waf-platform/HttpDNSSDK/sdk/ios/NewHttpDNSTests/Network/HttpdnsNWHTTPClient_EdgeCasesAndTimeoutTests.m

//
//  HttpdnsNWHTTPClient_EdgeCasesAndTimeoutTests.m
//  TrustHttpDNSTests
//
//  @author Created by Claude Code on 2025-11-01
//  Copyright © 2025 trustapp.com. All rights reserved.
//
//  边界æ<C592>¡ä»¶ä¸Žè¶…时测è¯?- 包å<E280A6>«è¾¹ç•Œæ<C592>¡ä»¶ (M)ã€<C3A3>超时交äº?(P) å’?Connection 头部 (R) 测试ç»?
//  测试总数�5 个（M:4 + P:6 + R:5�
//

#import "HttpdnsNWHTTPClientTestBase.h"

@interface HttpdnsNWHTTPClient_EdgeCasesAndTimeoutTests : HttpdnsNWHTTPClientTestBase

@end

@implementation HttpdnsNWHTTPClient_EdgeCasesAndTimeoutTests

#pragma mark - M. 边界æ<C592>¡ä»¶ä¸ŽéªŒè¯<C3A8>测è¯?

// M.1 连接å¤<C3A5>用边界：端å<C2AF>£å†…å¤<C3A5>用，端å<C2AF>£é—´éš”离
- (void)testEdgeCase_ConnectionReuseWithinPortOnly_NotAcross {
    XCTestExpectation *expectation = [self expectationWithDescription:@"Reuse boundaries"];

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        // 请求 A 到端å<C2AF>?11443
        CFAbsoluteTime timeA = CFAbsoluteTimeGetCurrent();
        NSError *errorA = nil;
        HttpdnsNWHTTPClientResponse *responseA = [self.client performRequestWithURLString:@"https://127.0.0.1:11443/get"
                                                                                 userAgent:@"RequestA"
                                                                                   timeout:15.0
                                                                                     error:&errorA];
        CFAbsoluteTime elapsedA = CFAbsoluteTimeGetCurrent() - timeA;
        XCTAssertNotNil(responseA);

        // 请求 B 到端å<C2AF>?11443（应该å¤<C3A5>用连接，å<C592>¯èƒ½æ›´å¿«ï¼?
        CFAbsoluteTime timeB = CFAbsoluteTimeGetCurrent();
        NSError *errorB = nil;
        HttpdnsNWHTTPClientResponse *responseB = [self.client performRequestWithURLString:@"https://127.0.0.1:11443/get"
                                                                                 userAgent:@"RequestB"
                                                                                   timeout:15.0
                                                                                     error:&errorB];
        CFAbsoluteTime elapsedB = CFAbsoluteTimeGetCurrent() - timeB;
        XCTAssertNotNil(responseB);

        // 请求 C 到端å<C2AF>?11444（应该创建新连接ï¼?
        CFAbsoluteTime timeC = CFAbsoluteTimeGetCurrent();
        NSError *errorC = nil;
        HttpdnsNWHTTPClientResponse *responseC = [self.client performRequestWithURLString:@"https://127.0.0.1:11444/get"
                                                                                 userAgent:@"RequestC"
                                                                                   timeout:15.0
                                                                                     error:&errorC];
        CFAbsoluteTime elapsedC = CFAbsoluteTimeGetCurrent() - timeC;
        XCTAssertNotNil(responseC);

        // 请求 D 到端å<C2AF>?11444（应该å¤<C3A5>用端å<C2AF>?11444 的连接）
        CFAbsoluteTime timeD = CFAbsoluteTimeGetCurrent();
        NSError *errorD = nil;
        HttpdnsNWHTTPClientResponse *responseD = [self.client performRequestWithURLString:@"https://127.0.0.1:11444/get"
                                                                                 userAgent:@"RequestD"
                                                                                   timeout:15.0
                                                                                     error:&errorD];
        CFAbsoluteTime elapsedD = CFAbsoluteTimeGetCurrent() - timeD;
        XCTAssertNotNil(responseD);

        // 验è¯<C3A8>所有请求都æˆ<C3A6>功
        XCTAssertEqual(responseA.statusCode, 200);
        XCTAssertEqual(responseB.statusCode, 200);
        XCTAssertEqual(responseC.statusCode, 200);
        XCTAssertEqual(responseD.statusCode, 200);

        [expectation fulfill];
    });

    [self waitForExpectations:@[expectation] timeout:70.0];
}

// M.2 高端å<C2AF>£æ•°é‡<C3A9>压力测è¯?
- (void)testEdgeCase_HighPortCount_AllPortsManaged {
    XCTestExpectation *expectation = [self expectationWithDescription:@"High port count"];

