Feature: Support reports on demand

CMakeLists.txt

@@ -23,9 +23,12 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 # Library
-add_library(heapusage SHARED src/humain.cpp src/hulog.cpp src/humalloc.cpp)
+add_library(heapusage SHARED src/humain.cpp src/hulog.cpp src/humalloc.cpp src/huapi.cpp)
+set_target_properties(heapusage PROPERTIES PUBLIC_HEADER "src/huapi.h")
 target_compile_features(heapusage PRIVATE cxx_variadic_templates)
-install(TARGETS heapusage LIBRARY DESTINATION lib)
+install(TARGETS heapusage
+    LIBRARY DESTINATION lib
+    PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 target_link_libraries(heapusage pthread dl)
 
 # Dependency backward-cpp providing more detailed stacktraces on Linux, when

README.md

@@ -136,6 +136,20 @@ Examples:
     heapusage -t all -m 0 ./ex002
            analyze heap allocations of any size with all tools.
 
+Programs being ran with Heapusage can themselves also request reports from
+Heapusage, while the program is running, by using the `hu_report()` public API
+function. For doing so, they must include the `huapi.h` public header file, link
+with the Heapusage shared library itself and call `hu_report()` when wanted.
+Still, this only works if the program is running through the `heapusage` tool.
+
+Alternatively, on Linux, sending a `SIGUSR1` signal to the program being run
+through Heapusage will also produce a Heapusage report on demand.
+
+For both `hu_report()` and `SIGUSR1`, it should be noted that the report will
+reflect the state when they are used, which can e.g. report non-freed memory
+that might be still released before the program exits and, therefore, not
+necessarily constitute a memory leak.
+
 Output Format
 =============
 Example output:

src/huapi.cpp

@@ -0,0 +1,22 @@
+/*
+ * huapi.cpp
+ *
+ * Copyright (C) 2017-2021 Kristofer Berggren
+ * All rights reserved.
+ *
+ * heapusage is distributed under the BSD 3-Clause license, see LICENSE for details.
+ *
+ */
+
+
+/* ----------- Includes ------------------------------------------ */
+#include "hulog.h"
+
+
+/* ----------- Global Functions ---------------------------------- */
+
+extern "C" void hu_report()
+{
+  log_message("hu_report: Request Log Summary\n");
+  log_summary_safe();
+}

src/huapi.h

@@ -0,0 +1,27 @@
+/*
+ * huapi.h
+ *
+ * Copyright (C) 2021 Kristofer Berggren
+ * All rights reserved.
+ *
+ * heapusage is distributed under the BSD 3-Clause license, see LICENSE for details.
+ *
+ */
+
+#ifndef _HUAPI_H_
+#define _HUAPI_H_
+
+
+/* ----------- Global Function Prototypes ------------------------ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void hu_report(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _HUAPI_H_ */

src/hulog.cpp

@@ -20,6 +20,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <stdarg.h>
 
 #include <map>
 #include <set>
@@ -385,6 +386,30 @@ void hu_sig_handler(int sig, siginfo_t* si, void* /*ucontext*/)
   exit(EXIT_FAILURE);
 }
 
+void log_message(const char *format, ...)
+{
+  va_list args;
+
+  FILE *f = NULL;
+  if (hu_log_file)
+  {
+    f = fopen(hu_log_file, "a");
+  }
+
+  if (!f)
+  {
+    return;
+  }
+
+  fprintf(f, "==%d== MESSAGE: ", pid);
+
+  va_start(args, format);
+  vfprintf(f, format, args);
+  va_end(args);
+
+  fclose(f);
+}
+
 void log_summary()
 {
   FILE *f = NULL;
@@ -402,7 +427,7 @@ void log_summary()
   unsigned long long leak_total_blocks = 0;
 
   /* Group results by callstack */
-  static std::map<std::vector<void*>, hu_allocinfo_t> allocations_by_callstack;
+  std::map<std::vector<void*>, hu_allocinfo_t> allocations_by_callstack;
   for (auto it = allocations->begin(); it != allocations->end(); ++it)
   {
     std::vector<void*> callstack;
@@ -465,6 +490,17 @@ void log_summary()
   fclose(f);
 }
 
+void log_summary_safe()
+{
+  hu_set_bypass(true);
+  log_enable(0);
+
+  log_summary();
+
+  log_enable(1);
+  hu_set_bypass(false);
+}
+
 void hu_log_remove_freed_allocation(void* ptr)
 {
   if (!hu_log_free)

src/hulog.h

@@ -24,5 +24,7 @@ void log_enable(int flag);
 void log_event(int event, void* ptr, size_t size);
 void log_invalid_access(void* ptr);
 void hu_sig_handler(int sig, siginfo_t* si, void* /*ucontext*/);
+void log_message(const char *format, ...);
 void log_summary();
+void log_summary_safe();
 void hu_log_remove_freed_allocation(void* ptr);

src/humain.cpp

@@ -91,6 +91,34 @@ static inline bool hu_get_env_bool(const char* name)
   return (strcmp(value, "1") == 0);
 }
 
+#if defined(__linux__)
+static void hu_sigusr_handler(int sig)
+{
+  switch (sig) {
+  case SIGUSR1:
+    log_message("Caught User Signal: SIGUSR1 (%d): Request Log Summary\n", sig);
+    log_summary_safe();
+    break;
+  default:
+    log_message("Caught User Signal: Unexpected Signal (%d): Ignore\n", sig);
+    break;
+  }
+}
+#endif
+
+static void hu_sigusr_init(void)
+{
+#if defined(__linux__)
+  struct sigaction sa;
+
+  sa.sa_handler = hu_sigusr_handler;
+  sa.sa_flags = 0;
+  sigemptyset(&sa.sa_mask);
+  sigaction(SIGUSR1, &sa, NULL);
+  sigaction(SIGUSR2, &sa, NULL);
+#endif
+}
+
 
 /* ----------- Global Functions ---------------------------------- */
 extern "C"
@@ -116,6 +144,8 @@ void __attribute__ ((constructor)) hu_init(void)
     hu_malloc_init(hu_overflow, hu_useafterfree, hu_minsize);
   }
 
+  hu_sigusr_init();
+
   /* Do not enable preload for child processes */
   unsetenv("DYLD_INSERT_LIBRARIES");
   unsetenv("LD_PRELOAD");