From: Ben Gras <ben@minix3.org>
Date: Wed, 27 Jul 2005 14:08:59 +0000 (+0000)
Subject: Added SENDREC_BUSY flag to indicate that process is doing sendrec() -
X-Git-Tag: v3.1.0~511
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/man.rndc.html?a=commitdiff_plain;h=31042a5a05abf1f6f0c319880d1f95e42852d8e4;p=minix.git

Added SENDREC_BUSY flag to indicate that process is doing sendrec() -
if so, alerts are not received before reply message.
---

diff --git a/kernel/priv.h b/kernel/priv.h
index 8dc5ed686..6444204c4 100755
--- a/kernel/priv.h
+++ b/kernel/priv.h
@@ -41,6 +41,7 @@ struct priv {
 #define RDY_Q_HEAD      0x02	/* add to queue head instead of tail */
 #define BILLABLE	0x04	/* some processes are not billable */
 #define SYS_PROC	0x10	/* system processes are privileged */
+#define SENDREC_BUSY	0x20	/* sendrec() in progress */
 
 /* Magic system structure table addresses. */
 #define BEG_PRIV_ADDR (&priv[0])
diff --git a/kernel/proc.c b/kernel/proc.c
index 8a01ef221..9cbbc424a 100755
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -167,7 +167,8 @@ message *m_ptr;			/* pointer to message in the caller's space */
    *   - ECHO:    nonblocking call; directly echo back the message 
    */
   switch(function) {
-  case SENDREC:					/* has FRESH_ANSWER flag */		
+  case SENDREC:
+  	caller_ptr->p_priv->s_flags |= SENDREC_BUSY;
       /* fall through */
   case SEND:			
       result = mini_send(caller_ptr, src_dst, m_ptr, flags);
@@ -175,6 +176,8 @@ message *m_ptr;			/* pointer to message in the caller's space */
           break;				/* done, or SEND failed */
       }						/* fall through for SENDREC */
   case RECEIVE:			
+      if(function == RECEIVE)
+      	caller_ptr->p_priv->s_flags &= ~SENDREC_BUSY;
       result = mini_receive(caller_ptr, src_dst, m_ptr, flags);
       break;
   case ALERT:
@@ -275,7 +278,7 @@ unsigned flags;				/* system call flags */
   if (!(caller_ptr->p_rts_flags & SENDING)) {
 
     /* Check if there are pending notifications, except for SENDREC. */
-    if (! (flags & FRESH_ANSWER)) {
+    if (! (caller_ptr->p_priv->s_flags & SENDREC_BUSY)) {
 
         map = &priv(caller_ptr)->s_notify_pending;
         for (chunk=&map->chunk[0]; chunk<&map->chunk[NR_SYS_CHUNKS]; chunk++) {
@@ -363,6 +366,7 @@ int dst;				/* which process to notify */
    * can be both sending and receiving during a SENDREC system call.
    */
   if ((dst_ptr->p_rts_flags & (RECEIVING|SENDING)) == RECEIVING &&
+      !(dst_ptr->p_priv->s_flags & SENDREC_BUSY) &&
       (dst_ptr->p_getfrom == ANY || dst_ptr->p_getfrom == caller_ptr->p_nr)) {
 
       /* Destination is indeed waiting for a message. Assemble a notification