diff options
Diffstat (limited to 'glcddrivers/port.c')
| -rw-r--r-- | glcddrivers/port.c | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/glcddrivers/port.c b/glcddrivers/port.c index 44d5956..cfb4156 100644 --- a/glcddrivers/port.c +++ b/glcddrivers/port.c @@ -17,6 +17,7 @@ #include <syslog.h> #include <unistd.h> #include <termios.h> +#include <pthread.h> #include <sys/io.h> #include <sys/ioctl.h> #include <linux/ppdev.h> @@ -33,6 +34,8 @@ namespace GLCD { +static pthread_mutex_t claimport_mutex; + static inline int port_in(int port) { #ifdef __HAS_DIRECTIO__ @@ -58,7 +61,8 @@ static inline void port_out(unsigned short int port, unsigned char val) cParallelPort::cParallelPort() : fd(-1), port(0), - usePPDev(false) + usePPDev(false), + portClaimed(false) { } @@ -109,7 +113,7 @@ int cParallelPort::Open(const char * device) return -1; } - if (ioctl(fd, PPCLAIM, NULL) == -1) + if (!Claim()) { syslog(LOG_ERR, "glcd drivers: ERROR cannot claim %s. Err:%s (cParallelPort::Init)\n", device, strerror(errno)); @@ -118,7 +122,7 @@ int cParallelPort::Open(const char * device) } int mode = PARPORT_MODE_PCSPP; - if (ioctl(fd, PPSETMODE, &mode) == -1) + if (ioctl(fd, PPSETMODE, &mode) != 0) { syslog(LOG_ERR, "glcd drivers: ERROR cannot setmode %s. Err:%s (cParallelPort::Init)\n", device, strerror(errno)); @@ -168,16 +172,27 @@ int cParallelPort::Close() return 0; } -void cParallelPort::Claim() +bool cParallelPort::Claim() { - if (usePPDev) - ioctl(fd, PPCLAIM); + if (!IsPortClaimed()) + { + if (usePPDev) + portClaimed = (ioctl(fd, PPCLAIM) == 0); + else + portClaimed = (pthread_mutex_lock(&claimport_mutex) == 0); + } + return IsPortClaimed(); } void cParallelPort::Release() { - if (usePPDev) - ioctl(fd, PPRELEASE); + if (IsPortClaimed()) + { + if (usePPDev) + portClaimed = !(ioctl(fd, PPRELEASE) == 0); + else + portClaimed = !(pthread_mutex_unlock(&claimport_mutex) == 0); + } } void cParallelPort::SetDirection(int direction) |