static int ListenUsingMach(size_t noteCount, const char **noteNames)
// Implements the "listenMach" command. Register for the noteCount
// notifications whose names are in the noteNames array. Then read
// the notification Mach port, printing information about any
// notifications that arrive.
{
int retVal;
uint32_t noteErr;
size_t noteIndex;
int noteTokens[noteCount];
mach_port_t port = MACH_PORT_NULL;
// Register. The first time around this loop fd == -1 and so we don't
// specify NOTIFY_REUSE. notify_register_mach_port then allocates
// a Mach port and returns it in port. For subsequent iterations
// we /do/ specify NOTIFY_REUSE and notify_register_mach_port just
// reuses the existing port.
noteErr = NOTIFY_STATUS_OK;
for (noteIndex = 0; noteIndex < noteCount; noteIndex++) {
noteErr = notify_register_mach_port(
noteNames[noteIndex],
&port,
(port == MACH_PORT_NULL) ? 0 : NOTIFY_REUSE,
¬eTokens[noteIndex]
);
if (noteErr != NOTIFY_STATUS_OK) {
break;
}
}
if (noteErr != NOTIFY_STATUS_OK) {
PrintNotifyError("registration failed", noteNames[noteIndex], noteErr);
retVal = EXIT_FAILURE;
} else {
kern_return_t kr;
mach_msg_empty_rcv_t msg;
// Listen for and print any incoming notifications.
fprintf(stdout, "Listening using Mach:\n");
fflush(stdout);
do {
msg.header.msgh_local_port = port;
msg.header.msgh_size = sizeof(msg);
kr = mach_msg_receive(&msg.header);
if (kr == KERN_SUCCESS) {
PrintToken(msg.header.msgh_id, noteCount, noteTokens, noteNames);
}
} while (kr == KERN_SUCCESS);
fprintf(stderr, "error reading Mach message: %s (0x%x)\n", mach_error_string(kr), kr);
retVal = EXIT_FAILURE;
}
return retVal;
}
int
OSMemoryNotificationCreate(OSMemoryNotificationRef *note)
{
OSMemoryNotificationRef ref = malloc(sizeof(struct _OSMemoryNotification));
if (NULL == ref) {
return ENOMEM;
}
if (NOTIFY_STATUS_OK != notify_register_mach_port(kOSMemoryNotificationName, &ref->port, 0, &ref->token))
return ENOMEM;
*note = ref;
return 0;
}
static int ListenUsingCoreFoundation(size_t noteCount, const char **noteNames)
// Implements the "listenCF" command. Register for the noteCount
// notifications whose names are in the noteNames array. Then wrap the
// notification Mach port in a CFMachPort and use CF to read the notification
// messages, printing the information about any notifications that arrive
// from our CFMachPort callback.
{
int retVal;
uint32_t noteErr;
size_t noteIndex;
int noteTokens[noteCount];
mach_port_t port = MACH_PORT_NULL;
// Register. The first time around this loop fd == -1 and so we don't
// specify NOTIFY_REUSE. notify_register_mach_port then allocates
// a Mach port and returns it in port. For subsequent iterations
// we /do/ specify NOTIFY_REUSE and notify_register_mach_port just
// reuses the existing port.
noteErr = NOTIFY_STATUS_OK;
for (noteIndex = 0; noteIndex < noteCount; noteIndex++) {
noteErr = notify_register_mach_port(
noteNames[noteIndex],
&port,
(port == MACH_PORT_NULL) ? 0 : NOTIFY_REUSE,
¬eTokens[noteIndex]
);
if (noteErr != NOTIFY_STATUS_OK) {
break;
}
}
if (noteErr != NOTIFY_STATUS_OK) {
PrintNotifyError("registration failed", noteNames[noteIndex], noteErr);
retVal = EXIT_FAILURE;
} else {
MyCFMachPortCallBackInfo myInfo;
CFMachPortContext context = { 0 };
CFMachPortRef cfPort;
Boolean shouldFreeInfo;
CFRunLoopSourceRef rls;
// Set up the context structure for MyCFMachPortCallBack.
myInfo.magic = 'CFpI';
myInfo.noteCount = noteCount;
myInfo.noteTokens = noteTokens;
myInfo.noteNames = noteNames;
// Create the CFMachPort.
context.info = &myInfo;
cfPort = CFMachPortCreateWithPort(
NULL,
port,
MyCFMachPortCallBack,
&context,
&shouldFreeInfo
);
assert(cfPort != NULL);
// There can only be one CFMachPort for a given Mach port name. Thus,
// if someone had already created a CFMachPort for "port", CFMachPort
// would not create a new CFMachPort but, rather, return the existing
// CFMachPort with the retain count bumped. In that case it hasn't
// taken any 'reference' on the data in context; the context.info
// on the /previous/ CFMachPort is still in use, but the context.info
// that we supply is now superfluous. In that case it returns
// shouldFreeInfo, telling us that we don't need to hold on to this
// information.
//
// In this specific case no one should have already created a CFMachPort
// for "port", so shouldFreeInfo should never be true. If it is, it's
// time to worry!
assert( ! shouldFreeInfo );
// Add it to the run loop.
rls = CFMachPortCreateRunLoopSource(NULL, cfPort, 0);
assert(rls != NULL);
CFRunLoopAddSource(CFRunLoopGetCurrent(), rls, kCFRunLoopDefaultMode);
CFRelease(rls);
// Run the run loop.
fprintf(stdout, "Listening using Core Foundation:\n");
fflush(stdout);
CFRunLoopRun();
fprintf(stderr, "CFRunLoopRun returned\n");
retVal = EXIT_FAILURE;
}
return retVal;
}
