annotate lock.cpp @ 601:82d23418d867

Fix some fd leaks in the command-line binary

Strictly speaking, they're not really leaks, because the only codepath
that suffers from these leaks exits immediately afterwards.  On the
other hand, this fix makes valgrind on e.g. tests/0025 happier, going
from 5 errors to none.

extern "C" {
#include "audioDB_API.h"
}
#include "audioDB-internals.h"

int acquire_lock(int fd, bool exclusive) {
#if !defined(WIN32)
  struct flock lock;
  int status;
  
  lock.l_type = exclusive ? F_WRLCK : F_RDLCK;
  lock.l_whence = SEEK_SET;
  lock.l_start = 0;
  lock.l_len = ADB_HEADER_SIZE;

 retry:
  do {
    status = fcntl(fd, F_SETLKW, &lock);
  } while (status != 0 && errno == EINTR);
  
  if (status) {
    if (errno == EAGAIN) {
      sleep(1);
      goto retry;
    } else {
      return status;
    }
  }
  return 0;
#else
  /* _locking() only supports exclusive locks */
  int status;

 retry:
  status = _locking(fd, _LK_NBLCK, ADB_HEADER_SIZE);
  if(status) {
    Sleep(1000);
    goto retry;
  }
  return 0;
#endif
}

int divest_lock(int fd) {
#if !defined(WIN32)
  struct flock lock;

  lock.l_type = F_UNLCK;
  lock.l_whence = SEEK_SET;
  lock.l_start = 0;
  lock.l_len = ADB_HEADER_SIZE;

  return fcntl(fd, F_SETLKW, &lock);
#else
  return _locking(fd, _LK_UNLCK, ADB_HEADER_SIZE);
#endif
}