Add support for the QNX operating system.

src/platform-qnx.cc

Index: src/platform-qnx.cc
diff --git a/src/platform-linux.cc b/src/platform-qnx.cc
similarity index 71%
copy from src/platform-linux.cc
copy to src/platform-qnx.cc
index eb2d10b3f9d911b5d0fbd607766724d5fa203f8b..ac49f216c5d01dd5462a4e6d0e1c9d87004a2b9d 100644
--- a/src/platform-linux.cc
+++ b/src/platform-qnx.cc
@@ -1,4 +1,4 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
+// Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
@@ -25,22 +25,21 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Platform specific code for Linux goes here. For the POSIX comaptible parts
-// the implementation is in platform-posix.cc.
+// Platform-specific code for QNX goes here. For the POSIX-compatible
+// parts the implementation is in platform-posix.cc.
 
 #include <pthread.h>
 #include <semaphore.h>
 #include <signal.h>
-#include <sys/prctl.h>
 #include <sys/time.h>
 #include <sys/resource.h>
-#include <sys/syscall.h>
 #include <sys/types.h>
 #include <stdlib.h>
+#include <ucontext.h>
+#include <backtrace.h>
 
-// Ubuntu Dapper requires memory pages to be marked as
-// executable. Otherwise, OS raises an exception when executing code
-// in that page.
+// QNX requires memory pages to be marked as executable.
+// Otherwise, the OS raises an exception when executing code in that page.
 #include <sys/types.h>  // mmap & munmap
 #include <sys/mman.h>   // mmap & munmap
 #include <sys/stat.h>   // open
@@ -49,13 +48,7 @@
 #include <strings.h>    // index
 #include <errno.h>
 #include <stdarg.h>
-
-// GLibc on ARM defines mcontext_t has a typedef for 'struct sigcontext'.
-// Old versions of the C library <signal.h> didn't define the type.
-#if defined(__ANDROID__) && !defined(__BIONIC_HAVE_UCONTEXT_T) && \
-    defined(__arm__) && !defined(__BIONIC_HAVE_STRUCT_SIGCONTEXT)
-#include <asm/sigcontext.h>
-#endif
+#include <sys/procfs.h>
 
 #undef MAP_TYPE
 
@@ -69,6 +62,10 @@
 namespace v8 {
 namespace internal {
 
+// 0 is never a valid thread id on Qnx since tids and pids share a
+// name space and pid 0 is reserved (see man 2 kill).
+static const pthread_t kNoThread = (pthread_t) 0;
+
 
 #ifdef __arm__
 
@@ -110,12 +107,12 @@ bool OS::ArmUsingHardFloat() {
 #undef GCC_VERSION
 }
 
-#endif  // def __arm__
+#endif  // __arm__
 
 
 const char* OS::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
-  time_t tv = static_cast<time_t>(floor(time/msPerSecond));
+  time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
   struct tm* t = localtime(&tv);
   if (NULL == t) return "";
   return t->tm_zone;
@@ -134,7 +131,7 @@ double OS::LocalTimeOffset() {
 void* OS::Allocate(const size_t requested,
                    size_t* allocated,
                    bool is_executable) {
-  const size_t msize = RoundUp(requested, AllocateAlignment());
+  const size_t msize = RoundUp(requested, sysconf(_SC_PAGESIZE));

[Benedikt Meurer, 2013/11/15 11:49:59]

Why not AllocateAlignment() here?

[c.truta, 2013/11/18 13:36:32]

Wasn't deliberate. Fixed.

   int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
   void* addr = OS::GetRandomMmapAddr();
   void* mbase = mmap(addr, msize, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
@@ -207,89 +204,77 @@ PosixMemoryMappedFile::~PosixMemoryMappedFile() {
 
