Requesting +and Cancelling Monitoring for a Process

Example

The +following code fragment illustrates how a client can request monitoring using +SHMA, specifying that the monitored process must be restarted in the event +of failure and that, if it cannot be restarted, the device must be rebooted.

... +// Monitoring a process using SysMon. + +LIT( KMonitoredProcess, "monitoredprocess.exe" ); + +// Properties for the application +CSsmStartupProperties *ssmProp = CSsmStartupProperties::NewLC( KMonitoredProcess, KNullDesC ); + +//ESsmWaitForSignal is the execution behaviour for starting the process. +ssmProp->SetExecutionBehaviour( ESsmWaitForSignal ); +TSsmMonitorInfo monitorInfo; +monitorInfo.iRestartPolicy = ESsmRestartOS; + +//Startup mode to restart the OS +monitorInfo.iRestartMode = 0; + +//Infinite time-out +monitorInfo.iTimeout = 0; + +//No of retries if an application or a process fails to start. +monitorInfo.iRetries = 1; + +ssmProp->SetMonitorInfoL( monitorInfo ); + +RProcess process; + +TInt err = process.Create( KMonitoredProcess, KNullDesC ); +User::LeaveIfError( err ); +CleanupClosePushL( &process ); +process.Resume(); + +// instantiate a session +RSysMonSession sess; + +//Open a session +sess.OpenL(); + +//Create a monitor for the session +TRAP( err, sess.MonitorL( *ssmProp, process ) ); +sess.Close(); +CleanupStack::PopAndDestroy( 2, ssmProp );

The following +code fragments illustrate the structs in a resource file used for process +monitoring:

STRUCT SSM_START_APP_INFO + { + // Must be the first entry in this struct - Zero means command is unconditional + LLINK conditional_information = 0; + // Must be the second entry in this struct and must not be changed + WORD type = ESsmCmdStartApp; + #ifndef SYMBIAN_SSM_FLEXIBLE_MERGE + // Must be the third entry in this struct + WORD version = ECmdStartAppInitialVersion; + #else + // This version supports priority of the command + WORD version = ECmdStartAppVersionWithPriority; + #endif + // Can have a higher severity defined in TCmdErrorSeverity + WORD severity = ECmdIgnoreFailure; + // VALUE REQUIRED - full path to the application + LTEXT name = ""; + // Passed to the "Tail End" at the command line + // see CApaCommandLine. Maximum argument length allowed is 256 chars. + LTEXT args = ""; + // Can also be ESsmWaitForSignal or ESsmDeferredWaitForSignal + BYTE execution_behaviour = ESsmFireAndForget; + // Time in milliseconds for every retry on failure + LONG timeout = 0; + // Number of times to retry on failure + WORD retries = 0; + // Set to 1 if app is viewless + BYTE viewless = 0; + // Set to 1 if app should be launched in the background + BYTE background = 0; + // zero means no monitoring is required, SSM_MONITOR_INFO + // should be used if monitoring is required + LLINK monitor_info = 0; + #ifdef SYMBIAN_SSM_FLEXIBLE_MERGE + // The order of the command in the list - range can be from 0x00 to 0xffffu + WORD priority = KDefaultCommandPriority; + #endif + } + +/** +Struct for starting processes. + +STRUCT SSM_START_PROCESS_INFO + { + // Must be the first entry in this struct - Zero means + // command is unconditional + LLINK conditional_information = 0; + // Must be the second entry in this struct and must not be changed + WORD type = ESsmCmdStartProcess; + #ifndef SYMBIAN_SSM_FLEXIBLE_MERGE + // Must be the third entry in this struct + WORD version = ECmdStartProcessInitialVersion; + #else + // This version supports priority of the command + WORD version = ECmdStartProcessVersionWithPriority; + #endif + // Can have a higher severity defined in TCmdErrorSeverity + WORD severity = ECmdIgnoreFailure; + // VALUE REQUIRED - full path to the process + LTEXT name = ""; + // Passed to the "Tail End" at the command line + // see CApaCommandLine. Maximum argument length allowed is 256 chars. + LTEXT args = ""; + // Can also be ESsmWaitForSignal or ESsmDeferredWaitForSignal + BYTE execution_behaviour = ESsmFireAndForget; + // Time in milliseconds for every retry on failure + LONG timeout = 0; + // Number of times to retry on failure + WORD retries = 0; + // zero means no monitoring is required, + // SSM_MONITOR_INFO should be used if monitoring is required + LLINK monitor_info = 0; + #ifdef SYMBIAN_SSM_FLEXIBLE_MERGE + // The order of the command in the list - range can be from 0x00 to 0xffffu + WORD priority = KDefaultCommandPriority; + #endif + } /** +Struct for monitoring information. + +STRUCT SSM_MONITOR_INFO + { + // Must be the first entry in this struct and must not be changed + WORD type = ESsmMonitorInfo; + // Must be the second entry in this struct + WORD version = ESsmMonitorInfoInitialVersion; + // OS Restart policy to be used if component restarting has failed + BYTE restart_policy = ESsmIgnoreOnFailure; + // Restart mode when restart_policy=ESsmRestartOSWithMode + BYTE restart_mode; + // Delay in milliseconds between retries + LONG timeout = 0; + // Number of times to attempt to restart a failed component + WORD retries = 0; + }