[mc] Get rid of the ugly "value" out parameter in MC_state_get_request()

[simgrid.git] / src / mc / Process.cpp

diff --git a/src/mc/Process.cpp b/src/mc/Process.cpp
index 12a1499..de44cf8 100644 (file)
--- a/src/mc/Process.cpp
+++ b/src/mc/Process.cpp
@@ -11,6 +11,10 @@
 #include <stdint.h>
 #include <errno.h>
 
+#include <sys/ptrace.h>
+
+#include <cstdio>
+
 #include <sys/types.h>
 #include <fcntl.h>
 #include <unistd.h>
@@ -435,17 +439,16 @@ void Process::read_variable(const char* name, void* target, size_t size) const
   this->read_bytes(target, size, remote(var->address));
 }
 
-char* Process::read_string(RemotePtr<void> address) const
+std::string Process::read_string(RemotePtr<void> address) const
 {
   if (!address)
-    return nullptr;
+    return {};
 
-  off_t len = 128;
-  char* res = (char*) malloc(len);
+  std::vector<char> res(128);
   off_t off = 0;
 
   while (1) {
-    ssize_t c = pread(this->memory_file, res + off, len - off, (off_t) address.address() + off);
+    ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t) address.address() + off);
     if (c == -1) {
       if (errno == EINTR)
         continue;
@@ -455,15 +458,13 @@ char* Process::read_string(RemotePtr<void> address) const
     if (c==0)
       xbt_die("Could not read string from remote process");
 
-    void* p = memchr(res + off, '\0', c);
+    void* p = memchr(res.data() + off, '\0', c);
     if (p)
-      return res;
+      return std::string(res.data());
 
     off += c;
-    if (off == len) {
-      len *= 2;
-      res = (char*) realloc(res, len);
-    }
+    if (off == (off_t) res.size())
+      res.resize(res.size() * 2);
   }
 }
 
@@ -680,5 +681,35 @@ std::vector<simgrid::mc::SimixProcessInformation>& Process::old_simix_processes(
   return smx_old_process_infos;
 }
 
+void Process::dumpStack()
+{
+  unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, __BYTE_ORDER);
+  if (as == nullptr) {
+    XBT_ERROR("Could not initialize ptrace address space");
+    return;
+  }
+
+  void* context = _UPT_create(this->pid_);
+  if (context == nullptr) {
+    unw_destroy_addr_space(as);
+    XBT_ERROR("Could not initialize ptrace context");
+    return;
+  }
+
+  unw_cursor_t cursor;
+  if (unw_init_remote(&cursor, as, context) != 0) {
+    _UPT_destroy(context);
+    unw_destroy_addr_space(as);
+    XBT_ERROR("Could not initialiez ptrace cursor");
+    return;
+  }
+
+  simgrid::mc::dumpStack(stderr, cursor);
+
+  _UPT_destroy(context);
+  unw_destroy_addr_space(as);
+  return;
+}
+
 }
 }