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//
// GTMSignalHandler.m
//
// Copyright 2008 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy
// of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
//
#import "GTMSignalHandler.h"
#import "GTMDefines.h"
#import <dispatch/dispatch.h>
#import "GTMDebugSelectorValidation.h"
#pragma clang diagnostic push
// Ignore all of the deprecation warnings for GTMSignalHandler
#pragma clang diagnostic ignored "-Wdeprecated-implementations"
// Simplifying assumption: No more than one handler for a particular signal is
// alive at a time. When the second signal is registered, kqueue just updates
// the info about the first signal, which makes -dealloc time complicated (what
// happens when handler1(SIGUSR1) is released before handler2(SIGUSR1)?). This
// could be solved by having one kqueue per signal, or keeping a list of
// handlers interested in a particular signal, but not really worth it for apps
// that register the handlers at startup and don't change them.
@implementation GTMSignalHandler
-(id)init {
// Folks shouldn't call init directly, so they get what they deserve.
_GTMDevLog(@"Don't call init, use "
@"initWithSignal:target:action:");
return [self initWithSignal:0 target:nil action:NULL];
}
- (id)initWithSignal:(int)signo
target:(id)target
action:(SEL)action {
if ((self = [super init])) {
if (signo == 0) {
[self release];
return nil;
}
GTMAssertSelectorNilOrImplementedWithArguments(target,
action,
@encode(int),
NULL);
// We're handling this signal via libdispatch, so turn off the usual signal
// handling.
if (signal(signo, SIG_IGN) == SIG_ERR) {
_GTMDevLog(@"could not ignore signal %d. Errno %d", signo, errno); // COV_NF_LINE
}
if (action != NULL) {
signalSource_ = dispatch_source_create(DISPATCH_SOURCE_TYPE_SIGNAL,
signo,
0,
dispatch_get_main_queue());
dispatch_source_set_event_handler(signalSource_, ^(void) {
NSMethodSignature *methodSig
= [target methodSignatureForSelector:action];
_GTMDevAssert(methodSig != nil, @"failed to get the signature?");
NSInvocation *invocation
= [NSInvocation invocationWithMethodSignature:methodSig];
[invocation setTarget:target];
[invocation setSelector:action];
[invocation setArgument:(void*)&signo atIndex:2];
[invocation invoke];
});
dispatch_resume(signalSource_);
}
}
return self;
}
- (void)dealloc {
[self invalidate];
[super dealloc];
}
- (void)invalidate {
if (signalSource_) {
dispatch_source_cancel(signalSource_);
dispatch_release(signalSource_);
signalSource_ = NULL;
}
}
@end
#pragma clang diagnostic pop
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