-/* Copyright (c) 2015-2017. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2015-2019. The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
+#include <algorithm>
#include <cerrno>
#include <climits>
#include <cstdint>
#include "src/xbt/memory_map.hpp"
#include "private.hpp"
-#include "smpi_process.hpp"
+#include "src/smpi/include/smpi_actor.hpp"
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smpi_memory, smpi, "Memory layout support for SMPI");
int smpi_loaded_page = -1;
char* smpi_data_exe_start = nullptr;
int smpi_data_exe_size = 0;
-int smpi_privatize_global_variables;
+SmpiPrivStrategies smpi_privatize_global_variables;
static void* smpi_data_exe_copy;
+// Initialized by smpi_prepare_global_memory_segment().
+static std::vector<simgrid::xbt::VmMap> initial_vm_map;
+
// We keep a copy of all the privatization regions: We can then delete everything easily by iterating over this
// collection and nothing can be leaked. We could also iterate over all actors but we would have to be diligent when two
// actors use the same privatization region (so, smart pointers would have to be used etc.)
// Use a std::deque so that pointers remain valid after push_back().
static std::deque<s_smpi_privatization_region_t> smpi_privatization_regions;
-static const int PROT_RWX = (PROT_READ | PROT_WRITE | PROT_EXEC);
-static const int PROT_RW = (PROT_READ | PROT_WRITE );
-XBT_ATTRIB_UNUSED static const int PROT_RX = (PROT_READ | PROT_EXEC );
+static constexpr int PROT_RWX = PROT_READ | PROT_WRITE | PROT_EXEC;
+static constexpr int PROT_RW = PROT_READ | PROT_WRITE;
+
+/** Take a snapshot of the process' memory map.
+ */
+void smpi_prepare_global_memory_segment()
+{
+ initial_vm_map = simgrid::xbt::get_memory_map(getpid());
+}
-void smpi_get_executable_global_size()
+static void smpi_get_executable_global_size()
{
char buffer[PATH_MAX];
char* full_name = realpath(xbt_binary_name, buffer);
- if (full_name == nullptr)
- xbt_die("Could not resolve binary file name");
+ xbt_assert(full_name != nullptr, "Could not resolve real path of binary file '%s'", xbt_binary_name);
std::vector<simgrid::xbt::VmMap> map = simgrid::xbt::get_memory_map(getpid());
for (auto i = map.begin(); i != map.end() ; ++i) {
if (i->pathname == full_name && (i->prot & PROT_RWX) == PROT_RW) {
smpi_data_exe_start = (char*)i->start_addr;
smpi_data_exe_size = i->end_addr - i->start_addr;
- ++i;
/* Here we are making the assumption that a suitable empty region
following the rw- area is the end of the data segment. It would
be better to check with the size of the data segment. */
+ ++i;
if (i != map.end() && i->pathname.empty() && (i->prot & PROT_RWX) == PROT_RW &&
(char*)i->start_addr == smpi_data_exe_start + smpi_data_exe_size) {
- smpi_data_exe_size = (char*)i->end_addr - smpi_data_exe_start;
+ // Only count the portion of this region not present in the initial map.
+ auto found = std::find_if(initial_vm_map.begin(), initial_vm_map.end(), [&i](const simgrid::xbt::VmMap& m) {
+ return i->start_addr <= m.start_addr && m.start_addr < i->end_addr;
+ });
+ auto end_addr = (found == initial_vm_map.end() ? i->end_addr : found->start_addr);
+ smpi_data_exe_size = (char*)end_addr - smpi_data_exe_start;
}
return;
}
}
#endif
-#if HAVE_SANITIZE_ADDRESS
+#if HAVE_SANITIZER_ADDRESS
#include <sanitizer/asan_interface.h>
static void* asan_safe_memcpy(void* dest, void* src, size_t n)
{
#define asan_safe_memcpy(dest, src, n) memcpy(dest, src, n)
#endif
-/** Map a given SMPI privatization segment (make a SMPI process active) */
-void smpi_switch_data_segment(int dest) {
- if (smpi_loaded_page == dest)//no need to switch, we've already loaded the one we want
- return;
-
- // So the job:
- smpi_really_switch_data_segment(dest);
-}
-
-/** Map a given SMPI privatization segment (make a SMPI process active) even if SMPI thinks it is already active
+/** Map a given SMPI privatization segment (make a SMPI process active)
*
* When doing a state restoration, the state of the restored variables might not be consistent with the state of the
* virtual memory. In this case, we to change the data segment.
