mono/metadata/w32semaphore-unix.c

   1 /*
   2  * w32semaphore-unix.c: Runtime support for managed Semaphore on Unix
   3  *
   4  * Author:
   5  *      Ludovic Henry (luhenry@microsoft.com)
   6  *
   7  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
   8  */
   9
  10 #include "w32semaphore.h"
  11
  12 #include "w32handle-namespace.h"
  13 #include "mono/io-layer/io-layer.h"
  14 #include "mono/utils/mono-logger-internals.h"
  15 #include "mono/metadata/w32handle.h"
  16
  17 typedef struct {
  18         guint32 val;
  19         gint32 max;
  20 } MonoW32HandleSemaphore;
  21
  22 struct MonoW32HandleNamedSemaphore {
  23         MonoW32HandleSemaphore s;
  24         MonoW32HandleNamespace sharedns;
  25 };
  26
  27 static gboolean sem_handle_own (gpointer handle, MonoW32HandleType type, gboolean *abandoned)
  28 {
  29         MonoW32HandleSemaphore *sem_handle;
  30
  31         *abandoned = FALSE;
  32
  33         if (!mono_w32handle_lookup (handle, type, (gpointer *)&sem_handle)) {
  34                 g_warning ("%s: error looking up %s handle %p",
  35                         __func__, mono_w32handle_get_typename (type), handle);
  36                 return FALSE;
  37         }
  38
  39         mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_IO_LAYER, "%s: owning %s handle %p",
  40                 __func__, mono_w32handle_get_typename (type), handle);
  41
  42         sem_handle->val--;
  43
  44         if (sem_handle->val == 0)
  45                 mono_w32handle_set_signal_state (handle, FALSE, FALSE);
  46
  47         return TRUE;
  48 }
  49
  50 static void sema_signal(gpointer handle)
  51 {
  52         ves_icall_System_Threading_Semaphore_ReleaseSemaphore_internal(handle, 1, NULL);
  53 }
  54
  55 static gboolean sema_own (gpointer handle, gboolean *abandoned)
  56 {
  57         return sem_handle_own (handle, MONO_W32HANDLE_SEM, abandoned);
  58 }
  59
  60 static void namedsema_signal (gpointer handle)
  61 {
  62         ves_icall_System_Threading_Semaphore_ReleaseSemaphore_internal (handle, 1, NULL);
  63 }
  64
  65 /* NB, always called with the shared handle lock held */
  66 static gboolean namedsema_own (gpointer handle, gboolean *abandoned)
  67 {
  68         return sem_handle_own (handle, MONO_W32HANDLE_NAMEDSEM, abandoned);
  69 }
  70
  71 static void sema_details (gpointer data)
  72 {
  73         MonoW32HandleSemaphore *sem = (MonoW32HandleSemaphore *)data;
  74         g_print ("val: %5u, max: %5d", sem->val, sem->max);
  75 }
  76
  77 static void namedsema_details (gpointer data)
  78 {
  79         MonoW32HandleNamedSemaphore *namedsem = (MonoW32HandleNamedSemaphore *)data;
  80         g_print ("val: %5u, max: %5d, name: \"%s\"", namedsem->s.val, namedsem->s.max, namedsem->sharedns.name);
  81 }
  82
  83 static const gchar* sema_typename (void)
  84 {
  85         return "Semaphore";
  86 }
  87
  88 static gsize sema_typesize (void)
  89 {
  90         return sizeof (MonoW32HandleSemaphore);
  91 }
  92
  93 static const gchar* namedsema_typename (void)
  94 {
  95         return "N.Semaphore";
  96 }
  97
  98 static gsize namedsema_typesize (void)
  99 {
 100         return sizeof (MonoW32HandleNamedSemaphore);
 101 }
 102
 103 void
 104 mono_w32semaphore_init (void)
 105 {
 106         static MonoW32HandleOps sem_ops = {
 107                 NULL,                   /* close */
 108                 sema_signal,            /* signal */
 109                 sema_own,               /* own */
 110                 NULL,                   /* is_owned */
 111                 NULL,                   /* special_wait */
 112                 NULL,                   /* prewait */
 113                 sema_details,   /* details */
 114                 sema_typename,  /* typename */
 115                 sema_typesize,  /* typesize */
 116         };
 117
 118         static MonoW32HandleOps namedsem_ops = {
 119                 NULL,                   /* close */
 120                 namedsema_signal,       /* signal */
 121                 namedsema_own,          /* own */
 122                 NULL,                   /* is_owned */
 123                 NULL,                   /* special_wait */
 124                 NULL,                   /* prewait */
 125                 namedsema_details,      /* details */
 126                 namedsema_typename,     /* typename */
 127                 namedsema_typesize,     /* typesize */
 128         };
 129
 130         mono_w32handle_register_ops (MONO_W32HANDLE_SEM,      &sem_ops);
 131         mono_w32handle_register_ops (MONO_W32HANDLE_NAMEDSEM, &namedsem_ops);
 132
