f9af37566
Denys Vlasenko
2011-02-11
Subject
wget: explain clearerr more clearly
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
networking/wget.c+10 -1
| @@ -466,6 +466,14 @@ static void NOINLINE retrieve_file_data(FILE *dfp, int output_fd) | |
| polldata.fd = fileno(dfp); | |
| polldata.events = POLLIN | POLLPRI; | |
| + | |
| + | /* Must use nonblocking I/O, otherwise fread will loop |
| + | * and *block* until it reads full buffer, |
| + | * which messes up progress bar and/or timing out. |
| + | * Because of nonblocking I/O, we need to dance |
| + | * very carefully around EAGAIN. See explanation at |
| + | * clearerr() call. |
| + | */ |
| ndelay_on(polldata.fd); | |
| #endif | |
| progress_meter(PROGRESS_START); | |
| @@ -504,7 +512,7 @@ static void NOINLINE retrieve_file_data(FILE *dfp, int output_fd) | |
| /* Needed for "stalled" indicator */ | |
| progress_meter(PROGRESS_BUMP); | |
| } | |
| - | #endif |
| + | |
| /* fread internally uses read loop, which in our case | |
| * is usually exited when we get EAGAIN. | |
| * In this case, libc sets error marker on the stream. | |
| @@ -515,6 +523,7 @@ static void NOINLINE retrieve_file_data(FILE *dfp, int output_fd) | |
| */ | |
| clearerr(dfp); | |
| errno = 0; | |
| + | #endif |
| n = fread(G.wget_buf, 1, rdsz, dfp); | |
| /* man fread: | |
| * If error occurs, or EOF is reached, the return value | |