// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//


/*	CFMessagePort.c
	Copyright (c) 1998 - 2015 Apple Inc. and the Swift project authors
	Responsibility: Christopher Kane
*/

#include <CoreFoundation/CFMessagePort.h>
#include <CoreFoundation/CFRunLoop.h>
#include <CoreFoundation/CFMachPort.h>
#include <CoreFoundation/CFDictionary.h>
#include <CoreFoundation/CFByteOrder.h>
#include <limits.h>
#include "CFInternal.h"
#include <mach/mach.h>
#include <mach/message.h>
#include <mach/mach_error.h>
#include <math.h>
#include <mach/mach_time.h>
#include <dlfcn.h>
#if __HAS_DISPATCH__
#include <dispatch/dispatch.h>
#if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED
#include <dispatch/private.h>
#endif
#endif

extern pid_t getpid(void);

#define __kCFMessagePortMaxNameLengthMax 255

#if defined(BOOTSTRAP_MAX_NAME_LEN)
    #define __kCFMessagePortMaxNameLength BOOTSTRAP_MAX_NAME_LEN
#else
    #define __kCFMessagePortMaxNameLength 128
#endif

#if __kCFMessagePortMaxNameLengthMax < __kCFMessagePortMaxNameLength
    #undef __kCFMessagePortMaxNameLength
    #define __kCFMessagePortMaxNameLength __kCFMessagePortMaxNameLengthMax
#endif

#define __CFMessagePortMaxDataSize 0x60000000L

static CFLock_t __CFAllMessagePortsLock = CFLockInit;
static CFMutableDictionaryRef __CFAllLocalMessagePorts = NULL;
static CFMutableDictionaryRef __CFAllRemoteMessagePorts = NULL;

struct __CFMessagePort {
    CFRuntimeBase _base;
    CFLock_t _lock;
    CFStringRef _name;
    CFMachPortRef _port;		/* immutable; invalidated */
    CFMutableDictionaryRef _replies;
    int32_t _convCounter;
    int32_t _perPID;			/* zero if not per-pid, else pid */
    CFMachPortRef _replyPort;		/* only used by remote port; immutable once created; invalidated */
    CFRunLoopSourceRef _source;		/* only used by local port; immutable once created; invalidated */
#if __HAS_DISPATCH__
    dispatch_source_t _dispatchSource;  /* only used by local port; invalidated */
    dispatch_queue_t _dispatchQ;	/* only used by local port */
#endif
    CFMessagePortInvalidationCallBack _icallout;
    CFMessagePortCallBack _callout;	/* only used by local port; immutable */
    CFMessagePortCallBackEx _calloutEx;	/* only used by local port; immutable */
    CFMessagePortContext _context;	/* not part of remote port; immutable; invalidated */
};

/* Bit 0 in the base reserved bits is used for invalid state */
/* Bit 1 of the base reserved bits is used for has-extra-port-refs state */
/* Bit 2 of the base reserved bits is used for is-remote state */
/* Bit 3 in the base reserved bits is used for is-deallocing state */

CF_INLINE Boolean __CFMessagePortIsValid(CFMessagePortRef ms) {
    return (Boolean)__CFBitfieldGetValue(((const CFRuntimeBase *)ms)->_cfinfo[CF_INFO_BITS], 0, 0);
}

CF_INLINE void __CFMessagePortSetValid(CFMessagePortRef ms) {
    __CFBitfieldSetValue(((CFRuntimeBase *)ms)->_cfinfo[CF_INFO_BITS], 0, 0, 1);
}

CF_INLINE void __CFMessagePortUnsetValid(CFMessagePortRef ms) {
    __CFBitfieldSetValue(((CFRuntimeBase *)ms)->_cfinfo[CF_INFO_BITS], 0, 0, 0);
}

CF_INLINE Boolean __CFMessagePortExtraMachRef(CFMessagePortRef ms) {
    return (Boolean)__CFBitfieldGetValue(((const CFRuntimeBase *)ms)->_cfinfo[CF_INFO_BITS], 1, 1);
}

CF_INLINE void __CFMessagePortSetExtraMachRef(CFMessagePortRef ms) {
    __CFBitfieldSetValue(((CFRuntimeBase *)ms)->_cfinfo[CF_INFO_BITS], 1, 1, 1);
}

CF_INLINE void __CFMessagePortUnsetExtraMachRef(CFMessagePortRef ms) {
    __CFBitfieldSetValue(((CFRuntimeBase *)ms)->_cfinfo[CF_INFO_BITS], 1, 1, 0);
}

CF_INLINE Boolean __CFMessagePortIsRemote(CFMessagePortRef ms) {
    return (Boolean)__CFBitfieldGetValue(((const CFRuntimeBase *)ms)->_cfinfo[CF_INFO_BITS], 2, 2);
}

CF_INLINE void __CFMessagePortSetRemote(CFMessagePortRef ms) {
    __CFBitfieldSetValue(((CFRuntimeBase *)ms)->_cfinfo[CF_INFO_BITS], 2, 2, 1);
}

CF_INLINE void __CFMessagePortUnsetRemote(CFMessagePortRef ms) {
    __CFBitfieldSetValue(((CFRuntimeBase *)ms)->_cfinfo[CF_INFO_BITS], 2, 2, 0);
}

CF_INLINE Boolean __CFMessagePortIsDeallocing(CFMessagePortRef ms) {
    return (Boolean)__CFBitfieldGetValue(((const CFRuntimeBase *)ms)->_cfinfo[CF_INFO_BITS], 3, 3);
}

CF_INLINE void __CFMessagePortSetIsDeallocing(CFMessagePortRef ms) {
    __CFBitfieldSetValue(((CFRuntimeBase *)ms)->_cfinfo[CF_INFO_BITS], 3, 3, 1);
}

CF_INLINE void __CFMessagePortLock(CFMessagePortRef ms) {
    __CFLock(&(ms->_lock));
}

CF_INLINE void __CFMessagePortUnlock(CFMessagePortRef ms) {
    __CFUnlock(&(ms->_lock));
}

#if !defined(__LP64__)
#define __LP64__ 0
#endif

// Just a heuristic
#define __CFMessagePortMaxInlineBytes ((int32_t)4000)

struct __CFMessagePortMachMessage {
    mach_msg_base_t base;
    mach_msg_ool_descriptor_t ool;
    struct innards {
        int32_t magic;
        int32_t msgid;
        int32_t convid;
        int32_t byteslen;
        uint8_t bytes[0];
    } innards;
};
#define __INNARD_OFFSET (((!(msgp->header.msgh_bits & MACH_MSGH_BITS_COMPLEX) && ((mach_msg_header_t *)msgp)->msgh_id == 0) || ( (msgp->header.msgh_bits & MACH_MSGH_BITS_COMPLEX) && !__LP64__)) ? 40 : 44)

