[LIBDCE] Mutual exclusion of Engine_open and Engine_close

[glsdk/libdce2.git] / libdce.c

diff --git a/libdce.c b/libdce.c
index cd10b71c2936dbd081538f14f2e5238c0ba24155..f791e18cc13a9d8630de6a7818ae6e24c4124302 100644 (file)
--- a/libdce.c
+++ b/libdce.c
@@ -66,8 +66,10 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
-#include <pthread.h>
 #include <errno.h>
+#include <fcntl.h>        /* For O_* constants */
+#include <sys/stat.h>     /* For mode constants */
+#include <semaphore.h>
 
 #include <xdc/std.h>
 
@@ -84,7 +86,7 @@
 /********************* GLOBALS ***********************/
 /* Hande used for Remote Communication                               */
 static MmRpc_Handle       MmRpcHandle = NULL;
-static pthread_mutex_t    mutex = PTHREAD_MUTEX_INITIALIZER;
+sem_t                    *dce_semaphore = NULL;
 static int                count = 0;
 
 
@@ -157,8 +159,6 @@ static int dce_ipc_init(void)
 
     printf(" >> dce_ipc_init\n");
 
-    pthread_mutex_lock(&mutex);
-
     count++;
     /* Check if already Initialized */
     _ASSERT(count == 1, DCE_EOK);
@@ -173,7 +173,6 @@ static int dce_ipc_init(void)
     printf("open(/dev/" DCE_DEVICE_NAME ") -> 0x%x\n", (int)MmRpcHandle);
 
 EXIT:
-    pthread_mutex_unlock(&mutex);
     return (eError);
 }
 
@@ -183,8 +182,6 @@ EXIT:
  */
 static void dce_ipc_deinit()
 {
-    pthread_mutex_lock(&mutex);
-
     count--;
     if( count > 0 ) {
         goto EXIT;
@@ -196,7 +193,6 @@ static void dce_ipc_deinit()
     MmRpcHandle = NULL;
 
 EXIT:
-    pthread_mutex_unlock(&mutex);
     return;
 }
 
@@ -219,6 +215,12 @@ Engine_Handle Engine_open(String name, Engine_Attrs *attrs, Engine_Error *ec)
 
     _ASSERT(name != '\0', DCE_EINVALID_INPUT);
 
+    if( dce_semaphore == NULL ) {
+        _ASSERT((dce_semaphore = sem_open("/dce_semaphore", O_CREAT, S_IRWXU | S_IRWXO | S_IRWXG, 1)) != SEM_FAILED, DCE_ESEMAPHORE_FAIL);
+    }
+    /* Lock dce_ipc_init() and Engine_open() IPU call to prevent hang*/
+    _ASSERT(sem_wait(dce_semaphore) == DCE_EOK, DCE_ESEMAPHORE_FAIL);
+
     /* Initialize IPC. In case of Error Deinitialize them */
     _ASSERT_AND_EXECUTE(dce_ipc_init() == DCE_EOK, DCE_EIPC_CREATE_FAIL, dce_ipc_deinit());
 
@@ -252,7 +254,11 @@ Engine_Handle Engine_open(String name, Engine_Attrs *attrs, Engine_Error *ec)
     if( ec ) {
         *ec = engine_open_msg->error_code;
     }
+
 EXIT:
+    /* Unlock dce_ipc_init() and Engine_open() IPU call */
+    _ASSERT(sem_post(dce_semaphore) == DCE_EOK, DCE_ESEMAPHORE_FAIL);
+
     memplugin_free(engine_open_msg, TILER_1D_BUFFER);
     if( engine_attrs ) {
         memplugin_free(engine_attrs, TILER_1D_BUFFER);
@@ -273,6 +279,9 @@ Void Engine_close(Engine_Handle engine)
 
     _ASSERT(engine != NULL, DCE_EINVALID_INPUT);
 
+    /* Lock dce_ipc_deinit() and Engine_close() IPU call */
+    _ASSERT(sem_wait(dce_semaphore) == DCE_EOK, DCE_ESEMAPHORE_FAIL);
+
     /* Marshall function arguments into the send buffer */
     Fill_MmRpc_fxnCtx(&fxnCtx, DCE_RPC_ENGINE_CLOSE, 1, 0, NULL);
     Fill_MmRpc_fxnCtx_Scalar_Params(fxnCtx.params, sizeof(Engine_Handle), (int32_t)engine);
@@ -284,6 +293,11 @@ Void Engine_close(Engine_Handle engine)
 
 EXIT:
     dce_ipc_deinit();
+
+    /* Unlock dce_ipc_deinit() and Engine_close() IPU call */
+    _ASSERT(sem_post(dce_semaphore) == DCE_EOK, DCE_ESEMAPHORE_FAIL);
+    sem_close(dce_semaphore);
+
     return;
 }