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New NOTIFY trap (IPC call) to send queued notification messages.

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The call works. Permission check, restriction of outstanding notifications
to be added. Low level code to make it work from within interrupt handlers
will be added as well.
This commit is contained in:
Jorrit Herder
2005-05-19 14:05:51 +00:00
parent 129b82d207
commit 307c825515
13 changed files with 151 additions and 30 deletions
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141
kernel/proc.c
View File

@@ -14,7 +14,6 @@
* unhold: repeat all held-up notifications
*
* Changes:
* Nov 05, 2004 removed lock_mini_send() (Jorrit N. Herder)
* Oct 28, 2004 non-blocking SEND and RECEIVE (Jorrit N. Herder)
* Oct 28, 2004 rewrite of sys_call() (Jorrit N. Herder)
* Oct 10, 2004 require BOTH for kernel sys_call() (Jorrit N. Herder)
@@ -23,7 +22,6 @@
* Sep 23, 2004 removed PM sig check in mini_rec() (Jorrit N. Herder)
* Aug 19, 2004 generalized ready()/unready() (Jorrit N. Herder)
* Aug 18, 2004 added notify() function (Jorrit N. Herder)
* May 01, 2004 check p_sendmask in mini_send() (Jorrit N. Herder)
*/
#include "kernel.h"
@@ -43,6 +41,8 @@ FORWARD _PROTOTYPE( void ready, (struct proc *rp) );
FORWARD _PROTOTYPE( void sched, (void) );
FORWARD _PROTOTYPE( void unready, (struct proc *rp) );
FORWARD _PROTOTYPE( void pick_proc, (void) );
FORWARD _PROTOTYPE( int alloc_notify_buf, (void) );
FORWARD _PROTOTYPE( void free_notify_buf, (int index) );
#if (CHIP == M68000)
FORWARD _PROTOTYPE( void cp_mess, (int src, struct proc *src_p, message *src_m,
@@ -66,8 +66,65 @@ FORWARD _PROTOTYPE( void cp_mess, (int src, struct proc *src_p, message *src_m,
#define clear_bit(mask, n) ((mask) &= ~(1 << (n)))
#define isset_bit(mask, n) ((mask) & (1 << (n)))
/* Declare buffer space for notifications. */
PRIVATE struct notification notify_buf[NR_NOTIFY_BUFS];
/* Constants and macros for the notification bit map. */
#define BITCHUNK_BITS (sizeof(bitchunk_t) * CHAR_BIT)
#define BITMAP_CHUNKS ((NR_NOTIFY_BUFS + BITCHUNK_BITS - 1)/BITCHUNK_BITS)
#define MAP_CHUNK(map,bit) (map)[((bit)/BITCHUNK_BITS)]
#define CHUNK_OFFSET(bit) ((bit)%BITCHUNK_BITS))
#define GET_BIT(map,bit) ( MAP_CHUNK(map,bit) & (1 << CHUNK_OFFSET(bit) )
#define SET_BIT(map,bit) ( MAP_CHUNK(map,bit) |= (1 << CHUNK_OFFSET(bit) )
#define UNSET_BIT(map,bit) ( MAP_CHUNK(map,bit) &= ~(1 << CHUNK_OFFSET(bit) )
/* Declare buffer space for notifications and bit map for administration. */
PRIVATE struct notification notify_buffer[NR_NOTIFY_BUFS];
PRIVATE bitchunk_t notify_bitmap[BITMAP_CHUNKS];
/*===========================================================================*
* free_notify_buf *
*===========================================================================*/
PRIVATE void free_notify_buf(buf_index)
int buf_index; /* buffer to release */
{
bitchunk_t *chunk;
if (buf_index >= NR_NOTIFY_BUFS) return;
chunk = &notify_bitmap[(buf_index/BITCHUNK_BITS)];
*chunk &= ~(buf_index % BITCHUNK_BITS);
}
/*===========================================================================*
* alloc_notify_buf *
*===========================================================================*/
PRIVATE int alloc_notify_buf()
{
bitchunk_t *chunk;
int i, bit_nr;
/* Iterate over the words in block. */
for (chunk = &notify_bitmap[0];
chunk < &notify_bitmap[BITMAP_CHUNKS]; chunk++) {
/* Does this chunk contain a free bit? */
if (*chunk == (bitchunk_t) ~0) continue;
/* Get bit number from the start of the bit map. */
for (i = 0; (*chunk & (1 << i)) != 0; ++i) {}
bit_nr = (chunk - &notify_bitmap[0]) * BITCHUNK_BITS + i;
/* Don't allocate bits beyond the end of the map. */
if (bit_nr >= NR_NOTIFY_BUFS) break;
*chunk |= 1 << bit_nr % BITCHUNK_BITS;
kprintf("Allocated bit %d\n", bit_nr);
return(bit_nr);
}
return(-1);
}
/*===========================================================================*
* lock_notify *
@@ -307,8 +364,8 @@ int may_block; /* (dis)allow blocking */
caller_ptr->p_sendto= dest;
/* Process is now blocked. Put in on the destination's queue. */
if ( (next_ptr = dest_ptr->p_callerq) == NIL_PROC)