#define MAGIC 0xF0F2F4F8

// These 3 macros should ONLY be used on RECEIVED messages, not ones being constructed on the sending side
#define MSGP_GET(msgp, ident)  (((struct __CFMessagePortMachMessage *)msgp)->ident)
#define MSGP_INFO(msgp, ident) ((struct innards *)((void *)msgp + __INNARD_OFFSET))->ident
#define MSGP_SIZE(msgp) (__INNARD_OFFSET + sizeof(struct innards))


static mach_msg_base_t *__CFMessagePortCreateMessage(bool reply, mach_port_t port, mach_port_t replyPort, int32_t convid, int32_t msgid, const uint8_t *bytes, int32_t byteslen) {
    if (__CFMessagePortMaxDataSize < byteslen) return NULL;
    if (byteslen < -1) return NULL;
    int32_t rounded_byteslen = (byteslen < 0) ? 0 : ((byteslen + 7) & ~0x7);
    int32_t size = (int32_t)sizeof(struct __CFMessagePortMachMessage) + ((rounded_byteslen <= __CFMessagePortMaxInlineBytes) ? rounded_byteslen : 0);
    struct __CFMessagePortMachMessage *msg = CFAllocatorAllocate(kCFAllocatorSystemDefault, size, 0);
    if (!msg) return NULL;
    memset(msg, 0, size);
#if __LP64__
    msg->base.header.msgh_id = 1;
#else
    msg->base.header.msgh_id = 0;
#endif
    msg->base.header.msgh_size = size;
    msg->base.header.msgh_remote_port = port;
    msg->base.header.msgh_local_port = replyPort;
    msg->base.header.msgh_bits = MACH_MSGH_BITS((reply ? MACH_MSG_TYPE_MOVE_SEND_ONCE : MACH_MSG_TYPE_COPY_SEND), (MACH_PORT_NULL != replyPort ? MACH_MSG_TYPE_MAKE_SEND_ONCE : 0));
    msg->base.body.msgh_descriptor_count = 0;
    msg->innards.magic = MAGIC;
    msg->innards.msgid = CFSwapInt32HostToLittle(msgid);
    msg->innards.convid = CFSwapInt32HostToLittle(convid);
    msg->innards.byteslen = CFSwapInt32HostToLittle(byteslen);
    if (rounded_byteslen <= __CFMessagePortMaxInlineBytes) {
	if (NULL != bytes && 0 < byteslen) {
	    memmove(msg->innards.bytes, bytes, byteslen);
	}
    } else {
	msg->base.header.msgh_bits |= MACH_MSGH_BITS_COMPLEX;
	msg->base.body.msgh_descriptor_count = 1;
	msg->ool.deallocate = false;
	msg->ool.copy = MACH_MSG_VIRTUAL_COPY;
	msg->ool.address = (void *)bytes;
	msg->ool.size = byteslen;
	msg->ool.type = MACH_MSG_OOL_DESCRIPTOR;
    }
    return (mach_msg_base_t *)msg;
}

static CFStringRef __CFMessagePortCopyDescription(CFTypeRef cf) {
    CFMessagePortRef ms = (CFMessagePortRef)cf;
    CFStringRef result;
    const char *locked;
    CFStringRef contextDesc = NULL;
    locked = "Maybe";
    if (__CFMessagePortIsRemote(ms)) {
	result = CFStringCreateWithFormat(kCFAllocatorSystemDefault, NULL, CFSTR("<CFMessagePort %p [%p]>{locked = %s, valid = %s, remote = %s, name = %@}"), cf, CFGetAllocator(ms), locked, (__CFMessagePortIsValid(ms) ? "Yes" : "No"), (__CFMessagePortIsRemote(ms) ? "Yes" : "No"), ms->_name);
    } else {
	if (NULL != ms->_context.info && NULL != ms->_context.copyDescription) {
	    contextDesc = ms->_context.copyDescription(ms->_context.info);
	}
	if (NULL == contextDesc) {
	    contextDesc = CFStringCreateWithFormat(kCFAllocatorSystemDefault, NULL, CFSTR("<CFMessagePort context %p>"), ms->_context.info);
	}
	void *addr = ms->_callout ? (void *)ms->_callout : (void *)ms->_calloutEx;
	Dl_info info;
	const char *name = (dladdr(addr, &info) && info.dli_saddr == addr && info.dli_sname) ? info.dli_sname : "???";
	result = CFStringCreateWithFormat(kCFAllocatorSystemDefault, NULL, CFSTR("<CFMessagePort %p [%p]>{locked = %s, valid = %s, remote = %s, name = %@, source = %p, callout = %s (%p), context = %@}"), cf, CFGetAllocator(ms), locked, (__CFMessagePortIsValid(ms) ? "Yes" : "No"), (__CFMessagePortIsRemote(ms) ? "Yes" : "No"), ms->_name, ms->_source, name, addr, (NULL != contextDesc ? contextDesc : CFSTR("<no description>")));
    }
    if (NULL != contextDesc) {
	CFRelease(contextDesc);
    }
    return result;
}

static void __CFMessagePortDeallocate(CFTypeRef cf) {
    CFMessagePortRef ms = (CFMessagePortRef)cf;
    __CFMessagePortSetIsDeallocing(ms);
    CFMessagePortInvalidate(ms);
    // Delay cleanup of _replies until here so that invalidation during
    // SendRequest does not cause _replies to disappear out from under that function.
    if (NULL != ms->_replies) {
	CFRelease(ms->_replies);
    }
    if (NULL != ms->_name) {
	CFRelease(ms->_name);
    }
    if (NULL != ms->_port) {
	if (__CFMessagePortExtraMachRef(ms)) {
	    mach_port_mod_refs(mach_task_self(), CFMachPortGetPort(ms->_port), MACH_PORT_RIGHT_SEND, -1);
	    mach_port_mod_refs(mach_task_self(), CFMachPortGetPort(ms->_port), MACH_PORT_RIGHT_RECEIVE, -1);
	}
	CFMachPortInvalidate(ms->_port);
	CFRelease(ms->_port);
    }

    // A remote message port for a local message port in the same process will get the
    // same mach port, and the remote port will keep the mach port from being torn down,
    // thus keeping the remote port from getting any sort of death notification and
    // auto-invalidating; so we manually implement the 'auto-invalidation' here by
    // tickling each remote port to check its state after any message port is destroyed,
    // but most importantly after local message ports are destroyed.
    __CFLock(&__CFAllMessagePortsLock);
    CFMessagePortRef *remotePorts = NULL;
    CFIndex cnt = 0;
    if (NULL != __CFAllRemoteMessagePorts) {
	cnt = CFDictionaryGetCount(__CFAllRemoteMessagePorts);
	remotePorts = CFAllocatorAllocate(kCFAllocatorSystemDefault, cnt * sizeof(CFMessagePortRef), __kCFAllocatorGCScannedMemory);
	CFDictionaryGetKeysAndValues(__CFAllRemoteMessagePorts, NULL, (const void **)remotePorts);
	for (CFIndex idx = 0; idx < cnt; idx++) {
	    CFRetain(remotePorts[idx]);
	}
    }
    __CFUnlock(&__CFAllMessagePortsLock);
    if (remotePorts) {
	for (CFIndex idx = 0; idx < cnt; idx++) {
	    // as a side-effect, this will auto-invalidate the CFMessagePort if the CFMachPort is invalid
	    CFMessagePortIsValid(remotePorts[idx]);
	    CFRelease(remotePorts[idx]);
	}
	CFAllocatorDeallocate(kCFAllocatorSystemDefault, remotePorts);
    }
}

static CFTypeID __kCFMessagePortTypeID = _kCFRuntimeNotATypeID;

static const CFRuntimeClass __CFMessagePortClass = {
    0,
    "CFMessagePort",
    NULL,      // init
    NULL,      // copy
    __CFMessagePortDeallocate,
    NULL,
    NULL,
    NULL,      // 
    __CFMessagePortCopyDescription
};