 
 void OS::LogSharedLibraryAddresses(Isolate* isolate) {
-  // This function assumes that the layout of the file is as follows:
-  // hex_start_addr-hex_end_addr rwxp <unused data> [binary_file_name]
-  // If we encounter an unexpected situation we abort scanning further entries.
-  FILE* fp = fopen("/proc/self/maps", "r");
-  if (fp == NULL) return;
-
-  // Allocate enough room to be able to store a full file name.
-  const int kLibNameLen = FILENAME_MAX + 1;
-  char* lib_name = reinterpret_cast<char*>(malloc(kLibNameLen));
-
-  // This loop will terminate once the scanning hits an EOF.
-  while (true) {
-    uintptr_t start, end;
-    char attr_r, attr_w, attr_x, attr_p;
-    // Parse the addresses and permission bits at the beginning of the line.
-    if (fscanf(fp, "%" V8PRIxPTR "-%" V8PRIxPTR, &start, &end) != 2) break;
-    if (fscanf(fp, " %c%c%c%c", &attr_r, &attr_w, &attr_x, &attr_p) != 4) break;
-
-    int c;
-    if (attr_r == 'r' && attr_w != 'w' && attr_x == 'x') {
-      // Found a read-only executable entry. Skip characters until we reach
-      // the beginning of the filename or the end of the line.
-      do {
-        c = getc(fp);
-      } while ((c != EOF) && (c != '\n') && (c != '/') && (c != '['));
-      if (c == EOF) break;  // EOF: Was unexpected, just exit.
-
-      // Process the filename if found.
-      if ((c == '/') || (c == '[')) {
-        // Push the '/' or '[' back into the stream to be read below.
-        ungetc(c, fp);
-
-        // Read to the end of the line. Exit if the read fails.
-        if (fgets(lib_name, kLibNameLen, fp) == NULL) break;
-
-        // Drop the newline character read by fgets. We do not need to check
-        // for a zero-length string because we know that we at least read the
-        // '/' or '[' character.
-        lib_name[strlen(lib_name) - 1] = '\0';
-      } else {
-        // No library name found, just record the raw address range.
-        snprintf(lib_name, kLibNameLen,
-                 "%08" V8PRIxPTR "-%08" V8PRIxPTR, start, end);
+  procfs_mapinfo *mapinfos = NULL, *mapinfo;
+  int proc_fd, num, i;
+
+  struct {
+    procfs_debuginfo info;
+    char buff[PATH_MAX];
+  } map;
+
+  char buf[PATH_MAX + 1];
+  snprintf(buf, PATH_MAX + 1, "/proc/%d/as", getpid());
+
+  if ((proc_fd = open(buf, O_RDONLY)) == -1) {
+    close(proc_fd);
+    return;
+  }
+
+  /* Get the number of map entries.  */
+  if (devctl(proc_fd, DCMD_PROC_MAPINFO, NULL, 0, &num) != EOK) {
+    close(proc_fd);
+    return;
+  }
+
+  mapinfos = reinterpret_cast<procfs_mapinfo *>(
+      malloc(num * sizeof(procfs_mapinfo)));
+  if (mapinfos == NULL) {
+    close(proc_fd);
+    return;
+  }
+
+  /* Fill the map entries.  */
+  if (devctl(proc_fd, DCMD_PROC_PAGEDATA,
+      mapinfos, num * sizeof(procfs_mapinfo), &num) != EOK) {
+    free(mapinfos);
+    close(proc_fd);
+    return;
+  }
+
+  for (i = 0; i < num; i++) {
+    mapinfo = mapinfos + i;
+    if (mapinfo->flags & MAP_ELF) {
+      map.info.vaddr = mapinfo->vaddr;
+      if (devctl(proc_fd, DCMD_PROC_MAPDEBUG, &map, sizeof(map), 0) != EOK) {
+        continue;
       }
-      LOG(isolate, SharedLibraryEvent(lib_name, start, end));
-    } else {
-      // Entry not describing executable data. Skip to end of line to set up
-      // reading the next entry.
-      do {
-        c = getc(fp);
-      } while ((c != EOF) && (c != '\n'));
-      if (c == EOF) break;
+      LOG(isolate, SharedLibraryEvent(map.info.path,
+                                      mapinfo->vaddr,
+                                      mapinfo->vaddr + mapinfo->size));
     }
   }
-  free(lib_name);
-  fclose(fp);
+  free(mapinfos);
+  close(proc_fd);
 }
 
 
+static const char kGCFakeMmap[] = "/tmp/__v8_gc__";
+
+
 void OS::SignalCodeMovingGC() {

[Benedikt Meurer, 2013/11/15 11:49:59]

Is there any support for perf/ll_prof in QNX? Otherwise you should just leave
this empty.

   // Support for ll_prof.py.
   //
-  // The Linux profiler built into the kernel logs all mmap's with
+  // The QNX profiler built into the kernel logs all mmap's with
   // PROT_EXEC so that analysis tools can properly attribute ticks. We
   // do a mmap with a name known by ll_prof.py and immediately munmap
   // it. This injects a GC marker into the stream of events generated
   // by the kernel and allows us to synchronize V8 code log and the
   // kernel log.
   int size = sysconf(_SC_PAGESIZE);
-  FILE* f = fopen(FLAG_gc_fake_mmap, "w+");
-  if (f == NULL) {
-    OS::PrintError("Failed to open %s\n", FLAG_gc_fake_mmap);
-    OS::Abort();
-  }
+  FILE* f = fopen(kGCFakeMmap, "w+");
   void* addr = mmap(OS::GetRandomMmapAddr(),
                     size,
-#if defined(__native_client__)
-                    // The Native Client port of V8 uses an interpreter,
-                    // so code pages don't need PROT_EXEC.
-                    PROT_READ,
-#else
                     PROT_READ | PROT_EXEC,
-#endif
                     MAP_PRIVATE,
                     fileno(f),
                     0);
@@ -319,7 +304,7 @@ VirtualMemory::VirtualMemory(size_t size, size_t alignment)
   void* reservation = mmap(OS::GetRandomMmapAddr(),
                            request_size,
                            PROT_NONE,
-                           MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE,
+                           MAP_PRIVATE | MAP_ANONYMOUS | MAP_LAZY,
                            kMmapFd,
                            kMmapFdOffset);
   if (reservation == MAP_FAILED) return;
@@ -391,7 +376,7 @@ void* VirtualMemory::ReserveRegion(size_t size) {
   void* result = mmap(OS::GetRandomMmapAddr(),
                       size,
                       PROT_NONE,
-                      MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE,
+                      MAP_PRIVATE | MAP_ANONYMOUS | MAP_LAZY,
                       kMmapFd,
                       kMmapFdOffset);
 
@@ -402,13 +387,7 @@ void* VirtualMemory::ReserveRegion(size_t size) {
 
 
 bool VirtualMemory::CommitRegion(void* base, size_t size, bool is_executable) {
-#if defined(__native_client__)
-  // The Native Client port of V8 uses an interpreter,
-  // so code pages don't need PROT_EXEC.
-  int prot = PROT_READ | PROT_WRITE;
-#else
   int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
-#endif
   if (MAP_FAILED == mmap(base,
                          size,
                          prot,
@@ -426,7 +405,7 @@ bool VirtualMemory::UncommitRegion(void* base, size_t size) {
   return mmap(base,
               size,
               PROT_NONE,
-              MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE | MAP_FIXED,
+              MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED | MAP_LAZY,
               kMmapFd,
               kMmapFdOffset) != MAP_FAILED;
 }
@@ -438,7 +417,7 @@ bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
 
 
 bool VirtualMemory::HasLazyCommits() {
-  return true;
+  return false;
 }
 
 } }  // namespace v8::internal