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        NSArray<NSNumber *> *ports = @[@11443, @11444, @11445, @11446];

        // 第一轮：å<C5A1>‘所有端å<C2AF>£å<C2A3>„å<E2809E>‘起一个请æ±?
        for (NSNumber *port in ports) {
            NSString *urlString = [NSString stringWithFormat:@"https://127.0.0.1:%@/get", port];
            NSError *error = nil;
            HttpdnsNWHTTPClientResponse *response = [self.client performRequestWithURLString:urlString
                                                                                    userAgent:@"Round1"
                                                                                      timeout:15.0
                                                                                        error:&error];
            XCTAssertNotNil(response, @"First round request to port %@ should succeed", port);
        }

        // 第二轮：å†<C3A5>次å<C2A1>‘所有端å<C2AF>£å<C2A3>‘起请求（应该å¤<C3A5>用连接ï¼?
        for (NSNumber *port in ports) {
            NSString *urlString = [NSString stringWithFormat:@"https://127.0.0.1:%@/get", port];
            NSError *error = nil;
            HttpdnsNWHTTPClientResponse *response = [self.client performRequestWithURLString:urlString
                                                                                    userAgent:@"Round2"
                                                                                      timeout:15.0
                                                                                        error:&error];
            XCTAssertNotNil(response, @"Second round request to port %@ should reuse connection", port);
        }

        [expectation fulfill];
    });

    [self waitForExpectations:@[expectation] timeout:120.0];
}

// M.3 并å<C2B6>‘池访问安全æ€?
- (void)testEdgeCase_ConcurrentPoolAccess_NoDataRace {
    NSMutableArray<XCTestExpectation *> *expectations = [NSMutableArray array];
    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

    NSArray<NSNumber *> *ports = @[@11443, @11444, @11445];
    NSInteger requestsPerPort = 5;

    // å<>‘三个端å<C2AF>£å¹¶å<C2B6>‘å<E28098>‘起请æ±?
    for (NSNumber *port in ports) {
        for (NSInteger i = 0; i < requestsPerPort; i++) {
            XCTestExpectation *expectation = [self expectationWithDescription:[NSString stringWithFormat:@"Port %@ Req %ld", port, (long)i]];
            [expectations addObject:expectation];

            dispatch_async(queue, ^{
                NSString *urlString = [NSString stringWithFormat:@"https://127.0.0.1:%@/get", port];
                NSError *error = nil;
                HttpdnsNWHTTPClientResponse *response = [self.client performRequestWithURLString:urlString
                                                                                        userAgent:@"ConcurrentAccess"
                                                                                          timeout:15.0
                                                                                            error:&error];
                // 如果没有崩溃或断言失败，说明并å<C2B6>‘访问安å…?
                XCTAssertTrue(response != nil || error != nil);
                [expectation fulfill];
            });
        }
    }

    [self waitForExpectations:expectations timeout:50.0];
}

// M.4 端å<C2AF>£è¿<C3A8>移模å¼<C3A5>
- (void)testEdgeCase_PortMigration_OldConnectionsEventuallyExpire {
    if (getenv("SKIP_SLOW_TESTS")) {
        return;
    }

    XCTestExpectation *expectation = [self expectationWithDescription:@"Port migration"];

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        // 阶段 1：å<C5A1>‘端å<C2AF>£ 11443 å<>‘起多个请求
        for (NSInteger i = 0; i < 5; i++) {
            NSError *error = nil;
            [self.client performRequestWithURLString:@"https://127.0.0.1:11443/get"
                                            userAgent:@"Port11443"
                                              timeout:15.0
                                                error:&error];
        }

        // 阶段 2：切æ<E280A1>¢åˆ°ç«¯å<C2AF>£ 11444，å<C592>‘起多个请æ±?
        for (NSInteger i = 0; i < 5; i++) {
            NSError *error = nil;
            [self.client performRequestWithURLString:@"https://127.0.0.1:11444/get"
                                            userAgent:@"Port11444"
                                              timeout:15.0
                                                error:&error];
        }

        // 等待超过 30 秒，让端å<C2AF>?11443 的连接过æœ?
        [NSThread sleepForTimeInterval:31.0];

        // 阶段 3：验è¯<C3A8>端å<C2AF>?11444 ä»<C3A4>然å<C2B6>¯ç”¨
        NSError *error1 = nil;
        HttpdnsNWHTTPClientResponse *response1 = [self.client performRequestWithURLString:@"https://127.0.0.1:11444/get"
                                                                                 userAgent:@"Port11444After"
                                                                                   timeout:15.0
                                                                                     error:&error1];
        XCTAssertNotNil(response1, @"Port 11444 should still work after 11443 expired");