CFTypeID CFMessagePortGetTypeID(void) {
    static dispatch_once_t initOnce = 0;
    dispatch_once(&initOnce, ^{ __kCFMessagePortTypeID = _CFRuntimeRegisterClass(&__CFMessagePortClass); });
    return __kCFMessagePortTypeID;
}

static CFStringRef __CFMessagePortSanitizeStringName(CFStringRef name, uint8_t **utfnamep, CFIndex *utfnamelenp) {
    uint8_t *utfname;
    CFIndex utflen;
    CFStringRef result = NULL;
    utfname = CFAllocatorAllocate(kCFAllocatorSystemDefault, __kCFMessagePortMaxNameLength + 1, 0);
    CFStringGetBytes(name, CFRangeMake(0, CFStringGetLength(name)), kCFStringEncodingUTF8, 0, false, utfname, __kCFMessagePortMaxNameLength, &utflen);
    utfname[utflen] = '\0';
    if (strlen((const char *)utfname) != utflen) {
	/* PCA 9194709: refuse to sanitize a string with an embedded nul character */
	CFAllocatorDeallocate(kCFAllocatorSystemDefault, utfname);
	utfname = NULL;
	utfnamelenp = 0;
    } else {
	/* A new string is created, because the original string may have been
	   truncated to the max length, and we want the string name to definitely
	   match the raw UTF-8 chunk that has been created. Also, this is useful
	   to get a constant string in case the original name string was mutable. */
	result = CFStringCreateWithBytes(kCFAllocatorSystemDefault, utfname, utflen, kCFStringEncodingUTF8, false);
    }
    if (NULL != utfnamep) {
	*utfnamep = utfname;
    } else if (NULL != utfname) {
	CFAllocatorDeallocate(kCFAllocatorSystemDefault, utfname);
    }
    if (NULL != utfnamelenp) {
	*utfnamelenp = utflen;
    }
    return result;
}

static void __CFMessagePortDummyCallback(CFMachPortRef port, void *msg, CFIndex size, void *info) {
    // not supposed to be implemented
}

static void __CFMessagePortInvalidationCallBack(CFMachPortRef port, void *info) {
    // info has been setup as the CFMessagePort owning the CFMachPort
    if (info) CFMessagePortInvalidate(info);
}

static CFMessagePortRef __CFMessagePortCreateLocal(CFAllocatorRef allocator, CFStringRef name, CFMessagePortCallBack callout, CFMessagePortContext *context, Boolean *shouldFreeInfo, Boolean perPID, CFMessagePortCallBackEx calloutEx) {
    CFMessagePortRef memory;
    uint8_t *utfname = NULL;

    if (shouldFreeInfo) *shouldFreeInfo = true;
    if (NULL != name) {
	name = __CFMessagePortSanitizeStringName(name, &utfname, NULL);
    }
    __CFLock(&__CFAllMessagePortsLock);
    if (!perPID && NULL != name) {
	CFMessagePortRef existing;
	if (NULL != __CFAllLocalMessagePorts && CFDictionaryGetValueIfPresent(__CFAllLocalMessagePorts, name, (const void **)&existing)) {
	    CFRetain(existing);
	    __CFUnlock(&__CFAllMessagePortsLock);
	    CFRelease(name);
	    CFAllocatorDeallocate(kCFAllocatorSystemDefault, utfname);
            if (!CFMessagePortIsValid(existing)) { // must do this outside lock to avoid deadlock
	        CFRelease(existing);
                existing = NULL;
            }
	    return (CFMessagePortRef)(existing);
	}
    }
    __CFUnlock(&__CFAllMessagePortsLock);
    CFIndex size = sizeof(struct __CFMessagePort) - sizeof(CFRuntimeBase);
    memory = (CFMessagePortRef)_CFRuntimeCreateInstance(allocator, CFMessagePortGetTypeID(), size, NULL);
    if (NULL == memory) {
	if (NULL != name) {
	    CFRelease(name);
	}
	CFAllocatorDeallocate(kCFAllocatorSystemDefault, utfname);
	return NULL;
    }
    __CFMessagePortUnsetValid(memory);
    __CFMessagePortUnsetExtraMachRef(memory);
    __CFMessagePortUnsetRemote(memory);
    memory->_lock = CFLockInit;
    memory->_name = name;
    memory->_port = NULL;
    memory->_replies = NULL;
    memory->_convCounter = 0;
    memory->_perPID = perPID ? getpid() : 0;	// actual value not terribly useful for local ports
    memory->_replyPort = NULL;
    memory->_source = NULL;
#if __HAS_DISPATCH__
    memory->_dispatchSource = NULL;
    memory->_dispatchQ = NULL;
#endif
    memory->_icallout = NULL;
    memory->_callout = callout;
    memory->_calloutEx = calloutEx;
    memory->_context.info = NULL;
    memory->_context.retain = NULL;
    memory->_context.release = NULL;
    memory->_context.copyDescription = NULL;

    if (NULL != name) {
	CFMachPortRef native = NULL;
	kern_return_t ret;
	mach_port_t bs, mp;
	task_get_bootstrap_port(mach_task_self(), &bs);
	if (!perPID) {
	}
	if (!native) {
	    CFMachPortContext ctx = {0, memory, NULL, NULL, NULL};
	    native = CFMachPortCreate(allocator, __CFMessagePortDummyCallback, &ctx, NULL);
	    if (!native) {
		CFAllocatorDeallocate(kCFAllocatorSystemDefault, utfname);
		// name is released by deallocation
		CFRelease(memory);
		return NULL;
	    }
	    mp = CFMachPortGetPort(native);
	}
	CFMachPortSetInvalidationCallBack(native, __CFMessagePortInvalidationCallBack);
	memory->_port = native;
    }

    CFAllocatorDeallocate(kCFAllocatorSystemDefault, utfname);
    __CFMessagePortSetValid(memory);
    if (NULL != context) {
	memmove(&memory->_context, context, sizeof(CFMessagePortContext));
	memory->_context.info = context->retain ? (void *)context->retain(context->info) : context->info;
    }
    __CFLock(&__CFAllMessagePortsLock);
    if (!perPID && NULL != name) {
        CFMessagePortRef existing;
        if (NULL != __CFAllLocalMessagePorts && CFDictionaryGetValueIfPresent(__CFAllLocalMessagePorts, name, (const void **)&existing)) {
            CFRetain(existing);
            __CFUnlock(&__CFAllMessagePortsLock); 
	    CFRelease(memory);
            return (CFMessagePortRef)(existing);
        }       
	if (NULL == __CFAllLocalMessagePorts) {
	    __CFAllLocalMessagePorts = CFDictionaryCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeDictionaryKeyCallBacks, NULL);
	}
	CFDictionaryAddValue(__CFAllLocalMessagePorts, name, memory);
    }
    __CFUnlock(&__CFAllMessagePortsLock);
    if (shouldFreeInfo) *shouldFreeInfo = false;
    return memory;
}

CFMessagePortRef CFMessagePortCreateLocal(CFAllocatorRef allocator, CFStringRef name, CFMessagePortCallBack callout, CFMessagePortContext *context, Boolean *shouldFreeInfo) {
    return __CFMessagePortCreateLocal(allocator, name, callout, context, shouldFreeInfo, false, NULL);
}

CFMessagePortRef CFMessagePortCreatePerProcessLocal(CFAllocatorRef allocator, CFStringRef name, CFMessagePortCallBack callout, CFMessagePortContext *context, Boolean *shouldFreeInfo) {
    return __CFMessagePortCreateLocal(allocator, name, callout, context, shouldFreeInfo, true, NULL);
}

