/** @file
Parser: commonly functions.
Copyright (c) 2001-2026 Art. Lebedev Studio (https://www.artlebedev.com)
Authors: Konstantin Morshnev <moko@design.ru>, Alexandr Petrosian <paf@design.ru>
*/
#include "pa_config_includes.h"
#include "pa_os.h"
volatile const char * IDENT_PA_OS_C="$Id: pa_os.C,v 1.28 2026/10/17 22:58:09 moko Exp $" IDENT_PA_OS_H;
unsigned int pa_lock_attempts=PA_LOCK_ATTEMPTS;
#ifdef _MSC_VER
#include <windows.h>
#define PA_SH_LOCK 2
#define PA_EX_LOCK 1
#define PA_ULOCK 0
#define FLOCK(operation) int status=pa_flock(fd, operation);
int pa_flock(int fd, int operation) {
HANDLE hFile = (HANDLE)_get_osfhandle(fd);
if (hFile == INVALID_HANDLE_VALUE) {
return -1;
}
OVERLAPPED overlapped = {0};
if (operation == PA_ULOCK) {
return pa_set_errno(UnlockFileEx(hFile, 0, MAXDWORD, MAXDWORD, &overlapped)) ? 0 : -1;
} else {
DWORD flags = LOCKFILE_FAIL_IMMEDIATELY;
if (operation == PA_EX_LOCK) {
flags |= LOCKFILE_EXCLUSIVE_LOCK;
}
return pa_set_errno(LockFileEx(hFile, flags, 0, MAXDWORD, MAXDWORD, &overlapped)) ? 0 : -1;
}
}
static int pa_errno() {
switch(GetLastError()) {
case ERROR_LOCK_VIOLATION: // real case: returning the same error as with _locking
return EACCES;
case ERROR_IO_PENDING:
return EAGAIN;
case ERROR_INVALID_HANDLE:
return EBADF;
case ERROR_NOT_LOCKED:
return ENOLCK;
case ERROR_FILE_NOT_FOUND: // the same errors as with opendir
case ERROR_PATH_NOT_FOUND:
return ENOENT;
case ERROR_DIRECTORY:
return ENOTDIR;
}
return EACCES;
}
int pa_set_errno(int status) {
if (!status)
errno = pa_errno();
return status;
}
#else
#ifdef HAVE_FLOCK
#define PA_SH_LOCK LOCK_SH|LOCK_NB
#define PA_EX_LOCK LOCK_EX|LOCK_NB
#define PA_ULOCK LOCK_UN
#define FLOCK(operation) int status=flock(fd, operation);
#else
#ifdef HAVE_FCNTL
#define PA_SH_LOCK F_RDLCK
#define PA_EX_LOCK F_WRLCK
#define PA_ULOCK F_UNLCK
#define FLOCK(operation) struct flock ls={operation, SEEK_SET}; int status=fcntl(fd, F_SETLK, &ls);
#else
#ifdef HAVE_LOCKF
#define PA_SH_LOCK F_TLOCK
#define PA_EX_LOCK F_TLOCK
#define PA_ULOCK F_ULOCK
#define FLOCK(operation) lseek(fd, 0, SEEK_SET); int status=lockf(fd, operation, 1);
#else
#error unable to find file locking func
#endif
#endif
#endif
#endif
int pa_lock(int fd, int attempts, int operation){
while(true){
FLOCK(operation);
if(status==0)
return 0;
if(--attempts<=0)
return errno;
pa_sleep(PA_LOCK_WAIT_TIMEOUT_SECS, PA_LOCK_WAIT_TIMEOUT_USECS);
}
};
int pa_lock_shared_blocking(int fd) {
return pa_lock(fd, pa_lock_attempts, PA_SH_LOCK);
}
int pa_lock_exclusive_blocking(int fd) {
return pa_lock(fd, pa_lock_attempts, PA_EX_LOCK);
}
int pa_lock_exclusive_nonblocking(int fd) {
return pa_lock(fd, 1, PA_EX_LOCK);
}
int pa_unlock(int fd) {
return pa_lock(fd, 1, PA_ULOCK);
}
int pa_sleep(unsigned long secs, unsigned long usecs) {
if(usecs >= 1000000){
secs += usecs/1000000;
usecs = usecs%1000000;
}
#ifdef _MSC_VER
Sleep(secs * 1000 + usecs / 1000);
return 0;
#else
struct timespec t;
t.tv_sec = secs;
t.tv_nsec = usecs * 1000;
// GC stops the threads with signals, the sleep goes on for the time left
int result;
while((result=nanosleep(&t, &t))<0 && errno==EINTR);
return result<0 ? errno : 0;
#endif
}
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