        // 阶段 4：端å<C2AF>?11443 应该创建新连接（旧连接已过期ï¼?
        NSError *error2 = nil;
        HttpdnsNWHTTPClientResponse *response2 = [self.client performRequestWithURLString:@"https://127.0.0.1:11443/get"
                                                                                 userAgent:@"Port11443New"
                                                                                   timeout:15.0
                                                                                     error:&error2];
        XCTAssertNotNil(response2, @"Port 11443 should work with new connection after expiry");

        [expectation fulfill];
    });

    [self waitForExpectations:@[expectation] timeout:120.0];
}

#pragma mark - P. 超时与连接池交互测试

// P.1 å<>•æ¬¡è¶…æ—¶å<C2B6>Žè¿žæŽ¥è¢«æ­£ç¡®ç§»é™¤
- (void)testTimeout_SingleRequest_ConnectionRemovedFromPool {
    [self.client resetPoolStatistics];
    NSString *poolKey = @"127.0.0.1:11080:tcp";

    // 验è¯<C3A8>åˆ<C3A5>始状æ€?
    XCTAssertEqual([self.client connectionPoolCountForKey:poolKey], 0,
                   @"Pool should be empty initially");

    // å<>‘起超时请求（delay 10s, timeout 1sï¼?
    NSError *error = nil;
    HttpdnsNWHTTPClientResponse *response = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/delay/10"
                                                                            userAgent:@"TimeoutTest"
                                                                              timeout:1.0
                                                                                error:&error];

    // 验è¯<C3A8>请求失败
    XCTAssertNil(response, @"Response should be nil on timeout");
    XCTAssertNotNil(error, @"Error should be set on timeout");

    // 等待异步 returnConnection 完æˆ<C3A6>
    [NSThread sleepForTimeInterval:0.5];

    // 验è¯<C3A8>池状æ€<C3A6>：超时连接应该被移é™?
    XCTAssertEqual([self.client connectionPoolCountForKey:poolKey], 0,
                   @"Timed-out connection should be removed from pool");
    XCTAssertEqual([self.client totalConnectionCount], 0,
                   @"No connections should remain in pool");

    // 验è¯<C3A8>统计
    XCTAssertEqual(self.client.connectionCreationCount, 1,
                   @"Should have created 1 connection");
    XCTAssertEqual(self.client.connectionReuseCount, 0,
                   @"No reuse for timed-out connection");
}

// P.2 超时å<C2B6>Žè¿žæŽ¥æ± æ<C2A0>¢å¤<C3A5>能力
- (void)testTimeout_PoolRecovery_SubsequentRequestSucceeds {
    [self.client resetPoolStatistics];
    NSString *poolKey = @"127.0.0.1:11080:tcp";

    // 第一个请求：超时
    NSError *error1 = nil;
    HttpdnsNWHTTPClientResponse *response1 = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/delay/10"
                                                                             userAgent:@"TimeoutTest"
                                                                               timeout:1.0
                                                                                 error:&error1];
    XCTAssertNil(response1, @"First request should timeout");
    XCTAssertNotNil(error1);

    // 等待清ç<E280A6>†å®Œæˆ<C3A6>
    [NSThread sleepForTimeInterval:0.5];

    // 第二个请求：正常（验è¯<C3A8>æ± å·²æ<C2B2>¢å¤<C3A5>）
    NSError *error2 = nil;
    HttpdnsNWHTTPClientResponse *response2 = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/get"
                                                                             userAgent:@"RecoveryTest"
                                                                               timeout:15.0
                                                                                 error:&error2];
    XCTAssertNotNil(response2, @"Second request should succeed after timeout");
    XCTAssertEqual(response2.statusCode, 200);

    // 等待 returnConnection
    [NSThread sleepForTimeInterval:0.5];

    // 验è¯<C3A8>æ± æ<C2A0>¢å¤<C3A5>：现在应该æœ?1 个连接（æ<CB86>¥è‡ªç¬¬äºŒä¸ªè¯·æ±‚）
    XCTAssertEqual([self.client connectionPoolCountForKey:poolKey], 1,
                   @"Pool should have 1 connection from second request");

    // 第三个请求：应该å¤<C3A5>用第二个请求的连接
    NSError *error3 = nil;
    HttpdnsNWHTTPClientResponse *response3 = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/get"
                                                                             userAgent:@"ReuseTest"
                                                                               timeout:15.0
                                                                                 error:&error3];
    XCTAssertNotNil(response3);
    XCTAssertEqual(response3.statusCode, 200);

