This chapter describes the predefined global variables of DPCL. There are certain probe expressions that are defined automatically by the DPCL system and are made available to analysis tools through the header file AisGlobal.h (the global variable Ais_msg_handle and the global function Ais_send). These expressions are used by probes to send information back the the analysis tool.
Synopsis
#include <AisGlobal.h> extern const ProbeExp Ais_msg_handle;
Description
This constant represents a probe-specific value that is used to send messages from the probe to the client. Each probe is able to send messages to the client any time the probe is invoked. The client is able to distinguish between messages from one probe and messages from another. Furthermore, more than one client can be connected to an application process, and the probe must maintain some record of the client to whom it belongs. All the necessary information to accomplish these things is stored in the probe message handle. The probe message handle is used as the first argument to the Ais_send function, that sends a message to the client, to be processed by a client data callback function.
See Also
Ais_send
Synopsis
#include <AisGlobal.h> extern const ProbeExp Ais_send;
Description
This constant represents a function that allows probes to send messages to the client. The function may be executed directly by the probe as any other function. The type signature for the send function is:
void Ais_send( void *msg_handle, char *buffer, int size )
where msg_handle is the constant Ais_msg_handle, buffer is the message to be sent, and size is the number of bytes in the message.
See Also
Ais_msg_handle, ProbeExp::call