diff options
| -rw-r--r-- | nx-X11/programs/Xserver/hw/nxagent/Display.c | 142 |
1 files changed, 118 insertions, 24 deletions
diff --git a/nx-X11/programs/Xserver/hw/nxagent/Display.c b/nx-X11/programs/Xserver/hw/nxagent/Display.c index ea58437ea..aa8ab26d1 100644 --- a/nx-X11/programs/Xserver/hw/nxagent/Display.c +++ b/nx-X11/programs/Xserver/hw/nxagent/Display.c @@ -45,6 +45,7 @@ is" without express or implied warranty. #include <unistd.h> #include <time.h> #include <errno.h> +#include <stdbool.h> #include <nx-X11/X.h> #include <nx-X11/Xproto.h> @@ -178,7 +179,7 @@ static void nxagentInitDepths(void); static void nxagentInitPixmapFormats(void); static int nxagentCheckForDefaultDepthCompatibility(void); -static int nxagentCheckForDepthsCompatibility(int flexibility); +static int nxagentCheckForDepthsCompatibility(void); static int nxagentCheckForPixmapFormatsCompatibility(void); static int nxagentInitAndCheckVisuals(int flexibility); static int nxagentCheckForColormapsCompatibility(int flexibility); @@ -2240,69 +2241,162 @@ static int nxagentCheckForDefaultDepthCompatibility() } } -static int nxagentCheckForDepthsCompatibility(int flexibility) +static int nxagentCheckForDepthsCompatibility() { - int i, j; - int matched; - int compatible; + /* + * Depending on the (reconnect) tolerance checks value, this + * function checks stricter or looser: + * - Strict means that the number of old and new depths must + * match exactly and every old depth value must be + * available in the new depth array. + * - Safe means that the number of depths might diverge, + * but all former depth must also be included in the + * new depth array. This is recommended, because + * it allows clients with more depths to still + * connect, but not lose functionality. + * - Risky means that the new depths array is allowed to be + * smaller than the old depths array, but at least + * one depth value must be included in both. + * This is potentially unsafe. + * - Bypass or higher means that all of these checks are + * essentially deactivated. This is a very bad idea. + */ + + const unsigned int tolerance = nxagentOption(ReconnectTolerance); + + if (ToleranceChecksBypass <= tolerance) + { + #ifdef WARNING + fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! Not proceeding with any checks, " + "because tolerance [%u] higher than or equal [%u]. Number of newly available depths " + "is [%d], number of old depths is [%d].\n", tolerance, ToleranceChecksBypass, + nxagentNumDepths, nxagentNumDepthsRecBackup); + #endif + + return 1; + } - if (nxagentNumDepths != nxagentNumDepthsRecBackup) + if ((ToleranceChecksStrict == tolerance) && (nxagentNumDepths != nxagentNumDepthsRecBackup)) { #ifdef WARNING - fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! Number of new available depths [%d] " - "doesn't match with old depths [%d].\n", nxagentNumDepths, - nxagentNumDepthsRecBackup); + fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! No tolerance allowed and " + "number of new available depths [%d] doesn't match with number of old " + "depths [%d].\n", nxagentNumDepths, + nxagentNumDepthsRecBackup); #endif return 0; } - compatible = 1; + if ((ToleranceChecksSafe == tolerance) && (nxagentNumDepths < nxagentNumDepthsRecBackup)) + { + #ifdef WARNING + fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! Tolerance [%u] not " + "high enough and number of new available depths [%d] " + "lower than number of old depths [%d].\n", tolerance, + nxagentNumDepths, nxagentNumDepthsRecBackup); + #endif + + return 0; + } + + /* + * By now the tolerance is either: + * - Strict and both depth numbers match + * - Safe and: + * o the number of old and new depths matches exactly, or + * o the number of old depths is lower than the number + * of new depths + * - Risky + */ + + bool compatible = true; + bool one_match = false; + bool matched = false; + int total_matches = 0; - for (i = 0; i < nxagentNumDepths; i++) + /* + * FIXME: within this loop, we try to match all "new" depths + * against the "old" depths. Depending upon the flexibility + * value, either all "new" depths must have a corresponding + * counterpart in the "old" array, or at least one value + * must be included in both. + * Is this safe enough though? + * Shouldn't we better try to match entries in the "old" + * depths array against the "new" depths array, such that + * we know that all "old" values are covered by "new" + * values? Or is it more important that "new" values are + * covered by "old" ones, with potentially more "old" + * values lingering around that cannot be displayed by the + * connected client? + * + * This section probably needs a revisit at some point in time. + */ + for (int i = 0; i < nxagentNumDepths; ++i) { - matched = 0; + matched = false; - for (j = 0; j < nxagentNumDepthsRecBackup; j++) + for (int j = 0; j < nxagentNumDepthsRecBackup; ++j) { if (nxagentDepths[i] == nxagentDepthsRecBackup[j]) { - matched = 1; + matched = true; + one_match = true; + ++total_matches; break; } } - if (matched == 0) + if ((ToleranceChecksRisky > tolerance) && (!matched)) { #ifdef WARNING - fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! Failed to match available depth [%d].\n", - nxagentDepths[i]); + fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! Tolerance [%u] too low and " + "failed to match available depth [%d].\n", tolerance, nxagentDepths[i]); #endif - compatible = 0; + compatible = false; break; } } + /* + * At Risky tolerance, only one match is necessary to be "compatible". + */ + if (ToleranceChecksRisky == tolerance) + { + compatible = one_match; + } - if (compatible == 1) + int ret = (!(!compatible)); + + if (compatible) { #ifdef TEST fprintf(stderr, "nxagentCheckForDepthsCompatibility: Internal depths match with " - "remote depths.\n"); + "remote depths at tolerance [%u].\n", tolerance); #endif + + if (total_matches != nxagentNumDepths) + { + #ifdef WARNING + fprintf(stderr, "nxagentCheckForDepthsCompatibility: only some [%d] of the new depths [%d] " + "match with old depths [%d] at tolerance [%u].\n", total_matches, nxagentNumDepths, + nxagentNumDepthsRecBackup, tolerance); + #endif + } } else { #ifdef WARNING - fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! New available depths don't match with " - "old depths.\n"); + fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! New available depths [%d] don't match " + "with old depths [%d] at tolerance [%u]. Only [%d] depth values matched.\n", + nxagentNumDepths, nxagentNumDepthsRecBackup, tolerance, total_matches); #endif } - return compatible; + return (ret); } static int nxagentCheckForPixmapFormatsCompatibility() @@ -2633,7 +2727,7 @@ Bool nxagentReconnectDisplay(void *p0) reconnectDisplayState = GOT_DEPTH_LIST; - if (nxagentCheckForDepthsCompatibility(flexibility) == 0) + if (nxagentCheckForDepthsCompatibility() == 0) { nxagentSetReconnectError(FAILED_RESUME_DEPTHS_ALERT, "Couldn't restore all the required depths."); |