CFMessagePortRef _CFMessagePortCreateLocalEx(CFAllocatorRef allocator, CFStringRef name, Boolean perPID, uintptr_t unused, CFMessagePortCallBackEx calloutEx, CFMessagePortContext *context, Boolean *shouldFreeInfo) {
    return __CFMessagePortCreateLocal(allocator, name, NULL, context, shouldFreeInfo, perPID, calloutEx);
}

static CFMessagePortRef __CFMessagePortCreateRemote(CFAllocatorRef allocator, CFStringRef name, Boolean perPID, CFIndex pid) {
    CFMessagePortRef memory;
    CFMachPortRef native = NULL;
    CFMachPortContext ctx;
    uint8_t *utfname = NULL;
    CFIndex size;
    mach_port_t bp, port;
    kern_return_t ret;

    name = __CFMessagePortSanitizeStringName(name, &utfname, NULL);
    if (NULL == name) {
	return NULL;
    }
    __CFLock(&__CFAllMessagePortsLock);
    if (!perPID && NULL != name) {
	CFMessagePortRef existing;
	if (NULL != __CFAllRemoteMessagePorts && CFDictionaryGetValueIfPresent(__CFAllRemoteMessagePorts, name, (const void **)&existing)) {
	    CFRetain(existing);
	    __CFUnlock(&__CFAllMessagePortsLock);
	    CFRelease(name);
	    CFAllocatorDeallocate(kCFAllocatorSystemDefault, utfname);
            if (!CFMessagePortIsValid(existing)) { // must do this outside lock to avoid deadlock
	        CFRelease(existing);
                existing = NULL;
            }
	    return (CFMessagePortRef)(existing);
	}
    }
    __CFUnlock(&__CFAllMessagePortsLock);
    size = sizeof(struct __CFMessagePort) - sizeof(CFMessagePortContext) - sizeof(CFRuntimeBase);
    memory = (CFMessagePortRef)_CFRuntimeCreateInstance(allocator, CFMessagePortGetTypeID(), size, NULL);
    if (NULL == memory) {
	if (NULL != name) {
	    CFRelease(name);
	}
	CFAllocatorDeallocate(kCFAllocatorSystemDefault, utfname);
	return NULL;
    }
    __CFMessagePortUnsetValid(memory);
    __CFMessagePortUnsetExtraMachRef(memory);
    __CFMessagePortSetRemote(memory);
    memory->_lock = CFLockInit;
    memory->_name = name;
    memory->_port = NULL;
    memory->_replies = CFDictionaryCreateMutable(kCFAllocatorSystemDefault, 0, NULL, NULL);
    memory->_convCounter = 0;
    memory->_perPID = perPID ? pid : 0;
    memory->_replyPort = NULL;
    memory->_source = NULL;
#if __HAS_DISPATCH__
    memory->_dispatchSource = NULL;
    memory->_dispatchQ = NULL;
#endif
    memory->_icallout = NULL;
    memory->_callout = NULL;
    memory->_calloutEx = NULL;
    ctx.version = 0;
    ctx.info = memory;
    ctx.retain = NULL;
    ctx.release = NULL;
    ctx.copyDescription = NULL;
    CFAllocatorDeallocate(kCFAllocatorSystemDefault, utfname);
    if (NULL == native) {
	// name is released by deallocation
	CFRelease(memory);
	return NULL;
    }
    memory->_port = native;
    __CFMessagePortSetValid(memory);
    __CFLock(&__CFAllMessagePortsLock);
    if (!perPID && NULL != name) {
	CFMessagePortRef existing;
	if (NULL != __CFAllRemoteMessagePorts && CFDictionaryGetValueIfPresent(__CFAllRemoteMessagePorts, name, (const void **)&existing)) {
	    CFRetain(existing);
	    __CFUnlock(&__CFAllMessagePortsLock);
	    CFRelease(memory);
	    return (CFMessagePortRef)(existing);
	}
	if (NULL == __CFAllRemoteMessagePorts) {
	    __CFAllRemoteMessagePorts = CFDictionaryCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeDictionaryKeyCallBacks, NULL);
	}
	CFDictionaryAddValue(__CFAllRemoteMessagePorts, name, memory);
    }
    CFRetain(native);
    __CFUnlock(&__CFAllMessagePortsLock);
    CFMachPortSetInvalidationCallBack(native, __CFMessagePortInvalidationCallBack);
    // that set-invalidation-callback might have called back into us
    // if the CFMachPort is already bad, but that was a no-op since
    // there was no callback setup at the (previous) time the CFMachPort
    // went invalid; so check for validity manually and react
    if (!CFMachPortIsValid(native)) {
        CFRelease(memory); // does the invalidate
        CFRelease(native);
        return NULL;
    }
    CFRelease(native);
    return (CFMessagePortRef)memory;
}

CFMessagePortRef CFMessagePortCreateRemote(CFAllocatorRef allocator, CFStringRef name) {
    return __CFMessagePortCreateRemote(allocator, name, false, 0);
}

CFMessagePortRef CFMessagePortCreatePerProcessRemote(CFAllocatorRef allocator, CFStringRef name, CFIndex pid) {
    return __CFMessagePortCreateRemote(allocator, name, true, pid);
}

Boolean CFMessagePortIsRemote(CFMessagePortRef ms) {
    __CFGenericValidateType(ms, CFMessagePortGetTypeID());
    return __CFMessagePortIsRemote(ms);
}

CFStringRef CFMessagePortGetName(CFMessagePortRef ms) {
    __CFGenericValidateType(ms, CFMessagePortGetTypeID());
    return ms->_name;
}

Boolean CFMessagePortSetName(CFMessagePortRef ms, CFStringRef name) {
    CFAllocatorRef allocator = CFGetAllocator(ms);
    uint8_t *utfname = NULL;

    __CFGenericValidateType(ms, CFMessagePortGetTypeID());
    if (ms->_perPID || __CFMessagePortIsRemote(ms)) return false;
    name = __CFMessagePortSanitizeStringName(name, &utfname, NULL);
    if (NULL == name) {
	return false;
    }
    __CFLock(&__CFAllMessagePortsLock);
    if (NULL != name) {
	CFMessagePortRef existing;
	if (NULL != __CFAllLocalMessagePorts && CFDictionaryGetValueIfPresent(__CFAllLocalMessagePorts, name, (const void **)&existing)) {
	    __CFUnlock(&__CFAllMessagePortsLock);
	    CFRelease(name);
	    CFAllocatorDeallocate(kCFAllocatorSystemDefault, utfname);
	    return false;
	}
    }
    __CFUnlock(&__CFAllMessagePortsLock);

    if (NULL != name && (NULL == ms->_name || !CFEqual(ms->_name, name))) {
	CFMachPortRef oldPort = ms->_port;
        CFMachPortRef native = NULL;
        kern_return_t ret;
        mach_port_t bs, mp;
        task_get_bootstrap_port(mach_task_self(), &bs);
        CFMachPortSetInvalidationCallBack(native, __CFMessagePortInvalidationCallBack);
        ms->_port = native;
	if (NULL != oldPort && oldPort != native) {
	    if (__CFMessagePortExtraMachRef(ms)) {
		mach_port_mod_refs(mach_task_self(), CFMachPortGetPort(oldPort), MACH_PORT_RIGHT_SEND, -1);
		mach_port_mod_refs(mach_task_self(), CFMachPortGetPort(oldPort), MACH_PORT_RIGHT_RECEIVE, -1);
	    }
	    CFMachPortInvalidate(oldPort);
	    CFRelease(oldPort);
	}
	__CFLock(&__CFAllMessagePortsLock);
	// This relocking without checking to see if something else has grabbed
	// that name in the cache is rather suspect, but what would that even
	// mean has happened?  We'd expect the bootstrap_* calls above to have
	// failed for this one and not gotten this far, or failed for all of the
	// other simultaneous attempts to get the name (and having succeeded for
	// this one, gotten here).  So we're not going to try very hard here
	// with the thread-safety.
	if (NULL == __CFAllLocalMessagePorts) {
	    __CFAllLocalMessagePorts = CFDictionaryCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeDictionaryKeyCallBacks, NULL);
	}
	if (NULL != ms->_name) {
	    CFDictionaryRemoveValue(__CFAllLocalMessagePorts, ms->_name);
	    CFRelease(ms->_name);
	}
	ms->_name = name;
	CFDictionaryAddValue(__CFAllLocalMessagePorts, name, ms);
	__CFUnlock(&__CFAllMessagePortsLock);
    }