*/
-void smpi_really_switch_data_segment(int dest)
+void smpi_switch_data_segment(simgrid::s4u::ActorPtr actor)
{
+ if (smpi_loaded_page == actor->get_pid()) // no need to switch, we've already loaded the one we want
+ return;
+
if (smpi_data_exe_size == 0) // no need to switch
return;
#if HAVE_PRIVATIZATION
// FIXME, cross-process support (mmap across process when necessary)
- simgrid::smpi::Process* process = smpi_process_remote(dest);
+ XBT_DEBUG("Switching data frame to the one of process %ld", actor->get_pid());
+ simgrid::smpi::ActorExt* process = smpi_process_remote(actor);
int current = process->privatized_region()->file_descriptor;
- XBT_DEBUG("Switching data frame to the one of process %d", dest);
- void* tmp =
- mmap(TOPAGE(smpi_data_exe_start), smpi_data_exe_size, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, current, 0);
+ void* tmp = mmap(TOPAGE(smpi_data_exe_start), smpi_data_exe_size, PROT_RW, MAP_FIXED | MAP_SHARED, current, 0);
if (tmp != TOPAGE(smpi_data_exe_start))
xbt_die("Couldn't map the new region (errno %d): %s", errno, strerror(errno));
- smpi_loaded_page = dest;
+ smpi_loaded_page = actor->get_pid();
#endif
}
-int smpi_is_privatization_file(char* file)
-{
- const std::string buffer_path("/dev/shm/my-buffer-");
- return buffer_path.compare(0, std::string::npos, file, buffer_path.length()) == 0;
-}
-
-// TODO: cheinrich: The behavior changed; this now only makes a backup of the
-// data segment. I think the function should be renamed.
+/**
+ * @brief Makes a backup of the segment in memory that stores the global variables of a process.
+ * This backup is then used to initialize the global variables for every single
+ * process that is added, regardless of the progress of the simulation.
+ */
void smpi_backup_global_memory_segment()
{
#if HAVE_PRIVATIZATION
smpi_get_executable_global_size();
+ initial_vm_map.clear();
+ initial_vm_map.shrink_to_fit();
XBT_DEBUG("bss+data segment found : size %d starting at %p", smpi_data_exe_size, smpi_data_exe_start);
if (smpi_data_exe_size == 0) { // no need to do anything as global variables don't exist
- smpi_privatize_global_variables=false;
+ smpi_privatize_global_variables = SmpiPrivStrategies::NONE;
return;
}
// of the simulation and can be used to initialize a dynamically added, new process.
asan_safe_memcpy(smpi_data_exe_copy, TOPAGE(smpi_data_exe_start), smpi_data_exe_size);
#else /* ! HAVE_PRIVATIZATION */
- smpi_privatize_global_variables = false;
xbt_die("You are trying to use privatization on a system that does not support it. Don't.");
- return;
#endif
}
char path[24];
int status;
- do {
- snprintf(path, sizeof(path), "/smpi-buffer-%06x", rand() % 0xffffffU);
+ constexpr unsigned VAL_MASK = 0xffffffU;
+ static unsigned prev_val = VAL_MASK;
+ for (unsigned i = (prev_val + 1) & VAL_MASK; i != prev_val; i = (i + 1) & VAL_MASK) {
+ snprintf(path, sizeof(path), "/smpi-buffer-%06x", i);
file_descriptor = shm_open(path, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
- } while (file_descriptor == -1 && errno == EEXIST);
+ if (file_descriptor != -1 || errno != EEXIST) {
+ prev_val = i;
+ break;
+ }
+ }
if (file_descriptor < 0) {
if (errno == EMFILE) {
xbt_die("Impossible to create temporary file for memory mapping: %s\n\
xbt_die("Impossible to set the size of the temporary file for memory mapping");
/* Ask for a free region */
- address = mmap(nullptr, smpi_data_exe_size, PROT_READ | PROT_WRITE, MAP_SHARED, file_descriptor, 0);
+ address = mmap(nullptr, smpi_data_exe_size, PROT_RW, MAP_SHARED, file_descriptor, 0);
if (address == MAP_FAILED)
xbt_die("Couldn't find a free region for memory mapping");
#endif
}
+static std::vector<unsigned char> sendbuffer;
+static std::vector<unsigned char> recvbuffer;
+
+//allocate a single buffer for all sends, growing it if needed
+unsigned char* smpi_get_tmp_sendbuffer(size_t size)
+{
+ if (not smpi_process()->replaying())
+ return new unsigned char[size];
+ // FIXME: a resize() may invalidate a previous pointer. Maybe we need to handle a queue of buffers with a reference
+ // counter. The same holds for smpi_get_tmp_recvbuffer.
+ if (sendbuffer.size() < size)
+ sendbuffer.resize(size);
+ return sendbuffer.data();
+}
+
+//allocate a single buffer for all recv
+unsigned char* smpi_get_tmp_recvbuffer(size_t size)
+{
+ if (not smpi_process()->replaying())
+ return new unsigned char[size];
+ if (recvbuffer.size() < size)
+ recvbuffer.resize(size);
+ return recvbuffer.data();
+}
+
+void smpi_free_tmp_buffer(const unsigned char* buf)
+{
+ if (not smpi_process()->replaying())
+ delete[] buf;
+}
+
+void smpi_free_replay_tmp_buffers()
+{
+ std::vector<unsigned char>().swap(sendbuffer);
+ std::vector<unsigned char>().swap(recvbuffer);
+}
