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am 1da90f0c: am feacf20d: Merge "adb: win32: file descriptor reliability improvements" 

* commit '1da90f0c14d315b10d8cc8cd2cfaacd794758ec3':
  adb: win32: file descriptor reliability improvements
This commit is contained in:
Elliott Hughes 2015-08-04 01:07:08 +00:00 committed by Android Git Automerger
parent 88f82b6650 1da90f0c14
commit 7ace565f6b
1 changed files with 27 additions and 20 deletions
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47
adb/sysdeps_win32.cpp
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@ -203,7 +203,7 @@ typedef struct FHRec_
static adb_mutex_t _win32_lock;
static FHRec _win32_fhs[ WIN32_MAX_FHS ];
static int _win32_fh_count;
static int _win32_fh_next; // where to start search for free FHRec
static FH
_fh_from_int( int fd, const char* func )
@ -212,7 +212,7 @@ _fh_from_int( int fd, const char* func )
fd -= WIN32_FH_BASE;
if (fd < 0 || fd >= _win32_fh_count) {
if (fd < 0 || fd >= WIN32_MAX_FHS) {
D( "_fh_from_int: invalid fd %d passed to %s\n", fd + WIN32_FH_BASE,
func );
errno = EBADF;
@ -244,28 +244,32 @@ _fh_to_int( FH f )
static FH
_fh_alloc( FHClass clazz )
{
int nn;
FH f = NULL;
adb_mutex_lock( &_win32_lock );
if (_win32_fh_count < WIN32_MAX_FHS) {
f = &_win32_fhs[ _win32_fh_count++ ];
goto Exit;
}
for (nn = 0; nn < WIN32_MAX_FHS; nn++) {
if ( _win32_fhs[nn].clazz == NULL) {
f = &_win32_fhs[nn];
// Search entire array, starting from _win32_fh_next.
for (int nn = 0; nn < WIN32_MAX_FHS; nn++) {
// Keep incrementing _win32_fh_next to avoid giving out an index that
// was recently closed, to try to avoid use-after-free.
const int index = _win32_fh_next++;
// Handle wrap-around of _win32_fh_next.
if (_win32_fh_next == WIN32_MAX_FHS) {
_win32_fh_next = 0;
}
if (_win32_fhs[index].clazz == NULL) {
f = &_win32_fhs[index];
goto Exit;
}
}
D( "_fh_alloc: no more free file descriptors\n" );
errno = EMFILE; // Too many open files
Exit:
if (f) {
f->clazz = clazz;
f->used = 1;
f->eof = 0;
f->clazz = clazz;
f->used = 1;
f->eof = 0;
f->name[0] = '\0';
clazz->_fh_init(f);
}
adb_mutex_unlock( &_win32_lock );
@ -276,12 +280,17 @@ Exit:
static int
_fh_close( FH f )
{
if ( f->used ) {
// Use lock so that closing only happens once and so that _fh_alloc can't
// allocate a FH that we're in the middle of closing.
adb_mutex_lock(&_win32_lock);
if (f->used) {
f->clazz->_fh_close( f );
f->used = 0;
f->eof = 0;
f->clazz = NULL;
f->name[0] = '\0';
f->eof = 0;
f->used = 0;
f->clazz = NULL;
}
adb_mutex_unlock(&_win32_lock);
return 0;
}
@ -404,7 +413,6 @@ int adb_open(const char* path, int options)
f = _fh_alloc( &_fh_file_class );
if ( !f ) {
errno = ENOMEM;
return -1;
}
@ -446,7 +454,6 @@ int adb_creat(const char* path, int mode)
f = _fh_alloc( &_fh_file_class );
if ( !f ) {
errno = ENOMEM;
return -1;
}