[Windows] rewrite of open_files() (#1660)

HISTORY.rst

@@ -20,6 +20,7 @@ XXXX-XX-XX
   due to a backward incompatible change in a C type introduced in 12.0.
 - 1656_: [Windows] Process.memory_full_info() raises AccessDenied even for the
   current user and os.getpid().
+- 1660_: [Windows] Process.open_files() complete rewrite + check of errors.
 
 5.6.7
 =====

psutil/_psutil_common.c

@@ -153,7 +153,8 @@ psutil_setup(void) {
 
 // Needed to make these globally visible.
 int PSUTIL_WINVER;
-SYSTEM_INFO PSUTIL_SYSTEM_INFO;
+SYSTEM_INFO          PSUTIL_SYSTEM_INFO;
+CRITICAL_SECTION     PSUTIL_CRITICAL_SECTION;
 
 #define NT_FACILITY_MASK 0xfff
 #define NT_FACILITY_SHIFT 16
@@ -326,22 +327,14 @@ psutil_set_winver() {
     return 0;
 }
 
-
-static int
-psutil_load_sysinfo() {
-    GetSystemInfo(&PSUTIL_SYSTEM_INFO);
-    return 0;
-}
-
-
 int
 psutil_load_globals() {
     if (psutil_loadlibs() != 0)
         return 1;
     if (psutil_set_winver() != 0)
         return 1;
-    if (psutil_load_sysinfo() != 0)
-        return 1;
+    GetSystemInfo(&PSUTIL_SYSTEM_INFO);
+    InitializeCriticalSection(&PSUTIL_CRITICAL_SECTION);
     return 0;
 }
 #endif  // PSUTIL_WINDOWS

psutil/_psutil_common.h

@@ -50,7 +50,8 @@ int psutil_setup(void);
     #include "arch/windows/ntextapi.h"
 
     extern int PSUTIL_WINVER;
-    extern SYSTEM_INFO PSUTIL_SYSTEM_INFO;
+    extern SYSTEM_INFO          PSUTIL_SYSTEM_INFO;
+    extern CRITICAL_SECTION     PSUTIL_CRITICAL_SECTION;
 
     #define PSUTIL_WINDOWS_VISTA 60
     #define PSUTIL_WINDOWS_7 61
@@ -60,7 +61,9 @@ int psutil_setup(void);
     #define PSUTIL_WINDOWS_NEW MAXLONG
 
     #define MALLOC(x) HeapAlloc(GetProcessHeap(), 0, (x))
+    #define MALLOC_ZERO(x) HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, (x))
     #define FREE(x) HeapFree(GetProcessHeap(), 0, (x))
+
     #define LO_T 1e-7
     #define HI_T 429.4967296