-/* Copyright (c) 2015-2017. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2015-2018. 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 <cstdint>
-#include <climits>
-#include <cstring>
-
-#include <vector>
-
#include <cerrno>
+#include <climits>
+#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
+#include <deque>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
+#include <vector>
#ifndef WIN32
#include <sys/mman.h>
#include "src/xbt/memory_map.hpp"
#include "private.hpp"
+#include "smpi_process.hpp"
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smpi_memory, smpi, "Memory layout support for SMPI");
char* smpi_data_exe_start = nullptr;
int smpi_data_exe_size = 0;
int smpi_privatize_global_variables;
-static char* smpi_data_exe_copy;
-smpi_privatization_region_t smpi_privatization_regions;
-// static std::set smpi_privatization_regions;
+static void* smpi_data_exe_copy;
+
+// 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 );
#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
+void smpi_switch_data_segment(simgrid::s4u::ActorPtr actor)
+{
+ if (smpi_loaded_page == actor->getPid()) // no need to switch, we've already loaded the one we want
return;
// So the job:
- smpi_really_switch_data_segment(dest);
+ smpi_really_switch_data_segment(actor);
}
/** Map a given SMPI privatization segment (make a SMPI process active) even if SMPI thinks it is already 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_really_switch_data_segment(simgrid::s4u::ActorPtr actor)
{
if (smpi_data_exe_size == 0) // no need to switch
return;
#if HAVE_PRIVATIZATION
- if (smpi_loaded_page == -1) { // initial switch, do the copy from the real page here
- asan_safe_memcpy(smpi_data_exe_copy, TOPAGE(smpi_data_exe_start), smpi_data_exe_size);
- }
-
// FIXME, cross-process support (mmap across process when necessary)
- int current = smpi_privatization_regions[dest].file_descriptor;
- XBT_DEBUG("Switching data frame to the one of process %d", dest);
+ XBT_DEBUG("Switching data frame to the one of process %ld", actor->getPid());
+ simgrid::smpi::Process* process = smpi_process_remote(actor);
+ int current = process->privatized_region()->file_descriptor;
void* tmp =
mmap(TOPAGE(smpi_data_exe_start), smpi_data_exe_size, PROT_READ | PROT_WRITE, 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->getPid();
#endif
}
return buffer_path.compare(0, std::string::npos, file, buffer_path.length()) == 0;
}
-void smpi_initialize_global_memory_segments()
+/**
+ * @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();
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 switch as global variables don't exist
+ if (smpi_data_exe_size == 0) { // no need to do anything as global variables don't exist
smpi_privatize_global_variables=false;
return;
}
- smpi_data_exe_copy = (char*)malloc(smpi_data_exe_size);
+ smpi_data_exe_copy = ::operator new(smpi_data_exe_size);
+ // Make a copy of the data segment. This clean copy is retained over the whole runtime
+ // 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);
- smpi_privatization_regions = new s_smpi_privatization_region_t[smpi_process_count()];
-
- for (int i=0; i< smpi_process_count(); i++){
- // create SIMIX_process_count() mappings of this size with the same data inside
- int file_descriptor;
- void* address = nullptr;
- char path[24];
- int status;
-
- do {
- snprintf(path, sizeof(path), "/smpi-buffer-%06x", rand() % 0xffffffU);
- file_descriptor = shm_open(path, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
- } while (file_descriptor == -1 && errno == EEXIST);
- if (file_descriptor < 0) {
- if (errno == EMFILE) {
- xbt_die("Impossible to create temporary file for memory mapping: %s\n\
+#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
+}
+
+// Initializes the memory mapping for a single process and returns the privatization region
+smpi_privatization_region_t smpi_init_global_memory_segment_process()
+{
+ int file_descriptor;
+ void* address = nullptr;
+ char path[24];
+ int status;
+
+ do {
+ snprintf(path, sizeof(path), "/smpi-buffer-%06x", rand() % 0xffffffU);
+ file_descriptor = shm_open(path, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
+ } while (file_descriptor == -1 && errno == EEXIST);
+ if (file_descriptor < 0) {
+ if (errno == EMFILE) {
+ xbt_die("Impossible to create temporary file for memory mapping: %s\n\
The open() system call failed with the EMFILE error code (too many files). \n\n\
This means that you reached the system limits concerning the amount of files per process. \
This is not a surprise if you are trying to virtualize many processes on top of SMPI. \
cat /proc/self/limits # Displays any per-process limitation (including the one given above)\n\n\
If one of these values is less than the amount of MPI processes that you try to run, then you got the explanation of this error. \
Ask the Internet about tutorials on how to increase the files limit such as: https://rtcamp.com/tutorials/linux/increase-open-files-limit/",
- strerror(errno));
- }
- xbt_die("Impossible to create temporary file for memory mapping: %s", strerror(errno));
+ strerror(errno));
}
+ xbt_die("Impossible to create temporary file for memory mapping: %s", strerror(errno));
+ }
- status = ftruncate(file_descriptor, smpi_data_exe_size);
- if (status)
- xbt_die("Impossible to set the size of the temporary file for memory mapping");
+ status = ftruncate(file_descriptor, smpi_data_exe_size);
+ if (status)
+ 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);
- if (address == MAP_FAILED)
- xbt_die("Couldn't find a free region for memory mapping");
+ /* Ask for a free region */
+ address = mmap(nullptr, smpi_data_exe_size, PROT_READ | PROT_WRITE, MAP_SHARED, file_descriptor, 0);
+ if (address == MAP_FAILED)
+ xbt_die("Couldn't find a free region for memory mapping");
- status = shm_unlink(path);
- if (status)
- xbt_die("Impossible to unlink temporary file for memory mapping");
+ status = shm_unlink(path);
+ if (status)
+ xbt_die("Impossible to unlink temporary file for memory mapping");
- // initialize the values
- asan_safe_memcpy(address, smpi_data_exe_copy, smpi_data_exe_size);
+ // initialize the values
+ asan_safe_memcpy(address, smpi_data_exe_copy, smpi_data_exe_size);
- // store the address of the mapping for further switches
- smpi_privatization_regions[i].file_descriptor = file_descriptor;
- smpi_privatization_regions[i].address = address;
- }
-#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
+ // store the address of the mapping for further switches
+ smpi_privatization_regions.emplace_back(s_smpi_privatization_region_t{address, file_descriptor});
+
+ return &smpi_privatization_regions.back();
}
void smpi_destroy_global_memory_segments(){
if (smpi_data_exe_size == 0) // no need to switch
return;
#if HAVE_PRIVATIZATION
- for (int i=0; i< smpi_process_count(); i++) {
- if (munmap(smpi_privatization_regions[i].address, smpi_data_exe_size) < 0)
- XBT_WARN("Unmapping of fd %d failed: %s", smpi_privatization_regions[i].file_descriptor, strerror(errno));
- close(smpi_privatization_regions[i].file_descriptor);
+ for (auto const& region : smpi_privatization_regions) {
+ if (munmap(region.address, smpi_data_exe_size) < 0)
+ XBT_WARN("Unmapping of fd %d failed: %s", region.file_descriptor, strerror(errno));
+ close(region.file_descriptor);
}
- delete[] smpi_privatization_regions;
+ smpi_privatization_regions.clear();
+ ::operator delete(smpi_data_exe_copy);
#endif
}