    CFAllocatorDeallocate(kCFAllocatorSystemDefault, utfname);
    return true;
}

void CFMessagePortGetContext(CFMessagePortRef ms, CFMessagePortContext *context) {
    __CFGenericValidateType(ms, CFMessagePortGetTypeID());
//#warning CF: assert that this is a local port
    CFAssert(0 == context->version, __kCFLogAssertion, "%s(): context version not initialized to 0", __PRETTY_FUNCTION__);
    memmove(context, &ms->_context, sizeof(CFMessagePortContext));
}

void CFMessagePortInvalidate(CFMessagePortRef ms) {
    __CFGenericValidateType(ms, CFMessagePortGetTypeID());
    if (!__CFMessagePortIsDeallocing(ms)) {
	CFRetain(ms);
    }
    __CFMessagePortLock(ms);
    if (__CFMessagePortIsValid(ms)) {
#if __HAS_DISPATCH__
        if (ms->_dispatchSource) {
            dispatch_source_cancel(ms->_dispatchSource);
            ms->_dispatchSource = NULL;
	    ms->_dispatchQ = NULL;
        }
#endif

	CFMessagePortInvalidationCallBack callout = ms->_icallout;
	CFRunLoopSourceRef source = ms->_source;
	CFMachPortRef replyPort = ms->_replyPort;
	CFMachPortRef port = ms->_port;
	CFStringRef name = ms->_name;
	void *info = NULL;

	__CFMessagePortUnsetValid(ms);
	if (!__CFMessagePortIsRemote(ms)) {
	    info = ms->_context.info;
	    ms->_context.info = NULL;
	}
	ms->_source = NULL;
	ms->_replyPort = NULL;
        ms->_port = NULL;
	__CFMessagePortUnlock(ms);

	__CFLock(&__CFAllMessagePortsLock);
	if (0 == ms->_perPID && NULL != name && NULL != (__CFMessagePortIsRemote(ms) ? __CFAllRemoteMessagePorts : __CFAllLocalMessagePorts)) {
	    CFDictionaryRemoveValue(__CFMessagePortIsRemote(ms) ? __CFAllRemoteMessagePorts : __CFAllLocalMessagePorts, name);
	}
	__CFUnlock(&__CFAllMessagePortsLock);
	if (NULL != callout) {
	    callout(ms, info);
	}
	if (!__CFMessagePortIsRemote(ms) && NULL != ms->_context.release) {
	    ms->_context.release(info);
	}
	if (NULL != source) {
	    CFRunLoopSourceInvalidate(source);
	    CFRelease(source);
	}
	if (NULL != replyPort) {
	    CFMachPortInvalidate(replyPort);
	    CFRelease(replyPort);
	}
	if (__CFMessagePortIsRemote(ms)) {
	    // Get rid of our extra ref on the Mach port gotten from bs server
	    mach_port_deallocate(mach_task_self(), CFMachPortGetPort(port));
	}
        if (NULL != port) {
	    // We already know we're going invalid, don't need this callback
	    // anymore; plus, this solves a reentrancy deadlock; also, this
	    // must be done before the deallocate of the Mach port, to
	    // avoid a race between the notification message which could be
	    // handled in another thread, and this NULL'ing out.
            CFMachPortSetInvalidationCallBack(port, NULL);
            if (__CFMessagePortExtraMachRef(ms)) {
                mach_port_mod_refs(mach_task_self(), CFMachPortGetPort(port), MACH_PORT_RIGHT_SEND, -1);
                mach_port_mod_refs(mach_task_self(), CFMachPortGetPort(port), MACH_PORT_RIGHT_RECEIVE, -1);
            }
            CFMachPortInvalidate(port);
            CFRelease(port);
        }
    } else {
	__CFMessagePortUnlock(ms);
    }
    if (!__CFMessagePortIsDeallocing(ms)) {
	CFRelease(ms);
    }
}

Boolean CFMessagePortIsValid(CFMessagePortRef ms) {
    __CFGenericValidateType(ms, CFMessagePortGetTypeID());
    if (!__CFMessagePortIsValid(ms)) return false;
    CFRetain(ms);
    if (NULL != ms->_port && !CFMachPortIsValid(ms->_port)) {
	CFMessagePortInvalidate(ms);
        CFRelease(ms);
	return false;
    }
    if (NULL != ms->_replyPort && !CFMachPortIsValid(ms->_replyPort)) {
	CFMessagePortInvalidate(ms);
        CFRelease(ms);
	return false;
    }
    CFRelease(ms);
    return true;
}

CFMessagePortInvalidationCallBack CFMessagePortGetInvalidationCallBack(CFMessagePortRef ms) {
    __CFGenericValidateType(ms, CFMessagePortGetTypeID());
    return ms->_icallout;
}

void CFMessagePortSetInvalidationCallBack(CFMessagePortRef ms, CFMessagePortInvalidationCallBack callout) {
    __CFGenericValidateType(ms, CFMessagePortGetTypeID());
    if (!__CFMessagePortIsValid(ms) && NULL != callout) {
	callout(ms, ms->_context.info);
    } else {
	ms->_icallout = callout;
    }
}

static void __CFMessagePortReplyCallBack(CFMachPortRef port, void *msg, CFIndex size, void *info) {
    CFMessagePortRef ms = info;
    mach_msg_base_t *msgp = msg;
    mach_msg_base_t *replymsg;
    __CFMessagePortLock(ms);
    if (!__CFMessagePortIsValid(ms)) {
	__CFMessagePortUnlock(ms);
	return;
    }

    int32_t byteslen = 0;

    Boolean wayTooSmall = size < sizeof(mach_msg_header_t) || size < MSGP_SIZE(msgp) || msgp->header.msgh_size < MSGP_SIZE(msgp);
    Boolean invalidMagic = false;
    Boolean invalidComplex = false;
    Boolean wayTooBig = false;
    if (!wayTooSmall) {
        invalidMagic = ((MSGP_INFO(msgp, magic) != MAGIC) && (CFSwapInt32(MSGP_INFO(msgp, magic)) != MAGIC));
        invalidComplex = (msgp->header.msgh_bits & MACH_MSGH_BITS_COMPLEX) && (1 != msgp->body.msgh_descriptor_count);
        wayTooBig = ((int32_t)MSGP_SIZE(msgp) + __CFMessagePortMaxInlineBytes) < msgp->header.msgh_size; // also less than a 32-bit signed int can hold
    }
    Boolean wrongSize = false;
    if (!(invalidComplex || wayTooBig || wayTooSmall)) {
        byteslen = CFSwapInt32LittleToHost(MSGP_INFO(msgp, byteslen));
        wrongSize = (byteslen < -1) || (__CFMessagePortMaxDataSize < byteslen);
        if (msgp->header.msgh_bits & MACH_MSGH_BITS_COMPLEX) {
            wrongSize = wrongSize || (MSGP_GET(msgp, ool).size != byteslen);
        } else {
            wrongSize = wrongSize || ((int32_t)msgp->header.msgh_size - (int32_t)MSGP_SIZE(msgp) < byteslen);
        }
    }
    Boolean invalidMsgID = wayTooSmall ? false : ((0 <= MSGP_INFO(msgp, convid)) && (MSGP_INFO(msgp, convid) <= INT32_MAX)); // conversation id
    if (invalidMagic || invalidComplex || wayTooBig || wayTooSmall || wrongSize || invalidMsgID) {
        CFLog(kCFLogLevelWarning, CFSTR("*** CFMessagePort: dropping corrupt reply Mach message (0b%d%d%d%d%d%d)"), invalidMagic, invalidComplex, wayTooBig, wayTooSmall, wrongSize, invalidMsgID);
        mach_msg_destroy((mach_msg_header_t *)msgp);
        __CFMessagePortUnlock(ms);
        return;
    }

