我的服務器需要向客戶端發送兩個大小爲500kb的圖像。客戶端在沒有丟失任何數據的情況下接收到第一張圖像,但是當服務器將其他圖像發送給客戶端時,recv()在從服務器發送數據之前返回0,並且服務器send()返回-1 。套接字接收大數據後,recv()返回0
這裏是我的send()和recv()代碼:
服務器:
fp2 = fopen(totaldir2,"rb");
if(fp1==NULL)
{
cout<<"ERROR while openning: "<<totaldir2<<endl;
getchar();
exit(1);
}
fseek (fp2, 0 , SEEK_END);
IFileSize2 = ftell (fp2);
rewind (fp2);
picture2 = new char[sizeof(char)*IFileSize2+1];
if (picture2 == NULL) {exit (2);}
itoa (IFileSize2,CFileSize2,10);
countData = 0;
do{
sentData = send(sConnect,CFileSize2,strlen(CFileSize2)+1,NULL);
countData+=sentData;
}while(countData<strlen(CFileSize2)+1);
read = fread_s(picture2, IFileSize2, sizeof(char),IFileSize2, fp2);
countData = 0;
do{
sentData = send(sConnect, picture2, read, 0);
countData += sentData ;
}while(countData<read);
此代碼運行兩次發送兩個圖像。
客戶:
recv(sConnect, len2, sizeof(len2) ,NULL); \\recv returns 0 here before server sends the data.
FileSize2 = atoi(len2);
picture2 = new char[sizeof(char)*FileSize2+1];
fp2 = fopen("temp\\image2.bin","wb");
if(fp2==NULL)
{
closesocket(sConnect);
WSACleanup();
exit(1);
}
recv(sConnect, picture2, FileSize2, 0); \\same here
fwrite(picture2, sizeof(char), Received2, fp2);
此代碼運行兩次收到兩個圖像。
當我將send()後的Sleep()放入服務器時,客戶端會收到所有數據和所有圖像,但睡眠取決於客戶端網絡。而服務器獲得了很多客戶。 連接與TCP一起使用。
我如何發送()文件的長度爲int? – eilonmore
像這樣:'int filesize = ...;發送(sConnect,(char *)&filesize,sizeof(int),0);'然後在接收端:'int filesize; recv(sConnect,(char *)&filesize,sizeof(int),0);'。這假定阻塞套接字。如果您使用非阻塞套接字,則必須調整此邏輯以解釋「EAGAIN」/「EWOULDBLOCK」錯誤,但核心概念仍然適用。 –