UniquePtr: Support SrsUniquePtr to replace SrsAutoFree. v6.0.136

[winlinvip]

To manage an object:

// Before
MyClass* ptr = new MyClass();
SrsAutoFree(MyClass, ptr);
ptr->do_something();

// Now
SrsUniquePtr<MyClass> ptr(new MyClass());
ptr->do_something();

To manage an array of objects:

// Before
char* ptr = new char[10];
SrsAutoFreeA(char, ptr);
ptr[0] = 0xf;

// Now
SrsUniquePtr<char[]> ptr(new char[10]);
ptr[0] = 0xf;

In fact, SrsUniquePtr is a limited subset of SrsAutoFree, mainly managing pointers and arrays. SrsUniquePtr is better than SrsAutoFree because it has the same API to standard unique ptr.

SrsUniquePtr<MyClass> ptr(new MyClass());
ptr->do_something();
MyClass* p = ptr.get();

SrsAutoFree actually uses a pointer to a pointer, so it can be set to NULL, allowing the pointer's value to be changed later (this usage is different from SrsUniquePtr).

// OK to free ptr correctly.
MyClass* ptr;
SrsAutoFree(MyClass, ptr);
ptr = new MyClass();

// Crash because ptr is an invalid pointer.
MyClass* ptr;
SrsUniquePtr<MyClass> ptr(ptr);
ptr = new MyClass();

Additionally, SrsAutoFreeH can use specific release functions, which SrsUniquePtr does not support.

---

Co-authored-by: Jacob Su suzp1984@gmail.com

[suzp1984]

this include header,srs_core.hpp, is useless, can be removed.

[winlinvip]

I want to make sure the first included file is this one.

Won't fix.

[suzp1984]

I don't know whether it's a code conventions or not, but an empty cpp, seems useless.

[winlinvip]

It will cause the utest fail. Please file another PR if you want to remove it.

Won't fix.

[suzp1984]

err need to freed and processed if it's not srs_success, otherwise err != srs_success would be a memory leak.

[winlinvip]

The err is returned:

    err = process_requests(&last_req_raw);
    if ((r0 = on_disconnect(last_req.get())) != srs_success) {
        err = srs_error_wrap(err, "on disconnect %s", srs_error_desc(r0).c_str());
        srs_freep(r0);
    }
    
    return err;

Won't fix.

[suzp1984]

consumer_raw will alway has value, no need to check with assert?

srs/trunk/src/app/srs_app_rtc_source.cpp

Lines 550 to 562 in baf22d0

	srs_error_t SrsRtcSource::create_consumer(SrsRtcConsumer*& consumer)
	{
	srs_error_t err = srs_success;
	consumer = new SrsRtcConsumer(this);
	consumers.push_back(consumer);
	stream_die_at_ = 0;
	// TODO: FIXME: Implements edge cluster.
	return err;
	}

[winlinvip]

Not a bug or logic error.

Won't fix.

[suzp1984]

I would rather use a srs_freep(raw_raw) manually in this else scope to simple the code.

[winlinvip]

Nop, it's used later:

        SrsUniquePtr<SrsRtpRawNALUs> raw(raw_raw);
        uint8_t header = raw->skip_first_byte();

Won't fix.

[suzp1984]

consumer_raw always true here

[winlinvip]

Not a bug or an error.

Won't fix.

[suzp1984]

all done