    if (CFDictionaryContainsKey(ms->_replies, (void *)(uintptr_t)MSGP_INFO(msgp, convid))) {
	CFDataRef reply = NULL;
	replymsg = (mach_msg_base_t *)msg;
	if (!(replymsg->header.msgh_bits & MACH_MSGH_BITS_COMPLEX)) {
	    uintptr_t msgp_extent = (uintptr_t)((uint8_t *)msgp + msgp->header.msgh_size);
	    uintptr_t data_extent = (uintptr_t)((uint8_t *)&(MSGP_INFO(replymsg, bytes)) + byteslen);
            if (byteslen < 0) byteslen = 0; // from here on, treat negative same as zero -- this is historical behavior: a NULL return from the callback on the other side results in empty data to the original requestor
	    if (0 <= byteslen && data_extent <= msgp_extent) {
		reply = CFDataCreate(kCFAllocatorSystemDefault, MSGP_INFO(replymsg, bytes), byteslen);
	    } else {
		reply = (void *)~0;	// means NULL data
	    }
	} else {
//#warning CF: should create a no-copy data here that has a custom VM-freeing allocator, and not vm_dealloc here
	    reply = CFDataCreate(kCFAllocatorSystemDefault, MSGP_GET(replymsg, ool).address, MSGP_GET(replymsg, ool).size);
	    vm_deallocate(mach_task_self(), (vm_address_t)MSGP_GET(replymsg, ool).address, MSGP_GET(replymsg, ool).size);
	}
	CFDictionarySetValue(ms->_replies, (void *)(uintptr_t)MSGP_INFO(msgp, convid), (void *)reply);
    } else {	/* discard message */
	if (msgp->header.msgh_bits & MACH_MSGH_BITS_COMPLEX) {
	    vm_deallocate(mach_task_self(), (vm_address_t)MSGP_GET(msgp, ool).address, MSGP_GET(msgp, ool).size);
	}
    }
    __CFMessagePortUnlock(ms);
}

SInt32 CFMessagePortSendRequest(CFMessagePortRef remote, SInt32 msgid, CFDataRef data, CFTimeInterval sendTimeout, CFTimeInterval rcvTimeout, CFStringRef replyMode, CFDataRef *returnDatap) {
    mach_msg_base_t *sendmsg;
    CFRunLoopRef currentRL = CFRunLoopGetCurrent();
    CFRunLoopSourceRef source = NULL;
    CFDataRef reply = NULL;
    uint64_t termTSR;
    uint32_t sendOpts = 0, sendTimeOut = 0;
    int32_t desiredReply;
    Boolean didRegister = false;
    kern_return_t ret;

    //#warning CF: This should be an assert
    // if (!__CFMessagePortIsRemote(remote)) return -999;
    if (data && __CFMessagePortMaxDataSize < CFDataGetLength(data)) {
        CFLog(kCFLogLevelWarning, CFSTR("*** CFMessagePortSendRequest: CFMessagePort cannot send more than %lu bytes of data"), __CFMessagePortMaxDataSize);
        return kCFMessagePortTransportError;
    }
    __CFMessagePortLock(remote);
    if (!__CFMessagePortIsValid(remote)) {
        __CFMessagePortUnlock(remote);
        return kCFMessagePortIsInvalid;
    }
    CFRetain(remote); // retain during run loop to avoid invalidation causing freeing
    if (NULL == remote->_replyPort) {
	CFMachPortContext context;
	context.version = 0;
	context.info = remote;
	context.retain = (const void *(*)(const void *))CFRetain;
	context.release = (void (*)(const void *))CFRelease;
	context.copyDescription = (CFStringRef (*)(const void *))__CFMessagePortCopyDescription;
	remote->_replyPort = CFMachPortCreate(CFGetAllocator(remote), __CFMessagePortReplyCallBack, &context, NULL);
    }
    remote->_convCounter++;
    desiredReply = -remote->_convCounter;
    sendmsg = __CFMessagePortCreateMessage(false, CFMachPortGetPort(remote->_port), (replyMode != NULL ? CFMachPortGetPort(remote->_replyPort) : MACH_PORT_NULL), -desiredReply, msgid, (data ? CFDataGetBytePtr(data) : NULL), (data ? CFDataGetLength(data) : -1));
    if (!sendmsg) {
        __CFMessagePortUnlock(remote);
        CFRelease(remote);
        return kCFMessagePortTransportError;
    }
    if (replyMode != NULL) {
        CFDictionarySetValue(remote->_replies, (void *)(uintptr_t)desiredReply, NULL);
        source = CFMachPortCreateRunLoopSource(CFGetAllocator(remote), remote->_replyPort, -100);
        didRegister = !CFRunLoopContainsSource(currentRL, source, replyMode);
	if (didRegister) {
            CFRunLoopAddSource(currentRL, source, replyMode);
	}
    }
    if (sendTimeout < 10.0*86400) {
	// anything more than 10 days is no timeout!
	sendOpts = MACH_SEND_TIMEOUT;
	sendTimeout *= 1000.0;
	if (sendTimeout < 1.0) sendTimeout = 0.0;
	sendTimeOut = floor(sendTimeout);
    }
    __CFMessagePortUnlock(remote);
    ret = mach_msg((mach_msg_header_t *)sendmsg, MACH_SEND_MSG|sendOpts, sendmsg->header.msgh_size, 0, MACH_PORT_NULL, sendTimeOut, MACH_PORT_NULL);
    __CFMessagePortLock(remote);
    if (KERN_SUCCESS != ret) {
	// need to deallocate the send-once right that might have been created
	if (replyMode != NULL) mach_port_deallocate(mach_task_self(), ((mach_msg_header_t *)sendmsg)->msgh_local_port);
	if (didRegister) {
	    CFRunLoopRemoveSource(currentRL, source, replyMode);
	}
	if (source) CFRelease(source);
        __CFMessagePortUnlock(remote);
        CFAllocatorDeallocate(kCFAllocatorSystemDefault, sendmsg);
        CFRelease(remote);
	return (MACH_SEND_TIMED_OUT == ret) ? kCFMessagePortSendTimeout : kCFMessagePortTransportError;
    }
    __CFMessagePortUnlock(remote);
    CFAllocatorDeallocate(kCFAllocatorSystemDefault, sendmsg);
    if (replyMode == NULL) {
        CFRelease(remote);
	return kCFMessagePortSuccess;
    }
    _CFMachPortInstallNotifyPort(currentRL, replyMode);
    termTSR = mach_absolute_time() + __CFTimeIntervalToTSR(rcvTimeout);
    for (;;) {
	CFRunLoopRunInMode(replyMode, __CFTimeIntervalUntilTSR(termTSR), true);
	// warning: what, if anything, should be done if remote is now invalid?
	reply = CFDictionaryGetValue(remote->_replies, (void *)(uintptr_t)desiredReply);
	if (NULL != reply || termTSR < mach_absolute_time()) {
	    break;
	}
	if (!CFMessagePortIsValid(remote)) {
	    // no reason that reply port alone should go invalid so we don't check for that
	    break;
	}
    }
    // Should we uninstall the notify port?  A complex question...
    if (didRegister) {
        CFRunLoopRemoveSource(currentRL, source, replyMode);
    }
    if (source) CFRelease(source);
    if (NULL == reply) {
	CFDictionaryRemoveValue(remote->_replies, (void *)(uintptr_t)desiredReply);
	CFRelease(remote);
	return CFMessagePortIsValid(remote) ? kCFMessagePortReceiveTimeout : kCFMessagePortBecameInvalidError;
    }
    if (NULL != returnDatap) {
	*returnDatap = ((void *)~0 == reply) ? NULL : reply;
    } else if ((void *)~0 != reply) {
	CFRelease(reply);
    }
    CFDictionaryRemoveValue(remote->_replies, (void *)(uintptr_t)desiredReply);
    CFRelease(remote);
    return kCFMessagePortSuccess;
}

