re PR go/61303 (gccgo: segfault, regression since 4.8.2)

PR go/61303
    runtime: don't overallocate in select code
    
    If we've already allocated an fd_set, don't allocate another one.
    
    Also, don't bother to read from rdwake if it wasn't returned in select.
    
    Fixes https://gcc.gnu.org/PR61303.
    
    Reviewed-on: https://go-review.googlesource.com/17243

From-SVN: r230923
This commit is contained in:
Ian Lance Taylor 2015-11-26 00:24:33 +00:00
parent 1f8e5bf5d2
commit c7ed358227
1 changed files with 10 additions and 6 deletions

View File

@ -135,6 +135,8 @@ runtime_netpoll(bool block)
byte b;
struct stat st;
allocatedfds = false;
retry:
runtime_lock(&selectlock);
@ -146,11 +148,13 @@ runtime_netpoll(bool block)
}
if(inuse) {
if(!allocatedfds) {
prfds = runtime_SysAlloc(4 * sizeof fds, &mstats.other_sys);
pwfds = prfds + 1;
pefds = pwfds + 1;
ptfds = pefds + 1;
allocatedfds = true;
}
} else {
prfds = &grfds;
pwfds = &gwfds;
@ -216,7 +220,7 @@ runtime_netpoll(bool block)
mode = 'r' + 'w';
--c;
}
if(i == rdwake) {
if(i == rdwake && mode != 0) {
while(read(rdwake, &b, sizeof b) > 0)
;
continue;