    // 验è¯<C3A8>统计ï¼? 个超时（创建å<C2BA>Žç§»é™¤ï¼‰+ 1 个æˆ<C3A6>功（创建ï¼? 1 个å¤<C3A5>ç”?
    XCTAssertEqual(self.client.connectionCreationCount, 2,
                   @"Should have created 2 connections (1 timed out, 1 succeeded)");
    XCTAssertEqual(self.client.connectionReuseCount, 1,
                   @"Third request should reuse second's connection");
}

// P.3 并å<C2B6>‘场景：部分超时ä¸<C3A4>å½±å“<C3A5>æˆ<C3A6>功请求的连接å¤<C3A5>ç”?
- (void)testTimeout_ConcurrentPartialTimeout_SuccessfulRequestsReuse {
    [self.client resetPoolStatistics];
    NSString *poolKey = @"127.0.0.1:11080:tcp";

    NSMutableArray<XCTestExpectation *> *expectations = [NSMutableArray array];
    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

    NSLock *successCountLock = [[NSLock alloc] init];
    NSLock *timeoutCountLock = [[NSLock alloc] init];
    __block NSInteger successCount = 0;
    __block NSInteger timeoutCount = 0;

    // å<>‘èµ· 10 个请求：5 个正常，5 个超æ—?
    for (NSInteger i = 0; i < 10; i++) {
        XCTestExpectation *expectation = [self expectationWithDescription:[NSString stringWithFormat:@"Request %ld", (long)i]];
        [expectations addObject:expectation];

        dispatch_async(queue, ^{
            NSError *error = nil;
            NSString *urlString;
            NSTimeInterval timeout;

            if (i % 2 == 0) {
                // å<>¶æ•°ï¼šæ­£å¸¸è¯·æ±?
                urlString = @"http://127.0.0.1:11080/get";
                timeout = 15.0;
            } else {
                // 奇数：超时请�
                urlString = @"http://127.0.0.1:11080/delay/10";
                timeout = 0.5;
            }

            HttpdnsNWHTTPClientResponse *response = [self.client performRequestWithURLString:urlString
                                                                                    userAgent:@"ConcurrentTest"
                                                                                      timeout:timeout
                                                                                        error:&error];

            if (response && response.statusCode == 200) {
                [successCountLock lock];
                successCount++;
                [successCountLock unlock];
            } else {
                [timeoutCountLock lock];
                timeoutCount++;
                [timeoutCountLock unlock];
            }

            [expectation fulfill];
        });
    }

    [self waitForExpectations:expectations timeout:20.0];

    // 验è¯<C3A8>结果
    XCTAssertEqual(successCount, 5, @"5 requests should succeed");
    XCTAssertEqual(timeoutCount, 5, @"5 requests should timeout");

    // 验è¯<C3A8>连接创建数å<C2B0>ˆç<CB86>†ï¼ˆ5个æˆ<C3A6>åŠ?+ 5个超æ—?= 最å¤?0个，å<C592>¯èƒ½æœ‰å¤<C3A5>用）
    XCTAssertGreaterThan(self.client.connectionCreationCount, 0,
                         @"Should have created connections for concurrent requests");
    XCTAssertLessThanOrEqual(self.client.connectionCreationCount, 10,
                             @"Should not create more than 10 connections");

    // 等待所有连接归还（异步æ“<C3A6>作需è¦<C3A8>更长时间）
    [NSThread sleepForTimeInterval:2.0];

    // 验è¯<C3A8>总连接数å<C2B0>ˆç<CB86>†ï¼ˆæ— æ³„æ¼<C3A6>ï¼? 关键验è¯<C3A8>ç‚?
    // 在并å<C2B6>‘场景下，æˆ<C3A6>功的连接å<C2A5>¯èƒ½å·²ç»<C3A7>被关闭（remote close），池å<C2A0>¯èƒ½ä¸ºç©?
    XCTAssertLessThanOrEqual([self.client totalConnectionCount], 4,
                             @"Total connections should not exceed pool limit (no leak)");

    // å<>‘起新请求验è¯<C3A8>æ± ä»<C3A4>然å<C2B6>¥åº·ï¼ˆèƒ½åˆ›å»ºæ–°è¿žæŽ¥ï¼‰
    NSError *recoveryError = nil;
    HttpdnsNWHTTPClientResponse *recoveryResponse = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/get"
                                                                                    userAgent:@"RecoveryTest"
                                                                                      timeout:15.0
                                                                                        error:&recoveryError];
    XCTAssertNotNil(recoveryResponse, @"Pool should recover and handle new requests after mixed timeout/success");
    XCTAssertEqual(recoveryResponse.statusCode, 200, @"Recovery request should succeed");
}

