X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fmisc%2Fcpu.c;h=83b95603b9982c4ce4b995f1e4d6a0c2e2c05e33;hb=034ae114634510d7cdf7fe15e2e76ac34c1a6ddf;hp=6c979fd24286c92098a3a9163747ea7ae109daa7;hpb=2a817cdbc2cd282b353cace71a8cd603d8151893;p=vlc

diff --git a/src/misc/cpu.c b/src/misc/cpu.c
index 6c979fd242..83b95603b9 100644
--- a/src/misc/cpu.c
+++ b/src/misc/cpu.c
@@ -37,19 +37,23 @@
 #ifndef WIN32
 #include <unistd.h>
 #include <sys/wait.h>
+#include <signal.h>
+#else
+#include <errno.h>
 #endif
+#include <assert.h>
 
 #include "libvlc.h"
 
-#if defined(__APPLE__) && (defined(__ppc__) || defined(__ppc64__))
+#if defined(__APPLE__)
 #include <sys/sysctl.h>
 #endif
 
 #if defined( __i386__ ) || defined( __x86_64__ ) || defined( __powerpc__ ) \
  || defined( __ppc__ ) || defined( __ppc64__ ) || defined( __powerpc64__ )
+# ifndef WIN32
 static bool check_OS_capability( const char *psz_capability, pid_t pid )
 {
-#ifndef WIN32
     int status;
 
     if( pid == -1 )
@@ -65,14 +69,25 @@ static bool check_OS_capability( const char *psz_capability, pid_t pid )
     fprintf( stderr, "         some optimizations will be disabled unless "
                      "you upgrade your OS\n" );
     return false;
-#else
-# warning FIXME!
-# define fork() (errno = ENOSYS, -1)
-    (void)pid;
-    (void)psz_capability;
-    return true;
-#endif
 }
+
+#  define check_capability(name, flag, code)   \
+     do {                                      \
+        pid_t pid = fork();                    \
+        if( pid == 0 )                         \
+        {                                      \
+            signal(SIGILL, SIG_DFL);           \
+            __asm__ __volatile__ ( code : : ); \
+            _exit(0);                          \
+        }                                      \
+        if( check_OS_capability((name), pid )) \
+            i_capabilities |= (flag);          \
+     } while(0)
+
+# else /* WIN32 */
+#  define check_capability(name, flag, code)   \
+        i_capabilities |= (flag);
+# endif
 #endif
 
 /*****************************************************************************
@@ -113,18 +128,6 @@ uint32_t CPUCapabilities( void )
                          : "cc" );
 #   endif
      /* Check if the OS really supports the requested instructions */
-#   define check_capability(name, flag, code)  \
-     do {                                      \
-        pid_t pid = fork();                    \
-        if( pid == 0 )                         \
-        {                                      \
-            __asm__ __volatile__ ( code : : ); \
-            _exit(0);                           \
-        }                                      \
-        if( check_OS_capability((name), pid )) \
-            i_capabilities |= (flag);          \
-     } while(0)
-
 # if defined (__i386__) && !defined (__i486__) && !defined (__i586__) \
   && !defined (__i686__) && !defined (__pentium4__) \
   && !defined (__k6__) && !defined (__athlon__) && !defined (__k8__)
@@ -269,6 +272,7 @@ out:
     pid_t pid = fork();
     if( pid == 0 )
     {
+        signal(SIGILL, SIG_DFL);
         asm volatile ("mtspr 256, %0\n\t"
                       "vand %%v0, %%v0, %%v0"
                       :
@@ -296,6 +300,86 @@ unsigned vlc_CPU (void)
     return cpu_flags;
 }
 
