From: Ben Gras <ben@minix3.org>
Date: Tue, 18 Oct 2005 10:34:54 +0000 (+0000)
Subject: printf() by kernel and servers now send messages to an array of processes,
X-Git-Tag: v3.1.2a~615
X-Git-Url: http://zhaoyanbai.com/repos/README?a=commitdiff_plain;h=ea75918df18b396076c47f55f69647159d391b61;p=minix.git

printf() by kernel and servers now send messages to an array of processes,
OUTPUT_PROCS_ARRAY in <minix/config.h>, in that order, terminated by NONE.
log no longer forwards messages to tty itself. This leads to less funny
loops and more robust debug-message handling. Also the list of
processes receiving messages can easily be changed around or disabled by
editing the array (e.g. disable it by changing the array to { NONE }.).
---

diff --git a/drivers/log/Makefile b/drivers/log/Makefile
index aae039630..8da0e46cb 100644
--- a/drivers/log/Makefile
+++ b/drivers/log/Makefile
@@ -29,8 +29,8 @@ $(LIBDRIVER):
 	cd $d/libdriver && $(MAKE) 
 
 # install with other drivers
-install:	/usr/sbin/$(DRIVER)
-/usr/sbin/$(DRIVER):	$(DRIVER)
+install:	/sbin/$(DRIVER)
+/sbin/$(DRIVER):	$(DRIVER)
 	install -o root -cs $? $@
 
 # clean up local files
diff --git a/drivers/log/diag.c b/drivers/log/diag.c
index 3776db969..7158678b7 100644
--- a/drivers/log/diag.c
+++ b/drivers/log/diag.c
@@ -91,7 +91,6 @@ PUBLIC int do_diagnostics(message *m)
  * user. It also saves a copy in a local buffer so that messages can be 
  * reviewed at a later time.
  */
-  int result;
   int proc_nr; 
   vir_bytes src;
   int count;
@@ -99,13 +98,9 @@ PUBLIC int do_diagnostics(message *m)
   int i = 0;
   static char diagbuf[10240];
 
-  /* Forward the message to the TTY driver. Inform the TTY driver about the
-   * original sender, so that it knows where the buffer to be printed is.
-   * The message type, DIAGNOSTICS, remains the same.
-   */ 
+  /* Change SELF to actual process number. */
   if ((proc_nr = m->DIAG_PROC_NR) == SELF)
       m->DIAG_PROC_NR = proc_nr = m->m_source;
-  result = _sendrec(TTY_PROC_NR, m);
 
   /* Now also make a copy for the private buffer at the LOG server, so
    * that the messages can be reviewed at a later time.
@@ -121,5 +116,5 @@ PUBLIC int do_diagnostics(message *m)
   }
   log_append(diagbuf, i);
 
-  return result;
+  return OK;
 }
diff --git a/include/minix/config.h b/include/minix/config.h
index 81985ac9e..afe8f342e 100755
--- a/include/minix/config.h
+++ b/include/minix/config.h
@@ -85,11 +85,16 @@
 #define ENABLE_BINCOMPAT   0	/* for binaries using obsolete calls */
 #define ENABLE_SRCCOMPAT   0	/* for sources using obsolete calls */
 
-/* Which process should receive diagnostics from the kernel and system? 
+/* Which processes should receive diagnostics from the kernel and system? 
  * Directly sending it to TTY only displays the output. Sending it to the
  * log driver will cause the diagnostics to be buffered and displayed.
+ * Messages are sent by src/lib/sysutil/kputc.c to these processes, in
+ * the order of this array, which must be terminated by NONE. This is used
+ * by drivers and servers that printf().
+ * The kernel does this for its own kprintf() in kernel/utility.c, also using
+ * this array, but a slightly different mechanism.
  */
-#define OUTPUT_PROC_NR	LOG_PROC_NR	/* TTY_PROC_NR or LOG_PROC_NR */
+#define OUTPUT_PROCS_ARRAY	{ TTY_PROC_NR, LOG_PROC_NR, NONE }
 
 /* NR_CONS, NR_RS_LINES, and NR_PTYS determine the number of terminals the
  * system can handle.
diff --git a/kernel/utility.c b/kernel/utility.c
index 5df0c4469..3faef77d8 100755
--- a/kernel/utility.c
+++ b/kernel/utility.c
@@ -139,7 +139,10 @@ int c;					/* character to append */
           kmess.km_size += 1;		
       kmess.km_next = (kmess.km_next + 1) % KMESS_BUF_SIZE;
   } else {
-      send_sig(OUTPUT_PROC_NR, SIGKMESS);
+      int p, outprocs[] = OUTPUT_PROCS_ARRAY;
+      for(p = 0; outprocs[p] != NONE; p++) {
+         send_sig(outprocs[p], SIGKMESS);
+      }
   }
 }
 
diff --git a/lib/sysutil/kputc.c b/lib/sysutil/kputc.c
index 0a52c2dc8..ca0e4457c 100644
--- a/lib/sysutil/kputc.c
+++ b/lib/sysutil/kputc.c
@@ -21,13 +21,17 @@ int c;
   message m;
 
   if ((c == 0 && buf_count > 0) || buf_count == sizeof(print_buf)) {
+	int procs[] = OUTPUT_PROCS_ARRAY;
+	int p;
 
-	/* Send the buffer to the OUTPUT_PROC_NR driver. */
-	m.DIAG_BUF_COUNT = buf_count;
-	m.DIAG_PRINT_BUF = print_buf;
-	m.DIAG_PROC_NR = SELF;
-	m.m_type = DIAGNOSTICS;
-	(void) _sendrec(OUTPUT_PROC_NR, &m);
+	for(p = 0; procs[p] != NONE; p++) {
+		/* Send the buffer to this output driver. */
+		m.DIAG_BUF_COUNT = buf_count;
+		m.DIAG_PRINT_BUF = print_buf;
+		m.DIAG_PROC_NR = SELF;
+		m.m_type = DIAGNOSTICS;
+		(void) _sendrec(procs[p], &m);
+	}
 	buf_count = 0;
 
 	/* If the output fails, e.g., due to an ELOCKED, do not retry output