sys_times(2) reply message to use the right field type
for the boot time.
Restructure the kernel internals a bit so as to have all the clock
stuff closer together.
Change-Id: Ifc050b7bd253aecbe46e3bd7d7cc75bd86e45555
The filtering also exposed the risk that a process be killed or
swapped while on the list of VM memory requests. These cases are
now handled properly as well.
Change-Id: Ibd3897b34abdf33bce19d37b8e5f65fbd0fd9316
. make arch-independent, and local to proc.c, reduce code duplication
. make vm_suspend public but unduplicated in proc.c
. ask VM for handling once, 2nd time SIGSEGV process
. remove debug printfs
. test case for bogus sendrec() address argument
Change-Id: I3893758910c01de60b8fe3e50edd594296a0b73e
Add support for compact address layout. This feature can be enabled
through the ac_layout=1 boot option.
Change-Id: Ie20b808fce32b5c54d0a7e7210e0084a540e9613
If an asynchronous message is delivered during an ipc_receive(2) call,
but a failure occurred while copying out the status to the sending
process, then the receiving process would be left in an inconsistent
state, leading to a kernel crash shortly after.
For now, we fix this by altogether ignoring errors while copying out
the status field to the sending process. While this resolves the
kernel crash, it is hardly ideal, since it will likely cause the same
message to be delivered repeatedly. It would be better to disable
asynchronous communication from the sender process altogether, but this
solution requires more changes and thus more testing.
Change-Id: Ib00bf01ad29cdd10a5dee731d4788254d9037a76
Previously, there was a tiny chance that tickdelay(3) would return
early or that it would fail to reinstate a previous alarm.
- sys_setalarm(2) now returns TMR_NEVER instead of 0 for the time
left if no previous alarm was set;
- sys_setalarm(2) now also returns the current time, to allow the
caller to determine whether it got an alarm notification for the
alarm it set or for a previous alarm that has just gone off;
- tickdelay(3) now makes use of these facilities.
Change-Id: Id4f8fe19a61ca8574f43131964e6f0317f613f49
. bitcode fixes
. switch to compiler-rt instead of netbsd libc functions
or libgcc for support functions for both x86 and arm
. minor build fixes
. allow build with llvm without crossbuilding llvm itself
. can now build minix/arm using llvm and eabi - without C++
support for now (hence crossbuilding llvm itself is turned off
for minix/arm)
Change-Id: If5c44ef766f5b4fc4394d4586ecc289927a0d6eb
The entire infrastructure relied on an ACK feature, and as such, it
has been broken for years now, with no easy way to repair it.
Change-Id: I783c2a21276967af115a642199f31fef0f14a572
Sanchayan Maity
