mojave man page for os_activity_initiate_f

os_activity_initiate(3) 				   BSD Library Functions Manual 				   os_activity_initiate(3)

NAME
     os_activity_initiate, os_activity_initiate_f -- activity related routines

SYNOPSIS
     #include <os/activity.h>

     void
     os_activity_initiate(const char *description, uint32_t flags, void (^activity_block)(void));

     void
     os_activity_initiate_f(const char *description, uint32_t flags, void *ctx, void function(void *ctx));

DESCRIPTION
     An activity is essentially an identifier that is created by the system. The identifier is transported with work via GCD, XPC and other mecha-
     nisms.  The identifier simplifies debugging programs since it correlates the trace and log messages to the area in question. Although an
     activity appears to have a start/end, it is only finished when no other work related to it is enqueued to be processed. Activity functions
     only allow constant strings for performance and privacy, similar to os_trace(3).

     Supported Activity Name:

	   os_activity_initiate("indexing database", OS_ACTIVITY_FLAG_DEFAULT, ^(void) {
		   [self indexDatabase];
	   });

     Unsupported Activity Name:

	   snprintf(buffer, "indexing database for %s", username);
	   os_activity_initiate(buffer, OS_ACTIVITY_FLAG_DEFAULT, ^(void) {
		   [self indexDatabase];
	   });

     os_activity_initiate and os_activity_initiate_f wraps the block or function with a new activity.

EXAMPLES
     Example use of activity with a message.

	   #include <os/trace.h>
	   #include <os/activity.h>

	   - (IBOutlet) indexDatabase:(id) sender {
		   os_activity_initiate("index database", OS_ACTIVITY_FLAG_DEFAULT, ^{
			   os_trace("re-indexing database for %d", self.uid);

			   [self reIndex: self.uid];
		   });
	   }

SEE ALSO
     os_trace(3), os_log(3)

Darwin								   June 1, 2019 							    Darwin