adb: fix adb_close() vs. unix_close() usage
Document the differences between adb_*() and unix_*() in the function
prototypes in sysdeps.h. See the file for the details (CR/LF
translation, well-known file descriptors, etc.).
Fix adb_read(), adb_write(), and adb_close() calls that should really be
unix_read(), unix_write(), and unix_close(). Note that this should have
no impact on unix because on unix, unix_read/unix_write/unix_close are
macros that map to adb_read/adb_write/adb_close.
Improve sysdeps_win32.cpp file descriptor diagnostic logging to output
the name of the function that was passed a bad file descriptor.
Change-Id: I0a1d9c28772656c80bcc303ef8b61fccf4cd637c
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>
diff --git a/adb/sysdeps.h b/adb/sysdeps.h
index 0aa1570..b7c16d9 100644
--- a/adb/sysdeps.h
+++ b/adb/sysdeps.h
@@ -125,6 +125,7 @@
#undef mkdir
#define mkdir ___xxx_mkdir
+// See the comments for the !defined(_WIN32) versions of adb_*().
extern int adb_open(const char* path, int options);
extern int adb_creat(const char* path, int mode);
extern int adb_read(int fd, void* buf, int len);
@@ -133,6 +134,7 @@
extern int adb_shutdown(int fd);
extern int adb_close(int fd);
+// See the comments for the !defined(_WIN32) version of unix_close().
static __inline__ int unix_close(int fd)
{
return close(fd);
@@ -140,11 +142,13 @@
#undef close
#define close ____xxx_close
+// See the comments for the !defined(_WIN32) version of unix_read().
extern int unix_read(int fd, void* buf, size_t len);
#undef read
#define read ___xxx_read
+// See the comments for the !defined(_WIN32) version of unix_write().
static __inline__ int unix_write(int fd, const void* buf, size_t len)
{
return write(fd, buf, len);
@@ -152,11 +156,13 @@
#undef write
#define write ___xxx_write
+// See the comments for the !defined(_WIN32) version of adb_open_mode().
static __inline__ int adb_open_mode(const char* path, int options, int mode)
{
return adb_open(path, options);
}
+// See the comments for the !defined(_WIN32) version of unix_open().
static __inline__ int unix_open(const char* path, int options,...)
{
if ((options & O_CREAT) == 0)
@@ -314,6 +320,15 @@
fcntl( fd, F_SETFD, FD_CLOEXEC );
}
+// Open a file and return a file descriptor that may be used with unix_read(),
+// unix_write(), unix_close(), but not adb_read(), adb_write(), adb_close().
+//
+// On Unix, this is based on open(), so the file descriptor is a real OS file
+// descriptor, but the Windows implementation (in sysdeps_win32.cpp) returns a
+// file descriptor that can only be used with C Runtime APIs (which are wrapped
+// by unix_read(), unix_write(), unix_close()). Also, the C Runtime has
+// configurable CR/LF translation which defaults to text mode, but is settable
+// with _setmode().
static __inline__ int unix_open(const char* path, int options,...)
{
if ((options & O_CREAT) == 0)
@@ -331,12 +346,21 @@
}
}
+// Similar to the two-argument adb_open(), but takes a mode parameter for file
+// creation. See adb_open() for more info.
static __inline__ int adb_open_mode( const char* pathname, int options, int mode )
{
return TEMP_FAILURE_RETRY( open( pathname, options, mode ) );
}
+// Open a file and return a file descriptor that may be used with adb_read(),
+// adb_write(), adb_close(), but not unix_read(), unix_write(), unix_close().
+//
+// On Unix, this is based on open(), but the Windows implementation (in
+// sysdeps_win32.cpp) uses Windows native file I/O and bypasses the C Runtime
+// and its CR/LF translation. The returned file descriptor should be used with
+// adb_read(), adb_write(), adb_close(), etc.
static __inline__ int adb_open( const char* pathname, int options )
{
int fd = TEMP_FAILURE_RETRY( open( pathname, options ) );
@@ -355,6 +379,9 @@
#undef shutdown
#define shutdown ____xxx_shutdown
+// Closes a file descriptor that came from adb_open() or adb_open_mode(), but
+// not designed to take a file descriptor from unix_open(). See the comments
+// for adb_open() for more info.
static __inline__ int adb_close(int fd)
{
return close(fd);
@@ -419,6 +446,14 @@
#undef accept
#define accept ___xxx_accept
+// Operate on a file descriptor returned from unix_open() or a well-known file
+// descriptor such as STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO.
+//
+// On Unix, unix_read(), unix_write(), unix_close() map to adb_read(),
+// adb_write(), adb_close() (which all map to Unix system calls), but the
+// Windows implementations (in the ifdef above and in sysdeps_win32.cpp) call
+// into the C Runtime and its configurable CR/LF translation (which is settable
+// via _setmode()).
#define unix_read adb_read
#define unix_write adb_write
#define unix_close adb_close