// P.4 连续超时ä¸<C3A4>导致连接泄æ¼?
- (void)testTimeout_ConsecutiveTimeouts_NoConnectionLeak {
    [self.client resetPoolStatistics];
    NSString *poolKey = @"127.0.0.1:11080:tcp";

    // è¿žç»­å<C2AD>‘èµ· 10 个超时请æ±?
    for (NSInteger i = 0; i < 10; i++) {
        NSError *error = nil;
        HttpdnsNWHTTPClientResponse *response = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/delay/10"
                                                                                userAgent:@"LeakTest"
                                                                                  timeout:0.5
                                                                                    error:&error];
        XCTAssertNil(response, @"Request %ld should timeout", (long)i);

        // 等待清ç<E280A6>†
        [NSThread sleepForTimeInterval:0.2];
    }

    // 验è¯<C3A8>池状æ€<C3A6>：无连接泄æ¼?
    XCTAssertEqual([self.client connectionPoolCountForKey:poolKey], 0,
                   @"Pool should be empty after consecutive timeouts");
    XCTAssertEqual([self.client totalConnectionCount], 0,
                   @"No connections should leak");

    // 验è¯<C3A8>统计：æ¯<C3A6>次都创建新连接（因为超时的被移除ï¼?
    XCTAssertEqual(self.client.connectionCreationCount, 10,
                   @"Should have created 10 connections (all timed out and removed)");
    XCTAssertEqual(self.client.connectionReuseCount, 0,
                   @"No reuse for timed-out connections");
}

// P.5 超时ä¸<C3A4>阻塞连接池（并å<C2B6>‘正常请求ä¸<C3A4>å<EFBFBD>—å½±å“<C3A5>）
- (void)testTimeout_NonBlocking_ConcurrentNormalRequestSucceeds {
    [self.client resetPoolStatistics];

    XCTestExpectation *timeoutExpectation = [self expectationWithDescription:@"Timeout request"];
    XCTestExpectation *successExpectation = [self expectationWithDescription:@"Success request"];

    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

    // 请求 A：超时（delay 10s, timeout 2s�
    dispatch_async(queue, ^{
        NSError *error = nil;
        HttpdnsNWHTTPClientResponse *response = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/delay/10"
                                                                                userAgent:@"TimeoutRequest"
                                                                                  timeout:2.0
                                                                                    error:&error];
        XCTAssertNil(response, @"Request A should timeout");
        [timeoutExpectation fulfill];
    });

    // 请求 B：正常（应该ä¸<C3A4>å<EFBFBD>— A 阻塞ï¼?
    dispatch_async(queue, ^{
        // ç¨<C3A7>微延迟，确ä¿?A 先开å§?
        [NSThread sleepForTimeInterval:0.1];

        CFAbsoluteTime startTime = CFAbsoluteTimeGetCurrent();
        NSError *error = nil;
        HttpdnsNWHTTPClientResponse *response = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/get"
                                                                                userAgent:@"NormalRequest"
                                                                                  timeout:15.0
                                                                                    error:&error];
        CFAbsoluteTime elapsed = CFAbsoluteTimeGetCurrent() - startTime;

        XCTAssertNotNil(response, @"Request B should succeed despite A timing out");
        XCTAssertEqual(response.statusCode, 200);

        // 验è¯<C3A8>请求 B 没有被请æ±?A 阻塞（应该很快完æˆ<C3A6>）
        XCTAssertLessThan(elapsed, 5.0,
                          @"Request B should complete quickly, not blocked by A's timeout");

        [successExpectation fulfill];
    });

    [self waitForExpectations:@[timeoutExpectation, successExpectation] timeout:20.0];

    // 等待连接归还
    [NSThread sleepForTimeInterval:0.5];

    // 验è¯<C3A8>池状æ€<C3A6>：å<C5A1>ªæœ‰è¯·æ±‚ B çš„è¿žæŽ?
    NSString *poolKey = @"127.0.0.1:11080:tcp";
    XCTAssertEqual([self.client connectionPoolCountForKey:poolKey], 1,
                   @"Pool should have 1 connection from successful request B");
}

// P.6 多端å<C2AF>£åœºæ™¯ä¸‹çš„超时隔ç¦?
- (void)testTimeout_MultiPort_IsolatedPoolCleaning {
    [self.client resetPoolStatistics];

    NSString *poolKey11443 = @"127.0.0.1:11443:tls";
    NSString *poolKey11444 = @"127.0.0.1:11444:tls";

    // 端å<C2AF>£ 11443：超时请æ±?
    NSError *error1 = nil;
    HttpdnsNWHTTPClientResponse *response1 = [self.client performRequestWithURLString:@"https://127.0.0.1:11443/delay/10"
                                                                             userAgent:@"Port11443Timeout"
                                                                               timeout:1.0
                                                                                 error:&error1];
    XCTAssertNil(response1, @"Port 11443 request should timeout");

