mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-06-28 07:18:30 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Share file offset across processes

Browse source 
This change ensures that if a file descriptor for an open disk file gets
shared by multiple processes within a process tree, then lseek() changes
will be visible across processes, and read() / write() are synchronized.
Note this only applies to Windows, because UNIX kernels already do this.
This commit is contained in:
Justine Tunney 2024-08-03 01:24:46 -07:00
parent a80ab3f8fe
commit 761c6ad615
No known key found for this signature in database
GPG key ID: BE714B4575D6E328
15 changed files with 256 additions and 63 deletions
Download patch file Download diff file Expand all files Collapse all files

14
libc/intrin/fds.h
View file

@ -1,5 +1,7 @@
#ifndef COSMOPOLITAN_LIBC_CALLS_STRUCT_FD_INTERNAL_H_
#define COSMOPOLITAN_LIBC_CALLS_STRUCT_FD_INTERNAL_H_
#include "libc/atomic.h"
#include "libc/thread/thread.h"
COSMOPOLITAN_C_START_
#define kFdEmpty 0
@ -13,19 +15,25 @@ COSMOPOLITAN_C_START_
#define kFdDevNull 9
#define kFdDevRandom 10
struct Cursor {
pthread_mutex_t lock;
long pointer;
};
struct Fd {
char kind;
bool isdup;
bool isbound;
unsigned flags;
unsigned mode;
long handle;
long pointer;
int family;
int type;
int protocol;
unsigned rcvtimeo; /* millis; 0 means wait forever */
unsigned sndtimeo; /* millis; 0 means wait forever */
void *connect_op;
struct Cursor *shared;
};
struct Fds {
@ -34,5 +42,9 @@ struct Fds {
struct Fd *p, *e;
};
void __fd_lock(struct Fd *);
void __fd_unlock(struct Fd *);
struct Cursor *__cursor_new(void);
COSMOPOLITAN_C_END_
#endif /* COSMOPOLITAN_LIBC_CALLS_STRUCT_FD_INTERNAL_H_ */