static mach_port_t __CFMessagePortGetPort(void *info) {
    CFMessagePortRef ms = info;
    if (!ms->_port && __CFMessagePortIsValid(ms)) CFLog(kCFLogLevelWarning, CFSTR("*** Warning: A local CFMessagePort (%p) is being put in a run loop or dispatch queue, but it has not been named yet, so this will be a no-op and no messages are going to be received, even if named later."), info);
    return ms->_port ? CFMachPortGetPort(ms->_port) : MACH_PORT_NULL;
}


static void *__CFMessagePortPerform(void *msg, CFIndex size, CFAllocatorRef allocator, void *info) {
    CFMessagePortRef ms = info;
    mach_msg_base_t *msgp = msg;
    mach_msg_base_t *replymsg;
    void *context_info;
    void (*context_release)(const void *);
    CFDataRef returnData, data = NULL;
    void *return_bytes = NULL;
    CFIndex return_len = -1;
    int32_t msgid;

    __CFMessagePortLock(ms);
    if (!__CFMessagePortIsValid(ms)) {
	__CFMessagePortUnlock(ms);
	return NULL;
    }
    if (NULL != ms->_context.retain) {
	context_info = (void *)ms->_context.retain(ms->_context.info);
	context_release = ms->_context.release;
    } else {
	context_info = ms->_context.info;
	context_release = NULL;
    }
    __CFMessagePortUnlock(ms);

    
    int32_t byteslen = 0;

    Boolean wayTooSmall = size < sizeof(mach_msg_header_t) || size < MSGP_SIZE(msgp) || msgp->header.msgh_size < MSGP_SIZE(msgp);
    Boolean invalidMagic = false;
    Boolean invalidComplex = false;
    Boolean wayTooBig = false;
    if (!wayTooSmall) {
        invalidMagic = ((MSGP_INFO(msgp, magic) != MAGIC) && (CFSwapInt32(MSGP_INFO(msgp, magic)) != MAGIC));
        invalidComplex = (msgp->header.msgh_bits & MACH_MSGH_BITS_COMPLEX) && (1 != msgp->body.msgh_descriptor_count);
        wayTooBig = ((int32_t)MSGP_SIZE(msgp) + __CFMessagePortMaxInlineBytes) < msgp->header.msgh_size; // also less than a 32-bit signed int can hold
    }
    Boolean wrongSize = false;
    if (!(invalidComplex || wayTooBig || wayTooSmall)) {
        byteslen = CFSwapInt32LittleToHost(MSGP_INFO(msgp, byteslen));
        wrongSize = (byteslen < -1) || (__CFMessagePortMaxDataSize < byteslen);
        if (msgp->header.msgh_bits & MACH_MSGH_BITS_COMPLEX) {
            wrongSize = wrongSize || (MSGP_GET(msgp, ool).size != byteslen);
        } else {
            wrongSize = wrongSize || ((int32_t)msgp->header.msgh_size - (int32_t)MSGP_SIZE(msgp) < byteslen);
        }
    }
    Boolean invalidMsgID = wayTooSmall ? false : ((MSGP_INFO(msgp, convid) <= 0) || (INT32_MAX < MSGP_INFO(msgp, convid))); // conversation id
    if (invalidMagic || invalidComplex || wayTooBig || wayTooSmall || wrongSize || invalidMsgID) {
	CFLog(kCFLogLevelWarning, CFSTR("*** CFMessagePort: dropping corrupt request Mach message (0b%d%d%d%d%d%d)"), invalidMagic, invalidComplex, wayTooBig, wayTooSmall, wrongSize, invalidMsgID);
        mach_msg_destroy((mach_msg_header_t *)msgp);
        return NULL;
    }

    if (byteslen < 0) byteslen = 0; // from here on, treat negative same as zero

    /* Create no-copy, no-free-bytes wrapper CFData */
    if (!(msgp->header.msgh_bits & MACH_MSGH_BITS_COMPLEX)) {
	uintptr_t msgp_extent = (uintptr_t)((uint8_t *)msgp + msgp->header.msgh_size);
	uintptr_t data_extent = (uintptr_t)((uint8_t *)&(MSGP_INFO(msgp, bytes)) + byteslen);
	msgid = CFSwapInt32LittleToHost(MSGP_INFO(msgp, msgid));
	if (0 <= byteslen && data_extent <= msgp_extent) {
	    data = CFDataCreateWithBytesNoCopy(allocator, MSGP_INFO(msgp, bytes), byteslen, kCFAllocatorNull);
        }
    } else {
	msgid = CFSwapInt32LittleToHost(MSGP_INFO(msgp, msgid));
	data = CFDataCreateWithBytesNoCopy(allocator, MSGP_GET(msgp, ool).address, MSGP_GET(msgp, ool).size, kCFAllocatorNull);
    }
    if (ms->_callout) {
        returnData = ms->_callout(ms, msgid, data, context_info);
    } else {
        mach_msg_trailer_t *trailer = (mach_msg_trailer_t *)(((uintptr_t)&(msgp->header) + msgp->header.msgh_size + sizeof(natural_t) - 1) & ~(sizeof(natural_t) - 1));
        returnData = ms->_calloutEx(ms, msgid, data, context_info, trailer, 0);
    }
    /* Now, returnData could be (1) NULL, (2) an ordinary data < MAX_INLINE,
    (3) ordinary data >= MAX_INLINE, (4) a no-copy data < MAX_INLINE,
    (5) a no-copy data >= MAX_INLINE. In cases (2) and (4), we send the return
    bytes inline in the Mach message, so can release the returnData object
    here. In cases (3) and (5), we'll send the data out-of-line, we need to
    create a copy of the memory, which we'll have the kernel autodeallocate
    for us on send. In case (4) also, the bytes in the return data may be part
    of the bytes in "data" that we sent into the callout, so if the incoming
    data was received out of line, we wouldn't be able to clean up the out-of-line
    wad until the message was sent either, if we didn't make the copy. */
    if (NULL != returnData) {
	return_len = CFDataGetLength(returnData);
        if (__CFMessagePortMaxDataSize < return_len) {
            CFLog(kCFLogLevelWarning, CFSTR("*** CFMessagePort reply: CFMessagePort cannot send more than %lu bytes of data"), __CFMessagePortMaxDataSize);
            return_len = 0;
            CFRelease(returnData);
            returnData = NULL;
        }
	if (returnData && return_len < __CFMessagePortMaxInlineBytes) {
	    return_bytes = (void *)CFDataGetBytePtr(returnData);
	} else if (returnData) {
	    return_bytes = NULL;
	    vm_allocate(mach_task_self(), (vm_address_t *)&return_bytes, return_len, VM_FLAGS_ANYWHERE | VM_MAKE_TAG(VM_MEMORY_MACH_MSG));
	    /* vm_copy would only be a win here if the source address
		is page aligned; it is a lose in all other cases, since
		the kernel will just do the memmove for us (but not in
		as simple a way). */
	    memmove(return_bytes, CFDataGetBytePtr(returnData), return_len);
	}
    }
    replymsg = __CFMessagePortCreateMessage(true, msgp->header.msgh_remote_port, MACH_PORT_NULL, -1 * (int32_t)MSGP_INFO(msgp, convid), msgid, return_bytes, return_len);
    if (replymsg->header.msgh_bits & MACH_MSGH_BITS_COMPLEX) {
	MSGP_GET(replymsg, ool).deallocate = true;
    }
    if (data) CFRelease(data);
    if (msgp->header.msgh_bits & MACH_MSGH_BITS_COMPLEX) {
	vm_deallocate(mach_task_self(), (vm_address_t)MSGP_GET(msgp, ool).address, MSGP_GET(msgp, ool).size);
    }
    if (returnData) CFRelease(returnData);
    if (context_release) {
	context_release(context_info);
    }
    return replymsg;
}