    // 端å<C2AF>£ 11444：正常请æ±?
    NSError *error2 = nil;
    HttpdnsNWHTTPClientResponse *response2 = [self.client performRequestWithURLString:@"https://127.0.0.1:11444/get"
                                                                             userAgent:@"Port11444Success"
                                                                               timeout:15.0
                                                                                 error:&error2];
    XCTAssertNotNil(response2, @"Port 11444 request should succeed");
    XCTAssertEqual(response2.statusCode, 200);

    // 等待连接归还
    [NSThread sleepForTimeInterval:0.5];

    // 验è¯<C3A8>端å<C2AF>£éš”离：端å<C2AF>?11443 无连接，端å<C2AF>£ 11444 æœ?1 个连æŽ?
    XCTAssertEqual([self.client connectionPoolCountForKey:poolKey11443], 0,
                   @"Port 11443 pool should be empty (timed out)");
    XCTAssertEqual([self.client connectionPoolCountForKey:poolKey11444], 1,
                   @"Port 11444 pool should have 1 connection");

    // 验è¯<C3A8>总连接数
    XCTAssertEqual([self.client totalConnectionCount], 1,
                   @"Total should be 1 (only from port 11444)");

    // å†<C3A5>次请求端å<C2AF>£ 11444：应该å¤<C3A5>用连æŽ?
    NSError *error3 = nil;
    HttpdnsNWHTTPClientResponse *response3 = [self.client performRequestWithURLString:@"https://127.0.0.1:11444/get"
                                                                             userAgent:@"Port11444Reuse"
                                                                               timeout:15.0
                                                                                 error:&error3];
    XCTAssertNotNil(response3);
    XCTAssertEqual(response3.statusCode, 200);

    // 验è¯<C3A8>å¤<C3A5>用å<C2A8>‘生
    XCTAssertEqual(self.client.connectionReuseCount, 1,
                   @"Second request to port 11444 should reuse connection");
}

#pragma mark - R. Connection 头部处ç<E2809E>†æµ‹è¯•

// R.1 Connection: close 导致连接被立å<E280B9>³å¤±æ•?
- (void)testConnectionHeader_Close_ConnectionInvalidated {
    [self.client resetPoolStatistics];
    NSString *poolKey = @"127.0.0.1:11080:tcp";

    // 请求 1：æœ<C3A6>务器返回 Connection: close
    NSError *error1 = nil;
    HttpdnsNWHTTPClientResponse *response1 = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/connection-test?mode=close"
                                                                            userAgent:@"CloseTest"
                                                                              timeout:15.0
                                                                                error:&error1];
    XCTAssertNotNil(response1, @"Request with Connection: close should succeed");
    XCTAssertEqual(response1.statusCode, 200);

    // 等待异步 returnConnection 完æˆ<C3A6>
    [NSThread sleepForTimeInterval:0.5];

    // 验è¯<C3A8>：连接ä¸<C3A4>在池中（已失效）
    XCTAssertEqual([self.client connectionPoolCountForKey:poolKey], 0,
                   @"Connection with 'Connection: close' header should be invalidated and not returned to pool");

    // 请求 2：应该创建新连接（第一个连接已失效�
    NSError *error2 = nil;
    HttpdnsNWHTTPClientResponse *response2 = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/connection-test?mode=keep-alive"
                                                                            userAgent:@"KeepAliveTest"
                                                                              timeout:15.0
                                                                                error:&error2];
    XCTAssertNotNil(response2);
    XCTAssertEqual(response2.statusCode, 200);

    // 验è¯<C3A8>统计：创建了 2 个连接（第一个被 close，第二个正常ï¼?
    XCTAssertEqual(self.client.connectionCreationCount, 2,
                   @"Should have created 2 connections (first closed by server)");
    XCTAssertEqual(self.client.connectionReuseCount, 0,
                   @"No reuse after Connection: close");
}

// R.2 Connection: keep-alive å…<C3A5>许连接å¤<C3A5>用
- (void)testConnectionHeader_KeepAlive_ConnectionReused {
    [self.client resetPoolStatistics];
    NSString *poolKey = @"127.0.0.1:11080:tcp";

    // 请求 1：æœ<C3A6>务器返回 Connection: keep-alive
    NSError *error1 = nil;
    HttpdnsNWHTTPClientResponse *response1 = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/connection-test?mode=keep-alive"
                                                                            userAgent:@"KeepAlive1"
                                                                              timeout:15.0
                                                                                error:&error1];
    XCTAssertNotNil(response1);
    XCTAssertEqual(response1.statusCode, 200);

