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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 #ifndef ANDROID_INCLUDE_HARDWARE_QEMU_PIPE_H
     17 #define ANDROID_INCLUDE_HARDWARE_QEMU_PIPE_H
     18 
     19 #include <sys/cdefs.h>
     20 #include <unistd.h>
     21 #include <fcntl.h>
     22 #include <sys/mman.h>
     23 #include <pthread.h>  /* for pthread_once() */
     24 #include <stdlib.h>
     25 #include <stdio.h>
     26 #include <errno.h>
     27 
     28 #ifndef D
     29 #  define  D(...)   do{}while(0)
     30 #endif
     31 
     32 /* Try to open a new Qemu fast-pipe. This function returns a file descriptor
     33  * that can be used to communicate with a named service managed by the
     34  * emulator.
     35  *
     36  * This file descriptor can be used as a standard pipe/socket descriptor.
     37  *
     38  * 'pipeName' is the name of the emulator service you want to connect to.
     39  * E.g. 'opengles' or 'camera'.
     40  *
     41  * On success, return a valid file descriptor
     42  * Returns -1 on error, and errno gives the error code, e.g.:
     43  *
     44  *    EINVAL  -> unknown/unsupported pipeName
     45  *    ENOSYS  -> fast pipes not available in this system.
     46  *
     47  * ENOSYS should never happen, except if you're trying to run within a
     48  * misconfigured emulator.
     49  *
     50  * You should be able to open several pipes to the same pipe service,
     51  * except for a few special cases (e.g. GSM modem), where EBUSY will be
     52  * returned if more than one client tries to connect to it.
     53  */
     54 static __inline__ int
     55 qemu_pipe_open(const char*  pipeName)
     56 {
     57     char  buff[256];
     58     int   buffLen;
     59     int   fd, ret;
     60 
     61     if (pipeName == NULL || pipeName[0] == '\0') {
     62         errno = EINVAL;
     63         return -1;
     64     }
     65 
     66     snprintf(buff, sizeof buff, "pipe:%s", pipeName);
     67 
     68     fd = open("/dev/qemu_pipe", O_RDWR);
     69     if (fd < 0 && errno == ENOENT)
     70         fd = open("/dev/goldfish_pipe", O_RDWR);
     71     if (fd < 0) {
     72         D("%s: Could not open /dev/qemu_pipe: %s", __FUNCTION__, strerror(errno));
     73         //errno = ENOSYS;
     74         return -1;
     75     }
     76 
     77     buffLen = strlen(buff);
     78 
     79     ret = TEMP_FAILURE_RETRY(write(fd, buff, buffLen+1));
     80     if (ret != buffLen+1) {
     81         D("%s: Could not connect to %s pipe service: %s", __FUNCTION__, pipeName, strerror(errno));
     82         if (ret == 0) {
     83             errno = ECONNRESET;
     84         } else if (ret > 0) {
     85             errno = EINVAL;
     86         }
     87         return -1;
     88     }
     89 
     90     return fd;
     91 }
     92 
     93 #endif /* ANDROID_INCLUDE_HARDWARE_QEMUD_PIPE_H */
     94