+const struct
+{
+    uint32_t value;
+    char name[12];
+} cap_dirs[] = {
+#if defined ( __i386__ ) || defined ( __x86_64__ )
+    { CPU_CAPABILITY_MMX,     "mmx" },
+    { CPU_CAPABILITY_MMXEXT,  "mmxext" },
+    { CPU_CAPABILITY_3DNOW,   "3dnow" },
+    { CPU_CAPABILITY_SSE,     "sse" },
+#endif
+#if defined (__ppc__) || defined (__ppc64__) || defined (__powerpc__)
+    { CPU_CAPABILITY_ALTIVEC, "altivec" },
+#endif
+#if defined (__arm__)
+    { CPU_CAPABILITY_NEON,    "arm_neon" },
+#endif
+};
+
+/**
+ * Return the number of available logical CPU.
+ */
+unsigned vlc_GetCPUCount(void)
+{
+#if defined(WIN32) && !defined(UNDER_CE)
+    DWORD process_mask;
+    DWORD system_mask;
+    if (!GetProcessAffinityMask(GetCurrentProcess(), &process_mask, &system_mask))
+        return 1;
+
+    unsigned count = 0;
+    while (system_mask) {
+        count++;
+        system_mask >>= 1;
+    }
+    return count;
+#elif defined(HAVE_SCHED_GETAFFINITY)
+    cpu_set_t cpu;
+    CPU_ZERO(&cpu);
+    if (sched_getaffinity(0, sizeof(cpu), &cpu) < 0)
+        return 1;
+    unsigned count = 0;
+    for (unsigned i = 0; i < CPU_SETSIZE; i++)
+        count += CPU_ISSET(i, &cpu) != 0;
+    return count;
+#elif defined(__APPLE__)
+    int count;
+    size_t size = sizeof(count) ;
+    if (sysctlbyname("hw.ncpu", &count, &size, NULL, 0))
+        return 1; /* Failure */
+    return count;
+#else
+#   warning "vlc_GetCPUCount is not implemented for your platform"
+    return 1;
+#endif
+}
+
+/**
+ * Check if a directory name contains usable plugins w.r.t. the hardware
+ * capabilities. Loading a plugin when the hardware has insufficient
+ * capabilities may lead to illegal instructions (SIGILL) and must be avoided.
+ *
+ * @param name the name of the directory (<b>not</b> the path)
+ *
+ * @return true if the hardware has sufficient capabilities or the directory
+ * does not require any special capability; false if the running hardware has
+ * insufficient capabilities.
+ */
+bool vlc_CPU_CheckPluginDir (const char *name)
+{
+    const unsigned flags = vlc_CPU ();
+    for (size_t i = 0; i < sizeof (cap_dirs) / sizeof (cap_dirs[0]); i++)
+    {
+        if (strcmp (name, cap_dirs[i].name))
+            continue;
+        return (flags & cap_dirs[i].value) != 0;
+    }
+    return true;
+}
+
 static vlc_memcpy_t pf_vlc_memcpy = memcpy;
 static vlc_memset_t pf_vlc_memset = memset;
 
@@ -322,3 +406,32 @@ void *vlc_memset (void *tgt, int c, size_t n)
 {
     return pf_vlc_memset (tgt, c, n);
 }
+
+/**
+ * Returned an aligned pointer on newly allocated memory.
+ * \param alignment must be a power of 2 and a multiple of sizeof(void*)
+ * \param size is the size of the usable memory returned.
+ *
+ * It must not be freed directly, *base must.
+ */
+void *vlc_memalign(void **base, size_t alignment, size_t size)
+{
+    assert(alignment >= sizeof(void*));
+    for (size_t t = alignment; t > 1; t >>= 1)
+        assert((t&1) == 0);
+#if defined(HAVE_POSIX_MEMALIGN)
+    if (posix_memalign(base, alignment, size)) {
+        *base = NULL;
+        return NULL;
+    }
+    return *base;
+#elif defined(HAVE_MEMALIGN)
+    return *base = memalign(alignment, size);
+#else
+    unsigned char *p = *base = malloc(size + alignment - 1);
+    if (!p)
+        return NULL;
+    return (void*)((uintptr_t)(p + alignment - 1) & ~(alignment - 1));
+#endif
+}
+