    // 等待连接归还
    [NSThread sleepForTimeInterval:0.5];

    // 验è¯<C3A8>：连接在池中
    XCTAssertEqual([self.client connectionPoolCountForKey:poolKey], 1,
                   @"Connection with 'Connection: keep-alive' should be returned to pool");

    // 请求 2：应该å¤<C3A5>用第一个连æŽ?
    NSError *error2 = nil;
    HttpdnsNWHTTPClientResponse *response2 = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/connection-test?mode=keep-alive"
                                                                            userAgent:@"KeepAlive2"
                                                                              timeout:15.0
                                                                                error:&error2];
    XCTAssertNotNil(response2);
    XCTAssertEqual(response2.statusCode, 200);

    // 验è¯<C3A8>统计：å<C5A1>ªåˆ›å»ºäº?1 个连接，第二个请求å¤<C3A5>用了å®?
    XCTAssertEqual(self.client.connectionCreationCount, 1,
                   @"Should have created only 1 connection");
    XCTAssertEqual(self.client.connectionReuseCount, 1,
                   @"Second request should reuse the first connection");
}

// R.3 Proxy-Connection: close 也会导致连接失效
- (void)testConnectionHeader_ProxyClose_ConnectionInvalidated {
    [self.client resetPoolStatistics];
    NSString *poolKey = @"127.0.0.1:11080:tcp";

    // 请求 1：æœ<C3A6>务器返回 Proxy-Connection: close (+ Connection: keep-alive)
    NSError *error1 = nil;
    HttpdnsNWHTTPClientResponse *response1 = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/connection-test?mode=proxy-close"
                                                                            userAgent:@"ProxyCloseTest"
                                                                              timeout:15.0
                                                                                error:&error1];
    XCTAssertNotNil(response1, @"Request with Proxy-Connection: close should succeed");
    XCTAssertEqual(response1.statusCode, 200);

    // 等待异步 returnConnection 完æˆ<C3A6>
    [NSThread sleepForTimeInterval:0.5];

    // 验è¯<C3A8>：连接ä¸<C3A4>在池中（Proxy-Connection: close 应该失效连接ï¼?
    XCTAssertEqual([self.client connectionPoolCountForKey:poolKey], 0,
                   @"Connection with 'Proxy-Connection: close' header should be invalidated");

    // 请求 2：应该创建新连接
    NSError *error2 = nil;
    HttpdnsNWHTTPClientResponse *response2 = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/connection-test?mode=keep-alive"
                                                                            userAgent:@"RecoveryTest"
                                                                              timeout:15.0
                                                                                error:&error2];
    XCTAssertNotNil(response2);
    XCTAssertEqual(response2.statusCode, 200);

    // 验è¯<C3A8>统计：创建了 2 个连æŽ?
    XCTAssertEqual(self.client.connectionCreationCount, 2,
                   @"Should have created 2 connections (first closed by proxy header)");
    XCTAssertEqual(self.client.connectionReuseCount, 0,
                   @"No reuse after Proxy-Connection: close");
}

// R.4 Connection 头部大å°<C3A5>写ä¸<C3A4>æ•<C3A6>æ„Ÿ
- (void)testConnectionHeader_CaseInsensitive_AllVariantsWork {
    [self.client resetPoolStatistics];
    NSString *poolKey = @"127.0.0.1:11080:tcp";

    // 测试 1：CONNECTION: CLOSE (全大�
    NSError *error1 = nil;
    HttpdnsNWHTTPClientResponse *response1 = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/connection-test?mode=close-uppercase"
                                                                            userAgent:@"UppercaseTest"
                                                                              timeout:15.0
                                                                                error:&error1];
    XCTAssertNotNil(response1);
    XCTAssertEqual(response1.statusCode, 200);

    [NSThread sleepForTimeInterval:0.5];

    // 验è¯<C3A8>：连接ä¸<C3A4>在池中（大写 CLOSE 也应生效ï¼?
    XCTAssertEqual([self.client connectionPoolCountForKey:poolKey], 0,
                   @"'CONNECTION: CLOSE' (uppercase) should also close connection");

    // 测试 2：Connection: Close (æ··å<C2B7>ˆå¤§å°<C3A5>å†?
    NSError *error2 = nil;
    HttpdnsNWHTTPClientResponse *response2 = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/connection-test?mode=close-mixed"
                                                                            userAgent:@"MixedCaseTest"
                                                                              timeout:15.0
                                                                                error:&error2];
    XCTAssertNotNil(response2);
    XCTAssertEqual(response2.statusCode, 200);

    [NSThread sleepForTimeInterval:0.5];

