Commit graph

20 commits

Author SHA1 Message Date
rsc f3d290220f add cons_puts for atomic (readable) output 2006-07-16 15:38:00 +00:00
rsc 856e1fc1ad Attempt to clean up newproc somewhat.
Also remove all calls to memcpy in favor of
memmove, which has defined semantics when
the ranges overlap.  The fact that memcpy was
working in console.c to scroll the screen is not
guaranteed by all implementations.
2006-07-16 01:47:40 +00:00
rsc 65bd8e139a New scheduler.
Removed cli and sti stack in favor of tracking
number of locks held on each CPU and explicit
conditionals in spinlock.c.
2006-07-16 01:15:28 +00:00
rsc 643b122b4a move everything having to do with proc_table_lock into proc.c 2006-07-15 17:24:54 +00:00
rsc 67a9314ad1 Add void for ANSI C 2006-07-15 17:17:00 +00:00
rsc 7f419a0d29 Change fetchint, fetcharg, and putint to return -1 on error, 0 on success.
They had been returning 0 on error, 1 on success, but all the callers
were checking for return value < 0.
2006-07-15 17:13:56 +00:00
rtm 46bbd72f3e no more recursive locks
wakeup1() assumes you hold proc_table_lock
sleep(chan, lock) provides atomic sleep-and-release to wait for condition
ugly code in swtch/scheduler to implement new sleep
fix lots of bugs in pipes, wait, and exit
fix bugs if timer interrupt goes off in schedule()
console locks per line, not per byte
2006-07-15 12:03:57 +00:00
rtm 4e8f237be8 no more big kernel lock
succeeds at usertests.c pipe test
2006-07-12 01:48:35 +00:00
rtm b548df152b pre-empt both user and kernel, in clock interrupt
usertest.c tests pre-emption
kill()
2006-07-11 17:39:45 +00:00
rsc 5ce9751cab Changes to allow use of native x86 ELF compilers, which on my
Linux 2.4 box using gcc 3.4.6 don't seem to follow the same
conventions as the i386-jos-elf-gcc compilers.
Can run make 'TOOLPREFIX=' or edit the Makefile.

curproc[cpu()] can now be NULL, indicating that no proc is running.
This seemed safer to me than having curproc[0] and curproc[1]
both pointing at proc[0] potentially.

The old implementation of swtch depended on the stack frame layout
used inside swtch being okay to return from on the other stack
(exactly the V6 you are not expected to understand this).
It also could be called in two contexts: at boot time, to schedule
the very first process, and later, on behalf of a process, to sleep
or schedule some other process.

I split this into two functions: scheduler and swtch.

The scheduler is now a separate never-returning function, invoked
by each cpu once set up.  The scheduler looks like:

	scheduler() {
		setjmp(cpu.context);

		pick proc to schedule
		blah blah blah

		longjmp(proc.context)
	}

The new swtch is intended to be called only when curproc[cpu()] is not NULL,
that is, only on behalf of a user proc.  It does:

	swtch() {
		if(setjmp(proc.context) == 0)
			longjmp(cpu.context)
	}

to save the current proc context and then jump over to the scheduler,
running on the cpu stack.

Similarly the system call stubs are now in assembly in usys.S to avoid
needing to know the details of stack frame layout used by the compiler.

Also various changes in the debugging prints.
2006-07-11 01:07:40 +00:00
kaashoek 7ea6c9d197 queue with disk requests 2006-07-10 19:06:48 +00:00
kaashoek 72ea69fbdf read the disk using interrupts 2006-07-10 13:08:37 +00:00
kaashoek 7837c71b32 disable all interrupts when acquiring lock
user program that makes a blocking system call
2006-07-06 21:47:22 +00:00
rtm 8b4e2a08fe swtch saves callee-saved registers
swtch idles on per-CPU stack, not on calling process's stack
fix pipe bugs
usertest.c tests pipes, fork, exit, close
2006-07-01 21:26:01 +00:00
rtm c41f1de5d4 file descriptors
pipes
2006-06-27 14:35:53 +00:00
rtm b61c2547b8 system call return values
initialize 2nd cpu's idt
2006-06-26 20:31:52 +00:00
rtm bf3903612d system call arguments 2006-06-26 15:11:19 +00:00
rtm df5cc91659 compile "user programs"
curproc array
2006-06-22 20:47:23 +00:00
rtm be0a7eacda sleep, wakeup, wait, exit 2006-06-15 19:58:01 +00:00
rtm a4c03dea09 primitive fork and exit system calls 2006-06-15 16:02:20 +00:00