xnu-2782.30.5.tar.gz

[apple/xnu.git] / bsd / kern / subr_log.c

diff --git a/bsd/kern/subr_log.c b/bsd/kern/subr_log.c
index 2cd5c3ac2e69d6928be17bba8b55226b15c99244..0f8c00b3696b7baed5ea4b4703f509de61ded2aa 100644 (file)
--- a/bsd/kern/subr_log.c
+++ b/bsd/kern/subr_log.c
@@ -84,7 +84,6 @@
 #include <pexpert/pexpert.h>
 
 /* XXX should be in a common header somewhere */
-extern void klogwakeup(void);
 extern void logwakeup(void);
 
 #define LOG_RDPRI      (PZERO + 1)
@@ -93,6 +92,7 @@ extern void logwakeup(void);
 #define LOG_ASYNC      0x04
 #define LOG_RDWAIT     0x08
 
+#define MAX_UNREAD_CHARS (CONFIG_MSG_BSIZE/2)
 /* All globals should be accessed under LOG_LOCK() */
 
 /* logsoftc only valid while log_open=1 */
@@ -105,8 +105,7 @@ struct logsoftc {
 int    log_open;                       /* also used in log() */
 char smsg_bufc[CONFIG_MSG_BSIZE]; /* static buffer */
 struct msgbuf msgbuf = {MSG_MAGIC,sizeof(smsg_bufc),0,0,smsg_bufc};
-struct msgbuf *msgbufp = &msgbuf;
-static int logentrypend = 0;
+struct msgbuf *msgbufp __attribute__((used)) = &msgbuf;
 
 /* the following are implemented in osfmk/kern/printf.c  */
 extern void bsd_log_lock(void);
@@ -189,8 +188,7 @@ logread(__unused dev_t dev, struct uio *uio, int flag)
                logsoftc.sc_state |= LOG_RDWAIT;
                LOG_UNLOCK();
                /*
-                * If the wakeup is missed the ligtening bolt will wake this up 
-                * if there are any new characters. If that doesn't do it
+                * If the wakeup is missed 
                 * then wait for 5 sec and reevaluate 
                 */
                if ((error = tsleep((caddr_t)msgbufp, LOG_RDPRI | PCATCH,
@@ -275,18 +273,6 @@ logwakeup(void)
        LOG_UNLOCK();
 }
 
-void
-klogwakeup(void)
-{
-       LOG_LOCK();
-       if (logentrypend && log_open) {
-               logentrypend = 0; /* only reset if someone will be reading */
-               LOG_UNLOCK();
-               logwakeup();
-       } else {
-               LOG_UNLOCK();
-       }
-}
 
 /*ARGSUSED*/
 int
@@ -364,7 +350,6 @@ log_putc_locked(char c)
 
        mbp = msgbufp; 
        mbp->msg_bufc[mbp->msg_bufx++] = c;
-       logentrypend = 1;
        if (mbp->msg_bufx >= msgbufp->msg_size)
                mbp->msg_bufx = 0;
 }
@@ -386,9 +371,16 @@ log_putc_locked(char c)
 void
 log_putc(char c)
 {
+       int unread_count = 0;
        LOG_LOCK();
        log_putc_locked(c);
+       unread_count = msgbufp->msg_bufx - msgbufp->msg_bufr;
        LOG_UNLOCK();
+
+       if (unread_count < 0)
+               unread_count = 0 - unread_count;
+       if (c == '\n' || unread_count >= MAX_UNREAD_CHARS)
+               logwakeup();
 }