    // 验è¯<C3A8>：连接ä¸<C3A4>在池中（混å<C2B7>ˆå¤§å°<C3A5>写也应生效）
    XCTAssertEqual([self.client connectionPoolCountForKey:poolKey], 0,
                   @"'Connection: Close' (mixed case) should also close connection");

    // 验è¯<C3A8>统计：创建了 2 个连接，都被 close
    XCTAssertEqual(self.client.connectionCreationCount, 2,
                   @"Should have created 2 connections (both closed due to case-insensitive matching)");
    XCTAssertEqual(self.client.connectionReuseCount, 0,
                   @"No reuse for any closed connections");
}

// R.5 并å<C2B6>‘场景：混å<C2B7>?close å’?keep-alive
- (void)testConnectionHeader_ConcurrentMixed_CloseAndKeepAliveIsolated {
    [self.client resetPoolStatistics];
    NSString *poolKey = @"127.0.0.1:11080:tcp";

    NSMutableArray<XCTestExpectation *> *expectations = [NSMutableArray array];
    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

    NSLock *closeCountLock = [[NSLock alloc] init];
    NSLock *keepAliveCountLock = [[NSLock alloc] init];
    __block NSInteger closeCount = 0;
    __block NSInteger keepAliveCount = 0;

    // å<>‘èµ· 10 个请求：5 ä¸?closeï¼? ä¸?keep-alive
    for (NSInteger i = 0; i < 10; i++) {
        XCTestExpectation *expectation = [self expectationWithDescription:[NSString stringWithFormat:@"Request %ld", (long)i]];
        [expectations addObject:expectation];

        dispatch_async(queue, ^{
            NSError *error = nil;
            NSString *urlString;

            if (i % 2 == 0) {
                // å<>¶æ•°ï¼šclose
                urlString = @"http://127.0.0.1:11080/connection-test?mode=close";
            } else {
                // 奇数：keep-alive
                urlString = @"http://127.0.0.1:11080/connection-test?mode=keep-alive";
            }

            HttpdnsNWHTTPClientResponse *response = [self.client performRequestWithURLString:urlString
                                                                                    userAgent:@"ConcurrentMixed"
                                                                                      timeout:15.0
                                                                                        error:&error];

            if (response && response.statusCode == 200) {
                if (i % 2 == 0) {
                    [closeCountLock lock];
                    closeCount++;
                    [closeCountLock unlock];
                } else {
                    [keepAliveCountLock lock];
                    keepAliveCount++;
                    [keepAliveCountLock unlock];
                }
            }

            [expectation fulfill];
        });
    }

    [self waitForExpectations:expectations timeout:30.0];

    // 验è¯<C3A8>结果
    XCTAssertEqual(closeCount, 5, @"5 close requests should succeed");
    XCTAssertEqual(keepAliveCount, 5, @"5 keep-alive requests should succeed");

    // 等待所有连接归�
    [NSThread sleepForTimeInterval:1.0];

    // 验è¯<C3A8>池状æ€<C3A6>：
    // - close 连接全部被失效（ä¸<C3A4>在池中ï¼?
    // - keep-alive 连接å<C2A5>¯èƒ½åœ¨æ± ä¸­ï¼ˆå<CB86>–决于并å<C2B6>‘æ—¶åº<C3A5>å’Œ remote closeï¼?
    // - 关键是：总数ä¸<C3A4>超è¿?4（池é™<C3A9>制），无泄æ¼?
    NSInteger poolSize = [self.client connectionPoolCountForKey:poolKey];
    XCTAssertLessThanOrEqual(poolSize, 4,
                             @"Pool size should not exceed limit (no leak from close connections)");

    // 验è¯<C3A8>统计：close 连接ä¸<C3A4>应该被å¤<C3A5>用
    // 创建数应è¯?>= 6 (至少 5 ä¸?close + 1 ä¸?keep-alive，因ä¸?close ä¸<C3A4>能å¤<C3A5>用)
    XCTAssertGreaterThanOrEqual(self.client.connectionCreationCount, 6,
                                @"Should have created at least 6 connections (5 close + at least 1 keep-alive)");

    // å<>Žç»­è¯·æ±‚验è¯<C3A8>æ± ä»<C3A4>然å<C2B6>¥åº?
    NSError *recoveryError = nil;
    HttpdnsNWHTTPClientResponse *recoveryResponse = [self.client performRequestWithURLString:@"http://127.0.0.1:11080/get"
                                                                                    userAgent:@"RecoveryTest"
                                                                                      timeout:15.0
                                                                                        error:&recoveryError];
    XCTAssertNotNil(recoveryResponse, @"Pool should still be healthy after mixed close/keep-alive scenario");
    XCTAssertEqual(recoveryResponse.statusCode, 200);
}

@end