Make important improvements

- Fix preadv() and pwritev() for old distros
- Introduce _npassert() and _unassert() macros
- Prove that file locks work properly on Windows
- Support fcntl(F_DUPFD_CLOEXEC) on more systems

libc/stdio/fdopen.c

@@ -38,7 +38,7 @@ FILE *fdopen(int fd, const char *mode) {
     f->fd = fd;
     f->bufmode = ischardev(fd) ? _IOLBF : _IOFBF;
     f->iomode = fopenflags(mode);
-    f->lock._type = PTHREAD_MUTEX_RECURSIVE;
+    ((pthread_mutex_t *)f->lock)->_type = PTHREAD_MUTEX_RECURSIVE;
     f->size = BUFSIZ;
     if ((f->buf = malloc(f->size))) {
       if ((f->iomode & O_ACCMODE) != O_RDONLY) {

libc/stdio/flockfile.c

@@ -23,5 +23,5 @@
  * Acquires reentrant lock on stdio object, blocking if needed.
  */
 void(flockfile)(FILE *f) {
-  pthread_mutex_lock(&f->lock);
+  pthread_mutex_lock((pthread_mutex_t *)f->lock);
 }

libc/stdio/fmemopen.c

@@ -54,7 +54,7 @@ FILE *fmemopen(void *buf, size_t size, const char *mode) {
   f->end = size;
   f->size = size;
   f->iomode = fopenflags(mode);
-  f->lock._type = PTHREAD_MUTEX_RECURSIVE;
+  ((pthread_mutex_t *)f->lock)->_type = PTHREAD_MUTEX_RECURSIVE;
   if (f->iomode & O_APPEND) {
     if ((p = memchr(buf, '\0', size))) {
       f->beg = p - (char *)buf;

libc/stdio/ftrylockfile.c

@@ -16,6 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/stdio/lock.internal.h"
 #include "libc/stdio/stdio.h"
 
 /**
@@ -24,5 +25,5 @@
  * @return 0 on success, or non-zero if another thread owns the lock
  */
 int(ftrylockfile)(FILE *f) {
-  return pthread_mutex_trylock(&f->lock);
+  return pthread_mutex_trylock((pthread_mutex_t *)f->lock);
 }

libc/stdio/funlockfile.c

@@ -16,11 +16,12 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/stdio/lock.internal.h"
 #include "libc/stdio/stdio.h"
 
 /**
  * Releases lock on stdio object.
  */
 void(funlockfile)(FILE *f) {
-  pthread_mutex_unlock(&f->lock);
+  pthread_mutex_unlock((pthread_mutex_t *)f->lock);
 }

libc/stdio/gets.c

@@ -19,6 +19,6 @@
 #include "libc/limits.h"
 #include "libc/stdio/stdio.h"
 
-compatfn char *gets(char *s) {
+char *gets(char *s) {
   return fgets(s, INT_MAX, stdin);
 }

libc/stdio/stdio.h

@@ -1,9 +1,7 @@
-#ifndef COSMOPOLITAN_LIBC_STDIO_STDIO_H_
-#define COSMOPOLITAN_LIBC_STDIO_STDIO_H_
-#include "libc/fmt/pflink.h"
-#include "libc/thread/thread.h"
-
+#ifndef _STDIO_H
 #define _STDIO_H
+#include "libc/fmt/pflink.h"
+
 #define L_ctermid    20
 #define FILENAME_MAX PATH_MAX
 #define FOPEN_MAX    1000
@@ -17,19 +15,19 @@ COSMOPOLITAN_C_START_
 ╚────────────────────────────────────────────────────────────────────────────│*/
 
 typedef struct FILE {
-  uint8_t bufmode;      /* 0x00 _IOFBF, etc. (ignored if fd=-1) */
-  bool noclose;         /* 0x01 for fake dup() todo delete! */
-  uint32_t iomode;      /* 0x04 O_RDONLY, etc. (ignored if fd=-1) */
-  int32_t state;        /* 0x08 0=OK, -1=EOF, >0=errno */
-  int fd;               /* 0x0c ≥0=fd, -1=closed|buffer */
-  uint32_t beg;         /* 0x10 */
-  uint32_t end;         /* 0x14 */
-  char *buf;            /* 0x18 */
-  uint32_t size;        /* 0x20 */
-  uint32_t nofree;      /* 0x24 */
-  int pid;              /* 0x28 */
-  char *getln;          /* 0x30 */
-  pthread_mutex_t lock; /* 0x38 */
+  uint8_t bufmode; /* 0x00 _IOFBF, etc. (ignored if fd=-1) */
+  bool noclose;    /* 0x01 for fake dup() todo delete! */
+  uint32_t iomode; /* 0x04 O_RDONLY, etc. (ignored if fd=-1) */
+  int32_t state;   /* 0x08 0=OK, -1=EOF, >0=errno */
+  int fd;          /* 0x0c ≥0=fd, -1=closed|buffer */
+  uint32_t beg;    /* 0x10 */
+  uint32_t end;    /* 0x14 */
+  char *buf;       /* 0x18 */
+  uint32_t size;   /* 0x20 */
+  uint32_t nofree; /* 0x24 */
+  int pid;         /* 0x28 */
+  char *getln;     /* 0x30 */
+  char lock[16];   /* 0x38 */
 } FILE;
 
 extern FILE *stdin;
@@ -91,9 +89,9 @@ char *ctermid(char *);
 void perror(const char *) relegated;
 
 typedef uint64_t fpos_t;
-compatfn char *gets(char *) paramsnonnull();
-compatfn int fgetpos(FILE *, fpos_t *) paramsnonnull();
-compatfn int fsetpos(FILE *, const fpos_t *) paramsnonnull();
+char *gets(char *) paramsnonnull();
+int fgetpos(FILE *, fpos_t *) paramsnonnull();
+int fsetpos(FILE *, const fpos_t *) paramsnonnull();
 
 int system(const char *);
 int systemexec(const char *);
@@ -195,4 +193,4 @@ int vfprintf_unlocked(FILE *, const char *, va_list)
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
-#endif /* COSMOPOLITAN_LIBC_STDIO_STDIO_H_ */
+#endif /* _STDIO_H */