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authorDenis Vlasenko <vda.linux@googlemail.com>2008-12-01 15:31:22 +0000
committerDenis Vlasenko <vda.linux@googlemail.com>2008-12-01 15:31:22 +0000
commit0e4d4dd89170d47a662f1cd0de1b4f3a5dbc1f2d (patch)
tree324429d9476664c8dff6d315daaf98b4a011c48d /libc/pwd_grp/lckpwdf.c
parent4298bd6e30f8841250f4912fdbda7a4a2230b561 (diff)
optimize signal mask ops. comment out "impossible" errors
text data bss dec hex filename - 1179 13 2 1194 4aa libc/misc/syslog/syslog.o + 1165 13 2 1180 49c libc/misc/syslog/syslog.o - 435 4 0 439 1b7 libc/pwd_grp/lckpwdf.o + 393 4 0 397 18d libc/pwd_grp/lckpwdf.o - 38 0 0 38 26 libc/signal/sigandset.o + 32 0 0 32 20 libc/signal/sigandset.o - 63 0 0 63 3f libc/signal/sigblock.o + 56 0 0 56 38 libc/signal/sigblock.o - 22 0 0 22 16 libc/signal/sigempty.o + 20 0 0 20 14 libc/signal/sigempty.o - 25 0 0 25 19 libc/signal/sigfillset.o + 20 0 0 20 14 libc/signal/sigfillset.o - 34 0 0 34 22 libc/signal/sigisempty.o + 16 0 0 16 10 libc/signal/sigisempty.o - 38 0 0 38 26 libc/signal/sigorset.o + 32 0 0 32 20 libc/signal/sigorset.o - 119 0 0 119 77 libc/signal/sigpause.o + 113 0 0 113 71 libc/signal/sigpause.o - 215 0 0 215 d7 libc/signal/sigset.o + 211 0 0 211 d3 libc/signal/sigset.o - 63 0 0 63 3f libc/signal/sigsetmask.o + 56 0 0 56 38 libc/signal/sigsetmask.o - 194 0 1 195 c3 libc/stdlib/abort.o + 183 0 1 184 b8 libc/stdlib/abort.o - 323 0 0 323 143 libc/unistd/sleep.o + 309 0 0 309 135 libc/unistd/sleep.o
Diffstat (limited to 'libc/pwd_grp/lckpwdf.c')
-rw-r--r--libc/pwd_grp/lckpwdf.c42
1 files changed, 23 insertions, 19 deletions
diff --git a/libc/pwd_grp/lckpwdf.c b/libc/pwd_grp/lckpwdf.c
index a9601d45d..41987ca5d 100644
--- a/libc/pwd_grp/lckpwdf.c
+++ b/libc/pwd_grp/lckpwdf.c
@@ -39,11 +39,9 @@
/* libc_hidden_proto(sigemptyset) */
/* libc_hidden_proto(alarm) */
-/* How long to wait for getting the lock before returning with an
- error. */
+/* How long to wait for getting the lock before returning with an error. */
#define TIMEOUT 15 /* sec */
-
/* File descriptor for lock file. */
static int lock_fd = -1;
@@ -51,7 +49,6 @@ static int lock_fd = -1;
#include <bits/uClibc_mutex.h>
__UCLIBC_MUTEX_STATIC(mylock, PTHREAD_MUTEX_INITIALIZER);
-
/* Prototypes for local functions. */
static void noop_handler (int __sig);
@@ -82,33 +79,39 @@ lckpwdf (void)
}
/* Make sure file gets correctly closed when process finished. */
- flags = fcntl (lock_fd, F_GETFD, 0);
+ flags = fcntl (lock_fd, F_GETFD);
+#if 0 /* never fails */
if (flags == -1) {
/* Cannot get file flags. */
close(lock_fd);
lock_fd = -1;
goto DONE;
}
- flags |= FD_CLOEXEC; /* Close on exit. */
+#endif
+ flags |= FD_CLOEXEC;
+#if 1
+ fcntl (lock_fd, F_SETFD, flags);
+#else /* never fails */
if (fcntl (lock_fd, F_SETFD, flags) < 0) {
/* Cannot set new flags. */
close(lock_fd);
lock_fd = -1;
goto DONE;
}
-
+#endif
/* Now we have to get exclusive write access. Since multiple
process could try this we won't stop when it first fails.
Instead we set a timeout for the system call. Once the timer
expires it is likely that there are some problems which cannot be
- resolved by waiting.
+ resolved by waiting. (sa_flags have no SA_RESTART. Thus SIGALRM
+ will EINTR fcntl(F_SETLKW)
It is important that we don't change the signal state. We must
restore the old signal behaviour. */
memset (&new_act, '\0', sizeof (struct sigaction));
new_act.sa_handler = noop_handler;
- sigfillset (&new_act.sa_mask);
- new_act.sa_flags = 0ul;
+ __sigfillset (&new_act.sa_mask);
+ /* new_act.sa_flags = 0; */
/* Install new action handler for alarm and save old. */
if (sigaction (SIGALRM, &new_act, &saved_act) < 0) {
@@ -119,34 +122,35 @@ lckpwdf (void)
}
/* Now make sure the alarm signal is not blocked. */
- sigemptyset (&new_set);
+ __sigemptyset (&new_set);
sigaddset (&new_set, SIGALRM);
+#if 1
+ sigprocmask (SIG_UNBLOCK, &new_set, &saved_set);
+#else /* never fails */
if (sigprocmask (SIG_UNBLOCK, &new_set, &saved_set) < 0) {
sigaction (SIGALRM, &saved_act, NULL);
close(lock_fd);
lock_fd = -1;
goto DONE;
}
+#endif
/* Start timer. If we cannot get the lock in the specified time we
get a signal. */
alarm (TIMEOUT);
/* Try to get the lock. */
- memset (&fl, '\0', sizeof (struct flock));
- fl.l_type = F_WRLCK;
- fl.l_whence = SEEK_SET;
+ memset (&fl, '\0', sizeof (fl));
+ if (F_WRLCK)
+ fl.l_type = F_WRLCK;
+ if (SEEK_SET)
+ fl.l_whence = SEEK_SET;
result = fcntl (lock_fd, F_SETLKW, &fl);
/* Clear alarm. */
alarm (0);
- /* Restore old set of handled signals. We don't need to know
- about the current one.*/
sigprocmask (SIG_SETMASK, &saved_set, NULL);
-
- /* Restore old action handler for alarm. We don't need to know
- about the current one. */
sigaction (SIGALRM, &saved_act, NULL);
if (result < 0) {