diff options
author | Miles Bader <miles@gnu.org> | 1995-12-11 04:34:06 +0000 |
---|---|---|
committer | Miles Bader <miles@gnu.org> | 1995-12-11 04:34:06 +0000 |
commit | 0b2b7a65c86306c656ac4809f310543c3d1b58d6 (patch) | |
tree | f51a5f72c7807f568c2eef19647f1593d2e71052 /boot | |
parent | c4778301f3628f7fac367a4e6416d5df633ffc2a (diff) |
(should_read): New variable.
(read_reply):
Set SHOULD_READ before attempting lock.
Use spin_try_lock() instead of spin_lock(), and abort if we can't get it.
Clear SHOULD_READ after getting the lock.
(ds_device_read, ds_device_read_inband, S_io_read):
Call unlock_readlock instead of directly unlocking READLOCK.
Don't block SIGIO.
(unlock_readlock): New function.
(main): Don't trap SIGMSG & SIGEMSG.
(SIGMSG, SIGEMSG): Macros deleted.
Diffstat (limited to 'boot')
-rw-r--r-- | boot/boot.c | 64 |
1 files changed, 36 insertions, 28 deletions
diff --git a/boot/boot.c b/boot/boot.c index 7daf66c2..192f4053 100644 --- a/boot/boot.c +++ b/boot/boot.c @@ -263,8 +263,7 @@ struct sgttyb #define SIGIO 23 -#define SIGEMSG 30 -#define SIGMSG 31 + struct sigvec { void (*sv_handler)(); @@ -370,11 +369,11 @@ request_server (mach_msg_header_t *inp, } else #endif - return (io_server (inp, outp) - || device_server (inp, outp) - || notify_server (inp, outp) - || term_server (inp, outp) -/* || tioctl_server (inp, outp) */); + return (io_server (inp, outp) + || device_server (inp, outp) + || notify_server (inp, outp) + || term_server (inp, outp) + /* || tioctl_server (inp, outp) */); } vm_address_t @@ -737,8 +736,6 @@ main (int argc, char **argv, char **envp) init_termstate (); ioctl (0, FIOASYNC, &foo); sigvec (SIGIO, &vec, 0); - sigvec (SIGMSG, &vec, 0); - sigvec (SIGEMSG, &vec, 0); /* The boot script has now been parsed into internal data structures. Now execute its directives. */ @@ -1009,6 +1006,10 @@ queue_read (enum read_type type, spin_unlock (&queuelock); } +/* TRUE if there's data available on stdin, which should be used to satisfy + console read requests. */ +static int should_read = 0; + /* Reply to a queued read. */ void read_reply () @@ -1018,7 +1019,16 @@ read_reply () char * buf; int amtread; - spin_lock (&readlock); + /* By forcing SHOULD_READ to true before trying the lock, we ensure that + either we get the lock ourselves or that whoever currently holds the + lock will service this read when he unlocks it. */ + should_read = 1; + if (! spin_try_lock (&readlock)) + return; + + /* Since we're commited to servicing the read, no one else need do so. */ + should_read = 0; + ioctl (0, FIONREAD, &avail); if (!avail) { @@ -1081,6 +1091,16 @@ read_reply () free (qr); } +/* Unlock READLOCK, and also service any new read requests that it was + blocking. */ +static void +unlock_readlock () +{ + spin_unlock (&readlock); + while (should_read) + read_reply (); +} + /* * Handle bootstrap requests. */ @@ -1411,7 +1431,6 @@ ds_device_read (device_t device, unsigned int *datalen) { int avail; - int mask; if (device != pseudo_console) return D_NO_SUCH_DEVICE; @@ -1425,22 +1444,19 @@ ds_device_read (device_t device, } #endif - mask = sigblock (sigmask (SIGIO)); spin_lock (&readlock); ioctl (0, FIONREAD, &avail); if (avail) { vm_allocate (mach_task_self (), (pointer_t *)data, bytes_wanted, 1); *datalen = read (0, *data, bytes_wanted); - spin_unlock (&readlock); - sigsetmask (mask); + unlock_readlock (); return (*datalen == -1 ? D_IO_ERROR : D_SUCCESS); } else { - spin_unlock (&readlock); + unlock_readlock (); queue_read (DEV_READ, reply_port, reply_type, bytes_wanted); - sigsetmask (mask); return MIG_NO_REPLY; } } @@ -1456,7 +1472,6 @@ ds_device_read_inband (device_t device, unsigned int *datalen) { int avail; - int mask; if (device != pseudo_console) return D_NO_SUCH_DEVICE; @@ -1470,21 +1485,18 @@ ds_device_read_inband (device_t device, } #endif - mask = sigblock (sigmask (SIGIO)); spin_lock (&readlock); ioctl (0, FIONREAD, &avail); if (avail) { *datalen = read (0, data, bytes_wanted); - spin_unlock (&readlock); - sigsetmask (mask); + unlock_readlock (); return (*datalen == -1 ? D_IO_ERROR : D_SUCCESS); } else { - spin_unlock (&readlock); + unlock_readlock (); queue_read (DEV_READI, reply_port, reply_type, bytes_wanted); - sigsetmask (mask); return MIG_NO_REPLY; } } @@ -1691,7 +1703,6 @@ S_io_read (mach_port_t object, mach_msg_type_number_t amount) { mach_msg_type_number_t avail; - int mask; if (object != pseudo_console) return EOPNOTSUPP; @@ -1705,7 +1716,6 @@ S_io_read (mach_port_t object, } #endif - mask = sigblock (sigmask (SIGIO)); spin_lock (&readlock); ioctl (0, FIONREAD, &avail); if (avail) @@ -1713,15 +1723,13 @@ S_io_read (mach_port_t object, if (amount > *datalen) vm_allocate (mach_task_self (), (vm_address_t *) data, amount, 1); *datalen = read (0, *data, amount); - spin_unlock (&readlock); - sigsetmask (mask); + unlock_readlock (); return *datalen == -1 ? errno : 0; } else { - spin_unlock (&readlock); + unlock_readlock (); queue_read (IO_READ, reply_port, reply_type, amount); - sigsetmask (mask); return MIG_NO_REPLY; } } |