[Mplayer-cvslog] CVS: main/linux shmem.c,1.2,1.3

Jürgen Keil jkeil at mplayer.dev.hu
Thu Jul 19 20:49:15 CEST 2001


Update of /cvsroot/mplayer/main/linux
In directory mplayer:/var/tmp.root/cvs-serv27987/linux

Modified Files:
	shmem.c 
Log Message:
Solaris 2.6 and older do not support MAP_ANON,  just fail the mmap MAP_ANON
attempt on such a system.  The code tries mmap with /dev/zero and MIT-shm next.


Index: shmem.c
===================================================================
RCS file: /cvsroot/mplayer/main/linux/shmem.c,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -r1.2 -r1.3
--- shmem.c	18 Apr 2001 01:25:09 -0000	1.2
+++ shmem.c	19 Jul 2001 18:49:13 -0000	1.3
@@ -33,51 +33,57 @@
 
 static int shmem_type=0;
 
-void* shmem_alloc(int size){
-void* p;
-int devzero;
-while(1){
-  switch(shmem_type){
-  case 0:  // ========= MAP_ANON|MAP_SHARED ==========
-    p=mmap(0,size,PROT_READ|PROT_WRITE,MAP_ANON|MAP_SHARED,-1,0);
-    if(p==MAP_FAILED) break; // failed
-//    printf("shmem: %d bytes allocated using mmap anon (%X)\n",size,p);
-    return p;
-  case 1:  // ========= MAP_SHARED + /dev/zero ==========
-	  if ((devzero = open("/dev/zero", O_RDWR, 0)) == -1) break;
-    p=mmap(0,size,PROT_READ|PROT_WRITE,MAP_SHARED,devzero,0);
-    if(p==MAP_FAILED) break; // failed
-//    printf("shmem: %d bytes allocated using mmap /dev/zero (%X)\n",size,p);
-    return p;
-  case 2: { // ========= shmget() ==========
-    struct shmid_ds shmemds;
-    int shmemid;
-    if ((shmemid = shmget(IPC_PRIVATE, size, IPC_CREAT | 0600)) == -1) break;
-    if ((int)(p = shmat(shmemid, 0, 0)) == -1){
-      perror ("shmat()");
-      shmctl (shmemid, IPC_RMID, &shmemds);
+void* shmem_alloc(int size) {
+  void* p;
+  static int devzero = -1;
+  while(1) {
+    switch(shmem_type) {
+    case 0:
+#ifdef	MAP_ANON
+      // ========= MAP_ANON|MAP_SHARED ==========
+      p=mmap(0,size,PROT_READ|PROT_WRITE,MAP_ANON|MAP_SHARED,-1,0);
+      if(p==MAP_FAILED) break; // failed
+      //printf("shmem: %d bytes allocated using mmap anon (%X)\n",size,p);
+      return p;
+#else
+      //system does not support MAP_ANON at all (e.g. solaris 2.5.1/2.6), just fail
       break;
+#endif
+    case 1:  // ========= MAP_SHARED + /dev/zero ==========
+      if (devzero == -1 && (devzero = open("/dev/zero", O_RDWR, 0)) == -1) break;
+      p=mmap(0,size,PROT_READ|PROT_WRITE,MAP_SHARED,devzero,0);
+      if(p==MAP_FAILED) break; // failed
+      //printf("shmem: %d bytes allocated using mmap /dev/zero (%X)\n",size,p);
+      return p;
+    case 2: { // ========= shmget() ==========
+      struct shmid_ds shmemds;
+      int shmemid;
+      if ((shmemid = shmget(IPC_PRIVATE, size, IPC_CREAT | 0600)) == -1) break;
+      if ((int)(p = shmat(shmemid, 0, 0)) == -1) {
+	perror ("shmat()");
+	shmctl (shmemid, IPC_RMID, &shmemds);
+	break;
+      }
+      if (shmctl(shmemid, IPC_RMID, &shmemds) == -1) {
+	perror ("shmctl()");
+	if (shmdt(p) == -1) perror ("shmdt()");
+	break;
+      }
+      //printf("shmem: %d bytes allocated using shmget() & shmat() (%X)\n",size,p);
+      return p;
     }
-    if (shmctl(shmemid, IPC_RMID, &shmemds) == -1) {
-      perror ("shmctl()");
-      if (shmdt(p) == -1) perror ("shmdt()");
-      break;
+    default:
+      printf("FATAL: Cannot alloate %d bytes shared memory :(\n",size);
+      return NULL;
     }
-//    printf("shmem: %d bytes allocated using shmget() & shmat() (%X)\n",size,p);
-    return p;
-	}
-  default:
-    printf("FATAL: Cannot alloate %d bytes shared memory :(\n",size);
-    return NULL;
+    ++shmem_type;
   }
-  ++shmem_type;
-}
 }
 
-void shmem_free(void* p){
-  switch(shmem_type){
-    case 2:
-	    if (shmdt(p) == -1) perror ("shmdt()");
-      break;
+void shmem_free(void* p) {
+  switch(shmem_type) {
+  case 2:
+    if (shmdt(p) == -1) perror ("shmdt()");
+    break;
   }
 }




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