v2 / vlib / os / filelock / filelock_helpers.h
63 lines · 54 sloc · 1.81 KB · 3914749f5694a7f1f938d07e303a8be61e227e94
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1#ifndef V_OS_FILELOCK_HELPERS_H


2#define V_OS_FILELOCK_HELPERS_H


3


4#include <string.h>


5


6#ifdef _WIN32


7#include <windows.h>


8


9static int v_filelock_lock(HANDLE handle, int exclusive, int immediate,


10    unsigned long long start, unsigned long long len) {


11    OVERLAPPED overlap;


12    memset(&overlap, 0, sizeof(overlap));


13    overlap.Offset = (DWORD)(start & 0xffffffffULL);


14    overlap.OffsetHigh = (DWORD)(start >> 32);


15    DWORD flags = immediate ? LOCKFILE_FAIL_IMMEDIATELY : 0;


16    if (exclusive) {


17        flags |= LOCKFILE_EXCLUSIVE_LOCK;


18    }


19    DWORD low = len == 0 ? MAXDWORD : (DWORD)(len & 0xffffffffULL);


20    DWORD high = len == 0 ? MAXDWORD : (DWORD)(len >> 32);


21    return LockFileEx(handle, flags, 0, low, high, &overlap) ? 0 : -1;


22}


23


24static int v_filelock_unlock(HANDLE handle, unsigned long long start,


25    unsigned long long len) {


26    OVERLAPPED overlap;


27    memset(&overlap, 0, sizeof(overlap));


28    overlap.Offset = (DWORD)(start & 0xffffffffULL);


29    overlap.OffsetHigh = (DWORD)(start >> 32);


30    DWORD low = len == 0 ? MAXDWORD : (DWORD)(len & 0xffffffffULL);


31    DWORD high = len == 0 ? MAXDWORD : (DWORD)(len >> 32);


32    return UnlockFileEx(handle, 0, low, high, &overlap) ? 0 : -1;


33}


34


35#else


36#include <fcntl.h>


37#include <unistd.h>


38


39static int v_filelock_lock(int fd, int exclusive, int immediate,


40    unsigned long long start, unsigned long long len) {


41    struct flock fl;


42    memset(&fl, 0, sizeof(fl));


43    fl.l_type = exclusive ? F_WRLCK : F_RDLCK;


44    fl.l_whence = SEEK_SET;


45    fl.l_start = (off_t)start;


46    fl.l_len = len == 0 ? 0 : (off_t)len;


47    return fcntl(fd, immediate ? F_SETLK : F_SETLKW, &fl);


48}


49


50static int v_filelock_unlock(int fd, unsigned long long start,


51    unsigned long long len) {


52    struct flock fl;


53    memset(&fl, 0, sizeof(fl));


54    fl.l_type = F_UNLCK;


55    fl.l_whence = SEEK_SET;


56    fl.l_start = (off_t)start;


57    fl.l_len = len == 0 ? 0 : (off_t)len;


58    return fcntl(fd, F_SETLK, &fl);


59}


60


61#endif


62


63#endif


64