 133         mono_w32handle_register_capabilities (MONO_W32HANDLE_SEM,
 134                 (MonoW32HandleCapability)(MONO_W32HANDLE_CAP_WAIT | MONO_W32HANDLE_CAP_SIGNAL));
 135         mono_w32handle_register_capabilities (MONO_W32HANDLE_NAMEDSEM,
 136                 (MonoW32HandleCapability)(MONO_W32HANDLE_CAP_WAIT | MONO_W32HANDLE_CAP_SIGNAL));
 137 }
 138
 139 static gpointer
 140 sem_handle_create (MonoW32HandleSemaphore *sem_handle, MonoW32HandleType type, gint32 initial, gint32 max)
 141 {
 142         gpointer handle;
 143
 144         sem_handle->val = initial;
 145         sem_handle->max = max;
 146
 147         handle = mono_w32handle_new (type, sem_handle);
 148         if (handle == INVALID_HANDLE_VALUE) {
 149                 g_warning ("%s: error creating %s handle",
 150                         __func__, mono_w32handle_get_typename (type));
 151                 SetLastError (ERROR_GEN_FAILURE);
 152                 return NULL;
 153         }
 154
 155         mono_w32handle_lock_handle (handle);
 156
 157         if (initial != 0)
 158                 mono_w32handle_set_signal_state (handle, TRUE, FALSE);
 159
 160         mono_w32handle_unlock_handle (handle);
 161
 162         mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_IO_LAYER, "%s: created %s handle %p",
 163                 __func__, mono_w32handle_get_typename (type), handle);
 164
 165         return handle;
 166 }
 167
 168 static gpointer
 169 sem_create (gint32 initial, gint32 max)
 170 {
 171         MonoW32HandleSemaphore sem_handle;
 172         mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_IO_LAYER, "%s: creating %s handle, initial %d max %d",
 173                 __func__, mono_w32handle_get_typename (MONO_W32HANDLE_SEM), initial, max);
 174         return sem_handle_create (&sem_handle, MONO_W32HANDLE_SEM, initial, max);
 175 }
 176
 177 static gpointer
 178 namedsem_create (gint32 initial, gint32 max, const gunichar2 *name)
 179 {
 180         gpointer handle;
 181         gchar *utf8_name;
 182
 183         mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_IO_LAYER, "%s: creating %s handle, initial %d max %d name \"%s\"",
 184                     __func__, mono_w32handle_get_typename (MONO_W32HANDLE_NAMEDSEM), initial, max, (const char*)name);
 185
 186         /* w32 seems to guarantee that opening named objects can't race each other */
 187         mono_w32handle_namespace_lock ();
 188
 189         utf8_name = g_utf16_to_utf8 (name, -1, NULL, NULL, NULL);
 190
 191         mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_IO_LAYER, "%s: Creating named sem name [%s] initial %d max %d", __func__, utf8_name, initial, max);
 192
 193         handle = mono_w32handle_namespace_search_handle (MONO_W32HANDLE_NAMEDSEM, utf8_name);
 194         if (handle == INVALID_HANDLE_VALUE) {
 195                 /* The name has already been used for a different object. */
 196                 handle = NULL;
 197                 SetLastError (ERROR_INVALID_HANDLE);
 198         } else if (handle) {
 199                 /* Not an error, but this is how the caller is informed that the semaphore wasn't freshly created */
 200                 SetLastError (ERROR_ALREADY_EXISTS);
 201
 202                 /* mono_w32handle_namespace_search_handle already adds a ref to the handle */
 203         } else {
 204                 /* A new named semaphore */
 205                 MonoW32HandleNamedSemaphore namedsem_handle;
 206
 207                 strncpy (&namedsem_handle.sharedns.name [0], utf8_name, MAX_PATH);
 208                 namedsem_handle.sharedns.name [MAX_PATH] = '\0';
 209
 210                 handle = sem_handle_create ((MonoW32HandleSemaphore*) &namedsem_handle, MONO_W32HANDLE_NAMEDSEM, initial, max);
 211         }
 212
 213         g_free (utf8_name);
 214
 215         mono_w32handle_namespace_unlock ();
 216
 217         return handle;
 218 }
 219
 220 gpointer
 221 ves_icall_System_Threading_Semaphore_CreateSemaphore_internal (gint32 initialCount, gint32 maximumCount, MonoString *name, gint32 *error)
 222 {
 223         gpointer sem;
 224
 225         if (maximumCount <= 0) {
 226                 mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_IO_LAYER, "%s: maximumCount <= 0", __func__);
 227
 228                 *error = ERROR_INVALID_PARAMETER;
 229                 return NULL;
 230         }
 231
 232         if (initialCount > maximumCount || initialCount < 0) {
 233                 mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_IO_LAYER, "%s: initialCount > maximumCount or < 0", __func__);
 234
 235                 *error = ERROR_INVALID_PARAMETER;
