diff options
Diffstat (limited to 'libusb/os/poll_windows.c')
| -rw-r--r-- | libusb/os/poll_windows.c | 63 |
1 files changed, 51 insertions, 12 deletions
diff --git a/libusb/os/poll_windows.c b/libusb/os/poll_windows.c index 5c57099..5282e7d 100644 --- a/libusb/os/poll_windows.c +++ b/libusb/os/poll_windows.c @@ -54,7 +54,32 @@ struct file_descriptor { }; static usbi_mutex_static_t fd_table_lock = USBI_MUTEX_INITIALIZER; -static struct file_descriptor *fd_table[MAX_FDS]; + +static struct file_descriptor **fd_table; +static size_t fd_count; +static size_t fd_size; +#define INC_FDS_EACH 256 + +static void usbi_dec_fd_table() +{ + fd_count--; + if (fd_count == 0) { + free(fd_table); + fd_table = NULL; + } +} + +static void smart_realloc_fd_table_space(int inc) +{ + if (fd_count + inc > fd_size) { + struct file_descriptor **p = (struct file_descriptor *)realloc(fd_table, (fd_size + INC_FDS_EACH) * sizeof(struct file_descriptor *)); + if (p != NULL) { + memset(p + fd_size, 0, INC_FDS_EACH * sizeof(struct file_descriptor *)); + fd_size += INC_FDS_EACH; + fd_table = p; + } + } +} static struct file_descriptor *create_fd(enum fd_type type) { @@ -101,15 +126,19 @@ struct winfd usbi_create_fd(void) return INVALID_WINFD; usbi_mutex_static_lock(&fd_table_lock); - for (wfd.fd = 0; wfd.fd < MAX_FDS; wfd.fd++) { + + smart_realloc_fd_table_space(1); + + for (wfd.fd = 0; wfd.fd < fd_size; wfd.fd++) { if (fd_table[wfd.fd] != NULL) continue; fd_table[wfd.fd] = fd; + fd_count++; break; } usbi_mutex_static_unlock(&fd_table_lock); - if (wfd.fd == MAX_FDS) { + if (wfd.fd == fd_size) { free_fd(fd); return INVALID_WINFD; } @@ -138,7 +167,8 @@ void usbi_dec_fds_ref(struct pollfd *fds, unsigned int nfds) for (n = 0; n < nfds; ++n) { fd = fd_table[fds[n].fd]; fd->refcount--; - if (fd->refcount == 0) + //FD_TYPE_PIPE map fd to two _fd + if (fd->refcount == 0 || (fd->refcount == 1 && fd->type == FD_TYPE_PIPE)) { if (fd->type == FD_TYPE_PIPE) { // InternalHigh is our reference count @@ -150,6 +180,7 @@ void usbi_dec_fds_ref(struct pollfd *fds, unsigned int nfds) free_fd(fd); } fd_table[fds[n].fd] = NULL; + usbi_dec_fd_table(); } } usbi_mutex_static_unlock(&fd_table_lock); @@ -176,7 +207,7 @@ static int check_pollfds(struct pollfd *fds, unsigned int nfds, continue; } - if ((fds[n].fd >= 0) && (fds[n].fd < MAX_FDS)) + if ((fds[n].fd >= 0) && (fds[n].fd < fd_size)) fd = fd_table[fds[n].fd]; else fd = NULL; @@ -243,14 +274,16 @@ int usbi_close(int _fd) { struct file_descriptor *fd; - if (_fd < 0 || _fd >= MAX_FDS) + if (_fd < 0 || _fd >= fd_size) goto err_badfd; usbi_mutex_static_lock(&fd_table_lock); fd = fd_table[_fd]; fd->refcount--; - if(fd->refcount==0) + //FD_TYPE_PIPE map fd to two _fd + if(fd->refcount==0 || (fd->refcount == 1 && fd->type == FD_TYPE_PIPE)) { fd_table[_fd] = NULL; + usbi_dec_fd_table(); if (fd->type == FD_TYPE_PIPE) { // InternalHigh is our reference count @@ -298,7 +331,9 @@ int usbi_pipe(int filedes[2]) usbi_mutex_static_lock(&fd_table_lock); do { - for (i = 0; i < MAX_FDS; i++) { + smart_realloc_fd_table_space(2); + + for (i = 0; i < fd_size; i++) { if (fd_table[i] != NULL) continue; if (r_fd == -1) { @@ -309,16 +344,20 @@ int usbi_pipe(int filedes[2]) } } - if (i == MAX_FDS) + if (i == fd_size) break; fd_table[r_fd] = fd; fd_table[w_fd] = fd; + fd->refcount++; //this fd reference twice for r and w. + + fd_count += 2; + } while (0); usbi_mutex_static_unlock(&fd_table_lock); - if (i == MAX_FDS) { + if (i == fd_size) { free_fd(fd); errno = EMFILE; return -1; @@ -339,7 +378,7 @@ ssize_t usbi_write(int fd, const void *buf, size_t count) UNUSED(buf); - if (fd < 0 || fd >= MAX_FDS) + if (fd < 0 || fd >= fd_size) goto err_out; if (count != sizeof(unsigned char)) { @@ -377,7 +416,7 @@ ssize_t usbi_read(int fd, void *buf, size_t count) UNUSED(buf); - if (fd < 0 || fd >= MAX_FDS) + if (fd < 0 || fd >= fd_size) goto err_out; if (count != sizeof(unsigned char)) { |