dest_ptr->p_callerq = caller_ptr;
if ( (next_ptr = dest_ptr->p_caller_q) == NIL_PROC)
dest_ptr->p_caller_q = caller_ptr;
else {
while (next_ptr->p_sendlink != NIL_PROC)
next_ptr = next_ptr->p_sendlink;
@@ -336,21 +393,22 @@ int may_block; /* (dis)allow blocking */
*/
register struct proc *sender_ptr;
register struct proc *previous_ptr;
register struct notification **ntf_q_pp;
message m;
int i;
int bit_nr, i;
/* Check to see if a message from desired source is already available. */
if (!(caller_ptr->p_flags & SENDING)) {
/* Check caller queue. */
for (sender_ptr = caller_ptr->p_callerq; sender_ptr != NIL_PROC;
for (sender_ptr = caller_ptr->p_caller_q; sender_ptr != NIL_PROC;
previous_ptr = sender_ptr, sender_ptr = sender_ptr->p_sendlink) {
if (src == ANY || src == proc_number(sender_ptr)) {
/* An acceptable message has been found. */
CopyMess(proc_number(sender_ptr), sender_ptr,
sender_ptr->p_messbuf, caller_ptr, m_ptr);
if (sender_ptr == caller_ptr->p_callerq)
caller_ptr->p_callerq = sender_ptr->p_sendlink;
if (sender_ptr == caller_ptr->p_caller_q)
caller_ptr->p_caller_q = sender_ptr->p_sendlink;
else
previous_ptr->p_sendlink = sender_ptr->p_sendlink;
if ((sender_ptr->p_flags &= ~SENDING) == 0)
@@ -359,6 +417,26 @@ int may_block; /* (dis)allow blocking */
}
}
/* Check if there are pending notifications. */
ntf_q_pp = &caller_ptr->p_ntf_q; /* get pointer pointer */
while (*ntf_q_pp) {
if (src == ANY || src == (*ntf_q_pp)->n_source) {
/* Found notification. Assemble and copy message. */
m.NOTIFY_TYPE = (*ntf_q_pp)->n_type;
m.NOTIFY_FLAGS = (*ntf_q_pp)->n_flags;
m.NOTIFY_ARG = (*ntf_q_pp)->n_arg;
CopyMess((*ntf_q_pp)->n_source, proc_addr(HARDWARE), &m,
caller_ptr, m_ptr);
/* Remove notification from queue and return. */
bit_nr = ((long)(*ntf_q_pp) - (long) &notify_buffer[0]) /
sizeof(struct notification);
*ntf_q_pp = (*ntf_q_pp)->n_next;/* remove from queue */
free_notify_buf(bit_nr); /* afterwards: prevent race */
return(OK); /* report success */
}
ntf_q_pp = &(*ntf_q_pp)->n_next; /* proceed to next */
}
/* Check bit mask for blocked notifications. If multiple bits are set,
* send the first notification encountered; the rest is handled later.
* This effectively prioritizes notifications. Notification also have
@@ -395,12 +473,49 @@ int may_block; /* (dis)allow blocking */
* mini_notify *
*===========================================================================*/
PRIVATE int mini_notify(caller_ptr, dst, m_ptr)
register struct proc *caller_ptr; /* process trying to get message */
register struct proc *caller_ptr; /* process trying to notify */
int dst; /* which process to notify */
message *m_ptr; /* pointer to message buffer */
{
kprintf("Kernel notify from %d", caller_ptr->p_nr);
kprintf("for %d\n", dst);
register struct proc *dest_ptr = proc_addr(dst);
register struct notification *ntf_p ;
register struct notification **ntf_q_pp;
int ntf_index;
message ntf_mess;
/* Check to see if target is blocked waiting for this message. */
if ( (dest_ptr->p_flags & (RECEIVING | SENDING)) == RECEIVING &&
(dest_ptr->p_getfrom == ANY ||
dest_ptr->p_getfrom == proc_number(caller_ptr))) {
/* Destination is indeed waiting for this message. */
CopyMess(proc_number(caller_ptr), caller_ptr, m_ptr, dest_ptr,
dest_ptr->p_messbuf);
dest_ptr->p_flags &= ~RECEIVING; /* deblock destination */
if (dest_ptr->p_flags == 0) ready(dest_ptr);
} else {
/* See if there is a free notification buffer. */
if ((ntf_index = alloc_notify_buf()) < 0)
return(ENOSPC); /* should be atomic! */
/* Copy details from notification message. */
CopyMess(proc_number(caller_ptr), caller_ptr, m_ptr,
proc_addr(HARDWARE), &ntf_mess);
ntf_p = &notify_buffer[ntf_index];
ntf_p->n_source = proc_number(caller_ptr);
ntf_p->n_type = ntf_mess.NOTIFY_TYPE;
ntf_p->n_flags = ntf_mess.NOTIFY_FLAGS;
ntf_p->n_arg = ntf_mess.NOTIFY_ARG;
/* Enqueue the notification message for later. New notifications
* are added to the end of the list. First find the NULL pointer,
* then add the new pointer to the end.
*/
ntf_q_pp = &dest_ptr->p_ntf_q;
while (*ntf_q_pp) ntf_q_pp = &(*ntf_q_pp)->n_next;
*ntf_q_pp = ntf_p;
ntf_p->n_next = NULL;
}
return(OK);
}