1 /* 2 * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #include "webrtc/modules/rtp_rtcp/source/ssrc_database.h" 12 13 #include "webrtc/base/checks.h" 14 #include "webrtc/system_wrappers/include/clock.h" 15 #include "webrtc/system_wrappers/include/critical_section_wrapper.h" 16 17 namespace webrtc { 18 namespace { 19 uint64_t Seed() { 20 return Clock::GetRealTimeClock()->TimeInMicroseconds(); 21 } 22 } // namespace 23 24 SSRCDatabase* SSRCDatabase::GetSSRCDatabase() { 25 return GetStaticInstance<SSRCDatabase>(kAddRef); 26 } 27 28 void SSRCDatabase::ReturnSSRCDatabase() { 29 GetStaticInstance<SSRCDatabase>(kRelease); 30 } 31 32 uint32_t SSRCDatabase::CreateSSRC() { 33 CriticalSectionScoped lock(crit_.get()); 34 35 while (true) { // Try until get a new ssrc. 36 // 0 and 0xffffffff are invalid values for SSRC. 37 uint32_t ssrc = random_.Rand(1u, 0xfffffffe); 38 if (ssrcs_.insert(ssrc).second) { 39 return ssrc; 40 } 41 } 42 } 43 44 void SSRCDatabase::RegisterSSRC(uint32_t ssrc) { 45 CriticalSectionScoped lock(crit_.get()); 46 ssrcs_.insert(ssrc); 47 } 48 49 void SSRCDatabase::ReturnSSRC(uint32_t ssrc) { 50 CriticalSectionScoped lock(crit_.get()); 51 ssrcs_.erase(ssrc); 52 } 53 54 SSRCDatabase::SSRCDatabase() 55 : crit_(CriticalSectionWrapper::CreateCriticalSection()), random_(Seed()) {} 56 57 SSRCDatabase::~SSRCDatabase() { 58 } 59 60 } // namespace webrtc 61