 236                 return NULL;
 237         }
 238
 239         /* Need to blow away any old errors here, because code tests
 240          * for ERROR_ALREADY_EXISTS on success (!) to see if a
 241          * semaphore was freshly created
 242          */
 243         SetLastError (ERROR_SUCCESS);
 244
 245         if (!name)
 246                 sem = sem_create (initialCount, maximumCount);
 247         else
 248                 sem = namedsem_create (initialCount, maximumCount, mono_string_chars (name));
 249
 250         *error = GetLastError ();
 251
 252         return sem;
 253 }
 254
 255 MonoBoolean
 256 ves_icall_System_Threading_Semaphore_ReleaseSemaphore_internal (gpointer handle, gint32 releaseCount, gint32 *prevcount)
 257 {
 258         MonoW32HandleType type;
 259         MonoW32HandleSemaphore *sem_handle;
 260         MonoBoolean ret;
 261
 262         if (!handle) {
 263                 SetLastError (ERROR_INVALID_HANDLE);
 264                 return FALSE;
 265         }
 266
 267         switch (type = mono_w32handle_get_type (handle)) {
 268         case MONO_W32HANDLE_SEM:
 269         case MONO_W32HANDLE_NAMEDSEM:
 270                 break;
 271         default:
 272                 SetLastError (ERROR_INVALID_HANDLE);
 273                 return FALSE;
 274         }
 275
 276         if (!mono_w32handle_lookup (handle, type, (gpointer *)&sem_handle)) {
 277                 g_warning ("%s: error looking up sem handle %p", __func__, handle);
 278                 return FALSE;
 279         }
 280
 281         mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_IO_LAYER, "%s: releasing %s handle %p",
 282                 __func__, mono_w32handle_get_typename (type), handle);
 283
 284         mono_w32handle_lock_handle (handle);
 285
 286         /* Do this before checking for count overflow, because overflowing
 287          * max is a listed technique for finding the current value */
 288         if (prevcount)
 289                 *prevcount = sem_handle->val;
 290
 291         /* No idea why max is signed, but thats the spec :-( */
 292         if (sem_handle->val + releaseCount > (guint32)sem_handle->max) {
 293                 mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_IO_LAYER, "%s: %s handle %p val %d count %d max %d, max value would be exceeded",
 294                         __func__, mono_w32handle_get_typename (type), handle, sem_handle->val, releaseCount, sem_handle->max);
 295
 296                 ret = FALSE;
 297         } else {
 298                 mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_IO_LAYER, "%s: %s handle %p val %d count %d max %d",
 299                         __func__, mono_w32handle_get_typename (type), handle, sem_handle->val, releaseCount, sem_handle->max);
 300
 301                 sem_handle->val += releaseCount;
 302                 mono_w32handle_set_signal_state (handle, TRUE, TRUE);
 303
 304                 ret = TRUE;
 305         }
 306
 307         mono_w32handle_unlock_handle (handle);
 308
 309         return ret;
 310 }
 311
 312 gpointer
 313 ves_icall_System_Threading_Semaphore_OpenSemaphore_internal (MonoString *name, gint32 rights, gint32 *error)
 314 {
 315         gpointer handle;
 316         gchar *utf8_name;
 317
 318         *error = ERROR_SUCCESS;
 319
 320         /* w32 seems to guarantee that opening named objects can't race each other */
 321         mono_w32handle_namespace_lock ();
 322
 323         utf8_name = g_utf16_to_utf8 (mono_string_chars (name), -1, NULL, NULL, NULL);
 324
 325         mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_IO_LAYER, "%s: Opening named sem [%s]", __func__, utf8_name);
 326
 327         handle = mono_w32handle_namespace_search_handle (MONO_W32HANDLE_NAMEDSEM, utf8_name);
 328         if (handle == INVALID_HANDLE_VALUE) {
 329                 /* The name has already been used for a different object. */
 330                 *error = ERROR_INVALID_HANDLE;
 331                 goto cleanup;
 332         } else if (!handle) {
 333                 /* This name doesn't exist */
 334                 *error = ERROR_FILE_NOT_FOUND;
 335                 goto cleanup;
 336         }
 337
 338         mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_IO_LAYER, "%s: returning named sem handle %p", __func__, handle);
 339
 340 cleanup:
 341         g_free (utf8_name);
 342
 343         mono_w32handle_namespace_unlock ();
 344
 345         return handle;
 346 }
 347
 348 MonoW32HandleNamespace*
 349 mono_w32semaphore_get_namespace (MonoW32HandleNamedSemaphore *semaphore)
 350 {
 351         return &semaphore->sharedns;
 352 }