Change the return value of sema_timedwait() so it returns 0 on
success and a proper errno value on failure. This makes it consistent with cv_timedwait(), and paves the way for the introduction of functions such as sema_timedwait_sig() which can fail in multiple ways. Bump __FreeBSD_version and add a note to UPDATING. Approved by: scottl (ips driver), arch
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Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=130481
6
UPDATING
6
UPDATING
@ -17,6 +17,12 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 5.x IS SLOW:
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developers choose to disable these features on build machines
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to maximize performance.
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20040614:
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The return value of sema_timedwait(9) has been changed to
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make it consistent with cv_timedwait(9). Be sure to recompile
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the ips module and any third-party modules which call
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sema_timedwait.
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20040613:
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ALTQ is now linked to the build. This breaks ABI for struct ifnet.
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Make sure to recompile modules and any userland that makes use of
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@ -98,13 +98,26 @@ argument to
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.Fn sema_timedwait
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specifies the minimum time in ticks to wait before returning with failure.
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.Fn sema_value
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is used to read the current value of the semaphore.
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.Sh RETURN VALUES
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.Fn sema_value
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returns the current value of the semaphore.
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.Pp
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.Fn sema_timedwait
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and
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If decrementing the semaphore would result in its value being negative,
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.Fn sema_trywait
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will return 0 if waiting on the semaphore failed; otherwise a non-zero value
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will be returned to indicate success.
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returns 0 to indicate failure.
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Otherwise, a non-zero value is returned to indicate success.
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.Pp
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.Fn sema_timedwait
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returns 0 if waiting on the semaphore succeeded; otherwise a
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non-zero error code is returned.
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.Sh ERRORS
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.Fn sema_timedwait
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will fail if:
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.Bl -tag -width Er
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.It Bq Er EWOULDBLOCK
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Timeout expired.
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.El
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.Sh SEE ALSO
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.Xr condvar 9 ,
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.Xr mtx_pool 9 ,
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@ -248,7 +248,7 @@ static int ips_send_adapter_info_cmd(ips_command_t *command)
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ips_adapter_info_callback, command, BUS_DMA_NOWAIT);
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if ((status->value == IPS_ERROR_STATUS) ||
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(sema_timedwait(&command->cmd_sema, 30*hz) == 0))
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(sema_timedwait(&command->cmd_sema, 30*hz) != 0))
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error = ETIMEDOUT;
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if (error == 0) {
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@ -352,7 +352,7 @@ static int ips_send_drive_info_cmd(ips_command_t *command)
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command->data_buffer,IPS_DRIVE_INFO_LEN,
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ips_drive_info_callback, command, BUS_DMA_NOWAIT);
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if ((status->value == IPS_ERROR_STATUS) ||
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(sema_timedwait(&command->cmd_sema, 10*hz) == 0))
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(sema_timedwait(&command->cmd_sema, 10*hz) != 0))
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error = ETIMEDOUT;
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if (error == 0) {
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@ -606,7 +606,7 @@ static int ips_read_nvram(ips_command_t *command){
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command->data_buffer,IPS_NVRAM_PAGE_SIZE,
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ips_read_nvram_callback, command, BUS_DMA_NOWAIT);
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if ((status->value == IPS_ERROR_STATUS) ||
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(sema_timedwait(&command->cmd_sema, 30*hz) == 0))
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(sema_timedwait(&command->cmd_sema, 30*hz) != 0))
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error = ETIMEDOUT;
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if (error == 0) {
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@ -108,7 +108,7 @@ _sema_wait(struct sema *sema, const char *file, int line)
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int
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_sema_timedwait(struct sema *sema, int timo, const char *file, int line)
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{
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int ret, timed_out;
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int error;
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mtx_lock(&sema->sema_mtx);
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@ -118,27 +118,25 @@ _sema_timedwait(struct sema *sema, int timo, const char *file, int line)
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* continuously, since the timeout period is merely a lower bound on how
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* long to wait.
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*/
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for (timed_out = 0; sema->sema_value == 0 && timed_out == 0;) {
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for (error = 0; sema->sema_value == 0 && error == 0;) {
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sema->sema_waiters++;
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timed_out = cv_timedwait(&sema->sema_cv, &sema->sema_mtx, timo);
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error = cv_timedwait(&sema->sema_cv, &sema->sema_mtx, timo);
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sema->sema_waiters--;
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}
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if (sema->sema_value > 0) {
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/* Success. */
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sema->sema_value--;
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ret = 1;
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error = 0;
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CTR6(KTR_LOCK, "%s(%p) \"%s\" v = %d at %s:%d", __func__, sema,
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cv_wmesg(&sema->sema_cv), sema->sema_value, file, line);
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} else {
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ret = 0;
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CTR5(KTR_LOCK, "%s(%p) \"%s\" fail at %s:%d", __func__, sema,
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cv_wmesg(&sema->sema_cv), file, line);
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}
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mtx_unlock(&sema->sema_mtx);
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return (ret);
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return (error);
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}
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int
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@ -55,7 +55,7 @@
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* scheme is: <major><two digit minor><0 if release branch, otherwise 1>xx
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*/
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#undef __FreeBSD_version
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#define __FreeBSD_version 502114 /* Master, propagated to newvers */
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#define __FreeBSD_version 502115 /* Master, propagated to newvers */
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#ifndef LOCORE
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#include <sys/types.h>
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