alarm_handler(3erl) [linux man page]
alarm_handler(3erl) Erlang Module Definition alarm_handler(3erl) NAME
alarm_handler - An Alarm Handling Process DESCRIPTION
The alarm handler process is a gen_event event manager process which receives alarms in the system. This process is not intended to be a complete alarm handler. It defines a place to which alarms can be sent. One simple event handler is installed in the alarm handler at start-up, but users are encouraged to write and install their own handlers. The simple event handler sends all alarms as info reports to the error logger, and saves all of them in a list which can be passed to a user defined event handler, which may be installed at a later stage. The list can grow large if many alarms are generated. So it is a good reason to install a better user defined handler. There are functions to set and clear alarms. The format of alarms are defined by the user. For example, an event handler for SNMP could be defined, together with an alarm MIB. The alarm handler is part of the SASL application. When writing new event handlers for the alarm handler, the following events must be handled: {set_alarm, {AlarmId, AlarmDescr}} : This event is generated by alarm_handler:set_alarm({AlarmId, AlarmDecsr}) . {clear_alarm, AlarmId} : This event is generated by alarm_handler:clear_alarm(AlarmId) . The default simple handler is called alarm_handler and it may be exchanged by calling gen_event:swap_handler/3 as gen_event:swap_han- dler(alarm_handler, {alarm_handler, swap}, {NewHandler, Args}) . NewHandler:init({Args, {alarm_handler, Alarms}}) is called. Refer to gen_event(3erl) for further details. EXPORTS
clear_alarm(AlarmId) -> void() Types AlarmId = term() Clears all alarms with id AlarmId . get_alarms() -> [alarm()] Returns a list of all active alarms. This function can only be used when the simple handler is installed. set_alarm(alarm()) Types alarm() = {AlarmId, AlarmDescription} AlarmId = term() AlarmDescription = term() Sets an alarm with id AlarmId . This id is used at a later stage when the alarm is cleared. SEE ALSO
error_logger(3erl), gen_event(3erl) Ericsson AB sasl 2.1.9.3 alarm_handler(3erl)
Check Out this Related Man Page
tsalarm(7D) Devices tsalarm(7D) NAME
tsalarm - Alarm device driver SYNOPSIS
tsalarm@0:ctl DESCRIPTION
The tsalarm driver is a Multi-threaded, loadable non-STREAMS pseudo driver that manages ALOM alarms. The tsalarm driver provides an inter- face through which alarm relays can be controlled on SUNW,Netra-240 and SUNW,Netra-440 platforms. HARDWARE INTERFACE
The alarm hardware differs depending on platform. The Netra 240 and 440 platforms features four dry contact alarm relays which are controlled by ALOM. You can set each alarm to "on" or "off" by using ioctl interfaces provided from the host. The four alarms are labeled as "critical," "major," "minor," and "user." The user alarm is set by a user application depending on system condition. LED's in front of the box provide a visual indication of the four alarms. The number of alarms and their meanings/labels may vary across platforms. IOCTLS
The interface provided by the tsalarm driver comprises ioctls that enable applications to manipulate the alarm module. The alarm module is accessed via two device nodes: i) /dev/lom and /dev/tsalarm:ctl. The following ioctls are supported by the /dev/lom and /dev/tsalarm:ctl devices: TSIOCALCTL - Turn an alarm on or off. The argument is a pointer to the ts_aldata_t/lom_aldata_t structure. This structure is described below. alarm_no member is an integer which specifies the alarm to which the command is to be applied. The alarm_state/state structure member indicates the state to which the alarm should be set (where 0 == off). An error (EINVAL) is returned if either an invalid alarm_no or invalid alarm_state is pro- vided. TSIOCALSTATE - Get the state of the alarms. The argument is a pointer to the ts_aldata_t/lom_aldata_t structure. This structure is described below. alarm_no member is an integer which indicates the alarm to which the command will be applied. The alarm_state member holds the alarm's current state and is filled in by the driver. A zero indicates that the alarm is off. An error (EINVAL) is returned if an invalid alarm_no is provided. The struc- tures and definitions for the values are defined below. Alarm values: The following old style values are defined in <lom.io.h> #define ALARM_NUM_0 0 /* number of zero'th alarm */ #define ALARM_NUM_1 1 /* number of first alarm */ #define ALARM_NUM_2 2 /* number of second alarm */ #define ALARM_NUM_3 3 /* number of third alarm */ Alarm values defined in <lom.io.h> #define ALARM_OFF 0 /* Turn off alarm */ #define ALARM_ON 1 /* Turn on alarm */ Alarm Data Structure: This structure is defined in <lom.io.h> typedef struct { int alarm_no; /* alarm to apply command to */ int alarm_state; /* state of alarm (0 == off) */ } ts_aldata_t; Use the following LOM interfaces to get and set the alarms. These definitions are included in <lom_io.h> #define ALARM_CRITICAL 0 /* number of critical alarm */ #define ALARM_MAJOR 1 /* number of major alarm */ #define ALARM_MINOR 2 /* number of minor alarm */ #define ALARM_USER 3 /* number of user alarm */ The following alarm data structure is provided in <lom_io.h>: typedef struct { int alarm_no; int state; } lom_aldata_t; ERRORS
An open() will fail if: ENXIO The driver is not installed in the system. An ioctl() will fail if: EFAULT There was a hardware failure during the specified operation. EINVAL The alarm number specified is not valid or an invalid value was supplied. ENXIO The driver is not installed in the system or the monitor callback routine could not be scheduled. EXAMPLES
How to set an alarm: #include <sys/unistd.h> #include <fcntl.h> #include <stdio.h> #include <lom_io.h> #define LOM_DEVICE "/dev/lom" int main() { lom_aldata_t lld; int fd = open(LOM_DEVICE, O_RDWR); if (fd == -1) { printf("Error opening device: %s0, LOM_DEVICE); exit(1); } lld.alarm_no = ALARM_CRITICAL; /* Set the critical alarm */ lld.state = ALARM_ON; /* Set the alarm */ if (ioctl(fd, LOMIOCALCTL, (char *)&lld) != 0) printf("Setting alarm failed"); else printf("Alarm set successfully"); close(fd); } FILES
/dev/lom LOM device. /dev/tsalarm:ctl Alarm control device. /platform/platform/kernel/drv/sparcv9/tsalarm Device driver module. /platform/SUNW,Netra-240/kernel/drv/tsalarm.conf Driver configuration file. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcarx.u | +-----------------------------+-----------------------------+ |Architecture |SPARC | +-----------------------------+-----------------------------+ SEE ALSO
attributes(5) Writing Device Drivers SunOS 5.10 16 Mar 2004 tsalarm(7D)