CFRunLoopSourceRef CFMessagePortCreateRunLoopSource(CFAllocatorRef allocator, CFMessagePortRef ms, CFIndex order) {
    CFRunLoopSourceRef result = NULL;
    __CFGenericValidateType(ms, CFMessagePortGetTypeID());
    if (!CFMessagePortIsValid(ms)) return NULL;
    if (__CFMessagePortIsRemote(ms)) return NULL;
    __CFMessagePortLock(ms);
    if (NULL != ms->_source && !CFRunLoopSourceIsValid(ms->_source)) {
        CFRelease(ms->_source);
        ms->_source = NULL;
    }
    Boolean hasDispatchSource = false;
#if __HAS_DISPATCH__
    hasDispatchSource = (NULL == ms->_dispatchSource);
#endif
    if (NULL == ms->_source && !hasDispatchSource && __CFMessagePortIsValid(ms))
    {
	CFRunLoopSourceContext1 context;
	context.version = 1;
	context.info = (void *)ms;
	context.retain = (const void *(*)(const void *))CFRetain;
	context.release = (void (*)(const void *))CFRelease;
	context.copyDescription = (CFStringRef (*)(const void *))__CFMessagePortCopyDescription;
	context.equal = NULL;
	context.hash = NULL;
	context.getPort = __CFMessagePortGetPort;
	context.perform = __CFMessagePortPerform;
	ms->_source = CFRunLoopSourceCreate(allocator, order, (CFRunLoopSourceContext *)&context);
    }
    if (NULL != ms->_source) {
	result = (CFRunLoopSourceRef)CFRetain(ms->_source);
    }
    __CFMessagePortUnlock(ms);
    return result;
}

#if __HAS_DISPATCH__

void CFMessagePortSetDispatchQueue(CFMessagePortRef ms, dispatch_queue_t queue) {
    __CFGenericValidateType(ms, CFMessagePortGetTypeID());
    __CFMessagePortLock(ms);
    if (!__CFMessagePortIsValid(ms)) {
	__CFMessagePortUnlock(ms);
	CFLog(kCFLogLevelWarning, CFSTR("*** CFMessagePortSetDispatchQueue(): CFMessagePort is invalid"));
	return;
    }
    if (__CFMessagePortIsRemote(ms)) {
	__CFMessagePortUnlock(ms);
	CFLog(kCFLogLevelWarning, CFSTR("*** CFMessagePortSetDispatchQueue(): CFMessagePort is not a local port, queue cannot be set"));
	return;
    }
    if (NULL != ms->_source) {
	__CFMessagePortUnlock(ms);
	CFLog(kCFLogLevelWarning, CFSTR("*** CFMessagePortSetDispatchQueue(): CFMessagePort already has a CFRunLoopSourceRef, queue cannot be set"));
	return;
    }

    if (ms->_dispatchSource) {
        dispatch_source_cancel(ms->_dispatchSource);
        ms->_dispatchSource = NULL;
        ms->_dispatchQ = NULL;
    }

    if (queue) {
        mach_port_t port = __CFMessagePortGetPort(ms);
        if (MACH_PORT_NULL != port) {
            static dispatch_queue_t mportQueue = NULL;
            static dispatch_once_t once = 0;
            dispatch_once(&once, ^{
                dispatch_queue_attr_t dqattr = dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_SERIAL, qos_class_main(), 0);
                mportQueue = dispatch_queue_create("com.apple.CFMessagePort", dqattr);
            });
            dispatch_source_t theSource = dispatch_source_create(DISPATCH_SOURCE_TYPE_MACH_RECV, port, 0, mportQueue);
            dispatch_source_set_cancel_handler(theSource, ^{
                dispatch_release(queue);
                dispatch_release(theSource);
            });
            dispatch_source_set_event_handler(theSource, ^{
                CFRetain(ms);
                mach_msg_header_t *msg = (mach_msg_header_t *)CFAllocatorAllocate(kCFAllocatorSystemDefault, 2048, 0);
                msg->msgh_size = 2048;

                for (;;) {
                    msg->msgh_bits = 0;
                    msg->msgh_local_port = port;
                    msg->msgh_remote_port = MACH_PORT_NULL;
                    msg->msgh_id = 0;

                    kern_return_t ret = mach_msg(msg, MACH_RCV_MSG|MACH_RCV_LARGE|MACH_RCV_TRAILER_TYPE(MACH_MSG_TRAILER_FORMAT_0)|MACH_RCV_TRAILER_ELEMENTS(MACH_RCV_TRAILER_AV), 0, msg->msgh_size, port, 0, MACH_PORT_NULL);
                    if (MACH_MSG_SUCCESS == ret) break;
                    if (MACH_RCV_TOO_LARGE != ret) HALT;

                    uint32_t newSize = round_msg(msg->msgh_size + MAX_TRAILER_SIZE);
                    msg = CFAllocatorReallocate(kCFAllocatorSystemDefault, msg, newSize, 0);
                    msg->msgh_size = newSize;
                }

                dispatch_async(queue, ^{
                    mach_msg_header_t *reply = __CFMessagePortPerform(msg, msg->msgh_size, kCFAllocatorSystemDefault, ms);
                    if (NULL != reply) {
                        kern_return_t ret = mach_msg(reply, MACH_SEND_MSG, reply->msgh_size, 0, MACH_PORT_NULL, 0, MACH_PORT_NULL);
                        if (KERN_SUCCESS != ret) mach_msg_destroy(reply);
                        CFAllocatorDeallocate(kCFAllocatorSystemDefault, reply);
                    }
                    CFAllocatorDeallocate(kCFAllocatorSystemDefault, msg);
                    CFRelease(ms);
                });
            });
            ms->_dispatchSource = theSource;
        }
        if (ms->_dispatchSource) {
            dispatch_retain(queue);
            ms->_dispatchQ = queue;
            dispatch_resume(ms->_dispatchSource);
        } else {
            CFLog(kCFLogLevelWarning, CFSTR("*** CFMessagePortSetDispatchQueue(): dispatch source could not be created"));
        }
    }
    __CFMessagePortUnlock(ms);
}
#endif